VII. LECTURE SYNOPSES
Michaelmas Term
Week 5
Tissue structure (3 lectures)
Basic tissue types (epithelium, connective tissue, nerve and muscle); classifications; form
and function.
Bone
Development of bone. Structure of mature bone. Significance as calcium store.
Body Fluids
Fluid compartments; their composition and measurement; water movement between
them; physiological significance; oedema formation.
Blood (2 lectures)
Composition of the blood, different types of protein and their roles. Development, life
history, and properties of red blood cells (overview of role in blood gas transport).
Classification of leucocytes (white blood cells). Roles in inflammation and
immunological responses.
Week 6
Organization of the central nervous system
Localization and appearance of main functional areas in brain and spinal cord.
Excitable cells
Extracellular and intracellular concentrations of common ions. Forces driving ion
movements. Cell membranes as a partial barrier to ion movement. Concept of ion
channels. Ion movements lead to electrical changes. K+ channels and resting membrane
potential.
Action potentials
Voltage-gated ion channels. Na+ channels and action potential. Timecourse of action
potential. Nervous conduction in myelinated & unmyelinated fibres. Refractory periods.
Week 7
Neurotransmission
Neurotransmitters. EPSPs & IPSPs. Temporal & spatial summation of post-synaptic
potentials. The axon hillock and development of post-synaptic action potential.
Regulation of frequency of post-synaptic action potentials by net input. Transmission
ratios.
Sensory perception
General principles of mechanisms of sensory perception. Primary and secondary sensory
receptors. General properties of receptors, including specificity, transduction and
alteration of stimulus intensity. Sensory coding of stimulus, including type, intensity,
location and duration. Adaptation of sensory receptor signalling, including rapid
(phasic) and slow (tonic) adaptation.
Somatic sensory system
Touch and pressure receptors in the skin. Basic morphological features of the receptors,
and the physiological response characteristics of each receptor to specific stimuli,
including adaptation properties. Pain receptors. Morphological and physiological
characteristics of the fast and slow pain systems.
Week 8
The eye
Electromagnetic spectra and visible light. Structure of the eye. Control of light entering
eye via pupil by radial and circular muscles. Focussing of light on retina for distant and
near sight by ciliary muscles. Myopia, presbyopia, cataract, glaucoma. The retina,
photoreceptors, rods and cones, photopigments, ganglion cells. Light stimuli necessary
to active photoreceptors and ganglion cells. Organisation of the pathway connecting the
retina to the visual cortex.
Week 9
The ear
Sound. Air pressure changes. Frequency and intensity of sound. Intensity of sound
heard by humans, curve of equal loudness. Structure of ear. Cochlea. Mechanism of
hearing. Role of hair cells and deflection of cilia. Detection of different frequencies of
sound. Deafness. Organs of balance. The vestibular organs. Semicircular canals.
Detection of rotation of head. Structure of ampulla. Mechanism of detection of rotation
of head. Role of hair cells and deflection of cilia. Otolith organs. Utricle and saccle.
Detection of head tilt.
Autonomic Nervous System
Layout of the sympathetic and parasympathetic nervous systems including organs
innervated. Pre- and post-ganglionic fibres and transmitters. Functions of sympathetic
and parasympathetic systems -example: control of heart rate.
Somatic Muscle Contraction
Structure of skeletal muscle. Muscle fibres and motor units. Sub-cellular structure,
myofibrils, actin and myosin filaments and banding. The tubule system, transverse and
longitudinal. Arrangement of control molecules (troponin and tropomyosin). Crossbridge formation and breaking.
Week 10
Neuromuscular transmission
The motor neuron. Structure of the motor end-plate. Acetylcholine vesicles. Calcium
channels. The end-plate potential and muscle action potential. Neuromuscular
transmission is 1:1. Passage of action potential promotes release of Ca2+ ions.
Vulnerability of the transmission process to poisons & disease.
Somatic Muscle Mechanics
Twitch and tetanic contractions. Length-tension curve. Anatomical arrangement,
optimal length and functional range of length. Force-velocity relationship. Concentric
and eccentric contraction. Trophic dependence of muscle on its motor innervation.
Cardiac and Smooth Muscles
General structure of cardiac muscle. Pacemaker cells. Timecourse and ionic basis of the
cardiac action potential. Innervation of cardiac muscle. General structure of smooth
muscle cells. Single unit and multi-unit smooth muscle. Pacemaker activity. Innervation
of smooth muscle. Plasticity. Comparisons of calcium sourcing and regulation of crossbridging between somatic, cardiac and smooth muscle cells.
Week 11
Principles of Reflexes
Role of the simple reflex. The monosynaptic reflex arc. Muscle spindle and regulation of
muscle length. Polysynaptic reflexes, e.g. antagonist inhibitory reflex and crossedextensor reflex. Central control of simple reflexes - suppression & spasticity.
Speed of reflex responses. Long-latency reflexes.
Organization of the cardiovascular system
Purpose of the circulatory system. Principles of pressure and flow. Anatomical
characteristics. Typical values for 70 kg adult of blood volume, vascular cross-sectional
areas, heart rate, stoke volume, blood distribution, intravascular pressures in right
(pulmonary) and left (systemic) circulations. Definitions of mean circulatory pressure,
total peripheral resistance. Distinction between volume flow and velocity of flow.
Organization of the heart
Two sets of pumping chambers in parallel, each consisting of weak priming pump
(atrium) and strong expulsion pump (ventricle). Certain properties are necessary for
effective continuous movement of blood around the body: rhythmic initiation of
contractions; time-scale of contraction/relaxation suitable for movement of liquid; coordination of right and left pumps; capacity to match emptying to filling.
Week 12
The electrocardiogram (ECG)
Physical reasons for being able to record electrical activity in the heart. The
characteristic waveform of the ECG; significance of P, QRS and T waves and PR and RT
intervals and their normal timecourses. Information obtained from ECGs recorded from
different sites. Common conduction defects. The ECG gives information about a large
number of parameters but NOT about mechanical effectiveness of the heart.
The cardiac cycle
Concept of diastole and systole. Temporal correlation between the sequence of electrical
events indicated by the ECG and the mechanical events reflecting filling and emptying.
Durations, magnitudes and correlations of changes in atrial (= central venous), ventricular
and arterial pressures and ventricular volume. Heart sounds - the basis of the
phonocardiogram (PCG). Implications of cardiac cycle for coronary blood flow.
Hilary Term
Week 18
Cardiac output
Definitions of cardiac output and cardiac index. Definitions of preload and afterload.
Determinants of cardiac output; intrinsic and extrinsic mechanisms; Frank-Starling
curves. Cardiac output is NOT a controlled parameter - changes induced by the nervous
and hormonal systems reflect control pathways for blood pressure and blood volume.
Haemodynamics
Ohm’s law and hydraulic equivalents. Pressure gradients cf. absolute pressures. Changes
in absolute pressures and velocities of flow around the circulation. Resistances in series
and in parallel. Viscosities of plasma and of blood. Poiseuille’s law. Turbulent and
laminar flow. Results of turbulent flow at different sites.
Properties of blood vessels
Functional significance of vessel compliance for continuity of blood flow. Laplace’s law
- significance of vessel diameter to prevent wall rupture; aneurysms. Why small
precapillary vessels are the site of most peripheral resistance. Regional differences in
capillary structure and function. Importance of lymphatic system. Unique properties of
veins; implications for upright posture; oedema.
Week 19
Blood pressure and its regulation
Distinctions between systolic, diastolic and mean arterial pressures. Changes in BP
between aorta and peripheral arteries. Measurement of BP using palpation and using
auscultation. Factors that affect BP. Baroreceptor regulation of blood pressure - high
pressure and low pressure baroreceptors; their sites and functions.
Hormonal regulation of blood pressure.
Regional circulations and their regulation
Concept of regional regulation of blood flow INDEPENDENT OF blood pressure
homeostasis. Vascular autoregulation. Counter-current loops. Typical distribution of
cardiac output at rest; relationship to oxygen usage and extraction. Capacity of different
regional blood flows to change with circumstances; relationship to local and systemic
controlling influences.
Typical pattern of distribution of cardiac output at rest (with indication of how much flow
can change in specific regional beds under different functional circumstances:
ORGAN
BRAIN
SPLANCHNIC
KIDNEY
SKELETAL M.
HEART
SKIN
% body
weight
2%
4%
0.5%
50%
0.5%
3%
% cardiac
output
15%
25%
25%
20%
5%
5%
O2 usage
(% of total)
25%
20%
5%
20%
10%
<1%
O2
extraction
medium
medium
low
medium
high
very low
Capacity for flow
change
x 3 (local)
x 7 (local/nerves)
x 2 (nerves)
x 20 (local/nerves)
x 6 (local)
x 100 (nerves)
Week 20
Organization of the respiratory system
Function of the lung, and its gross and microscopic organization. Protective mechanisms
for gas exchange. The use of notation in describing respiratory function - defining V,
Vprime, P, F, f, and the subscripts v,A, a.
Lung mechanics
The static lung volumes: defining Total Lung Capacity, Functional Residual Capacity,
Residual Volume. The dynamic lung volumes: defining Vital Capacity and Tidal
Volume. The essential principle of lung function is that air can only move down a
pressure gradient. Roles of chest wall, pleura and lung in creating pressure gradients.
Ventilation
The importance of airway calibre for air movement; control of airways calibre. Defining
Dead Space and Forced Expiratory Volume. Understanding the factors that limit
inspiratory and expiratory air flows. Understanding the principles of obstructive and
restrictive flow limitation.
Week 21
Gas exchange
Diffusion depends on concentration gradient and distance. The important effects of
atmospheric pressure and humidity. Why oxygen and carbon dioxide do not behave the
same. Time-limited vs. diffusion-limited gas exchange. Why perfusion and ventilation
may not match. What happens with pneumonia and pulmonary oedema.
Pulmonary circulation
How their different physical dimensions confer different properties on the pulmonary and
systemic circulations. The advantages and the dangers of having a low pulmonary
perfusion pressure gradient. The different effects of local gas tensions on pulmonary and
systemic arterioles. The non-respiratory functions of the lung as a filter, a reservoir and
an endocrine organ.
Gas transport
The important difference between partial pressure and content of gases in the blood.
How oxygen is carried and unloaded. How carbon dioxide is carried and unloaded. Why
carbon monoxide is dangerous. Different types of hypoxia.
Week 22
Respiratory control
Organization of the respiratory centres of the brain. Chemoreceptors and stretch
receptors in respiratory control. Effects on breathing of hyperventilation, hypercapnia
and hypoxia. How the lungs help regulate whole-body acid-base balance.
Effects of barometric pressure
Effects of hypobaric environment on absolute cf partial gas pressures; implications for
oxygen carriage; implications for acid-base balance; acute and chronic compensatory
processes.
Effects of hyperbaric environment on mechanics of cardiorespiratory
system and on gas handling. Physiology of SCUBA cf breath-hold dives. Implications
of hyperbaric conditions for toxicity of nitrogen and oxygen. Implications of gas
solubility.
Week 23
Thermoregulation
Advantages and disadvantages of maintaining a high, closely regulated core temperature.
Control of core temperature by regulating heat production, distribution and transfer. The
use of skin temperature receptors as a feed-forward homeostatic mechanism. Normal and
Consequences of hypothermia and
abnormal causes of temperature variation.
hyperthermia; limits to survival; likely risk situations; strategies and difficulties in
treatment.
Hormones & metabolism (2 lectures)
Chemical types of hormone; location of receptors; examples of hormonal signalling
systems.
Concepts of energy balance, metabolic rate, respiratory exchange rate and the factors that
effect them, with particular emphasis on influences of thyroid, adrenocorticoid and
adrenomedullary hormones.
Week 24
Organization of the digestive tract
Structure: Gross microscopic. Innervation: extrinsic, intrinsic. Gastrointestinal
hormones, gastrin, secretin, CCK, GIP. Motility: peristalsis, segmentation. Secretion:
neural, hormonal influences; ion transport; enzymes. Phases of digestion: cephalic,
gastric, enteric.
Upper G.I.T. function
Salivation; swallowing. Stomach : receptive relaxation, motility; secretion; emptying;
digestion.
Week 25
Digestion & absorption
Intestine: motility; secretion. Absorption : proteins, carbohydrates, fats. Inter-digestive
phase : “housekeeper”. Pancreatic secretion. Role of adrenocorticoids in inter-digestive
period. Causes of malabsorption.
Water & electrolyte absorption
Review structure/function. Normal absorption of water & electrolytes. Bi-directional
fluxes; transport routes and processes; absorption in different segments; lacteals and
lymph. Causes of diarrhoea.
Week 26
The liver (2 lectures)
Functional anatomy, role of liver in lipid digestion & significance of enterohepatic
circulation. Roles in lipid, carbohydrate, protein and metal metabolism. Roles as a
vitamin factory. Roles in erythropoiesis and coagulation. Roles in hormone action.
Roles in detoxification and excretion. Dual circulatory input and impact of low capillary
hydrostatic pressure. Ascites. Multiple effects of impaired hepatic function.
Distinguishing between haemolytic and obstructive jaundice.
Trinity Term
Week 30
Organization of the renal tract
Structure of kidney: vasculature, tubules. Autoregulation of blood flow. Basic renal
processes: filtration, secretion, reabsorption. Filtration barriers. Forces involved in
filtration.
filtration
Glomerular filtration rate. Measuring renal plasma flow and glomerular
Tubular function & solute excretion (2 lectures)
Mechanisms of reabsorption and secretion. Concept of tubular maximum and
significance for glucose. Central role of sodium handling in regulation of excretion of
other substances. Roles of renin/angiotension/aldosterone axis; atrial natriuretic peptide.
Pre-renal, renal and post-renal disruption of normal function.
Week 31
Water balance
Formation and roles of osmotic gradients. Changes in urinary water concentration along
tubule. Countercurrent exchange and urea. Osmoreceptors. Antidiuretic hormone
(ADH, vasopressin). Diabetes insipidus. Bladder function and micturition.
Acid-base balance
Renal regulation of plasma bicarbonate. Secretion of ammonia. Secretion of hydrogen
ions. Interactions of respiratory and renal systems. Acidosis and alkalosis; causes,
effects, compensatory adjustments.
Weeks 32-33
Endocrine regulation I-IV
Calcium in ICF, ECF and serum. Relation of ionised (free) and bound complexes. The
need for tight regulation of free plasma calcium; hypocalcaemia as a common
consequence of alkalosis. Hormonal control of calcium absorption and excretion. Bidirectional exchange of calcium between between blood and bone; roles of calcitonin and
parathyroid hormone. Links to phosphate metabolism. Causes and implications of
hypocalcaemia and hypercalcaemia.
Revision of the principles of systemic hormone action and neuroendocrine regulation.
The hypophysiotropic (hypothalamic) and hypophosyeal (pituitary) hormones. Anterior
pituitary corticotrophic and gonadotrophic functions; generic roles of ACTH, FSH and
LH. Adrenal and gonadal hormones; common pathways for synthesis of multiple steroid
hormones. Feedback mechanisms. The pineal as a regulator of hypothalamo-pituitarygonadal function.
Physiological roles of growth hormone (GH) and somatomedins. Regulation by
somatostatin and GH-releasing hormone. Interaction of GH with other hormones
affecting metabolism. Bone growth and puberty: growth cessation in males and females.
Abnormalities of growth - dwarfism, gigantism, acromegaly.
Endocrine regulation of gender
Femaleness as a default situation. Foetal development of male and female characteristics.
Postnatal roles of androgens and oestrogens in development of primary and secondary
sex characteristics; other phenotypic effects of gonadal hormones; significance of the
adrenal gland as a source of androgens. Implications of abnormal prenatal or postnatal
gonadal endocrine signalling; disorders of sexual development.
Week 34
Male and female reproductive systems
Overview of germ cell differentiation. Interaction of Sertoli and Leydig cell functions in
spermatogenesis. Essential roles of epididymis, vas deferens, seminal vesicles, prostate
and bulbourethral glands. Prenatal development of female germ cells and primary
follicles. Meiotic activation by oestrogens. Significance of the polar body.
The menstrual cycle and fertilisation
Purpose of a cycle for reproductive efficiency. Development of the secondary follicle.
Correlation of hormonal, ovarian and uterine changes during follicular, luteal and
menstrual phases. The need for both FSH and LH. Timing and site of fertilisation.
Week 35
Pregnancy
The delay between fertilization and implantation. Implications of ectopic fertilisation or
implantation. Roles of ovarian, placental and foetal hormones. Maternal adaptations –
circulatory, respiratory, renal and metabolic systems. Hormonal regulation of uterine,
foetal and mammary growth.
Parturition and lactation
Stages of labour. Roles of progesterone, oestrogens, cortisol, relaxin, oxytocin,
prostaglandins. Morphological and mechanical changes in uterine wall and cervix.
Control of milk secretion and ejection.
STUDY GUIDE
Michaelmas Term
Week 5
Learning objectives:
•
To be able to relate images of histological preparations to living tissues
•
To know the main characteristics of epithelial tissues,and connective tissue
•
To know the components of skin
•
To understand the processes involved in bone formation and repair
•
To know typical sizes of the main body water compartments and be able to outline the
homeostatic processes for their regulation
•
To be able to define osmotic pressure, oncotic pressure and osmolality
•
To be able to define oedema and understand the basic processes by which this can
occur
Revision questions:
•
List the features that are necessary in order for epithelium to fulfil its functions.
•
Which types of epithelium are found within the arm?
•
Compile a table comparing the properties of the different types of connective tissue.
•
Draw a labelled diagram comparing the structure of keratinous skin with that of a
mucous membrane.
•
Write notes on the different mechanisms by which glandular secretion can occur.
•
Draw a diagram illustrating the cellular composition at the end of a growing long
bone.
•
Compile a table showing typical values for the volumes of water in each compartment
of the body of a 70 kg individual.
Week 6
Learning objectives:
•
To know the basic composition of plasma
•
To know typical values for red blood cell size, circulating numbers and turnover rate
•
To understand the basic processes involved in blood cell formation (haemopoiesis)
and the sites at which red blood cell formation and breakdown occur
•
To be able to recognize the different types of white blood cell (leucocyte) and know
their functions
•
To be able to describe the basic organization of the brain and spinal cord
•
To know typical normal concentrations of sodium, potassium, calcium, bicarbonate
and chloride in intracellular and extracellular fluids
•
To know the structural characteristics of neurons and how these relate to their
function
•
•
To understand the ionic basis for the resting membrane potential and the role of
energy in its maintenance
To understand the ionic changes that underlie local (electrotonic) and propagated
depolarizations of an excitable cell membrane
Revision questions:
•
•
•
List the main types of protein in the blood, in ascending order of concentration, and
indicate their physiological roles.
Draw up a table showing typical normal values for erythryocyte diameter (µm),
volume (fl), numbers (/ml blood), packed cell volume (% blood volume) and lifespan
(days).
Draw up a table listing the functions of neutrophils, eosinophils, basophils,
lymphocytes and monocytes
•
Draw a cross-section of the spinal cord and show the locations of white matter and
grey matter.
•
On a saggital diagram of the brain, mark the locations of the motor cortex, the visual
cortex, the hypothalamus, the pituitary gland and the medulla.
•
List the ions that are most abundant in extracellular and intracellular fluids and give
typical normal values (mmol/litre).
•
Draw a diagram of a typical neuron, showing the area at which incoming electrical
information is received and where the outgoing action potential is initiated.
•
Show, using the Nernst equation, why the resting membrane potential of a human
neuron would be approximately -99mV if the membrane was permeable only to
potassium ions.
Week 7
Learning objectives:
• To understand why action potentials are ‘all-or-none’ phenomena
•
To be able to explain the roles of myelin and axon diameter in determining axonal
conduction velocity
•
To understand the processes involved in chemical neurotransmission
•
To understand the processes by which sensory information is detected and processed
To know the roles of spinal cord, hindbrain, thalamus and cerebral cortex in
processing somatosensory information
•
Revision questions:
•
Draw a calibrated diagram showing the time course of membrane potential change
during an action potential and superimpose the associated changes in sodium and
potassium conductances.
•
Draw a flow diagram of the events that occur between the arrival of an action
potential at the end of an axon and the initiation of an action potential in the
postsynaptic neuron.
•
Opening of channels for which ions could result in postsynaptic potential changes that
(i) depolarise or (ii) hyperpolarise a nerve cell?
•
List the different types of somatosensory receptors and the modalities of sensation
they detect.
Write notes on detection of pain.
Define proprioception and indicate the different types of proprioceptive signals that
contribute to movement control.
•
•
Week 8
Learning objectives:
•
To know the roles of the iris, lens and retina in vision
•
To understand the cellular basis of colour vision
•
To know the brain pathways that carry visual information and how these affect the
image that is detected
Revision questions:
•
Draw a diagram of the eyeball, showing how the function of the ciliary muscle affects
vision at close and distant ranges.
•
Draw a flow diagram to illustrate the sequence of events involved in retinal
transduction of light.
•
Draw a diagram of the routes taken by visual information as it travels to the visual
cortex from the medial and the lateral halves of each retina.
•
Draw outlines of the visual fields for left and right eyes following destruction of (a)
the left optic nerve (b) the optic chiasm or (c) the left lateral geniculate nucleus.
Week 9
Learning objectives:
•
To understand the functional anatomy of the ear in relation to audition
•
To understand the functional anatomy of the vestibular system
•
To know how the semicircular canals and macula enable control of balance and
posture
•
•
To comprehend the distinctions between the somatic and autonomic nervous systems
To be able to define the main differences between sympathetic and parasympathetic
components of the autonomic nervous system and to appreciate their overall
functional roles
•
To understand the 3-dimensional structure of a skeletal (somatic) muscle cell
•
To know the functional organization of the sarcomere and understand how it contracts
Revision questions:
•
•
•
Write notes on the processes by which sounds of different frequencies and intensities
are distinguished.
Compare the roles of the macula and the semi-circular canals in balance control.
What are the structural and functional differences between somatic and autonomic
nervous systems?
•
What are the structural differences between sympathetic and parasympathetic
outflows of the autonomic nervous system?
•
List the neurotransmitters used in the autonomic nervous system and indicate the
synapses at which they are released.
•
What effects might be seen in a person who has been administered a muscarinic
receptor antagonist?
•
Use a flow diagram to show the sequence of events that leads to shortening of a
sarcomere following initiation of an action potential in the muscle cell.
Week 10
Learning objectives:
•
To appreciate the main differences between transmission at the skeletal
neuromuscular junction and at other chemical synapses
•
To appreciate the vulnerability of neuromuscular transmission to poisons
To understand the factors which affect the amount of muscle tension that results from
muscle activation under different circumstances
•
•
To know that motor innervation is essential not only for somatic muscle contraction
but also for somatic muscle integrity
•
To comprehend the differences in structure and functional behaviour between
skeletal, cardiac and smooth muscles
Revision questions:
•
Draw a diagram of the membrane potential changes in a muscle cell that would be
seen (i) close to the motor end plate and (ii) remote from the motor end plate,
following arrival of a single action potential at the terminal of an alpha motor axon.
•
List, giving examples, the ways in which poisons might affect muscle contraction by
interference with events at the neuromuscular junction.
•
Draw a diagram showing the changes in passive and active tension in a skeletal
muscle sarcomere as its resting length is increased. Show diagrammatically how the
changes relate to the amount of overlap between actin and myosin filaments.
•
Draw a graph of tension against time to compare the active tension changes in a
skeletal muscle motor unit during (i) a twitch, (ii) a weak sustained contraction and
(iii) a maximum contraction.
•
Compile a table listing the similarities and differences between cardiac, skeletal and
smooth muscle tissues.
•
Draw a diagram of the membrane potential and tension changes that would be
expected over time in a spontaneously active smooth muscle tissue in which the
myogenic activity is due to (i) pacemaker cells or (ii) slow waves.
Week 11
Learning objectives:
•
To be able to define a reflex
•
To understand the circuitry and functional importance of the tendon jerk reflex and
the withdrawal (crossed-extensor) reflex
•
To understand how the brain has control over even simple reflexes
To understand the overall organization of the circulatory (cardiovascular) system
To recognize the relationships between pressure gradients, resistance and flow in a
moving fluid
•
To know typical normal values for blood volume, heart rate, stroke volume, diameters
of aorta, capillaries and vena cavae and mean arterial, capillary and central venous
blood pressures in pulmonary and systemic circulations
Revision questions:
•
•
•
Draw a diagram showing the neural circuitry associated with the reflex that is
initiated by hitting the patellar tendon.
•
A person steps on a sharp object and withdraws the injured foot. Draw a diagram
showing the spinal circuitry associated with this reflex action. Make sure you
indicate the directions of information movement and identify which are excitatory and
which are inhibitory synapses
•
Briefly outline two ways in which the brain can influence a tendon jerk reflex.
•
List typical values for mean aortic pressure, mean brachial arterial pressure, mean
systemic capillary pressure and mean central venous pressure
Week 12
Learning objectives:
•
•
•
To understand the properties of the heart that are essential for its function
To comprehend how the sequence of cardiac excitation can be interpreted in terms of
the electrocardiogram (ECG) and phonocardiogram (PCG)
To be able to describe the events that occur during the cardiac cycle
To know typical time courses, pressures and volumes involved in the cardiac cycle at
rest
Revision questions:
• Draw a diagram of the heart, cut in longitudinal section, showing the sequence of
excitation during a normal cardiac cycle and the absolute times after initiation of the
sino-atrial node action potential.
• Write notes on the main properties that the heart must have in order to function
effectively and indicate how these properties are ensured.
• Draw a diagram illustrating a typical electrocardiogram, label the different
components and indicate the periods during which atrial contraction and ventricular
contraction take place.
•
List the safety factors that normally guarantee an appropriate sequence of electrical
activation of the heart.
• Draw a calibrated diagram illustrating the pressure/volume relationship in the left
ventricle during one complete cardiac cycle (ie systole + diastole).
• Draw a calibrated diagram showing the changes during one cardiac cycle in central
venous pressure, ventricular pressure, aortic pressure and ventricular volume. On the
same time axis, superimpose the ECG record and indicate the timing of the first and
second heart sounds.
•
Hilary Term
Week 18
Learning objectives:
•
To be able to define cardiac output, cardiac index, preload and afterload
•
To understand the factors that affect cardiac output
•
To understand the main factors that affect resistance to and velocity of fluid flow in
the bloodstream and be able to relate these factors, using equations
•
To comprehend the structural properties of arteries, arterioles, capillaries, veins and
lymphatics and how these relate to the specialized functions of these vessels
•
To know the absolute effect of gravity on intravascular hydrostatic pressures in the
vasculature of the lower limbs when standing
•
To understand how gravity affects venous return and water movement between
plasma and interstitium
Revision questions:
•
List the main factors that might influence cardiac output in a resting subject.
•
Write notes on the significance of turbulent flow in the circulatory system.
•
Write notes on the variables that appear in Poiseuille’s equation.
•
Discuss briefly the factors that affect the viscosity of blood, indicating the functional
importance of these.
•
List the three functional types of capillary, indicate the different structural properties
that they possess and give two examples of organs in which each type is found.
Week 19
Learning objectives:
To be able to recognize typical normal values for systolic and diastolic arterial
pressures and appreciate how each of these is affected by heart rate, cardiac
contractility, aortic compliance and peripheral resistance
•
To recognize the importance of a stable arterial blood pressure and understand the
main processes by which blood pressure is regulated
•
To understand the principle of auscultatory measurement of blood pressure
•
To appreciate that total peripheral resistance and specific regional resistances may be
regulated independently
•
To comprehend the processes by which local regulation of regional blood flow can
occur
•
To know typical values for the distribution of cardiac output at rest
Revision questions:
•
Draw a flow diagram showing how blood pressure is regulated by the arterial
baroreceptor reflex.
•
Discuss the circulatory consequences of standing in a stationary position for 30
minutes.
•
Define syncope and list three ways in which it may be triggered.
•
Define vascular autoregulation and describe briefly the mechanisms that cause this
phenomenon.
•
Draw up a table showing typical absolute values (ml/min) for renal, cerebral,
coronary and splanchnic blood flows.
•
Week 20
Learning objectives:
•
To be able to describe the overall organization of the respiratory tract
•
To recognize the notations used to identify different respiratory parameters
•
To be able to define TLC, FRC, RV, VC, TV and FEV
•
To appreciate the absolute pressure gradients involved in respiratory air movements
and how these relate to flow rate during inspiration and expiration
•
To understand the concepts of anatomical and physiological dead spaces
•
To be able to describe the mechanisms that normal regulate airways resistance
•
To know the cellular processes that underlie development of asthma
Revision questions:
• Draw a diagram illustrating the subdivision of lung volume into its different static and
dynamic components.
• Compile a table showing typical absolute pressures (in mm Hg, atmospheric = 760) in
trachea, alveoli and pleural space (i) in mid-inspiration at rest, (ii) in mid-expiration at
rest, (iii) at end-expiration at rest and (iv) in mid-expiration during a forced expiratory
effort.
•
Draw a diagram of the bronchial wall, showing the sequences of events that cause an
asthmatic attack after inhalation of (i) pollen or (ii) SO2.
Week 21
Learning objectives:
•
To know the major reasons for ventilation/perfusion mismatching
To know the percentage composition and partial pressures of O2, CO2, H2O and N2
in atmospheric and alveolar air and understand the factors that can make these values
vary
•
To know why pressures in the pulmonary circulation are less than those in the
systemic circulation and recognise the functional consequences
•
To understand the non-respiratory importance of the lungs
•
To know why pneumonia and pulmonary oedema prejudice respiratory function
•
To be able to define obstructive and restrictive lung disease and be able to predict
how each of these types of disease will affect respiratory mechanics and gas exchange
•
To understand the different functional roles of dissolved and haemoglobin-bound
oxygen and know their absolute normal values in arterial and venous blood
•
To know how the relationship of plasma oxygen concentration to blood oxygen
content is altered by variations in haematocrit and by haemoglobin binding capacity
Revision questions:
• Write notes on the regional variations in ventilation and perfusion that are seen in the
normal lung and how this affects regional ventilation/perfusion matching.
•
Draw a calibrated diagram of the pressure changes that occur during one cardiac cycle
in right ventricle and pulmonary artery.
•
List the non-respiratory functions of the lung.
• Draw up a table showing typical pressures developed during the first second of a
forced maximal expiratory effort (a) in the pleural space, (b) in the alveoli, (c) in the
bronchi and (d) in the trachea for a normal subject and for a patient with emphysema.
• On a calibrated and labelled diagram, show typical flow/volume loops for inspiration
and expiration for a normal person, a patient with obstructive lung disease and a
patient with restrictive lung disease.
•
Draw a calibrated and labelled diagram showing the normal relationship at sea level
between plasma oxygen concentration and blood oxygen content and mark the values
on each axis that correspond to (i) systemic arterial and (ii) pulmonary arterial blood.
•
On the same diagram, show how the curve would be affected by (i) an increase in
haematocrit from 40% to 60% and (ii) inhalation of carbon monoxide.
•
Week 22
Learning objectives:
•
To appreciate the principles of respiratory control and the implications of changed
oxygen and carbon dioxide concentrations
•
To appreciate the consequences of ambient pressure on gas exchange and handling by
the body
•
To have an approximate knowledge of the absolute pressure changes experienced as
one ascends to high altitude
•
To comprehend the acute and chronic effects of breathing a hypoxic gas mixture
•
To know the rate at which absolute atmospheric pressure increases with descent
below the surface level of water
•
To comprehend the diverse effects of hyperbaric environments on the body
Revision questions:
•
Write notes on the effects on respiration of breathing air with the following alterations
from normal - (i) 12% oxygen, (ii) 50% oxygen, (iii) 5% carbon dioxide, (iv) 50%
carbon dioxide.
•
List the partial pressures of oxygen, carbon dioxide and nitrogen in room air and in
alveolar air of a normal individual at (a) sea level, and at altitudes which cause total
atmospheric pressure to be (b) 600 mmHg and (c) 500 mm Hg.
•
Discuss the acute (24 hr) and chronic (24 days) effects of residence at 5,000 metres of
a person acclimated to living at sea level.
•
Compare and contrast the effects on the body of descent to 200 metres below sea
level (i) in a mine shaft and (ii) underwater.
•
Compare the physiological implications of breath-hold diving and SCUBA diving to
100 metres.
Week 23
Learning objectives:
•
To understand the processes by which body core temperature is regulated, know its
normal variability and recognize the factors that normally affect it
•
To appreciate the specific consequences on body functions of hypothermia and
hyperthermia and the factors that must be borne in mind when treating these disorders
•
To know the main structural differences between the three families of hormones and
know the cellular locations of their respective receptors
•
to be able to define autocrine, paracrine, exocrine, and endocrine hormone actions
•
To be able to define metabolic rate and know typical ranges of normal values for it in
kCal and kJ
•
To understand the concept of the respiratory exchange ratio and the main factors that
affect it
To know the relationship of thyroid hormone secretion to metabolism
Revision questions:
• Draw a flow diagram showing the feedback control of deep body temperature.
• List factors that cause variability in deep body temperature in normal individuals.
• Discuss the progression of events that occurs in an individual who becomes
increasingly hypothermic through exposure to a cold, windy environment.
• Write notes on the physiological considerations that should be borne in mind during
treatment of this individual, who on rescue has a deep body temperature of 29oC.
•
Define ‘fever’ and write notes (not more than 3 lines) on the mechanism underlying
fever caused by a bacterial infection.
•
Draw up a table listing the three chemical types of hormone, the cellular locations of
their respective receptors and an example of each type.
•
•
Write an equation describing the relationship between energy input and energy output
in the body.
•
Compile a list showing typical values for metabolic rate (in kCal/kg/hr and in
kJ/kg/hr) in a normal, fasting College student (a) at rest (b) during quiet study (c)
while jogging and (d) while running upstairs.
•
Define respiratory exchange ratio, give its normal range and list some factors that will
cause it to be elevated or depressed beyond this normal range.
Week 24
Learning objectives:
•
To comprehend the functional architecture of the gastrointestinal tract (g.i.t.)
•
To appreciate the interactions of hormonal and neural factors in regulation of
digestive function
•
To revise Michaelmas Term material on properties of smooth muscle and to know the
basis of g.i.t. motility
•
To know which segments of the g.i.t. depend on somatic muscle and which on smooth
muscle
•
To understand the roles of the salivary glands and stomach in processing of ingested
food
•
To understand the mechanisms that underlie ulceration of the wall of stomach or
duodenum
Revision questions:
•
Compile a table showing the functional roles of gastrin, secretin, CCK, GIP and
pepsin.
•
List the functions of the stomach. Are any of these essential to survival?
•
Describe briefly the process of gastric secretion of acid.
•
A patient complains of chronic constipation. What possible causes come to mind?
•
Week 25
Learning objectives:
•
To know the processes by which carbohydrates, proteins and lipids are digested and
absorbed
•
To comprehends the volume of water normally entering the large intestine daily and
to understand how this water is handled
•
To understand the regional specialization of absorptive function in the G.I.T. and the
consequences for surgical resection of different areas
•
To comprehend the common causes of overt malabsorption syndromes of nutrients or
water
•
To understand the basis of diarrhoea and the different ways in which this might be
triggered
•
To appreciate the different causes of insulin-dependent and insulin-independent
diabetes
Revision questions:
•
Write notes on the secretions of the pancreas and how these are regulated.
•
Compile a flow diagram showing the sequence of events involved with digestion and
absorption of a carbohydrate meal after it is swallowed.
•
What are the effects on G.I.T. function of resection of the terminal ileum?
•
What is coeliac disease?
•
Describe the metabolic changes which result from Type I diabetes.
•
List possible underlying causes of diarrhoea in an apparently healthy young woman.
Week 26
Learning objectives:
To understand the roles of the biliary system in lipid absorption
To understand the roles of the liver in nutrient processing
To comprehend the wide range of other functions fulfilled by the liver
To comprehend the wide range of abnormalities that are consequently associated with
liver damage
• To understand the unique circulatory supply of the liver and the functional
consequences of this
• To be able to define jaundice, understand the three ways in which it may occur and
know how to distinguish between these
Revision questions:
•
Write notes on the roles of bile in absorption of fat.
• List the different physiological roles of the liver (you should be able to think of
about 12).
• Give a typical normal value for capillary hydrostatic pressure in a hepatic sinusoid.
• Define jaundice.
• Why is liver function often depressed in patients with right heart failure?
• Patients with hepatic disease may exhibit bruising, dark urine, pale stools and
confusion. What is the reason for each of these?
• Why might an individual with alcoholic liver disease suffer from oesophageal
bleeding?
• Why might a man with liver disease exhibit decreased body hair and swollen breasts?
•
•
•
•
Trinity Term
Week 30
Learning objectives:
•
To revise Michaelmas Term material on body water compartments
•
To understand the functional architecture of the kidney and its blood supply
•
To know typical normal values for renal plasma flow, glomerular filtration rate and
urine production
•
To understand the forces involved in filtration, secretion and reabsorption and
appreciate the roles of passive and active mechanisms in creating these forces
•
To understand the principles employed for evaluation of the adequacy of renal
function
Revision questions:
•
Draw a diagram showing the anatomical relationship between a nephron and its blood
supply.
•
List typical normal values for renal blood flow, renal plasma flow, glomerular
filtration rate, filtration fraction and urine production (make sure you indicate the
units in which each parameter is expressed).
•
Discuss the non-excretory functions of the kidney.
•
Describe the characteristics required of markers to be used to measure (i) renal
plasma flow or (ii) GFR and give examples of each.
Week 31
Learning objectives
•
To comprehend in general how the kidney handles filtered solutes
•
To understand in detail the processes by which sodium and potassium are handled in
the nephron
•
•
To comprehend the mechanisms by which osmolality of the tubular filtrate is altered
in different segments of the nephron
To understand the renal processes that maintain water balance
•
To know the absolute limits to urinary osmolality and volume
•
To know how urine is handled in the post-renal urinary tract
•
To understand the renal processes that maintain acid-base balance
•
To appreciate the interaction of renal and respiratory systems in acid-base regulation
•
To understand how prerenal, renal and postrenal factors can cause failure of effective
renal function
Revision questions:
•
Compare and contrast the processes of sodium reabsorption in the proximal and distal
tubules, indicating the approximate amounts of sodium handled at each site.
•
Write notes on the effects of angiotensin and aldosterone on plasma electrolyte
balance.
•
Discuss briefly the significance of renal processing of urea.
•
Draw a diagram showing the involvement of vasopressin in regulation of plasma
osmolality.
Define countercurrent exchange and explain (not more than 5 lines) why this
principle is essential for effective renal function
How is urea used to help regulate water balance by the kidney?
Draw a flow diagram illustrating the micturition reflex.
Write notes on the buffer systems that are involved in renal regulation of acid/base
balance.
Discuss the factors that might result in metabolic acidosis; how would you distinguish
this from respiratory acidosis?
Describe the renal compensations that occur in response to respiratory alkalosis.
List some consequences of complete cessation of renal function.
•
•
•
•
•
•
•
Week 32
Learning objectives
•
To understand the principle of feedback regulation of endocrine function
•
To know the normal range of plasma free calcium concentrations
•
To know the principles of hormonal regulation of calcium balance
•
To know how hypocalcaemia is most commonly caused and the consequences of this
•
To be able to describe the hypothalamo-pituitary axis and how this relates to
regulation of peripheral endocrine function
Revision questions:
•
Give the normal limits of plasma free calcium (mmol/litre).
•
What common circumstances can led to large falls in plasma calcium over a few
minutes and what effects might this have?
•
Describe the role of the kidney in regulating plasma calcium.
•
Describe the sources and metabolism of vitamin D.
•
Draw up a table showing the various hypothalamic releasing factors and the
respective anterior pituitary hormones that are released.
•
What is different about release of hormones from anterior and from posterior pituitary
glands?
Week 33
Learning objectives
•
To be able to list the peripheral effects produced by each of the pituitary hormones
•
To understand that all adrenal and gonadal steroid hormones are synthesised through
a common pathway
•
To comprehend the major role of the pineal gland in endocrine regulation
•
To understand how growth is regulated by hormones
•
To understand why puberty initiates both growth and its cessation
•
To understand why abnormal growth hormone levels before and after puberty have
different effects
To understand the roles of gonadal hormones in prenatal sexual development
•
To understand the importance of adrenal androgens in female development
•
To be able to predict the consequences of foetal deprivation of testosterone,
dihydrotestosterone or dihydroepiandrosterone
•
To recognise the major differences between germ cell maturation in males and
females
• To understand the roles of gonadal hormones in postnatal sexual development
Revision questions:
•
List the peripheral hormones that are released in response to each anterior pituitary
hormone.
•
List the functions of the various adrenocortical hormones (aka adrenocorticoids).
•
Write notes on the location and function of the pineal gland.
•
Draw a flow diagram showing the pituitary regulation of body growth.
•
List the biological effects of growth hormone.
•
Describe the visible differences between an individual who has growth hormone
oversecretion in childhood and one who begins to have growth hormone
oversecretion at age 30.
•
Why is femaleness the default sexual phenotype?
•
List the effects of testosterone and of dihydrotestosterone on male phenotype.
•
List the effects of oestrogens and of dihydroepiandrosterone on female phenotype.
•
Write notes on the effect on genital development of defective prenatal (i) synthesis of
testosterone in a male, (ii) conversion of testosterone to dihydrotestosterone in a male
and (iii) synthesis of cortisol in a female.
•
List the effects of oestrogens and androgens on postnatal development of males and
females.
•
Week 34
Learning objectives:
• To understand the hormonal control of spermatogenesis
• To know the organization of the male and female reproductive tracts
• To understand the functional significance of the different components of semen
• To be able to describe the sequence of hormonal changes that occurs during the
menstrual cycle and its functional consequences
Revision questions:
•
Draw a diagram to show the feedback endocrine control of testicular function.
•
List the functions of the seminal vesicles and of the prostate gland.
•
Draw a diagram showing the changes in plasma LH, FSH, oestrogens and
progesterone during a 28-day cycle, indicating how the hormonal profile relates to the
day of ovulation.
•
What specific effects do (i) oestrogens and (ii) progesterone have on the
endometrium?
•
Why can the day of ovulation be identified by daily monitoring of body temperature?
• Describe the functions of the corpus luteum.
Week 35
Learning objectives:
To be able to describe the processes that occur between fertilisation and implantation
of the conceptus
•
To know the functional organisation of the placenta and appreciate its roles
•
To understand the hormonal changes that occur during pregnancy and how these
contribute to maternal and foetal functions
•
To appreciate the main maternal adaptations to pregnancy
•
To know the events that are important in initiating and regulating the progress of
labour (parturition)
•
To understand the processes that are involved in the growth and function of the
mammary glands
Revision questions:
• Write notes on the events that occur between the moment of fertilisation and the time
of implantation.
• Draw a diagram illustrating the relationship of placenta and foetus.
• Draw a graph illustrating the timecourses of changes in maternal plasma hCG,
oestradiol and progesterone during pregnancy.
• What are the primary sources of maternal oestrogen and progesterone during the last
half of pregnancy?
• List the effects of oestrogens and of progesterone on the physiology of the mother
during pregnancy.
• Show, in the form of a flow diagram, the events that initiate parturition and maintain
its progress.
• Draw a flow diagram of the suckling reflex.
•