Section 3 Workbook (units 7, 8 & 9)
Name: _______KEY______
Nervous System: C11. Analyze the transmission of nerve impulses
1. Identify the 3 main parts of the neuron (dendrite, cell body, axon).
2. Complete the table.
Name of
Structure
Function
Receives signal and conduct the nerve impulse TOWARDS the cell body
dendrite
Controls and maintains the cell because it contains the nucleus
cell body
Conducts the nerve impulse AWAY from the cell body
axon
3. Identify the 3 types of neurons as well as X & Y in the diagram.
4.
Differentiate among sensory, motor, and interneuron by completing the table.
Name of
Neuron
Sensory neuron
Diagram
Long dendrite, short axon
Location
Peripheral nervous
system (PNS) and
Central nervous
system (CNS)
Function
Carries the message (nerve
impulse) from the sensory
receptor to the CNS
Interneuron
CNS only
Receives the nerve impulse
from the sensory neuron and
sends the impulse to the brain
and motor neuron.
Short dendrite, long or short axon
Draw a motor neuron
CNS & PNS
Motor
neuron
Carries the nerve impulse /
message from the interneuron
to an effector (muscle or gland)
Short dendrite, long axon
5.
Identify the parts of the reflex arc in the diagram and explain what a reflex is.
A reflex is an involuntary, automatic response to a large stimulus. It just happens; there is no need to
think about it.
6. What is a dorsal-root ganglion?
A collection of sensory neuron cell bodies that are located along the vertebral column by the spine
7. Relate the structure of a myelinated nerve fibre to the speed of impulse conduction, with reference to
myelin sheath, Schwann cell, node of Ranvier, and saltatory transmission / conduction.



Myelin is a fatty substance wrapped around some nerve fibres to form what is called the
myelin sheath. Myelin is produced by Schwann cells (a neuroglia cell).
The myelin sheath speeds up the nerve impulse by causing saltatory conduction / transmission
to occur where the impulse jumps from one node of Ranvier to the next node of Ranvier.
The nodes of Ranvier is a place on the nerve fibre where there is no myelin and are the points
between Schwann cells.
Action Potential
8. Explain the transmission of a nerve impulse through a neuron, using the following terms:
resting and action potential
refractory period
sodium-potassium
pump
depolarization and repolarization
sodium and potassium gates
axoplasm
polarity
Nerve impulse = resting potential + action potential
Resting Potential: outside of the neuron is positive, the inside of the neuron (axoplasm) is negative due
to the distribution of Na+, K+, and negative ions.
 At rest, there is more K+ inside and more Na+ outside of the neuron.

At rest, sodium and potassium gates are closed so these ions cannot move
Depolarization: If the stimulus reaches the threshold level of -40mV, the sodium gates open and Na+
enters the neuron and joins K+ in the axoplasm.

There are now more positive ions than negative ions inside the axoplasm so the polarity
changes to positive inside and negative outside.
Repolarization: When the voltage reaches +40mV, the K+ gates open and K+ leaves the neuron and
goes to the outside.
 The polarity now changes again and the axoplasm goes back to being negative and the outside
of the neuron is positive again.

The Na+ gates are closed during repolarization.
Refractory Period: recovery phase. The Na+ & K+ voltage gated ion channels close during the
refractory period.
 The sodium- potassium pump resets the neuron for the next nerve impulse by pumping K+
back into the axoplasm and Na+ back outside of the neuron.

The neuron has now re-established the resting condition so the neuron can receive another
nerve impulse.
9. What is the sodium-potassium pump? In what phase of the action potential is it active?
 It is a form of active transport requiring ATP. There is a carrier protein that actively moves Na+
outside of the cell and K+ into the cell. This restores the original conditions of the resting potential
 It occurs during the refractory period
10. What is diffusion?
The movement of a substance from high to low concentration
11. What is an oscilloscope?
A small voltmeter that measures the potential difference across the axomembrane of a neuron.
12. What is an action potential?
A rapid change in the polarity across an axomembrane as the nerve impulse is conducted along the
neuron
13. What are sodium gates? When do the sodium gates open?
Sodium gates are proteins that allow Na+ to move across the axomembrane. The sodium gates open
during depolarization (-65mV to +40 mV).
14. What are potassium gates? When do the potassium gates open?
Potassium gates are proteins that allow K+ to move across the axomembrane. The potassium gates open
during repolarization (+40mV to -70mV).
15. Nerve impulse – Action potential
Range of mV
Resting
potential
-65 mV
Charge
inside the
neuron
Negative
Charge
outside the
neuron
Positive
Describe Na+ and K+ concentrations
or movement
Na+ greater outside the neuron
K+ greater inside the neuron
Depolarization
-65 mV to
+ 40 mV
Positive
Negative
Na+ moves inside neuron and joins
K+ still inside the neuron
Repolarization
+40 mV to
-65 mV
Negative
Positive
Na+ stays inside the neuron
K+ moves outside of the neuron
Refractory
period
-70 mV to
-65 mV
Negative
Positive
Na+ greater outside the neuron
K+ greater inside the neuron
16. On the following nerve impulse label:
a)
b)
c)
d)
e)
Threshold
Resting potential
Depolarization
Repolarization
Action potential
f)
g)
h)
i)
Refractory period
When sodium ions move inside
When potassium ions move outside
When Na+/K+ pump in action
17. During the refractory period, why are the sodium and potassium gates unable to open for a brief
amount of time?
So the action potential cannot move backwards
18. Put the following statements in proper order.
___3___ Membrane is depolarized
___4___ Potassium gates open
___6___ Sodium-potassium pump restores resting potential
___5___ Sodium is inside neuron, potassium is outside
___1___ Sodium is outside neuron, potassium is inside
___2___ Sodium gates open
19. Explain what is happening in the following diagrams
Explanation:
Resting potential:
No nerve impulse therefore, no
movement of ions.
Na+ greater outside the neuron while
K+ is greater inside the neuron.
Sodium gates open:
The membrane potential changes to
+40 mV inside the axon (axoplasm).
This causes depolarization to occur.
Potassium gates open:
The membrane potential goes back to -65 mV inside the axon.
This causes repolarization to occur
6
Synaptic Transmission:
20. What is a synapse?

Space / area where an axon bulb of one neuron and the postsynaptic cell (dendrite, muscle or
gland) are close together but not touching.
 It allows the nerve impulse (electrical) to be transmitted to the next neuron (chemically with
neurotransmitters).
21. Explain the concepts of threshold, ‘all or none’ response, inhibitory and excitatory
neurotransmitters, and summation as they relate to synaptic transmission.
 Threshold = the minimum amount of stimuli required to produce a nerve impulse. All the
excitatory and inhibitory signals on the dendrite (from inhibitory and excitatory
neurotransmitters) are integrated (summed up) to determine if the neuron will fire or not.
 As long as the threshold stimulus of -40 mV has been reached, there will be an impulse. So,
the neuron fires or not. There is no half impulse created. The impulse is always the same size.
This is the all or none response
22. Label these major components of a synapse: presynaptic membrane, postsynaptic membrane,
synaptic cleft, synaptic vesicle, axon bulb, neurotransmitter, calcium ions and contractile proteins
23. What is a neurotransmitter?
 Molecules / chemicals stored in the axon bulb that are responsible for synaptic transmission
(linking nerve impulse to next neuron)
24. Number the following events for synaptic transmission in the correct order
__6__ An action potential is stimulated at the postsynaptic membrane and impulse travels down dendrite
__7__ An enzyme cleaves the neurotransmitter substance and clears out the synaptic cleft
__1__ Impulse reaches synapse from the axon
__2__ Impulse stimulates synaptic vesicles to move to presynaptic membrane
__4__ Neurotransmitter substance diffuses across the cleft
__5__ Neurotransmitter substance fits into receptor sites on postsynaptic membrane
__3__ Synaptic vesicles dump neurotransmitter substance into synaptic cleft
7
25. What is exocytosis? Where does it occur in synaptic transmission?


Where a vesicle, inside the neuron’s axon bulb, fuses with the plasma membrane and releases its
contents outside of the cell and into the synaptic cleft / gap.
Exocytosis occurs in the axon bulb
26. A) Name the enzyme that breaks down acetylcholine
Acetylcholinesterase (AchE)
B) Name the enzyme that breaks down norepinephrine/noradrenalin
Monoamine oxidase
27. If the neurotransmitter is not broken down by an enzyme, what happens to it?

It is rapidly reabsorbed by the presynaptic membrane and recycler molecules can be involved
to help with this process
28. Why is a neurotransmitter in the synaptic cleft for only a short period of time?

It is broken down by enzymes or taken back up by endocytosis by the presynaptic cell

It prevents constant stimulation of the postsynaptic membrane.
29. Why would the axon bulb have mitochondria?

Exocytosis = active transport and therefore need ATP. ATP is made by the mitochondria.
Therefore, the axon bulb also has lots of mitochondria.

Calcium ions are also returned by active transport so cell needs ATP
30. How does the design of a synapse ensure nerve impulses travel in one direction?

Because the neurotransmitter is only released from the presynaptic membrane (axon bulb)
and the receptors for the neurotransmitter are only on the postsynaptic membrane (dendrite).
This ensures that the nerve impulse travels in only one direction.
8
threshold
resting
sodium
depolarizing
repolarizing
potassium
axon bulb
pre
integration
calcium
excitatory
calcium
neurotransmitter
post
enzymes
9
C12.
Analyze the functional inter-relationships of the divisions of the nervous system
31. What are the two main divisions of the nervous system and describe their function(s)?

Central nervous system (CNS)- control centre, integrates sensory information and formulates
response

Peripheral nervous system (PNS) – gathers stimuli, relays it to CNS, and relays response to
appropriate effector
32. What are the two main parts of the central nervous system?

Brain and spinal cord
33. What is the job of the central nervous system?

Control centre – receives the sensory input from the PNS and integrates / formulates the
response(s) (if any) to the stimuli detected
34. What is the function of the peripheral nervous system?

Carries information between the CNS and the body; gathers stimuli, relays it to CNS, and relays
response to appropriate effector
35. Complete the chart to compare the effects of the sympathetic and parasympathetic divisions of the
autonomic nervous system.
Autonomic Nervous System
Body Function
Sympathetic NS
heart rate
Increases
breathing rate
breathing
Increasesrate
neurotransmitter
Dialate
pupil size
breathing
rate
Decreases / stops
digestion
pupil
size
Noradrenalin
neurotransmitter
digestion
overall response
“fight or flight”
neurotransmitter
pupil size
digestion
Parasympathetic NS
Decreases
Decreases
Increases
Decreases
Constrict
Dialate
Increases
Constrict
Decreases
Increases
/ starts
Decreases
/ stops
Dialate
Increases
/ sta
Constrict
Acetylcholine
Noradrenalin
Decreases
/ stops
Acetylcholin
Increases
/ sta
Noradrenalin
relaxed state
Acetylcholin
36. What is the source gland for adrenalin? Explain its role in the “fight or flight” response.

Adrenal gland makes adrenalin

Adrenalin is involved in the “fight or flight” response by increasing the activity of the receiving
cells / tissues/ organs (except the digestive system)

Examples – increase heart rate, breathing rate, blood pressure, decreases digestion.
10
The Brain
37. What are ventricles?
Spaces / cavities in the brain that are connected which produce and store cerebral spinal fluid. There are
4 of them
38. What is the function of the midbrain?
 It acts as a relay station for tracts passing to the cerebrum and spinal cord / cerebellum. It also
has the reflex centres for vision, hearting (auditory), and tactile responses.
39. Complete the table and identify the parts on the diagram.
Parts of the Brain
Structure
Function
medulla oblongata
Vital centres – regulates heartbeat, breathing & vasoconstriction. Has reflex centres for
vomiting, coughing, sneezing, hiccupping & swallowing.
cerebrum
Responsible for consciousness and higher level mental function. Receives sensory
input and carries out integration and coordinates responses.
“sorting centre” that directs input to the proper region of the brain for interpretation.
thalamus
cerebellum
Maintains muscle tone, posture, balance and coordination.
hypothalamus
Maintains homeostasis by regulating hunger, sleep, thirst, body temperature and water
balance. It is the neuroendocrine control centre (hormones). It also directly controls the
pituitary
gland (anterior
posterior)
Makes
hormones,
stores&the
hormones and releases them. It has some control over
anterior pituitary
gland
other endocrine glands. Examples: GH, TSH, ACTH, melatonin, FSH, LH and PRL.
posterior pituitary
gland
Stores and releases hormones made by the hypothalamus such as ADH & oxytocin.
corpus callosum
Connects the left & right side of the brain (the 2 hemispheres). It allows connections and
communication between the 2 hemispheres.
meninges
Triple membrane covering filled with cerebrospinal fluid that protect and cushion the
brain and spinal cord.
40. Label:
meninges
thalamus
cerebrum
corpus callosum
skull
hypothalamus
cerebellum
anterior pituitary gland
posterior pituitary gland
spinal cord
medulla oblongata
11
41. Explain how the hypothalamus and the pituitary gland interact as the neuroendocrine control
centre.


The hypothalamus is the part of the brain that has control over the internal organs.
It samples the blood that travels through it and causes the anterior & / or posterior pituitary glands
to release hormones to influence and regulate other organs of the body
42. Label the lobes of the cerebral cortex
Frontal
Parietal
Occipital
Temporal
Urinary System
C13. Analyze the functional inter-relationships of the structures of the urinary system.
43. Draw lines to identify the following structures on the diagram and complete the table.
Urinary System
Structure
Kidney
Function
Produces urine. Removes water, wastes &
foreign substances. It also maintains pH, &
blood plasma volume.
ureter
Conducts urine from the kidney pelvis to the
urinary bladder by peristalsis
urethra
Conducts urine from the urinary bladder to the
outside of the body
Stores urine until urination occurs
urinary bladder
Produces adrenalin
Adrenal Gland
12
44. Explain the urinary reflex (urination and the nervous system)
 When the bladder has about 250 mL of urine, stretch receptors send sensory nerve impulses
to the spinal cord. Motor nerve impulses from the spinal cord cause the urinary bladder to
contract & sphincter muscles to relax. This allows urination to occur. (Brain controls it)
45. Urinary tract infections:
a. Define:
An infection of the urinary system
b. Symptoms
Pain, burning sensation, chills, fever, nausea, and vomiting
c. Where do urinary tract infections occur?
Commonly in the urethra and urinary bladder but can infect the kidneys too
d. Causes of these infections?
E. coli from the large intestine enter the urethra
e. Treatment?
Antibiotics
f.
Tips to prevent infection are:
Drink lots of water, wash well (hygiene), urinate before and after sex, & wipe front to back
46. Label the structures on the diagram and complete the table.
The Kidney
Structure
renal cortex
Renal artery
Filtration of blood plasma – receives nutrients
and wastes from blood plasma
Renal artery and
Vein
Reabsorption of nutrients such as glucose, amino
acids, salts and water (substances want to keep).
And
tubular
secretion
of substances
still inand
excess
Collects
the urine
formed
by the nephron
funnels it to the ureter.
Renal artery brings blood to the kidney to be
filtered and renal vein takes blood away from the
kidney that has been filtered
ureter
Conducts urine from the kidney pelvis to the
urinary bladder by peristalsis
renal medulla
renal pelvis
Renal vein
Function
ureter
13
47. Complete the table and label these structures on the diagram of the nephron.
The Nephron
Structure
Function
Site where pressure filtration occurs. Smaller substances, good and bad, leave
glomerulus
the glomerulus plasma and enter the nephron (Bowman’s capsule) and water
too.
Receives
the substances of the blood plasma from the glomerulus. Start of the
Bowman’s capsule
nephron (functional unit of the kidney).
Increases the blood pressure as the blood enters the glomerulus so pressure
afferent arteriole
filtration can occur
Conducts thicker blood (because lost water & substances) from glomerulus to
efferent arteriole
the peritubular capillary network.
Surrounds the nephron and allows for the exchange of wastes and nutrients
peritubular capillary network between the blood and nephron (in both directions). Returns water and
nutrients
that enter
the nephron
to the
circulatory
system.
Site
of selective
reabsorption
where
water,
most glucose,
amino acids, other
proximal convoluted tubule nutrients & required salts are transported from nephron filtrate to blood
plasma
Site of tubular secretion where any excess substances in blood (creatinine,
distal convoluted tubule
drugs, antibiotics, H+) still enter the filtrate (movement from blood to nephron).
Site where water can be reabsorbed to concentrate the urine in the filtrate.
collecting duct
Regulates blood volume and pH.
Site where water and salts can be reabsorbed from the filtrate into the
loop of Henle
peritubular capillary network.
Filtration of blood plasma – receives nutrients and wastes from blood plasma
Renal Cortex
Renal Medulla
Reabsorption of nutrients such as glucose, amino acids, salts and water
(substances want to keep). And tubular secretion of substances still in excess.
14
48. Label the following diagram where indicated. Shade in the nephron & colour the
blood vessels.
15
49. List the pathway of a red blood cell from the aorta to the inferior vena cava through the
nephron.
Aorta → renal artery → afferent arteriole → glomerulus → efferent arteriole → peritubular capillary
network → renal venule → renal vein → inferior vena cava
50. Describe how these processes contribute to the formation of urine.
a) pressure filtration



It is the movement of small substance from the glomerulus (with small pores) into the
Bowman’s capsule due to high blood pressure in the glomerulus.
Substances such as amino acids, salts, nitrogenous wastes, glucose, water, nutrients, and
other ions move into the Bowman’s capsule.
The larger substances such as proteins, red blood cells, white blood cells and platelets
remain in the blood in the glomerulus.
b) selective reabsorption



This occurs in the proximal convoluted tubule.
It involves the active transport of glucose, amino acids, and some salts from the filtrate in the
nephron, to the blood plasma in the peritubular capillary network (PCN).
Water is also reabsorbed and follows the salt passively
c) tubular excretion



This occurs in the distal convoluted tubule.
It involves the active transport of excess substances from the blood plasma in the
peritubular capillary network into the nephron filtrate.
Excess substances such as H+, drugs, creatinine, antibiotics (penicillin), and pesticides.
d) Describe the reabsorption of water in the nephron.





Water reabsorption occurs mainly at the loop of Henle and the collecting duct of the
nephron.
The nephron pumps out salt & urea into the renal medulla to make it hypertonic to the filtrate
to draw water out of the nephron by osmosis. Remember tonicity!!
The blood in the peritubular capillary network is hypertonic as well and water moves from the
descending loop of Henle into these capillaries by osmosis. (This loss of water concentrates
the filtrate / urine in the nephron)
The collecting duct is permeable to water when the hormone ADH (antidiuretic hormone)
reaches it. (This loss of water concentrates the filtrate / urine in the nephron).
The water leaves the collecting duct due to the saltiness (tonicity) of the renal medulla.
Certain carrier proteins actively transport amino acids, glucose, penicillin, histamines, bicarbonate
ions, and creatinine during urine formation.
51. Describe the components of urine.



Urine = glomerular filtration, substances that were reabsorbed into the blood and substances
secreted into the filtrate.
Urine is composed of nitrogenous wastes (uric acid & urea), excess salts and ions, some
water, H+, creatinine, drugs, antibiotics like penicillin, and excess vitamins.
You should NEVER see formed elements (RBC, WBC, and platelets) or proteins in the urine.
If these are detected it means there is a problem with the kidneys.
16
52. In each box, names the process that occurs to produce urine and label all the indicated
structures
53. Describe how the kidneys maintain blood pH.



Kidneys maintain the acid – base balance of the blood.
They do this by monitoring and controlling the levels of H+ ions and HCO3- ions (bicarbonate
ions).
The kidneys will excrete H+ or reabsorb bicarbonate ions to maintain pH of the blood.
Sodium bicarbonate regulates blood pH at the distal convoluted tubule
54. Compare urea and glucose content of blood in the renal artery with that of the renal vein and
explain the differences.

Renal artery = has high levels of urea and glucose since it has not been processed by the
kidney yet.

Renal vein = has low levels of urea and high levels of glucose still because virtually all of the
glucose is reabsorbed during selective reabsorption but the urea is a nitrogenous waste that
your body wants to get rid of and therefore does not reabsorb as much of it back into the
blood plasma.
o
If high levels of glucose are found in the urine this can be an indication of diabetes
17
55. Identify the source gland(s) for antidiuretic hormone (ADH).
ADH is made by the hypothalamus but it is stored and secreted from the posterior pituitary gland.
56. Describe how the hypothalamus, posterior pituitary gland, ADH, and the nephron achieve
homeostasis of water levels in the blood.




The hypothalamus makes ADH. ADH is then stored and released from the posterior pituitary gland
when water levels in the blood are low and you are dehydrated. ADH is controlled by negative
feedback.
DEHYDRATION:
When you are dehydrated, the kidneys reabsorb most of the water from the filtrate. This occurs
because the blood passes through the hypothalamus. This allows the hypothalamus to detect a low
concentration of water in the blood and cause the posterior pituitary gland to release ADH.
ADH travels through the blood to the collecting duct. The collecting duct becomes permeable to water
in response to ADH which allows water to be reabsorbed into the peritubular capillary network (PCN)
to increase the concentration of water which increases the blood volume. Once the blood volume is at
normal levels, negative feedback occurs which prevents the release of ADH.
TOO MUCH WATER or HIGH WATER CONCENTRATION IN BLOOD:
When the hypothalamus detects a high concentration of water and prevents the posterior pituitary
gland from releasing ADH. With no ADH present, the collecting duct is impermeable to water and the
water remains in the filtrate to become part of urine that is eliminated from the body.
Male Reproductive System:
C14. Analyze the functional inter-relationships of the structures of the male
reproductive system.
57. Complete the table and label these structures on the diagram of the male reproductive system.
The Male Reproductive System
Structure
testes
seminiferous tubules
interstitial cells
scrotum
Made up of seminiferous tubules &
interstitial cells. Suspended in
scrotum.
Tightly coiled tubes
Function
Produces sex hormones in interstitial cells &
sperm in the seminiferous tubules.
Has cells for making sperm = spermatogenesis
Cells found between the seminiferous Produces & releases testosterone.
tubules.
Pouch of skin that encloses the testes Regulates the temperature of the testes by
that is lined with smooth muscle
contraction & relaxation of the smooth muscle
Tightly coiled tubules
Maturation of the sperm and stores some of the
sperm
Long tubule
Conducts sperm from epididymis and stores
sperm.
Doughnut-shaped gland surrounding
the urethra.
Contributes buffer to the semen
Pea-sized, round organ
Contributes lubrication to the semen
Long sac-like structure
Contributes nutrients (fructose) &
prostaglandins (uterine contraction) to semen
penis
Shaft with enlarged tip, foreskin, and
spongy erectile tissue
Transfers sperm to the female
urethra
Tube / duct from the urinary bladder
through the penis
Conducts sperm to the outside of the male & to
the female. Releases urine to the outside too.
epididymis
Vas deferens
prostate gland
Cowper’s glands
seminal vesicles
18
58. Label the structures in the diagram.
19
59. Label the parts of the testis.
60. Where do sperm mature and get the ability to swim?
epididymis_____________________________________
61. Where does spermatogenesis occur?
Seminiferous tubules of the testes________________________________________________
62. Describe the path of sperm from the seminiferous tubules to the urethral
opening.
Seminiferous tubules of the testes → epididymis → vas deferens → ejaculatory duct → urethra →
urethral opening of penis
63. List the components of seminal fluid and describe the functions of each component.
Seminal fluid is the liquid part of semen. It is composed of:




Fructose (nutrients for the sperm to make energy) – made by seminal vesicle
Prostaglandins to trigger uterine contractions and aid sperm’s movement to oviduct – made by
seminal vesicle
Alkaline buffer to protect sperm against vagina’s acidity – made by prostate gland
Lubrication to aid sperm movement – made by Cowper’s gland
64. Complete the table and label these structures on the diagram of a sperm cell.
A Sperm Cell
Structure
flagellum
midpiece
head
acrosome
Function
Tail to allow the sperm to swim to the egg
Contains spiral mitochondria to provide the energy needed for the tail to
move
Contains the nucleus which transmits the genetic information
Contains enzymes to digest a hole through the egg jelly coat so the sperm
nuclei can enter the egg.
20
65. Complete the following table in reference to the MALE reproductive system.
LH
FSH
Testosterone
Where is the
hormone produced?
Anterior pituitary gland
Anterior pituitary gland
What is the function
of the hormone?
Stimulates the testes
to produce
testosterone
Stimulates the testes
to produce sperm
Interstitial cells



How is the hormone
controlled?
Negative feedback to
the hypothalamus
Negative feedback to
the hypothalamus
Normal development
& function of male
sex organs
needed for sperm
maturation
male sex
characteristics
Negative feedback to
the hypothalamus
66. Describe the homeostatic regulation of testosterone levels by the hypothalamus, anterior
pituitary gland, and testes.
 GnRH (gonadotropic releasing hormone) “turns on” LH (causes testosterone production)
and FSH (causes spermatogenesis).
 GnRH travels down from the hypothalamus to the anterior pituitary gland causing it to
release FSH and LH.
 LH & FSH travel to the testes to cause the production of sperm & testosterone.
 These hormones are controlled by negative feedback so when levels are normal, the
hypothalamus stops releasing GnRH which in turn stops the release of FSH & LH from the
anterior pituitary gland
 With no FSH or LH travelling to the testes, they stop producing sperm & testosterone.
Female Reproductive System
C15. Analyze the functional inter-relationships of the structures of the female reproductive
system.
67. Label.
21
68. Female reproductive system: Please label
69. Complete the table.
The Female Reproductive System
Structure
ovaries
oviducts
uterus
endometrium
cervix
vagina
Function
Female gonad where eggs made. Sex hormones are made here.
Tube lined with cilia to transport the egg or fertilized egg (embryo) to the uterus.
Fertilization of the egg occurs here
Where fetus grows and develops.
Inner spongy layer full of blood that is expelled during menstruation.
Involved in the formation of the placenta.
Opening to the uterus that is normally closed to keep unwanted microbes out of
the uterus. It opens slightly to allow endometrium out. Dilates to allow birth of
fetus
Receives the penis during sexual intercourse, serves as the birth canal, and the
place where the endometrium / menstrual flow exits the body
follicles
The immature eggs that are at various stages of maturation in the ovary.
Each female born with about 2 million immature follicles
corpus luteum
The empty follicle that has developed into a fatty structure that produces the
sex hormones progesterone and estrogen.
70. Describe the functions of estrogen.

Primary sex characteristics: causes the vagina and uterus grow, eggs mature, & starts the uterine
cycle

Secondary sex characteristics: causes body hair, widening of the pelvis and hips, breast enlargement,
and the development of a fat layer beneath the skin
22
71. What is ovulation?

The release of the mature egg from the ovary
72. Where are cilia found in the female reproductive system and what is their function?
 In the oviduct to create a current to move the egg to the uterus
73. Complete the following diagram:
Anterior pituitary
gland
FSH
LH
Ovarian
Follicular phase
Luteal phase
progesterone
estrogen
estrogen
progesterone
Uterine
menses
Proliferative
phase
ovulation
Secretory phase
Menstruation
(menses)
23
Use the following diagram to assist you in answering the next 3 questions.
74. Describe the sequence of events in the ovarian cycle, with reference to the follicular phase (days 1-13),
ovulation (day 14), and the luteal phase (days 15-28) including the hormones involved.
OVARIAN CYCLE

Follicular phase: (Days 1 – 13):
o
o
o

Ovulation (Day 14):
o
o
o

LH and FSH released from the anterior pituitary gland.
FSH causes a few follicles to mature in the ovary
LH causes estrogen to be released which rebuilds the uterus after menses /
menstruation
The egg is released from the ovary due to a spike in LH
LH spike promotes the development of the corpus luteum
The corpus luteum forms in the empty follicle and produces estrogen & progesterone.
Luteal Phase (Days 15 – 28):
o
o
o
o
Estrogen & progesterone from the corpus luteum cause the endometrium to continue
to thicken in the uterus
LH continues to promote the development of the corpus luteum
Progesterone is released by the corpus luteum and the endometrium becomes
secretory.
At the end of the luteal phase, menstruation occurs.
As you can see, the ovarian cycle controls the uterine cycle.
24
75. Describe the sequence of events in the uterine cycle, with reference to menstruation (days 15), the proliferative phase (days 6-13), and the secretory phase (days 15-28) including the
hormones involved.
UTERINE CYCLE

Menstruation (Days 1 – 5):
o

Proliferative Phase (Days 6 – 13):
o

The endometrium breaks down and is released through the vagina due to a decrease
in estrogen and progesterone coming from the corpus luteum (the corpus luteum has
disintegrated).
The endometrium is rebuilt and becomes thicker and vascularized due to increasing
levels of estrogen from the new ovarian follicle.
Secretory Phase (Days 15 – 28):
o
The endometrium becomes thicker and more vascularized (many blood vessels) due
to an increase in progesterone from the corpus luteum.
76. Describe the control of the ovarian and uterine cycles by hormones including
gonadotropin-releasing hormone (GnRH), follicle-stimulating hormone (FSH), luteinizing
hormone (LH), estrogen, and progesterone.

The hypothalamus releases GnRH which causes the anterior pituitary gland to secrete LH &
FSH.
o LH travels in the blood to the ovary where it causes the production of estrogen and
progesterone.
o
FSH travels in the blood to the ovary where it stimulates the development of the
immature follicle in the ovarian cycle from days 1 to 14

A spike in LH on day 14 causes ovulation to occur where the ovum is released from the ovary
– ovarian cycle.

LH also causes the corpus luteum to form after ovulation and secrete progesterone.

This progesterone, secreted by the corpus luteum, causes the endometrium to thicken &
become highly vascularized (uterine cycle) in preparation for a potential pregnancy.

Estrogen, secreted from the corpus luteum, stops the secretion of LH and FSH by negative
feedback in preparation for a potential pregnancy.

Eventually, the corpus luteum disintegrates and is unable to produce significant levels of
progesterone and estrogen. The decrease of these hormones causes menstruation to occur
and the endometrium is shed.
25
77. Describe the hormonal changes that occur as a result of implantation, including production of
human chorionic gonadotropin (HCG) to maintain the corpus luteum increased production of
progesterone by the corpus luteum.

During implantation, the cells surrounding he embryo release a hormone called HCG. HCG
prevents the disintegration of the corpus luteum and stimulates the corpus luteum to
produce progesterone.

Once the placenta has formed, it continues to produce HCG, estrogen and progesterone.

In doing this, it prevents the release of LH & FSH & it maintains the endometrium to prevent
menstruation. As a result, the corpus luteum is no longer needed to maintain the
endometrium and it disintegrates.

If the activity of the corpus luteum decreases, or there is not enough HCG present, there is a
decrease in the level of progesterone which causes the breakdown of the endometrium and
the loss of the embryo = miscarriage.
78. Describe a positive feedback mechanism involving oxytocin.

The hypothalamus makes the hormone oxytocin which is stored and released from the
posterior pituitary gland.

Oxytocin causes milk production by positive feedback which means that the more the baby
feeds, the more oxytocin produced, which results in more milk production = positive
feedback

Oxytocin also stimulates uterine contractions during labor where the more oxytocin that is
produced, the stronger the uterine contractions get which causes the fetus to push on the
cervix.
o
The more the baby pushes on the cervix, the more oxytocin produced and the
stronger and more frequent the uterine contractions become until the baby is
delivered = positive feedback.
79. Label the following:
Developing egg /
immature follicle
Corpus
luteum
Mature egg
called the ovum
26
80. Label:
LH
FSH
81. What do birth control pills do?

Birth control pills are a combination of estrogen and progesterone that cause the
shutdown of the anterior pituitary glands’ production of both LH & FSH so that no
follicle will develop in the ovary.

Therefore, no ovulation occurs so a pregnancy cannot result.
82. What is menopause?
When a woman’s uterine and ovarian cycles stop
END
27