GLOSSARY:
Accessory glands: Two pairs of glands in 17th and 19th segments of
earthworm that help in copulation of earthworms.
Aestivation: A period of inactivity or dormancy, resulting from
unfavourable moisture conditions.
Alimentary canal: The system of organs, within multicellular animals that
takes in food, digests it to extract energy and nutrients and expels the
remaining waste.
Annelid: An animal, having a segmented body, giving it a ringed
appearance. [The segments are arranged one beside each other
symmetrically along the length of the earthworm to form the body].
Artery: Blood vessels, which carry blood to various organs of the body.
Arthropod: An invertebrate, having jointed limbs and a segmented body
with an exoskeleton made of chitin.
Bile duct: The common duct through which bile juice from liver and
pancreatic juice from pancreas are jointly poured into duodenum.
Blood glands: Follicles clustered in the pharyngeal region, supposed to
function in the production of haemoglobin and blood corpuscles in
earthworm.
Buccopharyngeal cavity: The cavity between two jaws.
Calciferous gland: Whitish gland, secreting calcium carbonate and opens
into the gut via oesophageal pouches in earthworms.
Camouflage: A method of cryptic or concealing coloration, that allows an
otherwise visible organisms to remain indiscernible from the surrounding
environment through deception.
Castings: Earthworm feces, the voided earth and other waste materials
deposited on the surface of the ground, for not all species form their casts
above ground.
Cerci: Small, sensitive hairs at the back end of a cockroach.
Clitellum: A glandular ring-like structure located in segments 14 to 16 of
an adult earthworm.
Cloaca: The distal region of large intestine.
Cloacal aperture: Cloaca opens to the outside through a cloacal aperture.
Cocoon: The structure formed by group of fertilized eggs.
Coelomate: An organism, having cavity between body wall and alimentary
canal.
Colon: The proximal region of large intestine.
Crop: A widened portion or area of the digestive system, where food is
stored, and which lacks the muscularity of the gizzard, located after the
esophagus but before the gizzard.
Cuticle: A thin, non-cellular, colourless, transparent outer layer of the body
wall of earthworms.
Dorsal pore: Small, single inter-segmental apertures in the mid-dorsal line
leading to the coelomic cavity in earthworms.
Dorsal vessel: A major blood vessel located above the dorsal surface of
the alimentary canal in earthworms.
Endocrine glands: Any of the thyroid, parathyroid, anterior - posterior
pituitary, pancreas, adrenals, pineal and gonads glands, producing a
hormonal secretion that passes directly into the bloodstream.
Enteronephric excretion: The excretion by septal and pharyngeal
nephridia into the cavity of alimentary canal.
Exocrine glands: Externally secreting glands (such as a salivary gland or
sweat gland), releasing its secretions directly or through a duct.
Exonephric excretion: The excretion by integumentary nephridia on
surface of the body.
Exoskeleton: External skeleton, which supports and protects an animal's
body, in contrast to the internal endoskeleton.
Genital pouch: The structure formed by joining of 8th and 9th sterna in
female cockroach.
Germinative layer: The innermost layer of epidermis.
Gullet: An opening at the posterior region of buccal cavity, leading into
oesophagus.
Haemocoel: The blood filled body cavity of cockroach.
Hermaphrodite: An organism, having both male and female reproductive
organs.
Hibernation: State of inactivity and metabolic depression in animals,
characterized by lower body temperature, slower breathing and lower
metabolic rate.
Intersegmental septa: The structures by which body segments of
earthworm are separated.
Malpighian tubules: Present at the junction of midgut and hindgut helping
in excretion.
Metameres: The individual cylindrical segment separated by
intersegmental septa.
Midgut: The middle part of intestine, where the cockroach absorbs
nutrients.
Nephridia: Excretory organs in earthworm, which occur as segmentally
arranged coiled tubules.
Nephridiopore: Part of the nephridia (an excretory organ) found in
organisms like flatworms or annelids.
Nerve-ring: The structure formed by interconnection of supraoesophageal
ganglions with suboesophageal ganglia through circumoesophageal
commisuers.
Nictitating membrane: A transparent or translucent third eyelid, present
in some animals that can be drawn across the eye for protection and to
moisten the eye while also keeping visibility.
Ostia: The two valved openings between two nearby funnel-like units of
heart in cockroach.
Pericardial sinus: The dorsal sinus in which heart region of cockroach is
located.
Perineural sinus: The ventral sinus in which nervous system of cockroach
is located.
Peripheral nervous system: The nervous system formed by nerves
arising from the brain and spinal cord.
Peristomium: The first body segment in Earthworm containing mouth.
Physiology: The branch of biology that deals with the normal functions of
living organisms and their parts.
Poikilotherm: An animal, whose internal temperature varies along with
that of the surrounding environmental temperature.
Prostomium: A shelf-like projection developed from the roof of the mouth
in earthworm.
Pyloric stomach: The distal region of the stomach.
Rectum: The proximal region of colon.
Sinus venosus: A triangular sac-like structure located on the dorsal side of
heart in cockroach.
Spermatophores: A capsule or compact mass of spermatozoa extruded by
the males of certain invertebrates and primitive vertebrates and directly
transferred to the reproductive parts of the female.
Storage excretion: The removal of some excretory substances stored in
the chitinous exoskeleton during moulting.
Uricotelic: The organisms, excreting uric acid as the chief component of
nitrogenous waste.
Vein: The blood vessels, which collect blood from various organs of the
body and carry it towards the heart.
Venous system: The system constituted by veins.
Vermicomposting: The process of increasing fertility of soil by the
earthworms.
Villi: Tiny, finger-like projections, that come out from the wall of the small
intestine and have additional extensions called ‘microvilli’.
Worm casting: Cylindrical mass of Earth voided by burrowing earthworms.