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Definition
coiled masses of DNa in the nuclei of cells Each cell in an animal's body (except spermatozoa or ova) contains identical chromosomes Diploid chromosome number - total number of chromosomes in the nucleus of each body cell is the same (except for reproductive cells) - always an even number - chromosomes occur in pairs |
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designated as either "X" chromosomes or "Y" chromosomes if both of the sex chromosomes are X chromosomes (XX) the individual is genetically a female if one is an X and the other is Y (XY) then the individual is genetically a male |
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Haploid Chromosome Number |
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Definition
reduction division - total number of chromosomes in each of the daughter cells is reduced to hald the number of the parent cell ensures that the fertilized ovum from the union of spermatozoa and the ova has diploid number haploid chromosome number in the reproductive cells results from meiosis |
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most body cells divide after the cell first makes a duplicate copy of its chromosomes half the chromosomes go to the one daughter cell and half go to the other genetic make up of the two daughter cells is exactly the same as each other and as the parent cell |
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chromosomes do not produce duplicate copies of themselves before daughter cells divide half of the total chromosomes (one from each diploid chromosomes pair and one sex chromosome) got to each daughter cell which chromosomes go to which daughter cell is entirely random |
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production of male sex cells occurs in seminiferous tubules of the testes producted continuously and in very large numbers primary spermatocyte divides by meiosis into secondary spermatocytes divide by mitosis into four spermatids spermatids grow tails and undgo other physical changes that convert them to spermatozoa when the spermatozoa are fully developed, they detach and are carried to the epididymis for storage before ejaculation half of the spermatozoa produced have an X sex chromosome and half have a Y sex chromosome |
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Definition
production of female sex cells occurs in ovarian follicles female has fixed primary oocytes at or soon after birth oogenesis produces small numbers of ova at a time primary oocyte divides by meiosis into a large secondary oocyte and a small 'polar body' each has the haploid chromosome number secondary oocyte and the first polar body divide by mitosis into an ovum and three polar bodies |
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produces male sex hormones developes spermatozoa deliver the spermatozoa to the female system at the appropriate time |
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produce sperm and hormones located outside the abdomen in the inguinal region housed in a sac of skin - the scrotum |
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Definition
1) head - contains nucleus of the cell - convered by the acrosome; contains digestive enzymes that help the spermatozoon reach and penetrate the ovum 2) midpiece - large concentration of mitchondria arranged in a spiral pattern 3) Tail - contains musclelike contractile fibrils - produces a whiplike movement of the tail and propel the cell fwd. |
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Gubernaculum - band of connective tissue that attaches testes to scrotum Testes gradually pulled caudally and ventrally inguinal rings - openings in abdrominal muscles through which testes descend |
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sac of skin that houses the testes helps regulate temp of testes - testes must be kept slightly cooler then body temp cremaster muscle passes down through the inguinal ring and attaches to the scrotum adjusts the position of the testes relative to the body depending on temp |
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Definition
blood and lymphatic vessels, nerves, and the vas deferens. Pampiniform plexus - meshwork of veins that surrounds testicular artery - maintains testes at a temp slightly lower then body temp - warms blood back to body temp before it returns to abdomen |
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Definition
connective tissue that forms sheath-like layers around the testes and the spermatic cord visceral vaginal tunic - very thin inner layer parietal vaginal tunic - thick outer layer - forms a fibrous sac around each testis and spermatic cord tunica albuginea - fibrous connective tissue capsule surrounding each testis beneath tunics |
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site of spermatogenesis long, convoluted U-shaped tube attached at both ends to system of ducts (rete testis) interstitial cells - endocrine cells between the seminiferous tubules - produce androgens Sertoli cells - support developing spermatids |
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Definition
after detaching from Sertoli cells, spermatozoa enter the rete testis then flow through the efferent ducts to the epididymis -single, long, convoluted tube that connects the efferent ducts of the testis with the vas deferens -storage and maturation of spermatozoa |
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Definition
'head' region - site where spermatozoa enter from efferent ducts 'body' region - lies along surface of testis 'tail' region - continues on as the vas deferens |
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Definition
ductus deferens; part of the spermatic cord passes through inguinal ring then separates from spermatic cord and connects with urethra Ampulla - enlargement of the vas deferens just before it joins the urethra found in some species - contain glands that contribute material to semen. Thick smooth muscle walls functions to propel sperm quickly from epididymis to urethra at time of ejaculation |
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Definition
Pelvic portion - entry portion - entry point of vas deferens and accessory reproductive glands Penile portion - runs down the length of the penis spermatozoa from vas deferens and secretions from accessory reproductive glands eneter urethra and are pumped out as semen carries urine from the urinary bladder outside the body - urine flow is temporarily blocked when ejaculation occurs |
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Term
Accessory Reproductive Glands |
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Definition
ducts of all accessory reproductive glands enter pelvic portion of the urethra different species have different combinations of accessory reproductive glands produce alkaline fluid that helps counteract the acidity of the female reproductive tract Prostate gland -surrounds the urethra -multiple ducts carry secretions into urethra Bulbourethral glands -cowper's glands -ducts enter urethra neat caudal border of pelvis -secrete mucinous fluid just before ejaculation that clears and lubricates the urethra |
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Definition
composed of muscle, erectile tissue, and connective tissue large blood supply and many sensory nerve endings three main parts of the penis - the roots, the body and the glans roots of the penis: bands of connective tissue (crura) that attach the penis to the brim of the pelvis body of the penis: two bundles of erectile tissue (corpus cavernosum urethrae and corpus cavernosum penis) - fibrous connective tissue and blood-filled sinuses -when sinuses engorge with blood, inelastic connective tissue around the sinuses generates hydraulic pressure glans of the penis: distal end; numerous sensory nerve Prepuce - sheath of the skin that encloses the penis when it is not erect - inner portion is smooth, moist mucous membrane
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os penis - bone in the penis; urethra runs through the groove on the ventral surface bulb of the glans - enlargement twd the rear of the glans - engorges with blood, reaches full size after ejaculation - remains clamped in place by contractions of the muscles surrounding vagina and vulva - erection of the bulb subsides in 15-20minutes |
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Definition
S shape of nonerect penis of the bull, ram and boar higher proportion of connective tissue to erectile tissue than other species erection results from straighening of the sigmoid flexure from internal hydraulic pressure causes the penis to protrude from the prepuce for breeding |
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Definition
Erection: results from a parasympathetic reflex triggered by sexual stimuli - often involves olfactory cues and behavioural changes - arteries dilate and increase blood flow into penis - veins are compressed against brim of the pelvis by contractions of muscles in roots of the penis Ejaculation: Reflex expulsion of semen - semen moves from accessory reproductive glands into pelvic portion of the urethra - rhythmic contractions of the urethra pump the semen out into the female reproductive tract |
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Female reproductive system |
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Definition
ligaments Ovaries Oviducts Uterus Cervix Vagina Vulva |
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Definition
Broad ligaments: sheets of peritoneum suspend ovaries, oviducts and uterus - mesovarium - mesosalpinx - mesometrium contain blood vessels and nerves suspensory ligament of the ovary - ovarian end of broad ligament attached to body wall in area of last rib round ligament of the uterus - fibrous tissue and smooth muscle in lateral fold of the broad ligament on each side |
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Definition
in dorsal abdomen near kidneys species variation in appearance site of oogenesis proction of estrogen and progestins development of ovum, ovulation, formation of corpus luteum, and degeneration of unripened follicles abd corpus luteum influenced by follicle stimulating hormone (FSH) and luteinizing hormone (LH)
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Definition
Uniparous species - one mature ovum produced per cycle - horse, cow, and human Multiparous species - multile ova produced per cycle - cat, dog, and sow Primordial (primary) follicle: immature oocyte surrounded by a single layer of folliclar cells Follicular recruitment or follicular activation: follicle growth is triggered Follicular cells thicken and multiply into multiple layers: granulosa cells Follicle grows rapidly as granulosa cells multiply Granulosa cells produce increasing amounts of estrogens as follicle become larger fluid- filled spaces form between granulosa cells - spaces gradually merge into one large fluid-filled space: the antrum Mature follicle (graafian follicle, vesicular ovarian follicle)-production of estrogens peaks - oocyte on top of granulosa cell mound (cumulus oophorus) surrounded by thin layer of granulosa cells (corona radiata) |
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Definition
rupture of mature follicle and release of reproductive cell into oviduct surface of mature follicle weakens, ruptures fluid released from antrum along with ovum (still surrounded by cornea radiata) Empty follicle fills with blood (Corpus hemorrhagicum) occurs spontaneously in most species as a result of rising levels of LH induced ovulators: ovulation occurs after breeding - cat, rabbit, and ferret |
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Definition
formed by divisions of granulosa cells that line the blood filled follicle influenced by continued stimulation of LH Produces progestins (primarily progesterone) - necessary for maintenance of pregnancy Endocrine signal to ovary causes corpus luteum to be maintained if ovum implants in uterus |
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Term
Oviducts aka Fallopian Tubes and Uterine Tubes
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Definition
Extend from the tips of the uterine horns Infundibulum: enlarged opening at the ovarian end of each oviduct Fimbriae: muscular projections form margin of infundibulum; help properly position infundibulum smooth muscle fibers in walls cilliated cells in lining muscle contractions and cilia movments guide the ovum twd the uterus usual site of fertilization |
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Term
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Definition
hollow muscular organ usually Y shaped - uterine body forms the base of the Y - uterine horns form the arms Uterine wall layers: -Endometrium: lining composed of simple columnar epithelium and simple tubular glands - secretes mucus and other substances Myometrium: thick layers of smooth muscle Perimetrium: outermost layer covered by the visceral layer of peritoneum |
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Definition
smooth muscle sphincter between the body of the uterus and the vagina - controles acces to the lumen of the uterus from the vagina normally tightly closed, except during estrus and partiruition |
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Definition
Vagina: muscular tube extends caudally from the cervix and connects it with the vulva Vulva: composed of the vestibule, clitoris and labia - utethra opens on teh floor of the vestibule |
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Definition
Polyestrous: animals that cycle continuously throughout the year if they are not pregnant (cattle and swine) Seasonally polyestrous: animals with seasonal variations in estrous cycles (horse, sheep, cat) Diestrous: animals with two cycles per year, usually spring and fall (dog) Monoestrous: animals with one cycle per year (fox and mink) |
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Definition
Time from the beginning of one heat period (estrus) to the next Stages: Proestrus Estrus Metestrus Diestrus Anestrus (in some species) Proestrus: -follicles begin developing and growing -output of estrogen increases accordingly -linings of oviduct, uterus, and vagina thicken -vaginal epithelium begins to cornify; forms layer of keratin on its surface Estrus: -peroid of sexual receptivity in the female -estrogen level production peaks -ovulation occurs near end of estrus in some species -induced ovulator species (eg. cat, rabbit) remain in prolonged state of estrus if not bred Metestrus: -period during which corpus luteum develops -progesterone produced by corpus luteum temporarily inhibits follicular development in the ovary -lining of the uterus prepared for implantation of fertilized ovum -cornified epithelial lining that developed in the vagina during proestrus and estrus is lost Diestrus: -corpus luteum at maximum size and exerting maximum effect -if fertilized ovum implants, corpus luteum degernates at the end of diestrus - animal then either goes back into proestrus of ovary shuts fown and animal goes into anestrus Anestrus: -period of temporary ovarian inactivity -seen in seasonally polyestrous, diestrus and monoestrous animals -ovary temporarily shuts down |
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Definition
copulation: act of breeding; intromission, thrusting, and ejaculation - copulation triggers oxytocin release from posterior pituitary gland of the female -oxytocin causes contraction of smooth muscle of the female reproductive organs Semen is usually deposited in the upper portion of the vagina -spermatozoa transported by swimming, by contractions of uterus and oviducts, and by action of cilia in oviducts capacitation: series of changes spermatozoa undergo in the female reproductive tract - changes in ion movement through the cell membranes; increase in cells' metabolic rates -release of digestive enzymes from acrosome -help the sperm penetrate through layers surrounding the ovum to accomplish fertilization large number of sperm find and swarm the ovum in the oviduct some begin tunneling through the layers surrounding the ovum - aided by the digestive enzymes of their acrosomes once a single spermatozoon penetrates the cell membrane of the ovum, a change in the membrane blocks other sperm from entering |
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Definition
Male pronucleus: nucleus of the fertilizing spermatozoon Female pronucleus: nucleus of the fertilized ovum each pronucleus contains the haploid chromosome number male and female pronuclei join together - restores the diploid chromosome number |
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rapid mitosis of zygote overall size of zygote does not change morula: solid mass of cells blastocyst: hallow ball of cells |
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Definition
enzymes produced by the blastocyst dissolve away a small pit in the endometrium - blastocyst attached to endometrium in this pit in multiparous species, the multiple blastocyts randomly space along the horns and the body of the uterus Placenta begins to form as soon as the blastocyst implants in the uterus |
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Term
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Definition
-multilayered, fluid-filled sac -outermost layer of the placenta attaches to uterine lining in some areas - fetal and maternal blood vessels are in close proximity to each other in this area - site of exchange of blood nutrients and wastes Amnion: membranous layer immediately surrounding the fetus - forms the amniotic sac - fetus floats in amniotic fluid inside the amniotic sac Allentoid: layer surrounding amniotic sac; forms the allantoic sac, which accumulates wastes - outside of allantoic sac is covered by the chorion - chorion attaches to lining of uterus - chorion is linked to fetus by the umbillical cord |
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Definition
1)diffuse attachments: spread over the whole surface of the placenta and uterine lining 2) Cotyledonary attachment: many small, separate attachment sites (placentomes) - placentome: cotyledon on placental surface joing with caruncle in the uterine lining 3) zonary attachment: belt-shaped attachment that encircles the placenta 4) discoid attachment: placenta and uterus attached at a single disk-shaped area |
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Definition
1) mechanical (touch, hearing, balance) 2) thermal stimuli (hot and cold) 3) electromagnetic stimuli (vision) 4) chemical stimuli (taste and smell) |
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Visceral sensations: hunger, thirst, hollow-organ fullness (chemical and mechanical) Touch: touch and pressure (mechanical) temperature: heat and cold (thermal) pain: intense stimuli of any type (mechanical, chemical, thermal) proprioception: body position and movement (mechanical) |
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Definition
most are vague and poorly localized sensations of hunger and thirst also include visceral stretch receptors in GI and urinary system |
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Tactile sense: sensation of something being in contact with the surface of the body pressure: sensation of something pressing on the body surface different touch and pressure receptors produce sensations of light contact, deep pressure, vibration or hair movement |
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superficial temperature receptors - in the skin detect upward or downward changes in skin temp central temperature receptors - in the hypothalamus monitor the temp of the blood CNS can activate mechanisms (eg. sweating, piloerection) to correct hypothermia or hyperthermia |
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Definition
nociceptors - pain receptors pain receptors are widely distributed inside and on the surface of the body -not present in the brain may be simple free nerve endings or more specialized forces, temperature etc. pain processes transduction: conversion of painful stimulus into nerve impulse transmission: conduction of nerve impulse to the spinal cord Modulation: changes the sensory nerve impulse - can amplify or suppress sensory impulses Perception: concious awareness of painful stimuli |
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sense of body position and movement: stretch receptors in skeletal muscles, tendons, ligaments, and joint capsules sense movements of limbs, positions of joints, the state of contraction of muscles, and the amount of tension being exerted on tendons and ligaments. |
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taste: tastes (chemical) smell: odors (chemical) hearing: sounds (mechanical) equilibrium: balance and head position (mechanical) Vision: light (electromagnetic) |
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Definition
gustatory sense chemical receptors: taste buds in oral cavity papillae-small elevated structures on the tongue also found in the lining of the mouth and pharynx |
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olfactory sense very important in most nonhuman animals olfactory cells and supporting cells in epithelial patches in nasal passages hairlike processes project up from olfactory cells into the mucous layer that covers the nasal epithelium odor molecules dissolve in the mucus and contact the sensory processes -nerve impulses are generated, travel to the brain, and are interpreted as particular smells. |
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Definition
auditory sense converts vibrations of air molecules into nerve impulses most structures of the ear are located in the temporal bones of the skull External ear: acts as funnel to collect sound wave vibrations and direct them to the eardrum Middle ear: amplifies and transmits the vibrations from the eardrum to the inner ear Inner ear: contains the sensory receptors that convert the mechanical vibrations to nerve impulses, along with receptors for the equilibrium sense |
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Definition
pinna: elastic cartilage and skin external auditory canal: membrane -lined tube tympanic membrane: thin connective tissue membrane - tightly stretched across the opening between the external auditory canal and the middle ear cavity -sound wave vibrations strike the tympanic membrane and cause it to vibrate |
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Definition
three ossicles (small bones) link the tympanic membrane with the cochlea of the inner ear - act as a system of levers that transmit sound wave vibrations from the tympanic membrane to the cochlea Eustachian tube: connects the middle ear cavity with the pharynx - equalizes air pressure on the two sides of the tympanic membrane malleus: outermost bone; attached to the tympanic membrane incus: middle bone stapes: medial-most bone; attached to membrane that covers the oval window of the cochlea |
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Definition
cochlea: shel-shaped spiral cavity in the temporal bone organ of corti: fluid-filled portion that makes up the receptor organ of hearing - runs along the cochlear duct on the basilar membrane - consists of hair cells (hearing receptors), supporting cells, and the tectorial membrane |
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Definition
sound wave vibrations cause the tympanic membrane and ossicles in the middle ear to vibrate - causes vibration of fluid aorund the cochlear duct fluid filled vibration cause the cochlear duct to move - causes the tectoral membrane and the hair cells of the organ of corti to rub against each other - generates nerve impulses that travel to the brain and are interpreted as sound different frequencies of sound wave vibrations stimulate different areas along the length of the organ of corti |
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mechanical sense: helps maintain balance by keeping track of the position and movements of the head involves equilibrium receptors and information from eyes and proprioceptors receptors are located at the vestibule and semicircular canals in the inner ear |
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Definition
between the cochlea and semicircular canals composed of utricle and saccule hair cells covered by a gelaninous matrix that contains crystals of calcium carbonate (otoliths) gravity causes otoliths and the gelantinous matrix to put pressure on the hairs movement of the head bends sensory hairs generates nerve impulses that give the brain information about position of the head |
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Definition
located opposite the vestibule from the cochlea contain fluid-filled membranous tubes ampulla: enlarged area near the utricle end of each semi-circular canal crista ampullaris: receptor within ampulla - supporting cells and hair cells with modified dendrites sticking up into gelantinous structur (cupula) when the head moves, fluid movement lags behind the movement of the canal itself movement of the fluid pulls on the cupula and bends the hairs generates nerve impulses that five the brain information about motion of the head |
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Definition
most components of the eye function to help form an accurate visual image, not detect it photoreceptors that detect the image and generate visual nerve impulses are in a single layer of cells in the retina |
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Definition
outer fibrous layer middle vascular layer inner nervous layer |
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Term
eyeball outer fibrous layer |
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Definition
cornea and sclera cornea: transparent; admits light to interior of the eye - arragement of collagen fiber, no blood vessels scelera: "white" of the eye - dense fibrous connective tissue limbus: junction of the cornea and the sclera |
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Term
eyeball middle vascular layer |
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Definition
choroid: between the sclera and the retina - pigment and blood vessels - in most animals, choroid forms the tapetum - highly reflective area in the rear of the eye Iris: pigmented muscular diaphragm - controls amt of light that enters the posterior part of the eyeball pupil: opening at center of iris cilliary body: ring shaped structure behind the iris - muscles that adjust shape of the lens to allow near and far vision |
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Term
Eyeball inner nervous layer |
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Definition
retina - lines the back of the eye - contains the sensory receptors for vision, the rods and cones |
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Term
compartments of the eyeball |
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Definition
aqueous compartment - subdivided by the iris into anterior and posterior chambers -contains a clear watery fluid: aqeous humor - produced in the posterior chamber by cells of the cilliary body vitreous compartment - contains a clear gelantinous fluid called vitreous humor - vitreous humor fills the whole back of the eyeball behind the lens and cilliary body |
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Definition
layers of fibers elastic and biconvex front surface is in contact with aqueous humor; back surface is in contact with vitreous humor helps focus a clear image on the retina accomodation: process by which the shape of the lens is changed to allow close-up and distant vision - relaxation of cilliary muscles causes tension on suspensory ligaments; flattens the lens - contraction of cilliary muscles releases tension on the suspensory ligaments |
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Definition
multilayered lines most of the vitreous compartment 1) pigment layer 2) photoreceptor layer 3) bipolar cell layer 4) ganglion cell layer 5) layer of nerve fibers optic disc: wite where nerve fibers on the inside surface of the retina converge and leave the eye to form the optic nerve photoreceptor cells: neurons with modified dendrites - rods - more sensitive to light - cones - more sensitive to color and detail |
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Term
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Definition
conjunctiva: thin transparent membrane - covers the fron portion of the eyeball and lines the interior surfaces of the eyelids conjunctival sac: space between the bulbar and palpebral portions of the conjunctiva eyelids: upper and lower folds of skin lined by the thin, moist conjunctiva lateral and medial canthus: corners where the eyelids come together tarsal glands: produce waxy substance that helps prevent tears from overflowing onto the face nictitating membrane: third eyelid of domestic animals located medially between eyelids and eyeball - T-shaped plate of cartilege covered by conjunctiva lacrimal apparatus: - structures taht produce and secrete tears and drain them away from the surface of the eye lacrimal puncta lacrimal sac nasolacrimal duct eye muscles attach to the sclera of the eye capable of a wide range of movments dorsal, ventral, medial and lateral muscles dorsal and ventral oblique muscles |
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Term
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Definition
Epidermis: thin layer of flattened epithelial called that produce keratin - fibrous protein necessary for the production of scales, feathers and outer sheath of beaks and claws Dermis: thick layer of fibrous connective tissue - stores fat for nutrition and insulation - smooth muscles in dermis innervate feather follicles to aid in heat regulation |
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Term
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Definition
Uropygial (preen) gland: - on dorsal surface at upper base of the tail - preening stimulates secretion of an oily, fatty substance - bird uses beak to spread the oil throughout its feathers to clean and waterproof them |
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Term
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Definition
derivative of skin upper and lower mandible covered with a horny keratin layer grows continuously variable hardness and flexibility, depending on the function |
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Definition
horny sheath derived from specialized scales at the end of each toe grow continuously variable types of claws, depending on perching habits and method of procurring food |
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Term
Feathers and feather structure |
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Definition
outgrowth of skin made or protein functions: 1) flight 2) protect thin skin from trauma, rain, and excessive radiation from sunlight 3) assist in thermoregulation and camouflage 4) used in communication behaviours (eg. courtship, defense and recognition) structure inferior umbillicus: opening at base of feather superior unbillicus: opening on feather shaft where webbed part of the feather begins - may give rise to an afterfeather, accessory feather thought to provide addiontion insulation calamus: quill, round, hollow, semitransparant -extends from inferior to superior umbillicus Rachis: main feather shaft vane: flattened part of a feather -numerous slender, closely spaced barbs that give rise to barbules containing hooklets (hamuli) - hooklets interlock each barb with an adjacent one |
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Term
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Definition
contour feathers - flight feathers of the wings and tail (remiges and retrices) - moved by muscles attached to the walls of the follicles Auriculars: small contour feathers around external ear openings - improve bird's hearing ability Semiplume -have main rachis with barbs and no barbules or hooklets -found under contour feathers -provide insulation -provide flexibility for movement of contour feathers -help with buoyancy in water birds down feathers: soft fluffy feathers -lack true shaft -no barbules or hooklets -located next to skin under contour feathers -function in insulation filoplume - bare shaft with barbs on the tip - located on the nape and upper back near contour feathers - nerve endings in follicles may play role in controlling feather movment bristles -modified contour feathers -stiff rachis with few barbs at the base -may play a role ub sense of touch -may be found around the eyes, nostrils, mouth and toes powder down -grow continuously at the base -disintegrate at their tip -create waxy powder that spreads throughout the rest of the plumage -birds without a uropygial gland have abundant powder down feathers Pterylae: tracts where feathers are located Apteria: bare areas of skin between pterylae feathers in pterylae overlap one another |
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Term
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Definition
feather mites and other external parasites can chew and consume parts of the feather vanes daily wear and tear: lighter tups of flight and tail feathers can be worn off fault bar: weakened area on the feather vane where barbs lack barbules - results from stress that interrupts blood flow during feather growth -common stressor: poor diet
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Term
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Definition
process of feather replacement occurs once to several times a year depending on th species in most species, feather replacement is symmetrical - one or two pairs of flight feathers molded at a time - many species of waterfowl molt all flight feathers at once after the breeding season feathers develop from papillae in feather tracts of the dermis contain cells with genetic info that dictates type, size and colour of feathers hormones stimulate molting, activate cells in papillae newly developing feather pushes old feather out feather emerges covered in periderm - periderm removed by preening blood vessels from dermis reach into new feather - when feather is fully grown, blood dries up |
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Term
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Definition
skeletal modification allow for flight and walking: 1) reduction in number of bones 2) fusion of some bones to form plates 3) reduction in bone density 4) loss of internal bone matrix; bone becomes hollow and filled with air spaces |
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Term
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Definition
skull bones are thinner than in other animals jaws extend into a keratinized bill large eye sockets bordered by scleric ring - protective bony plates |
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Term
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Definition
cervical vertebrae: - atlas contains a single condyle for attachement of the skull -allows greater range of motion of head g reat number of cerivical vertebrae than mammals - variable in dif species thoracic vertebrae: rigid and provide a strong support for the rib cage -first few ribs are relatively short and incomplete - remaining ribs attache to underside of sternum and have a projection (uncinate process) that overlaps the adjoining rear rib to strengthen the rib cage lumbar and sacral vertebrae: synsacrum: strong bony plate created from fusion of several distal lumbar vertebrae, sacral vertebrae and first few coccygeal vertebrae - synsacrum fuses with the pelvis, supports the legs coccygeal vertebrae: -first few are mobile pygostyle: bony structure created from fusion of some coccydeal vertebrae |
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Term
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Definition
large and concave site of origin of flight muscles in some species, muscles attach to large bony ridge or keel in flightless birds sternum lacks a keel |
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