Final review Flashcards
What is the pituitary gland?
In the sphenoid bone of the skull, anterior has pars distalis (associated with sinusoids, has chromophobes and acidophils-produce growth hormone and prolactin-basophils-TSH/LH/FSH/ACTH/tuberalis (forms a collar)/intermedia (MSH and ACTH), posterior has pars nervosa and infundibular stalk
What is the neurohypophysis?
Pars nervosa and pituitary stalk, has unmyelinated axons and cell bodies in hypothalamus, secretes oxytocin and vasopressin, can see Herring bodies
What is the thyroid gland?
From buccal cavity, have follicles full of colloid made of thyroglobulin, have follicular cells with microvilli and has thyroglobulin (stored in lumen, broken down to produce T4 and active T3 which increases active metabolic rate and increases mitochondria) which is strong antigen, parafollicular cells are isolated clusters of paler cells producing calcitonin; has endocrine and storage functions; calcium sensitivity through CaSR protein
What are the parathyroid glands?
has capsule and parenchyma; chief cells-dark ones produce parathyroid hormone (raise calcium levels) and oxyphil cells are acidophilic
Describe the adrenal glands
Cortex-glomerulosa-produces mineralocorticoids (aldosterone) which is stimulated by angiotensin; fasciculata-glucocorticoids like cortisol stimulated by ACTH; reticularis-weak androgens; medulla-has chromaffin cells which have catecholamines and are stimulated by preganglionic sympathetic fibers
What is the pineal gland?
Photoreceptor is for lower vertebrates, secretes melatonin and serotonin, divided into lobules, has pinealocytes/astrocytes and brain sand
What is the overview of male repro organs?
Testes-produce spermatozoa and testosterone, duct system collects/stores/waits for sperm maturation, seminal vesicles and prostate are exocrine-produce seminal fluid which is nutritious and lubricating, semen has fluid, sperm, and duct lining cells, penis with bulbourethral glands secrete fluid which lubricates urethra for semen passage
Describe the testes
exocrine-produces spermatozoa, endocrine-Leydig for TTT and Sertoli for estrogen production, tnica albuginea has tunica serosa on it, mediastinum testis at anterior pole made of areolar CT and part of rete testis, septula testis divides testes into lobules; seminiferous tubules-has basal lamina and is space for spermatogenesis, myoid cells, Sertoli/nurse cells (tall triangle shape with vesicular nucleus, for support, phagocytosis, androgen binding protein, activin, inhibin, create blood-testis barrier with tight junctions)
What is spermatogenesis?
Divided into three phases: mitosis, meiosis, and metamorphosis; spermatogonia is most primitive and located in the periphery of seminiferous tubules (A=stem cells, upon mitosis one remains A cell (asymmetric division))and the other divides to get I->B cells->primary spermatocytes which are the largest and has 4N DNA with an extended prophase of meiosis for genetic diversity->secondary spermatocytes with 2N DNA and undergo 2nd meiotic division to get->spermatid where nuclei become flattened and heterochromatic and haploid DESCENDANTS OF SPERMATOGONIUM ARE CONNECTED BY CYTOPLASMIC BRIDGES EXCEPT SPERMATOZOA
What are spermatozoa?
Mature formed during metamorphosis stage, development of acrosome (cap with hyaluronidase), flagellum; waves of development occur in s. tubules
What is cryptorchidism?
Retention of at least testicle in the abdominal cavity, in swine and horses it is hereditary, bilateral retention->infertility because sperm are sensitive to temp, should be removed unless FSH/HcG is given pre-puberty
Describe testicular stroma and ducts
Leydig cells-interstitial between s. tubules, acidophilic, produce TTT and controlled by LH; straight tubules-cuboidal epithelium and are connections; rete testis-tubules in mediastinum and secretes fluid, microvilliated; ductuli efferentes-connect rete to epididymis, ciliated simple columnar epithelium; rete and ductuli move non motile sperm to epididymis.
What are the genital ducts?
ductus epididymis: stores sperm while it matures, stereociliated pseudostratified and connects with ductus deferens, takes sperm 13 days to get through epididymis and when they do they are motile and can partially fertilise; ductus deferens: pseudostratified columnar but loses stereocilia, has spermatozoa in mature animals and has a thick muscular layer, peristaltic contractions controlled by sympathetic during ejac
What is a seminal vesicle?
secretes major seminal fluid, which is alkaline to neutralise vaginal acidity, contains proteins/fructose/mucous/flavins/etc.; vesicular glands are found as a cluster, absent in carnivores, has lipofuscin granules in cytoplasm and intranuclear fluid
What are the male accessory organs?
Ampulla-terminal part of vas deferens; prostate-laminated concretions of secretory product found in tubules and aleveoli, produces half of seminal fluid with fibrinolysin (liquefy coagulated semen and disperse sperm in vagina) and citric acid; ejaculatory ducts are short part of d.d. joined with duct of s. vesicles
What is the ovary?
Endocrine gland (produces hormones) and exocrine gland (oocyte) that has a tunica albuginea surrounding the cortex. Hormones are produced by developing follicles, which are transformed after ovulation to corpora lutea. Responds to pituitary hormones like FSH and LH. the cortex has the developing follicles, the tissue between them is stroma, and the mesovarium sits on top of the ovary. The medulla has blood vessels for the ovary and possibly rete ovarii which can form cysts. Primary oocytes becomes arrested in meiosis prophase 1 and when stimulated, form the secondary one and a polar body, formed just prior to ovulation except in dog. After fertilization, the secondary oocyte undergoes 2nd meiotic division and becomes an ovum
What are the oocytes?
Inside follicles, surrounded by zona pellucida (glycoprotein layer secreted by oocyte and granulosa cells) and granulosa cells, a theca outside the follicle
Describe the follicles
Primary-oocyte surrounded by granulosa cells, secondary-follicular fluid shows up between granulosa cells, tertiary-has large fluid filled cavity/antrum with granulosa cells on outside (cumulus oophorus), corona radiata is the layer of cells directly in contact with zona pellucida; interstitial cells from theca interna
Describe the ovarian cycle
Luteal phase: corpus luteum produces progesterone to stimulate endometrium and regresses, influenced by uterine PGF2a which causes decline of CL and oxytocin, granulosa cells proliferate, uterine glands are secreting, LH declines; follicular phase: CL degenerates, follicle starts to mature, estrogen produced by granulosa cells in response to FSH->expression of LH receptors leads to surge which starts ovulation and has primary oocyte complete meiosis and starts CL formation in ovulated follicle; after ovulation a corpus hemorrhagicum forms when blood fills lumen; some animals need copulation for ovulation to occur
What is the uterus?
Endometrium (tunica mucosa and submucosa, has uterne glands), myometrium (tunica muscularis), perimetrium (tunica serosa)
What are ruminant caruncles?
elevated vascular areas with no glands, site of attachment of placenta, combined maternal and fetal structure is placentome
What is the cervix?
Stratified squamous in female dogs, columnar in others, tunica muscularis has inner circular and outer longitudinal layers
What is the vagina and vestibule?
No muscularis mucosa so lamina propria directly joined to submucosa; distal to urethral opening, has glands, part of the vulva