Histology Flashcards
Kidney
Collagenous fibrous capsule Connective tissue lining renal sinus Cortex and medulla Medullary pyramids Minor calyces Hilum- renal artery enters, renal vein and ureter exit
Nephron
Renal corpuscle- filtrate plasma, Bowman’s capsule and glomerulus
Bowman’s capsule- simple squamous epithelium
Glomerulus- network of capillaries that invaginate Bowman’s capsule- supplied by afferent arterioles and drained by efferent arterioles
Cell layers that separate blood form glomerula filtrate; capillary endothelium and podocytes
Glomerulus- contains mesangial cells that produce a connective tissue core and remove debris
Duct system
Renal tubule- from the Bowman’s capsule to junction with collecting duct- selectively reabsorbs water from glomerula filtrate
Proximal convoluted tubules(PCT)- simple cuboidal epithelium with brush border and mitochondria
Loop of henle- creates hypertonic environment in medulla
Vasa recta- blood vessels dip down into medulla and up to cortex
Distal convoluted tubules(DCT)- continuation of thick limbs
Collecting tubules- converge to form collecting ducts. Bundles through the cortex form medullary rays.
Medullary rays- open ducts of Bellini to release urine into minor calyx
Extraglomerular apparatus
Macula densa- tall epithelium, between efferent and afferent arterioles, senses sodium content in DCT
Juxtaglomerular cells- modified smooth muscle cells in wall of afferent arteriole
Extraglomerular mesangial cells- modified mesangial cells extending out renal corpuscle
Male reproductive system
Production of spermatozoa
Delivery of semen into the female reproductive tract
Testis
Produce male gametes- spermatozoa and testosterone
Surrounded by thick fibrous capsule, tunica albuginea and mesothelium
Each lobe- 1-4 convoluted seminiferous tubules; lined by seminiferous epithelium and germ cells and support cells(sertoli)
Sertoli cells- support developing spermatozoa and control production
Leydig cells- synthesise and secrete testosterone
Seminiferous tubules
Connected at end of each straight tubule
Rete testis- cilliated simple cuboidal epithelium, convey spermatozoa out of testis to efferent ducts.
Efferent ducts
About 12- carry spermatozoa to head of epididymis; lined by cilliated pseudostratified cuboidal to columnar
Leaves testis via common duct to the epididymis
Stores spermatozoa that matures and becomes motile
Epididymis
Highly coiled- pseudostratified columnar with stereocilia
Smooth muscle produces strong peristalsis during ejaculation
Prostate and seminal vesicles
Seminal vesicles- sac with complex folds, contains fructose; pseudostratified columnar epithelium and smooth muscle
Duct from seminal vesicle joins vas deferens= ejaculatory duct
Prostate- largest accessory gland, produces watery fluid
Fibromusclar capsule
3 zones; transition zone, central zone, peripheral zone
External genitalia
Penis- skin keratinised stratified squamous epithelium
3 Erectile columns- 2 corpus cavernosa, 1 corpus spongiosum
Erectile tissue- blood sinuses
Sinuses- supplied by the helicine arteries
Penile urethra- stratified columnar epithelium to non-keratinised stratified squamous
Spermatogenesis
Type A- spermatogonia, self renewing stem cells, divide mitotically to form B spermatogonia
Type B- not stem cells, divide repeatedly into primary spermatocytes
Primary spermatocytes- enter prolonged phase of first meiotic division and form secondary spermatocyte
Secondary spermatocyte- enter second meiotic division to form spermatids
Spermatids- turn into spermatozoa by terminal phase of spermatogenesis
Acrosomal cap- access of spermozoa through corona radiata and the zone of pellucida of the oocyte.
The female reproductive system
Organs; internal- ovaries, oviducts, uterus
External- labia minora, labia majora, clitoris, bulb of vestibule
Ovaries
Function- production and ovulation of oocyte, production and secretion of hormones
Surface- simple cuboidal (germinal epithelium)
Fibrous connective tissue forms thin capsules- tunica albuginea
Follicular development
Primordial follicle- one layer of squamous pregranulsa cells, surrounded by stromal cells
Primary follicle- cuboidal or columnar granulosa cells, proflieration changes them to stratified epithelium. Stromal cells form theca follicula. Zone of pellucida forms.
Late primary follicle- thecal cells divide, interna and externa.
Sceondary follicle- enlarges and form antrum in granulsa cell layer. Granulsa and thecal layers proliferate.
Graafian follicle- antrum enlarges. Cumulus cells form around oocyte. Corona radiata will separate form lining granulsa cells.
After ovulation
Corpus luteum- follicle changes into this. If no implantation occurs it becomes a white coloured connective tissue, corpus albicans.
If implantation occurs, HCG is secreted which prevents it from being degraded.
Uterine tubes
Mucosa- folded and formed by cilliated and secretory epithelium
Secretory cells- peg cells
Uterus
Wall- endometrium
Endometrium- pseudostratified columnar with cilliated and secretory cells
2 layers- stratum basalis- not shed
Stratum functionalis- shed
Cervix
Fibrous connective tissue- mucous secreting simple columnar epithelium to stratified squamous.
Non-lactating breast
Subcutaneous fat and secretory tissue with mammary glands
Secretory tissue- 15-25 lobules
Terminal duct lobular unit(TDLU)- contains an individual tubule, acinar gland
Lactiferous duct- cuboidal basal cell and columnar superficial cells.
Branched of lactiferous ducts- lined with stratified cuboidal or columnar epithelium to stratified squamous.
Nipple
Surface- non-keratinised stratified squamous
Lactating breast
Mammary glands- large amount of growth occurs
Blood vessel: layers
Inner layer; tunica intima, single layer of squamous epithelial cells, endothelial cells.
Middle layer; tunica media
Outer layer; tunica adventitia
Erythrocytes
Biconcave discs
Transports oxygen and carbon dioxide around body
Leukocytes: white blood cells
Neutrophils- 40-75% Eosinophils- 5% Basophils- 0.5% Lymphocytes- 20-50% Monocytes- 1-5%
Neutrophils
Most common type of leukocyte
Muti-lobed nucleus
Circulate in an inactive state, stimulated by bacteria or inflammation
Eosinophils
Released from marrow
Circulate for 8-12 hours and then move into tissue
Slightly longer than nerutrophils
Typically bi-lobed nucleus
Basophils
Most rare
Bilobed nucleus but is often obscured by granules
Act as efferent cells in allergic reactions
Mast cells
Cells found in many tissue
Contain granules of heparin and histamine
Monocytes
Found in bone marrow and blood
Forms mononuclear phagocyte system
Largest cells circulating in the blood
Non-lobed nucleus- kidney bean shaped
Lymphocytes
Round nucleus
Two classes; B and T cells
Arise form bone marrow
Platelets
Small cell fragments
Found in large numbers in the blood
Clot the blood
Oral mucosa
Stratified squamous epithelium
Tongue
Papillae; Filiform-no taste buds Fungiform- blunt Foliate- ‘slit-like’ on margin of tongue Circumvallate- large dome-shaped
Von Ebners glands
Associated with circumvallate and foliate papilllae
Helps dissolve food molecules to aid taste and keep the cleft flushed
