Histology

Question 1

Kidney

Answer 1

Collagenous fibrous capsule 
Connective tissue lining renal sinus
Cortex and medulla 
Medullary pyramids
Minor calyces 
Hilum- renal artery enters, renal vein and ureter exit

Question 2

Nephron

Answer 2

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

Question 3

Duct system

Answer 3

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

Question 4

Extraglomerular apparatus

Answer 4

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

Question 5

Male reproductive system

Answer 5

Production of spermatozoa

Delivery of semen into the female reproductive tract

Question 6

Testis

Answer 6

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

Question 7

Seminiferous tubules

Answer 7

Connected at end of each straight tubule

Rete testis- cilliated simple cuboidal epithelium, convey spermatozoa out of testis to efferent ducts.

Question 8

Efferent ducts

Answer 8

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

Question 9

Epididymis

Answer 9

Highly coiled- pseudostratified columnar with stereocilia

Smooth muscle produces strong peristalsis during ejaculation

Question 10

Prostate and seminal vesicles

Answer 10

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

Question 11

External genitalia

Answer 11

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

Question 12

Spermatogenesis

Answer 12

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.

Question 13

The female reproductive system

Answer 13

Organs; internal- ovaries, oviducts, uterus

External- labia minora, labia majora, clitoris, bulb of vestibule

Question 14

Ovaries

Answer 14

Function- production and ovulation of oocyte, production and secretion of hormones
Surface- simple cuboidal (germinal epithelium)
Fibrous connective tissue forms thin capsules- tunica albuginea

Question 15

Follicular development

Answer 15

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.

Question 16

After ovulation

Answer 16

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.

Question 17

Uterine tubes

Answer 17

Mucosa- folded and formed by cilliated and secretory epithelium
Secretory cells- peg cells

Question 18

Uterus

Answer 18

Wall- endometrium
Endometrium- pseudostratified columnar with cilliated and secretory cells
2 layers- stratum basalis- not shed
Stratum functionalis- shed

Question 19

Cervix

Answer 19

Fibrous connective tissue- mucous secreting simple columnar epithelium to stratified squamous.

Question 20

Non-lactating breast

Answer 20

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.

Question 21

Nipple

Answer 21

Surface- non-keratinised stratified squamous

Question 22

Lactating breast

Answer 22

Mammary glands- large amount of growth occurs

Question 23

Blood vessel: layers

Answer 23

Inner layer; tunica intima, single layer of squamous epithelial cells, endothelial cells.
Middle layer; tunica media
Outer layer; tunica adventitia

Question 24

Erythrocytes

Answer 24

Biconcave discs

Transports oxygen and carbon dioxide around body

Question 25

Leukocytes: white blood cells

Answer 25

Neutrophils- 40-75%
Eosinophils- 5%
Basophils- 0.5%
Lymphocytes- 20-50%
Monocytes- 1-5%

Question 26

Neutrophils

Answer 26

Most common type of leukocyte
Muti-lobed nucleus
Circulate in an inactive state, stimulated by bacteria or inflammation

Question 27

Eosinophils

Answer 27

Released from marrow
Circulate for 8-12 hours and then move into tissue
Slightly longer than nerutrophils
Typically bi-lobed nucleus

Question 28

Basophils

Answer 28

Most rare
Bilobed nucleus but is often obscured by granules
Act as efferent cells in allergic reactions

Question 29

Mast cells

Answer 29

Cells found in many tissue

Contain granules of heparin and histamine

Question 30

Monocytes

Answer 30

Found in bone marrow and blood
Forms mononuclear phagocyte system
Largest cells circulating in the blood
Non-lobed nucleus- kidney bean shaped

Question 31

Lymphocytes

Answer 31

Round nucleus
Two classes; B and T cells
Arise form bone marrow

Question 32

Platelets

Answer 32

Small cell fragments
Found in large numbers in the blood
Clot the blood

Question 33

Oral mucosa

Answer 33

Stratified squamous epithelium

Question 34

Tongue

Answer 34

Papillae;
Filiform-no taste buds
Fungiform- blunt
Foliate- ‘slit-like’ on margin of tongue 
Circumvallate- large dome-shaped

Question 35

Von Ebners glands

Answer 35

Associated with circumvallate and foliate papilllae

Helps dissolve food molecules to aid taste and keep the cleft flushed