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Histology

Tommy Dadg Inglés 19 fichas

Oesophagus -E = stratified squamous epithelium -Ly = lamina propria (containing lymphoid aggregates -MM = muscularis mucosa…

Fichas del conjunto (19)

1—Oesophagus
-E = stratified squamous epithelium
-Ly = lamina propria (containing lymphoid aggregates
-MM = muscularis mucosa
-SM = submucosa (loose with elastin to allow for distension when food passes)
-G = small seromucous glands which aid lubrication
-CM & LM = inner circular and outer longitudinal layers of smooth muscles (muscularis propria)
*Note upper 1/3 has more skeletal muscle as this is a lower third segement due to the amount of smooth muscle
2—Stomach
- In the non-distended state, the stomach mucosa is thrown into prominent longitudinal folds called rugae that allow distension after eating
- 4 regions include; cardia, fundus, body and pylorus (pyloric antrum +canal)
 Cardia – mucus-secreting glands
 Fundus and body – glands that secrete acid-pepsin gastric juices, as well as protective mucous
 Pylorus – glands secrete mucous, and there are endocrine cells which secrete the hormone gastrin
3—Stomach (body in non-distended state)
M= The mucosa thrown into prominent folds of rugae and consists of gastric glands that extend from muscularis mucosa
MM= muscularis mucosa
GP= Gastric pits opening into stomach lumen
C & L = inner circular and outer longitudinal layers
O = inner oblique layer (reinforcing C)
SM = submucosa that is loose and distensible containing large blood vessels
4—Oesophago-gastric junction
*Here the mucosa undergoes abrupt transition from a protective stratified squamous epithelium (SE) to a glandular secretory mucosa (GM)
MM = muscularis mucosa
SM = Sub mucosa
MP = Muscularis propria
5—Liver
*hepatic lobule hexagonal in shape
V= Terminal hepatic venule (central vein)
T = portal tracts positioned at the angles of the hexagon (Hepatic artery, vein and duct)
*Blood travels to the central vein and bile to the portal tract
F = fibrous tissue (clear in this spec as it's a pig however less clear in most other species)
6—The Gallbladder
*Lacks muscularis mucosa and sub mucosa muscularis
*Contracts in response to CCK and vagal stimulation
Mucosa: simple columnar epithelium with microvilli
Adventitia/Serosa: Surface attached to liver has adventitia and rest has a serosa
7—Pancreas
*Exocrine portion consists of closely packed acini which drain into branched duct system (main pancreatic duct --> common pile --> major papilla)
SP = septa between lobulated glands (thin collagenous capsule)
D = interlobar ducts
L= islets of langerhans
AC = adipocytes scattered through parenchyma
8—Colon
*Muscular wall is thick for peristaltic activity
*Mucosa is the same from caecum to rectum --> folded in a non-distended state
CM & LM = inner circular and longitudinal outer (teniae coli formed by LM)
Muscular mucosa is prominent --> functions of water absorption and faecal movement lubrication
9—Appendix
*small blind ended tubular sac extending from the caecum (general structure similar to large intestine)
M= suspensory mesoappendix continuous with serosa (GIT mesenteries conduct blood vessels, lymphatics and nerves)
S = Serosal layer
F = Lymphoid follicles containing germinal centres
*Presence of lymphoid tissue masses within mucosa and submucosa (infiltrated with lymphocytes_
10—Spleen
WP = White pulp embedded within the red matrix
RP = Red pulp making up the bulk of the organ, is highly vascular tissue
C= Thin fibroelastic capsule which has an outer-surface covering of mesothelium from which short trabeculae extend into the parenchyma
T= Trabeculae
*Capsule is thickened at the hilum and continuous with supporting tissue that sheath vessels leaving/entering
*Has no afferent lymphatics just efferent leaving
11—Lymph node
Cx = Cortex (highly cellular)
M= medulla (less cellular)
H= Hilum drains efferent lymph
C= collagenous capsule
T= Trabeculae
SF= secondary follicles containing a germinal centre
PF = inactive primary follicles
P= Deeper cortex/paracortex where T-lymphocytes interact with antigen presenting cells here
MS= medullary sinuses which converge upon the hilum
MC= medullary cord
12—Kidney
-Convex surface laterally
-Internally outer cortex continuous with medulla consisting of renal pyramids
P = papilla
U= ureter
H= Hilum
C= Cortex
M= medulla
Cp= fibrous capsule
13—Transitional epithelium of the bladder
 Found in the renal pelvis, ureters and bladder
 Cells of the basal layer are cuboidal or columnar
 Apical cells VARY IN APPEARANCE, depending on the degree of distension (amount of urine)
 i.e. their appearance TRANSITIONS between STRATIFIED CUBOIDAL and STRATIFIED SQUAMOUS epithelia
 In the relaxed state, this type of epithelium appears ~6 cell layers thick
 In the stretched state (distended with urine), it appears only 2 or 3 cells thick (although the actual number of cells remains constant)
14—Ovary
CL= corpus luteum responsible for progesterone production
F= Follicle
H= Helicine artery
L= Broad ligament (ovarian artery and vein anastomose here with the mesovarium)
M= medulla is the central zone and highly vascular
15—Uterus
ENDOMETRIUM
*spiral artery branches of uterine that extend into the LP
 Mucosal lining of simple columnar epithelium underlain by a thick lamina propria – can be divided into two layers
 FUNCTIONAL LAYER
• Undergoes cyclical changes, shed during menstruation
 BASAL LAYER
• Has stem cells that form a new functional layer
 UTERINE GLANDS
• Extend the length of the endometrium
• Make secretions which help nourish the fertilised ovum
MYOMETRIUM
 Thick muscular wall consisting of bundles; longitudinal, circular and spiral fibres
PERIMETRIUM
 Visceral peritoneum supported by a thin layer of connective tissue
16—Testes
E= epididymis (posterior aspect which extends down the whole length of the posterior testes for spermatozoa testes)
S= interlobular septa
TA= Tunica albuginea (dense fibrous capsule)
-contains fibroblasts, myofibroblasts and smooth muscle cells
-scattered leydig cells are found here
RT= Rete testis (where spermatozoa pass from seminiferous tubules into here via it's connection with the epididymis)
17—Prostate Gland
U= Urethra
St= Fibrous stroma surrounding the urethra
Sp = partial fibrous septa
TZ= Transition zone (surrounds prostatic urethra)
CZ= central zone (posterior to the TZ)
ED= ejaculatory duct (encircled by the CZ)
PZ= peripheral zone (makes up the main bulk of the gland)
C= urethral crest
*Different zones can be the sites of different disease processes
Cap= capsule (continuous with the anterior fibromuscular stroma)
18—Adrenal gland
C= outer cortex
M= inner medulla
Cap= dense fibrous tissue capsule (provides external support for collagenous framework supporting secretory cells)
V= Prominent vein (located in the centre of the medulla)
G= zone glomerulosa (contains secretory cells arranged in round clusters)
F= Zona fasciculata (parallel cords of secretory cells)
R= zone reticularis (consists of small closely packed cells arranged in irregular cords)
19—Thyroid gland
F= thyroid follicles (single layered cuboidal epithelial cells, bounded by basement membrane)
Colloid = stained in pink contained within the follicles
*enveloped by a fibrous capsule from which fine collagenous septa extend into the gland dividing it into lobules
*Septa conveys rich blood, lymph and nerve supply
*Tiny capillaries percolate through tissue and surround follicles