Histology

fibroblasts

synthesises extracellular matrix

simple squamous epithelium

endothelium, type 1 alveoli cells, peritoneum, form walls of lymphatic vessels

simple cuboidal

line tubules & ducts for excretory/ secretory/ absorptive processes, small bronchioles, exocrine glands

transitional epithelium

surface of bladder, ureters and part of urethra

simple columnar

bronchi (ciliated), digestive tract (intestine, stomach) and some glands; involved in absorption and secretion

pseudostratified

trachea- ciliated

stratified squamous

lining oesophagus, skin (keratinous), oral cavity

stratified cuboidal

common in ducts

thick skin vs thin skin

thicker epidermis (clear zone), lack hair follicles & sebaceous glands

5 layers of skin

basal cell layer

prickle cell layer

granule cell layer

clear layer- only thick skin

keratinised squames layer- thicker in thick skin and thinner in thin skin.

apocrine vs merocrine (eccrine) glands

apocrine: secrete into hair follicle, secrete viscous milky substance

merocine (eccrine): produce sweat

epithelium type of merocrine gland

excretory part= stratified cuboidal

secretory part (earlier)= simple columnar

pacinian corpuscle- deep pressure and vibration (in dermis and hypodermis)

Meissner’s corpuscle: light touch- elliptical structures in dermal projections/ papillae

sebaceous gland- secrete sebum into hair follicles

skeletal muscle- dark red= type 1 (slow twitch) and light red= type 2 (fast twitch) fibers.

cardiac muscle with visible intercalated discs

smooth muscle

hyaline cartilage

elastic cartilage- pink in purple from elastin fibres (easier to see when stained)

fibrocartilage- no perichondrium

compact (left) and spongy/ cancellous/ trabecular bone (right)

zones of growth at epiphyseal plate

nerve

which ganglion

dorsal root ganglion- variable body size, neat circle of satellite cells,

which ganglion

sympathetic, smaller and more uniform body size- no clear ring of satellite cells (scattered)

which ganglion

parasympathetic nucleus not centrally located & no neat ring of satellite cells

trachea- sero-mucous glands on right

bronchi

primary bronchi- contain club (clara) cells

respiratory bronchioles

type 1 pneumocytes vs type 2 pneumocytes

type 1 (40%) make up 90% of SA of alveoli

3 layers of blood vessels

tunica intimia- thin layer with endothelium, basement membrane & subendothelial connective tissue & internal elastic laminae

Tunica media- smooth muscle cells, elastic laminae & collagen fibres

Tunica adventitia- external elastic lamina, lots of connective tissue with many collagen fibres (vasa vasorum & nerves)

staining of WBCs

digestive system general layers

oesophagus, stratified squamous epithelium

fundus/ body of stomach- simple columnar epithelium

body of stomach, what are the two groups of cells

top: parietal cells, fried egg appearance, then bottom: chief/ peptic cells: zymogen granules visible

which part of SI?

duodenum due to the Brunner’s glands in the submucosa

what is the mound in the middle

Peyer’s patch of ileum

defining feature of SI compared to stomach & colon

villi also they have columnar epithelial cells called enterocytes (not distinguishing)

large intestine, no villi, extensive invaginations- colonic crypts, simple columnar

parotid gland (one of salivary glands), mostly serous cells visible

serous vs mucous cells

serous- produce protein rich fluid (amylase, lysozyme)- visible secretory granules, centrally located nuclei

mucous- produce mucin (glycosylated protein)- poorly staining cytoplasm, peripheral nuclei

levels of ducts in salivary gland

intralobular (intercalated & striated ducts) to the interlobular ducts (PNS innervation, ganglia present)

islet of langerhans- only 1-2% of pancreas volume

pancreas

liver lobule- functional unit of liver

space of disse

perisinusoidal space- between sinusoidal capillary and hepatocytes

kidney, renal papilla and minor calyx visible

renal corpuscle structure

PCT vs DCT

PCT has brush border, stains more intensely than DCT

thin descending/ ascending vs thick ascending

simple squamous vs simple cuboidal

transitional epithelium- bladder, ureter and upper urethra, umbrella cells on top

cells in anterior pituitary

are cuboidal to columnar epithelial cells that secrete various hormones such as GH, ACTH, TSH, FSH, and LH.

cells in posterior pituitary

most nuclei= pituicyte cells, herring bodies= axonal swellings full of secretory granules that store and release hormones like oxytocin and vasopressin, produced in the hypothalamus.

zoomed in on the thyroid gland- distinctive follicles with colloid in the lumen- gaps are artefact

parafollicular cells/ C cells/ Clear cells?

produce calcitonin (inhibits bone resorption), in periphery of follicles, stain poorly with H&E

parathyroid gland

cells in the parathyroid gland?

oxyphil cells & chief cells (produce PTH)

zones of the adrenal cortex

The adrenal cortex is divided into three zones: zona glomerulosa on outside (produces aldosterone), zona fasciculata (makes up most of cortex) (produces cortisol), and zona reticularis (produces androgens).

Adrenal medulla containing ganglion cells and chromaffin cells that produce catecholamines like adrenaline or noradrenaline (or dopamine)