Histology Flashcards
What is this?
A glomerulus
What is in the yellow circle?
Proximal Tubules
Which type of tubule is indicated by the blue arrow?
Straight portion of the proximal tubule
What are the cells of the distal tubule like?
They have a few short microvilli and do not display a brush border. They appear paler than the proximal tubule. They have deep invaginations of the basal plasme-membrane with numerous mitchondria
What are the cells of the bladder?
The lining urothelium sits on a fibrous lamina propria and the thickened epithelium is often thrown into folds
What is the function of an umbrella cell?
They are adapted to be urine prood and protect the underlying cells of the urothelium
What is the lining of the male urethra?
It is lined mainly by pseudo-stratified columnar epithelium (urothelium) except at it’s distal (penile) end. Mucous glands are found along the entire length
What is the lining of the female urethra?
It is lined by stratified squamous epithelium punctuated by areas of mucous glands
Do both sexes have a urethral sphincter?
They both have a striated (voluntary) muscle sphincter derived from the muscles of the pelvic diaphragm surrounding the membranous part of the urethra
What type of epithelium lines the distal end of both the male and female urethra?
Stratified squamous epithelium
What is the epithelial lining of the seminiferous tubules?
They are lined by a stratified epithelium consisting of supporting cells (sertoli cells) and the cells of the germline (developing spermatozoa)
What is the prime function of the Sertolli cells?
To nurture the developing sperm
What is the epithalial lining of the seminiferous tubules?
The cells cloest to the thin fibrous capsule form germinal epithelium interspersed with large cells who regular nucei contain chromatin with a speckled appearance
What shape nuclei do primary and seconday spermatocytes or spermatids contain?
Small dense round nuclei
What shape nuclei do mature spermatozoa have?
Narrow elongated nuclei (heads)
What is this?
Adipose Tissue
What is this?
Alveoli
What is this?
An exocrine duct
What is this?
Arterioles
What is this?
Atheroma
What is this?
Basophil
What is this?
Bronchiole
What is this?
Capillaries
What is this?
The blue cells are mucous cells
What is this?
Collagen strands in dense irregular connective tissue
What is this?
Collecting ducts
What is this?
Colonic muscosa
What arrow D pointing to?
Spermatid
What is this?
Decalcified bone
What is this?
Dense fibrous connective tissue
What is this?
Distal tubules
What is this?
Duodenal mucosa
What is this?
Elastic cartilage
What is this?
Elastic in a large arterial wall
What is this?
Eosoniphil
What is this?
Fibrous cartilage
What is this?
Gall bladder wall
What is this?
Gastric glands
What is this?
Gastric mucosa
What is this?
Hyaline cartilage
What is this?
Ileum mucosa
What is the arrow pointing to?
Intercalated discs in the heart
What is this?
Irregular connective tissue
What is this?
An isolated peripheral nerve
What is this?
Jejunum mucosa
What is this?
It is a large elastic artery
What is this?
It is a large muscular artery
What is this?
Large muscular artery wall
What is this?
Large muscular vein wall
What is this?
Leydig cells of the testicles. They produce testosterone
What is this?
Liver lobule
What is this?
Liver sinusoids
What is this?
Lymphatics
What is this?
Lymphocytes
What is this?
A macrophage
What is this?
Microvilli
What is this?
Mineralised bone
What is this?
Monocytes
What is this?
Muscular vein
What is this?
Myocardium
What is this?
A nerve cell body
What type of epithelium is this?
Non-keratined stratified squamous epithelium
What in the body is this?
The nose
What the green arrow pointing at?
An osteoclast
What is this?
Osteocytes in bone
What is this?
Peripheral nerve
What is this?
Platelets
What is this?
Neutrophils
What is this?
The prostatic urethra
What is this?
Proximal tubules of the kidney
What epithelium is this?
Pseudo-stratified epithelium
What is this?
Purkinje fibres
What are these arrows pointing to?
A - Spermatogonium
B - Germ cells
C - Sertolli cell
D - Spermatid
What is this?
Recto-anal junction mucosa
What type of cells are these?
Red blood cells
What is this cell?
Reticulocyte
What are these?
Seminiferous tubules
What are these?
Serous glands on the left, mucous glands on the right
What type of epithelium is this?
Simple ciliated epithelium
What type of epithelium is this?
Simple columnar epithelium
What type of epithelium is this?
Simple cuboidal epithelium
What type of epithelium is this?
Simple squamous epithelium
What is this?
A small nerve of the bladder
What is this?
Smooth muscle of the ureter
What type of epithelium is this?
Stratified squamous keratinised epithelium
What type of duct is this?
A striated duct
What are these?
Taste buds
What is this?
A terminal bronchiole
What is this?
A bronchus
What is this?
The larynx
What is this?
A thin-walled urothelium venule
What is the yellow arrow pointing at?
An umbrella cell
What is this?
A ureter
What is this?
The urinary bladder
What type of epithelium is this?
The urothelium
What is this?
The venules
Where are these cells from?
The anterior pituitary
What is this?
An arteriole in the penis
What are arrows B, C and D pointing at?
B - acidophil
C - basophil (not like the leukocyte)
D - chromophobe
What is the blue arrow pointing at?
The zone pellucida of a developing ovum
Where are these cells from?
The body of the uterus
What are these cells?
C cells
What is this?
Cavernous spongiosum of the penis
What is this?
It is the cervical lining
Where are these cells from?
The cervix
What is this?
The corpus luteum
Where are these cells from?
The corpus luteum
What is this?
The cortex of the ovary
What is the blue arrow pointing to?
The cumulus oophorus
Where are these cells from?
The anterior pituitary
What is in the elipse
Graafian in the ovary
What is this?
Epididymis
What are these cells?
Epithelial squames
What zone is this?
Fascicular of the suprarenal gland
What are these cells?
Developing follicular cells
What zone are these cells from?
It is the glomerular zone of the suprarenal gland
What are the green arrows pointing at?
Dividing cells in the glands of proliferative endothelium
What is this?
The infundibulum of the ovarian (fallopian) tube
What are these cells?
Lymphocytes of the thyroid gland
What is this?
Mesovarium
What are these cells?
The pancreatic islets of langerhans
What is this?
Parathyroid gland
Where are these cells from?
Parathyroid gland cells
Where are these cells from?
The penile urethra
What is this?
A penis hehe lol cheeky
Where are these cells from?
The pineal gland
What is this?
The posterior pituitary gland
Where are these cells from?
The posterior pituitary gland
What is this?
A primary follicle in the ovary
What is this?
A primodial follicle in the ovary
What type of epithelium is this?
Proliferative epithelium
Where are these cells from?
The prostate
What are the arrows pointing at?
The two layers of the Graafian follicle
What zone is this?
The reticular zone of the suprarenal gland
What is this?
A secondary follicle in the ovary
Where are these cells from?
Secretory endothelium
What is this?
The secretory endothelium
What phase of secretory endothelium is this?
The secretory phase
What is this?
Small mucous glands in the penis
What is this from?
The seminal vesicles
What epithelium is this? where is it from?
Simple columnar epithelium in the seminal vesicles
What is the green arrow pointing at?
Simple columnar epithelium of the cervical canal
What is the green arrow pointing at?
Small blood vessels in the pia mater
What is this?
A small nerve in the penis
Where are these cells from?
Smooth muscle fibres in the adventitia of the vagina
Where are these cells from?
Smooth muscle in the seminal vesicles
What is this?
Spermatic cord
What are the green arrows pointing at?
Stereo-cilia in the epididymis
What is the green arrow pointing at?
Stratified squamous epithelium of the cervix
What is this?
The suprarenal cortex
Where are these cells from?
Suprarenal medulla
What is this?
The prostate gland
What is this?
The theca externa
Where are these cells from?
The theca interna
What are these big things?
Thyroid follicles
What is this?
The thyroid gland
Where are these cells from?
Uterine tube epithelium
What is this?
The uterus
What is this?
Vagina
Where are these cells from?
The vagina
What are these body parts?
It is the vagina at the top and part of the cervix at the bottom
What is this?
A vaginal smear
When in the menstrual cycle is this smear from?
It is late in the menstrual cycle
What is this?
The vas deferens
What are these muscle fibres stained with?
Iron haemotoxylin
What is this?
Developing membrane in primitive mesenchyme
Whis this dye and what does it stain?
It is alcian blue.
It stains: GAG; Mucous; Mast cells; Cartilage
What dye is this and what does it stain?
It is eosin, it stains colliod proteins and plasma.
What dye is this and what does it stain?
It is iron haemotoxlyin, it stains nuclei and elastic fibres
What dye is this and what does it stain?
It is periodic acid schiff (PAS). It stains: Hexose sugars (complex carb); Goblet cell mucins; Cartilage matrix; Glycogen; Basement membranes; Brush border
What dye is this and what does it stain?
It is toluidine blue. It stains Nuclei / Ribosomes (DARK BLUE); Cytoplasm (PALE BLUE); Cartilage / matrix / mast cell / GAG rich (BRIGHT PURPLE) !
What dye is this and what does it stain?
It is haemotoxylin. It stains nucei and RNA and other Basophilic things Blue.
What is the stain used to stain the neurons in this picture?
Silver stain
How many dendritic processes do neurons have?
1-5 but you can’t see them because of the thickness of the slide
What does intestinal epithelium consist of?
Enterocytes with goblet cells; Epithelia sit on BM - permeability barrier between epithelium and connective tissue
Where are microvilli in intestinal epithelium?
Microvilli at apical surface = BRUSH BORDER
Brush border - inc s.a. / attachment of exo-enzymes.
Microvilli are rich in glycocalyx.
Where is ciliated simple columnar epithelium?
Nose, larynx, bronchial tree and the fallopian tubes. (this slide is the nose)
What aids cilia movement?
Tubulin and dynein
Where is cuboidal epithelium?
In the ducts of exocrine glands - sweat glands, salivary, pancreas and kidney tissue
Where is squamous epithelium?
Outer surface of most thoracic and abdominal organs Simple squamous epithelium (SEROSA)
Also lines pleural and peritoneal cavities
Air sacs of lungs (alveoli)
(this slide is serosa in the outer intestinal wall)
What makes up the air/blood barrier?
2 x capillary endothelial ells, 2 x T1 pneumocytes and capillary lumen
overall thickness = 5-10 microns !
Where is stratified squamous epithelium?
mouth, throat, oesophagus, anus, vagina (this slide is from the mouth)
Where is keratinised stratified squamous epithelium?
In the epidermis of the skin. This slide is from the lips.
How is keratin created in the skin?
Lower layers epidermis similar to stratified squamous.
Upper layers synthesise unique collection of proteins - interact with cytoskeleton of cell to produce keratin.
When full of keratin, cells die and are sloughed off
What are the different parts of this slide? (which are living, which are not)
Blue / purple = living
Pink = dead keratinised squames
At the boundary there is a layer with blue keratohyaline granules!
STRATUM GRANULOSUM - intermediate with blue granules
STEM CELLS at basal layers
Where is pseudostratified epithelium?
The trachea, bronchi and urinary tract (specialised UROTHELIUM) This slide is the trachea.
How are new pseudostratified epithelial cells replaced?
By lateral migration not vertical
What and where is this slide?
DENSE IRREGULAR CONNECTIVE TISSUE! Long fibres of collagen in many directions; Dermis of scalp
What and where is this slide?
DENSE REGULAR CONNECTIVE TISSUE!
- Ligament
- Thick ribbons of parallel collagen • Fibroblasts at layer between compact and regular
Where are fibroblasts in dense irregular connective tissue?
Fibres with dark nuclei (fibroblasts) alongside the collagen fibres, which are not uniform thickness
• INSET - fibroblast
• COLLAGEN FIBRES = EXTRACELLULAR
What are where is this slide?
LOOSE AND DENSE connective tissue
Dense irregular at penis erectile compartment (inner) forms a capsule/sheath. This is common between cells of most organs and tissues
Outside = loose
What are where is this slide?
It is reticulin.
TISSUE OF RETICULO - ENDOTHELIAL SYSTEM i.e. lymph nodes, spleen, liver
RETICULIN FORMS BRANCHED FIBRES - most collagen forms linear fibres
What is this stain?
This is elastic fibres.
Microfibres of fibrillin set in amorphous matrix of elastin; forms fine fibres or sheets of elastin.
This slide is from a large elastic artery
What is this?
Elastic fibres stained with elastic Van Gieson’s trichrome
What is on this slide? Label, A, B, C and D
Axons in transverse section!
- Each axon surrounded by Schwann cell
- A - Schwann cell nucleus
- B - axon w/ myelin sheath
- C - unmyelinated axon
- D - myelin sheath
What is this?
An isolated peripheral nerve
What is this?
Longitudinal peripheral nerves. The arrow is pointing at a node of ranvier
What is this?
Synapse
Why do we use silver stain on nerve cell bodies?
Silver stain has affinity for cytoskeleton of cells.
Neurons have developed cytoskeleton therefore stain heavily
What is the difference between a sensory nerve cell body and a motor one?
Sensory cell bodies at Dorsal Route Ganglion; Large; One axon; One major dendrite; Appear more rounded than motor neurons
What is the structure of this muscle?
It is cardiac muscle. Branching chains of cardiac myocytes. Striations (myofibrils and repeat sarcolemmas). Dark Intercalated disks (myocyte junctions). Mononuclear (central), no stem cells!
What are the functions of junctions in the disc the arrow is pointing at?
It is an intercalated disc.
Desmosomes and adherent junctions - anchor one cardiac muscle to next by immediate cytoskeleton filaments.
Gap junctions - allow ion transfer between cardiac smooth muscle electrochemical coupling - not cardiac conduction.
Why do we stain these fibres with PAS?
These are Purkinje fibres, they contain lots of glycogen to allow for rapid depolarisation. PAS staind glycogen
What are the structures of both the artery on the left and the vein on the left?
INTIMA (innermost) - endothelial cells on loose connective tissue with occasional myo-intimal cells (contractile potential)
2) MEDIA (middle) - thicker in arts than veins - smooth muscle, elastic, collagen
3) ADVENTITIA (outermost) - dense collagen and elastic
What is special about the tunica media of this vessel?
This is a muscular artery.
Well defined medial layer (smooth muscle in concentric rings)
Medial layer interspersed with elastic
Media - intima divide = wavy internal elastic lamina (condensed perforated elastic)
What is special about the tunica adventitia of this vessel?
This is a muscular artery
adventitia - thick strands of collagen/elastic (fibrocollagenous) with vasa vasorum and nerves
adventitia - media divide = external elastic lamina only in large muscular
Where is this vessel found?
This is a elastic artery, you can tell because the elastic stains red and the collagen and muscle stain blue.
It is found in the AORTA and GREAT VESSELS close to heart.
How is this vessel different from other vessels?
This is an elastic artery.
It has a medial layer thick with concentric SHEETS of elastic interspersed with smooth muscle
As the vessel is large - contain own blood supply vasa vasorum!
How is the structure of this vessel different from other vessels?
This is an arteriole
3 layers or fewer of muscle in the media.
No internal elastic lamina - therefore may completely close when muscle contracts.
Poor adventitia - mainly collagen and elastin.
What is the function of this vessel?
This vessel is an arteriole.
Highly responsive to vasoactive stimuli - regulation of peripheral resistance
What is on this slide? What is it lined by?
This is an glandular acinus.
Lined by enterocytes and goblet cells
What is the function of these cells?
These are endothelial cells.
- Action transport of molecules across into and out of the cytoplasm 2. Influence muscle tone 3. Coagulation 4. Produce cell adhesion mols - influence lymphocyte/neutrophil migration
How do pericytes change alongside these vessels?
This is a venule.
Pericytes alongside them.
Pericytes become continuous as vessel gets bigger. In veins no pericytes, replaced by smooth muscle)
What is the structure of this vessel?
This is a large vein wall.
Thick wall. Distinct intima/media and medial layer with longitudinal smooth muscle. The adventitia is thick with longitudinally arranged muscle fibers
What are these vessel walls made of?
This is a lymph vessel.
The walls are made of connective tissue with some muscle. They have less pressure than venules
How long do these cells last for?
They are red blood cells. They last for 120 days.
When is the level of these cells highest?
This is an eosinophil. They are diurnal, they are highest in the morning
What is the function of this cell?
This is an eosinophil. They phagocytose antigen/antibody complexes, assoc with PARASITIC INFECTION! They neutralise histamine.
What granules does this cell contain?
This is a neutrophil. It contains:
primary granules- lysosomes, acid hydrolases, antibac and digest!
secondary granules - neutrophil specific, regulation of inflammation response!
tertiary granules - facilitate insertion of proteins to cell mem
What is the function of this cell?
This is a basophil. Similar role to MAST cells. Secrete HISTAMINE and other vasoactive subs - increased blood flow locally
What is the most common non-granulocyte?
A lymphocyte
What is this cell?
It is a monocyte. They are immature cells which diff to one of various forms when leave blood and enter connective tissue
What are the types of granules in these cells?
They are platelets. They contain:
1) alpha granules - clotting
2) dense granules
3) lysosomes
4) peroxisomes - elimination of oxygen radicals
What is the black stuff? What is it stained with?
ELASTIC TISSUE (ELASTIC VAN GIESON’S WITH IRON HAEMATOXYLIN COUNTER STAIN)
What is this epithelium? Where is it?
It is respiratory epithelium: SIMPLE/PSEUDO-STRATIFIED COLUMNAR CILIATED E!PITHELIUM! It is in the nose, nasopharynx, larynx, trachea, bronchi, bronchioles
Name all the parts of this nose:
mucous/cartilage blue
central bone plate (pink)
resp epithelium either side
thin walled blood vessels between epithelium and bone
mucous containing goblet cells stain bright blue
What is the epithelium of the nose?
Simple ciliated respiratory epithelium except at opening (hairy skin). The concha are covered in respiratory epithelium.
Where and what is olfactory epithelium?
In the roof of nose below cribriform plate
Pseudo-stratified columnar epithelium with basal and sustenacular (supporting cells) with bipolar neurons - dendritic process to surface (arrow). Serous glands to surface (solvent for odorous substances). It is thicker than other respiratory epithelium
What is the epithelium of the larynx?
Respiratory epithelium except vocal folds. Vocal folds - stratified squamous epithelium (more robust, may withstand vibration)
What are the vocal folds made of?
Contain free upper margin of elastic tissue (conus elasticus). Tensioned by voluntary skeletal muscle - vocalis muscle!
What is the epithelium of the trachea?
Pseudo-stratified, ciliated, columnar epithelium (respiratory epithelium)
What is the epithelium of the vocal cords?
Stratified squamous epithelium
What are the red and green arrows pointing at?
Red arrow points to voluntary skeletal muscle
Green arrow points to sero-mucous glands
Where is this slide from and what does it consist of?
This is the trachea.
lumen of trachea = top
C-shaped cartilage = bottom
epithelium = pseudo-stratified columnar epithelium
note serous glands visible which secrete to surface
Where is this slide from and what does it consist of?
This is a bronchus.
Respiratory epithelium
Held open by hyaline cartilage framework (dark stain) which appear as isolated islands
Smooth muscle band under epithelium
Lymph nodules (MALT- mucosa associated lymph tissue) at the connective tissue
What are the arrows pointing at?
Left arrow points to MALT nodule
Right arrow points to smooth muscle band
What is in this slide and what does it consist of?
This is a bronchiole.
simple ciliated respiratory epithelium
no hyaline cartilage
smooth muscle (to bronchoconstrict)
lymph nodules
closely associated arteries and veins (branches of p.a. and p.v)
no goblet cells
What is in this slide and what does it consist of?
TERMINAL BRONCHIOLE
SIMPLE CUBOIDAL EPITHELIUM
sparsely ciliated
CLARA CELLS - many large ribosomes, ER, and granules ->
What are the walls of the vessel in this slide?
This is an alveoli.
walls = capillaries between SIMPLE SQUAMOUS EPITHELIUM!
fibroblasts in walls - produce type 3 collagen (reticulin) and elastic tissue (recoil)
What are type 1 and 2 pneumocytes like?
TYPE 1 CELLS (thin)
• flat cells, flat nuclei, 40% pop, 90% s.a.
TYPE 2 CELLS (globular)
• secretes surfactant (lipid rich), 60%, 10% s.a., rounded, round !dark stain nuclei!
Where are these cells from and why are they black?
They are alveolar macrophages.
From monocytes in blood
Contain black ingested dust particles (carbon)
What are the types of macrophages?
ALVEOLAR -> enter term/resp bronchioles and pass to lymphatics or be transported by muco-ciliary escalator
FIXED/SEPTAIL -> remain in interstitium between cells and tissue
What is the epithelium of the lip?
Mucosa, which is typical of mouth SSNKE
At the margin - abrupt transfer to skin SSKE (shown in the slide)
What are the layers of the lip?
Epithelium
Connective tissue (sub-mucosa) - collagen and elastin
Deeper layers - glands and striated skeletal muscle (change shape of oral cavity)
What special cells does the inner lip have?
Small clumps of salivary tissue
Sebaceous glands (Fordyce’s spots) open to surface rather than hair follicles
Small blood vessels in sub-mucosa helps keep the lips moist
Where and what is this?
A hair follicle on the keratinised side of the lip
What is the epithelium of the tongue?
SSNKE on ventral surface (lower)
SSKE on dorsal surface (upper) - constant abrasion
Where do the different types of muscle of the tongue insert?
Coarse multi-directional skeletal muscle bundles
EXTRINSIC FIBERS
Skeletal muscle insert to lower jaw
INTRINSIC FIBERS
Skeletal muscle insert to fibrous connective tissue underlying mucosa
What type of salivary glands does the tongue have?
Both mucosal and serous. This slide is serous
Where are lymph nodules in the tongue?
particularly at the posterior 1/3 of tongue (linguinal tonsils)
What type of glands are these?
Mucous glands
Where is taste detected on the tongue?
sweet (tip)
salty (front/side)
sour (further back)
bitter (whole back)
What do nerves of the tongue do?
Small nerves lying in sub-mucosa of tongue.
Supply close by taste buds
What does the parotid gland do?
Synthesise alpha- amylase
Secreted via ducts to mouth
Ducts can alter ionic concentrations
What are the two types of cell in the parotid gland?
SECRETORY CELLS
pyramidal, spherical nucleus, basal cyt full of rER, apex c!ontains prominent secretory granules (pink staining)
DUCT CELLS
simple cuboidal (stratified at distal end)
What is the insert in the slide? Where is it from?
It is a lymph node in the parotid gland
What are the types of cells in the sublingual salivary gland?
Pale staining secretory cells
Darker staining duct w/ simple cuboidal epithelium
Flattened oval nuclei to base of cells
Branched tubular acinar glands
What is this? What is it mainly involved in?
It is a parasympathetic nerve ganglion.
Many nerve cell bodies
Involved heavily in secretion regulation (this one is sublingual)
What does this gland secrete?
Sticky mucus rich secretion (food bolus)
Major constituent - polysaccharide
What is the grey arrow pointing at? What gland is this?
DEMI-LUNES - serous cells form demi-lunes (half moons) at closed ends of tubules!
This is the submandibular salivary gland
What is this?
It is a lymph nodule in the submandibular salivary gland
What is the epithelium of this slide?
This is the epiglottis.
mostly stratified squamous non keratinising epithelium
lower part posterior - pseudo-stratified columnar ciliated !epithelium (respiratory)
What does the epiglottis contain?
Contains:
1) elastic cartilage plate
2) lymph nodules (submucosa)
3!) salivary glands (submucosa)
What is this epithelium?
Straified squamous non-keratinised epithelium
What is this?
This is a tastebud surrounded by squamous epithelium
This cell has:
Mucinous acini
Basally located nuclei
Ducts lined by cuboidal/columnar epithelium.
What is it?
This is the sublingual gland
Where is the slide from? What does it contain?
This is the submandibular gland.
Serous glands at bottom • Mucus glands at top
How can you tell what gland this is?
This is the parotid gland because this is purely serous (granules).
What is the epithelium of the oesophagus?
It is stratified squamous non-keratinising epithelium above the diaphragm and simple columnar epithelium below the epithelium
What are the layers of the oesophagus?
Mucosa:
• SSNKE (above diaphragm)
• thin lamina propria
Sub-mucosa:
sero-mucous glands (lubrication), large thin walled veins (@ distal end - oesophageal varicosities)
Muscularis Externa:
Upper 1/3 = skeletal / Middle 1/3 = mixed / Lower 1/3 = smooth !
What does the stomach body consist of?
Simple columnar epithelium - produce acid resistant mucin
Gastric pit invaginations (green arrows)
Several tall straight or branched glands to each pit
Submucosa = loose connective tissue with abundant vessels
Muscularis externa = 3 layers smooth muscle
Muscularis mucosa also contains elastic (black) to stop stomach collapse on empty
Where are parietal cells in the stomach?
In the gastric glands body / fundus
In the upper part of gland close to pits
Where are chief cells in the stomach?
Pyramidal in the deeper gland
In the body and fundus
Close to muscularis mucosa
What are the key feature in the the pyloric region of the stomach?
cardiac and pyloric gastric glands shorter
glands coiled
mainly mucus neck cells
scattered with cells that produce gastrin!
What is this?
The gastroduodenal junction
What is the function of this cell? What features show this?
These are enterocytes.
They are a major absorptive cell
300 short microvilli on apical surface - brush border
At outer surf brush border they have a glycocalyx (enzymes) filter
Most nutrients through this
Water and glucose (some) via intracellular pathways
What are the key features of the area this slide?
It is from the duodenum, which is 12 inches with few plicae circularis
• Villi - broad and leaf like
• Few goblet cells
• submucosa contains mucus secreting BRUNNER’S GLAND (not in the ileum or jejunum). This alkaline secretion neutralises CHYME.
The inner circular layer thicker than outer longitudinal layer of muscularis externa
What is the function of the duodenal crypts?
Crypts form new enterocytes and goblet cells
Dividing cells have very dark staining nuclei or sets of chromosomes
At the bottom of crypts = DIFFERENTIATED PANETH CELLS
Secrete lysozyme - breakdown of bacterial cell walls
Regulate flora of gut
What are the key features of the jejunum?
close-packed plicae circularis
MANY goblet cells
long narrow villi (finger like)
short crypts
loose submucosa (almost detached from muscularis externa)
no Brunner’s gland or Peyer’s patches
Lymph nodules at lamina propria but do not penetrate submucosa
What are the key features of the ileum?
final segment of small int therefore fewer plicae and shorter villi (less absorb)
goblet cells increase towards distal end
large PEYER’S PATCHES @ submucosa (lymphoid tissue w/ ith lymphocytes)
Peyer’s patches erupt through muscularis mucosa to lamina propria
What are the key features of the vermiform appendix?
from caecum
simple columnar epithelium
goblet cells
no villi
simple crypts
lamina propria and submucosa full of lymphoid tissue
no muscularis mucosa
muscularis externa present
transverse smooth muscle at muscularis externa = taenia colis
fat filled
What are the key features of the colon?
All segments similar histologically
Little folding
No villi
Mucosa contains close packed crypts with abundant goblet cells and enterocytes
restricted lamina propria (by crypts)
prominent muscularis mucosa
mucosa and sub-mucosa contain lots of lymph - GALT (gut)
muscularis externa - thickened inner circular layer, outer layer drawn into 3 longitudinal bands = taeniae coli
Where is this from? What are the key features of it?
This is the recto-anal junction
Rectum = similar to colon
• simple columnar epithelium
• anal canal - stratified squamous epithelium, keratinised at distal end (as lip)
• submucosa with FAT, VEIN PLEXUS (anal varicosity) • smooth muscle of muscularis externa thickened and
surrounded by STRIATED MUSCLE of EXTERNAL ANAL SPHINCTER
What is in box b and d?
box b - striated muscle of sphincter • box d - anal glands
Where is this from? How could you tell?
This is from the duodenum.
Villous
• Sub-mucosa with Brunner’s glands
• duodenal epithelium contains some lymphocytes between !epithelium
Where is this from? How can you tell?
Vermiform apendix
All of this fits on a microscopic slide therefore not colon
• flat mucosa with no villi
• abundant lymphoid tissue in lamina propria and submucosa • lacks a muscularis mucosa
•receives blood from superior mesenteric artery
Where is this from? How could you tell?
Colonic mucosa
flat surface
• no villi
• numerous straight crypts
• abundant goblet cells
• prominent muscularis mucosa •!stem cells at base of crypts
What are the functions of hepatocytes?
creation/store energy as glycogen & fat
synthesise plasma proteins
de-amination of amino acids and production urea uptake, synthesis, excretion of bilirubin and bile acids detox and inactivation of drugs by oxidation, methylation or conjugation
This is a portal triad, spot where the vessels are?
small muscular arteriole (top left), venule (bottom), bile ductule (top right, simple cuboidal)
What are sinusoids made of?
wide, thin walled, fenestrated capillaries
• endothelial cells interspersed with:
1. KUPFFER CELLS - fixed macrophages
2. ITO CELLS - perisinusoidal cells (fat storing - cirrhosis)
• too thin to resolve
sit on meshwork of reticulin (collagen 3)
Where are these cells and what do they do?
The blue and black dots are sinusoidal macrophages.
Kupffer cells in lining of endothelium
• phagocytose blood borne pathogens
• part production of bilirubin (taken up and excreted by !hepatocytes)
What are the key features of the gallbladder?
simple columnar with poor brush border
• adapted for water reabs (bile conc)
• epithelium (on submucosa) thrown into folds (not villi) • gallstones may be present at lumen
• large veins in walls / venule (in image)
• smooth muscle at outer surface
•serosa visible at top (simple squamous)
What is the function of these cells?
This is the exocrine pancreas.
exocrine = 90% mass of gland
SEROUS (watery/enzyme rich)
digestive enzymes from same cell, secretion granules at upper part cell
enzymes released as food enters duod
What are the insets of this picture? Where is it from?
It is from the pancreas
Inset:
PACINIAN CORPUSCLE - pressure sensor in pancreas (and skin)
NERVE PLEXUS - with vagus nerve
What is the structure of this duct? Where is it from?
It is an exocrine duct of the pancreas.
Each acinus has narrow intercalated duct (ID)
• IDs connect acinus to main duct (MD)
• Larger ducts -> 1/2 MDs that enter duodenum with bile duct !
SIMPLE CUBOIDAL EPITHELIUM (stratified at distal end, as GB)
What is this?
It is a portal triad
What separates the glomerulus from the surrounding urinary space?
Bowman’s capsule
What is the arrow pointing to? What is between that and the glomerulus?
The arrow is pointing to a distal tubule. The macula densa cells are between that and the glomerulus. They are around the blood vessels and they regulate blood flow and provide a framework for the glomerulus.
How is this made?
This is the filtration barrier. It is synthesised and maintained by endothelial capillary cells and epithelial cells (podocytes) that ensheath them. The endothelial is fenestrated, podocytes stand off membrane with foot processes. This creates physical pores.
What is the function of this?
This is the filtration barrier. The endothelial is fenestrated, podocytes stand off membrane with foot processes. This creates physical pores. Pores guarded by filtration membrane
Membrane is charged and resists passage of some mols. Water and solutes to 50’000 DALTONS may pass to urinary space = primary filtrate!
What are the key features of these cells?
They are proximal tubules.
Highly coiled (sometimes with straight projection to medulla)
Prominent brush border and complex invaginations at the basolateral membrane dark pink
What is the function of these cells?
These are proximal tubules.
extensive reabsorption here
Na+ active trans with gluc (cotrans)
Take up protein and polypep by endocytosis
cells contain lyzosomes which break down proteins before return to circulation
any small negatively charged protein can enter primary filtrate
What are these cells? What do they lead to?
It is the straight portion of the proximal tubules. They lead to the loop of Henle.
Where are these cells? What are they similar to?
They are from the loop of Henle, mostly in the medulla. The thick descending loop is similar to the proximal tubule. The thick ascending limb is similar to the distal tubule.
What are the functions of these cells?
This is the loop of Henle. The thin descending limb has a low permeabilty to ions and urea and a high permeability to water. The thin ascending limb retains water but reabsrobes Na+ and Cl-. This produces a dilute/hypotonic filtrate but a hypertonic interstitium.
Where are these cells? What are the key features of their appearance?
These are from the distal tubule. They are from the medullar to the cortex then to the vascular pole of the glomerulus. They have a few short microvilli and no brush border. They are paler than proximal tubules.
What is the function of these cells?
These are from the distal tubule. The macula densa here monitors sodium levels to influence the initial filtration of the glomerulus. There are deep ingainations of basal plasme membrane with numerous mitochondria, which are indicative of control acid/base balance and concentration of urine. Bicarbonate is reabsorbed and hydrogen is excreted.
What is this cell? How could you tell?
They are collecting ducts.
Pale cuboidal cells
Wide lumen
Few organelles
Collecting tubules - dark intercalated cells with high mitochondria
Where are these cells? What is their function?
They are the collecting ducts. They start at the cortex, where the filtrate is collected in collecting tubules then into larger collecting ducts. Collecting tubules from many nephrons coalesce to larger ducts and form visible streaks - medullary rays
What are the cells and the function of the juxtaglomerulus apparatus?
Afferent/efferent arterioles, macula densa, lacis cells (gmatrix)
Afferent - cells produce renin - granules in cytoplasm
Lacis cells and macula densa regulate renin secretion by monitor sodium levels
Where and what is this epithelium?
This is urothelium. It is psuedo-stratified epithelium. It is in the ureters, bladder and most male urethra.
What is the function of umbrella cells in urothelium?
UMBRELLA CELLS!
1) thickened membrane plates joined by thin membrane bands
2) lipid composition (unique)
3) relaxed plated = perpendicular to membrane (fuzzy)
4) stretched = drawn to surface of cell
What is this? How can you tell?
Ureter
Epithelial tube with 2 helical layers smooth muscle!
STAR SHAPED LUMEN
Towards bladder = longitudinal smooth muscle!
What are the three constrictions of the ureter?
Origin (pelvis of kidney)
At sacro-iliac joint (passes to true pelvis)
As enters postero-inferior bladder surface
What is the structure of smooth muscle in this organ?
This is the urinary bladder.
Wall = thick bundles of smooth muscle with no preferred direction except neck = 3 distinct layers
The innermost is longitudinal projects inferiorly and turns transversely to form a sphincter around prostatic urethra
What are cells in the male urethra?
Urothelium (pseudo-stratified columnar) except at distal end
Mucus glands along length
distal urethra = stratified squamous (male and female)
both sexes = striated (voluntary) muscle sphincter from muscles of pelvic diaphragm around membranous part
under prostatic urothelium = dense fibrous connective tissue to prevent distension
What cells are in the seminiferous tubules?
thin fibrous capsule
closest to membrane = germinal epithelium with spermatogonia (speckled)
between cells are smaller primary spermatocytes and Sertoli cells (pale irregular nuclei)
towards centre depends on stage in cycle
sometimes prim/sec spermatocytes (small dense nuclei)
otherms more mature (narrow and elongated heads) between tubules = LEYDIG CLUMPS!
What is the epididymis?
Thick fibrous capsule attached to mediastinum of testes posteriorly - storage and maturation site for sperm
aggregated within lumen
What cells make up the epididymis?
Tall pseudo-stratified columnar epithelium
Small rounded basal cells support tall columnar with microvilli (stereocilia). The stereocilia (non-motile) reabsorb seminal fluid, phagocytose damaged sperm and cell debris, also reabsorb nutrients for sperm.
Thin layer of smooth muscle thicker as approaches vas
What cells make up the vas deferens?
spirally arranged smooth muscle
similar epididymis but shorter cells and microvilli
sometimes longitudinal folds - lamina propria
How does the vas deferens work?
Vudden and rhythmical contraction expels sperm
What is this? What cells is it made of?
This is a seminal vesicle.
Highly coiled glands at postero inferior bladder. It has a double layered capsule of smooth muscle. It is thrown into long narrow folds.
What is the function of the seminal vesicle?
It is stimulated by testosterone enlarge and secrete creamy opalescent fluid with acid pH. Rich in globulin vit C, amino acids and sugars
What are the cells in the prostatic epithelium?
Glands varied - straight, coiled, branched
Epithelium thrown into broad branching folds
How does testosterone affect the prostatic epithelium?
With testosterone cells increase in height and secrete digestive enzymes - acid phosphatase - major component of seminal fluid - PSA prostate specific antigen
What are the two sides of this slide? Where are they both from?
They are both from the prostate.
Left - skeletal muscle at underside of prostate - pelvic diaphragm with levator ani
Right - spiral tubular gland at submucosal level
What is the epithelium of the penile urethra?
Membranous and penile = non- secreting pseudo-stratified columnar ! At distal end = stratified squamous ep (within glans)!
What are the cells of the erectile compartments of the penis?
erectile compartments = large endothelium lined blood vessels supported by connective tissue
each surrounded by compact collagen layer = tunica albuginea
What is the blood supply of the penis? How does it change when flaccid?
Helicine branches of pudendal artery
When flaccid arteries transmit very little blood due to arterio-venous shunts. Parasympathetic nervous system stimulation shuts shunts
What is the epithelium of the vagina? How does it alter with age?
stratified squamous thinly keratinised at vulval end
thin pre puberty and post menopause
What is beneath and surrounding the vaginal epithelium?
beneath epithelium = lamina propria with small blood vessels (moisture by diffusion)
surrounding epithelium = fibro muscular tube with collagen/elastic and smooth muscle
sphincter of skeletal muscle at lower end!
Where are bartholin glands? What do they do?
BARTHOLIN GLANDS - mucus posterolaterally at lower end of vagina
What is the function of these cells?
These are epithelial squames.
In menstrual cycle surface cells accumulate glycogen and flake off. Desquamated cells rupture and bacteria generate lactic acid, which creates low pH at vagina (immune function)
How does the proportion of these cells during menstruation?
These are epithelial squames. Pale cells predominate during the first half of the menstrual cycle.
What is the epithelial lining of the cervix?
Outer surface - stratified squamous non keratinising epithelium (identical vagina)
Cervical canal (between internal and external openings ostia) = tall columnar epithelium thrown into deep gland like folds
This picture is the external os.
What is the stroma of the cervix made of?
Stroma = fibrous connective and smooth muscle.
This picture is the external os
What does the cervix secrete?
Secretes mucus *consistency of which varies throughout menstrual cycle
FIRST HALF - thin and watery
SECOND HALF - viscous after ovulation as plug to prevent microorganism entry
How many layers does the uterine body have?
3 poorly defined layers of the myometrium smooth muscle
• lined by epithelial endometrium
• myometrium hormonally sensitive
How does the uterine body differ during pregnancy?
HYPERPLASIA - increase in number
HYPERTROPHY - increase in size - main mechanism
What are the key features of proliferative endometrium?
TUBULAR GLANDS APPEAR STRAIGHT and cells do not secrete endometrial mucus
Stroma compact
Uncoiled arteries and veins
Mitotically dividing cells within glands and stroma
Simple glands (often circular)
Loose connective tissue
What are the key features of secretory endometrium?
Cells have large vacuole of glycogen below nuclei, from these stores synthesise mucins
Glands = irregular / sacculated with secretions at lumen
Stroma oedematous
Arteries lengthen and become spiral
At the end (late phase) spiral arteries close down and blood leaks to stroma = anoxia therefore decidua detaches and menses begins
What are the layers of the uterine tubes? What type of epithelium do they have?
Two helical layers of smooth muscle (inner circular) and outer (longitudinal) … almost!
simple columnar epithelium - ciliated and mucous secreting
What alters the uterine tube epithelium? How does it change?
Epithelium is hormonally sensitive - cells taller and cilia beat more strongly around ovulation. Also secretions thinner and more copious at this time
How does the theca change during follicular development?
THECA - simple squamous (primordial), later to cuboidal or columnar.
Differentiates to granulosa cells = theca interna that begin to secrete oestrogen and theca externa (flattened) and follicle becomes secondary
Further growth and devel -> mature Graafian follicle with fluid filled antrum
Once oocyte released from Graafian follicle theca persists and releases oestrogen and progesterone as corpus luteum
Which box is at what stage of follicular development?
Top Left - secondary follicle
Top Right - primary follicle
Bottom Left -mature graafian follicle
Bottom Right - primordial folllicle
How is the corpus luteum formed?
When Graafian follicle ruptures - antrum collapses = central blood clot. The remaining thecal cells persist as corpus luteum. This is the theca interna.
What does the corpus luteum secrete?
With lutinising hormone cells continue to secrete oestrogen and progesterone for 10 days - support secretory endometrium
How long does the corpus luteum last for?
10 days - support secretory endometrium. If fertilisation occurs corpus luteum persists for 4 weeks till placenta can secrete enough oestrogen and progesteron
Which thecal cells secrete what?
Most thecal cells produce progesterone but some at centre synths oestrogen - thecal lutein cells. Final involution forms pale fibrous mass - corpus albicans. This is the theca interna.
What are the layers of the corpus luteum? How can you tell them apart?
Centre contains pale staining amorphous material and blood clot surround is wide band of cells from theca interna invaded by blood vessels, theca externa also contains many blood vessels
THECA EXTERNA - stellate shape, small, pale
THECA INTERNA - large, globular, intense pink.
What are the three cells of this gland?
This is the anterior pituitary gland.
1) Stain heavily with acid dyes - alpha cells / acidophils /eosinophilic (dark red) growth hormone!
2) stain heavily with basic dyes - beta cells / basophils (dark blue) thyrotrophs/gonadotrophs/corticotrophs
3) stain weakly chromophobes, undiff and no hormone
Cells with no stain may be immature of any type
What are the black dots? Which cells are they in?
This is the anterior pituitary gland.
Peptide based hormones in GRANULES
Acidophils / basophils = small dark hormone containing granules
Chromophobes = few or none
What are the brown dots?
This is the posterior pituitary gland. Swollen nerve teminals (Herring bodies) contain dark neuro-sec granules brown
Granules contain:
1) OXYTOCIN, 2) VASOPRESSIN
What are the two types of cell in this slide?
There are loose layers of meninges at the bottom, with small blood vessels in the pia. The top if the pineal gland.
What are these cells?
This is in the thyroid. Thyroxine producing cells arranged = follicles (hollow spheres)
Simple cuboidal epithelium
The centre of each follicle with colloid rich thyroglobulin!
What affects the thyroid follicle cells? What are these changes?
height of cells varies with metabolic activity
flattened when dormant
emptying when active / full when dormant
What are where are these cells?
These are C cells.
Calcitonin producing cells
Clumps between follicles
Parafollicular
Sometimes between basement membrane and follicular cells in the thyroid
What cells make up this gland?
This is a parathyroid gland.
mixture of fat cells and other secretory cells in clusters or short cords
CHIEF CELL - small and palely stained - very small granules = parathormone (calcium from bone to serum)
Larger pink staining OXYPHIL cells fewer in number
What is this cell?
It is a pancreatic islet
How many layers does this area have? What do they secrete?
This is the suprarenal cortex.
3 ZONES
1) OUTER GLOMERULAR (narrow) - ALDOSTERONE AND MINERALOCORTICOIDS!
2) INTERMEDIATE THICK FASCICULAR long parallel cords responsible for CORTISOL and GLUCOCORTICOIDS!
3) INNER RETICULAR ZONE anastomosing cords of cells that produce testosterone and other androgenic (DARKER STAINING)
What cells make up this area?
This is the suprarenal medulla.
Irregular clumps interspersed with blood vessels. 2 types of secretory cells:
1) ADRENALINE
2) NORADRENALINE
They are stored in small neurosecretory granules in cytoplasm of cell until required. Bathed in blood draining from suprarenal cortex thus influenced by steroid hormones
What do these cells secrete?
These are leydig cells in between sesminiferous tubules in the testis. They secrete testosterone.
What layer of skin is this? What cells does it contain?
This is the spinous (prickle) layer of skin.
Thickest layer of skin- joined by desmosomes - prevent skin splitting @ stretch. If shrink - desmosomes become obvious and cells appear spiny
LANGERHAN’S CELLS = pale cytoplasm and irregular shaped nucleus
Where do hair cells originate?
Roots of hair project to dermis but of epidermal origin. Arise from germinative epithelium within hair bulb that contains melanocytes - hair colour
What surrounds the hair follicle?
Surrounded by collagenous follicle sheath with erector pili (smooth muscle) (& autonomic nerve) sebaceous glands (lubrication)
What is this made of? Where does it arise from?
This is a finger nail.
It is made of compacted keratin
It arises from nail matrix cell under a fold of skin (eponychium/cuticle) at proximal end of nail.
What is this?
Sweat glands
What are the nerve endings in the skin?
PACINIAN CORPUSCLE (PRESSURE @ dermis / pancreas) - large structure with nerve ending at core
MEISSNER’S CORPUSCLE - numerous with spiral appearance @ dermal papillae ***
What is this?
Eyelid
Where is this from?
Nipple
Is this breast tissue lactating or not? How do you know?
Yes it is.
Alveoli displace much of fat
Contain secretory cells that produce milk proteins and fats and ion rich watery solution
Milk protein and fat synthesised by same cells within alveoli but discharge is different
What type of duct is this?
This is a lactiferous duct
What type of muscle is this? How did you know?
Skeletal muscle in longitudinal section.
Long unbranched
Many nuclei
What type of muscle fibre is this? How did you know?
This is skeletal muscle in transverse section.
Loosely aggregated to fasciculi by PERIMYSIUM
Nuclei at periphery of fibre
What is this?
It is lots of sarcomeres
What type of muscle is this? How could you tell?
It is cardiac muscle.
Discrete rectangular cells - end to end
Central nuclei
Branch
Connected by INTERCALATED DISCS - hold cells physically and electrically couple desmosomes, adherent junctions, gap junctions
Sarcomeres i.e. STRIATED with myofibrils but with different protein isoforms to skeletal
What type of muscle is this? How did you know?
Skeletal muscle. Each fibre = many nuclei under plasmalemma at side of fibre - DISTINGUISHING POINT
What type of muscle is this? How did you know?
Polygonal pink fibres
Arranged in clumps = fascicles
What type of fibre arrangement is this?
Longitudinal
What type of fibre arrangement is this?
Transverse
What type of muscle is this?
Skeletal muscle, type 1 and 2
What type of skeletal muscle is this? How did you know this?
Type 1 - rows of mitochondria between myofibrils
Fat globules alongside that mitochondria use for ATP production!
What type of skeletal muscle is this? How did you know?
Type 2- fewer/smaller mitochondria
Large reserves of carbohydrate/glycogen
What is the function of the thing coming off the periosteum?
This is a sharpey’s fibre.
Muscles connected to bones via CONNECTIVE TISSUE (MYSIUM)
Either as: Small collagen bundles (SHARPEY’S FIBRES) or Discrete tendons
Sharpey’s merge with fibrous periosteum of bone and collagenous bone matrix
Spreads muscle force over wide area
How is this created?
This is a tendon.
Tendons and aponeuroses = condensed parallel bundles of collagen fibres interspersed with fibroblasts
At end of muscle fasciculi split becoming smaller but more numerous. Connective tissue between more numerous fasciculi.
Where is a muscle spindle? Is it motor or sensory?
Sensory
• Embedded within muscle
• Small number intrafusal
• Surrounding muscle = extrafusal, separated by connective tissue sheath
What is this made of?
This is hyaline cartilage
GAG rich
• invisible collagen/elastic - glassy
• clumped chondrocytes in matrix (in pale staining lacunae) • MATRIX BINDS WATER - when compressed exudes water !(reabsorbed when pressure released)
How is elastic cartilage different from other cartilages?
Larger amounts elastin
• PINK STAINING STRANDS
•may be fractured (though tougher than hyaline/fibrous)
How is fibrous cartilage different from other types of cartilage?
Large amount of collagen arranged in sheets
Why are these cells stained so dark?
dark blue/purple cytoplasm (as large amounts of RNA)
What is this involved in?
This is proformer cartilage.
Long bone formation
Cartilaginous proformer -> converted to bone
What is this?
It is growing long bone
What is this?
Developing membrane bone.
small clusters of progenitor cells within mesenchyme ->osteoblasts
deposit isolated islands of bone
islands coalesce - meshwork of bone
osteoblasts continue till mesh filled - primary plate of bone
