2 - Epithelia & Glands Flashcards
List 5 areas to find simple cuboidal epithelium. (Hint: mainly found in areas requiring secretion and absorption.)
- Thyroid follicles
- Kidney tubules
- Ovary
- Respiratory bronchioles
- Small ducts of many exocrine glands
What type of epithelium is mainly found in areas requiring secretion and absorption?
Simple cuboidal
What type of epithelium would you find in the thyroid follicles?
Simple cuboidal
What type of epithelium would you find in the kidney tubules?
Simple cuboidal
What type of epithelium would you find in the ovaries?
Simple cuboidal
What type of epithelium would you find lining the respiratory bronchioles?
Simple cuboidal
List 4 functions of simple cuboidal epithelium.
- Absorption and conduit (exocrine glands)
- Absorption, conduit, and secretion (kidney tubules)
- Barrier/covering (ovaries)
- Hormone synthesis and mobilization (thyroid)
List 7 areas to find simple squamous epithelium. (Hint: mainly found in areas requiring rapid diffusion.)
- Lining of blood and lymph vessels
- Lining of body cavities (pericardium, pleura, peritoneum)
- Respiratory epithelium (pulmonary alveoli)
- Bowman’s capsule (kidney)
- Loop of Henle (kidney)
- Inner and middle ear
- Intercalated pancreatic ducts
What type of epithelium in mainly found in areas requiring rapid diffusion?
Simple squamous
What type of epithelium would you find lining the blood and lymph vessels?
Simple squamous
What type of epithelium would you find lining body cavities (pericardium, pleura, peritoneum)?
Simple squamous
What type of epithelium would you find lining the pulmonary alveoli?
Simple squamous
What type of epithelium would you find in the Bowman’s capsule of the kidney?
Simple squamous
What type of epithelium would you find in the loop of Henle of the kidney?
Simple squamous
What type of epithelium would you find in the inner and middle ear?
Simple squamous
What type of epithelium would you find in the intercalated pancreatic ducts?
Simple squamous
List 4 functions of simple squamous epithelium
- Lubrication (pericardium, pleura, peritoneum)
- Gas exchange (pulmonary alveoli)
- Barrier (Bowman’s capsule)
- Active transport (mesothelium and endothelium)
List 7 areas to find simple columnar epithelium. (Hint: mainly found in the digestive or reproductive system.)
- Stomach lining and gastric glands
- Small intestine and colon
- Gallbladder
- Oviducts
- Uterus
- Ductuli efferentes of testes
- Large ducts of many exocrine glands
What type of epithelium is mainly found in the digestive or reproductive system?
Simple columnar
What type of epithelium would you find in the stomach lining and gastric glands?
Simple columnar
What type of epithelium would you find in the small intestine and colon?
Simple columnar
What type of epithelium would you find in the gallbladder?
Simple columnar
What type of epithelium would you find in the oviducts?
Simple columnar
What type of epithelium would you find in the uterus?
Simple columnar
What type of epithelium would you find in the ductuli efferentes of testes?
Simple columnar
What 2 types of epithelium would you find in the large ducts of exocrine glands?
- Simple columnar
- Pseudostratified columnar
Compare epithelium found in the small ducts of exocrine glands to the large ducts of exocrine glands.
Small: simple cuboidal
Large: simple columnar or pseudostratified columnar
List 4 functions of simple columnar epithelium.
- Absorption (small intestine, colon, gallbladder)
- Secretion (small intestine, colon, stomach lining, gastric glands)
- Lubrication (small intestine, colon)
- Transport (oviduct)
List 5 areas to find pseudostratified columnar epithelium. (Hint: mainly found from the neck up or in the male reproductive system.)
- UPPER RESPIRATORY TRACT (i.e., lining of the bronchi, trachea, and nasal cavity)
- Auditory tube and part of the tympanic cavity
- Lacrimal sac
- Epididymis
- Large ducts of many exocrine glands (e.g., salivary glands)
What type of epithelium is mainly found from the neck up or in the male reproductive system?
Pseudostratified columnar
What type of epithelia would you find in the upper respiratory tract?
PSEUDOSTRATIFIED COLUMNAR CILIATED
What type of epithelia would you find in the auditory tube and part of the tympanic cavity?
Pseudostratified columnar
What type of epithelia would you find in the lacrimal sac?
Pseudostratified columnar
What type of epithelia would you find in the epididymis?
Pseudostratified columnar
What type of epithelia would you find in the ducts of the salivary glands?
Pseudostratified columnar
List 4 functions of pseudostratified columnar epithelium.
- Conduit (respiratory tract, vas deferens)
- Mucus secretion (respiratory tract)
- Particle trapping and removal (respiratory tract)
- Absorption (epididymis)
List 8 areas to find stratified squamous non-keratinized epithelium. (Hint: mainly found in areas that undergo wear-and-tear.)
- Oral cavity
- Larynx
- Esophagus
- Vagina
- Medial urethra
- Distal anal canal
- Surface of the cornea
- Inner surface of the eyelid
What type of epithelium is mainly found in areas that undergo wear-and-tear?
Stratified squamous non-keratinized
What type of epithelium would you find in the oral cavity?
Stratified squamous non-keratinized
What type of epithelium would you find in the larynx?
Stratified squamous non-keratinized
What type of epithelium would you find in the esophagus?
Stratified squamous non-keratinized
What type of epithelium would you find in the vagina?
Stratified squamous non-keratinized
What type of epithelium would you find in the medial urethra?
Stratified squamous non-keratinized
What type of epithelium would you find in the distal anal canal?
Stratified squamous non-keratinized
What type of epithelium would you find on the surface of the cornea?
Stratified squamous non-keratinized
What type of epithelium would you on the inner surface of the eyelid?
Stratified squamous non-keratinized
List 3 functions of stratified squamous non-keratinized epithelium.
- Protection
- Prevent water loss while keeping surface moist
- Secretion (vagina)
List 4 places where you would find transitional epithelium. (Hint: mainly found in the urinary tract.)
- Renal calyces
- Ureter
- Bladder
- Proximal urethra
What type of epithelium is mainly found in the urinary tract?
Transitional
What type of epithelium would you find in the renal calyces?
Transitional
What type of epithelium would you find in the ureter?
Transitional
What type of epithelium would you find in the bladder?
Transitional
What type of epithelium would you find in the proximal urethra?
Transitional
List 2 functions of transitional epithelium.
- Distension
- Protection from toxic substances
Where would you find umbrella cells?
Surface of transitional epithelium
List 2 places where you would find stratified squamous keratinized epithelium. (Hint: mainly found lining external surfaces.)
- Skin
- Limited distribution in oral cavity (e.g., gums)
What type of epithelium would you find in the skin?
Stratified squamous keratinized
What type of epithelium would you find in the gums?
Stratified squamous keratinized
What type of epithelium is mainly found lining external surfaces?
Stratified squamous keratinized
List 3 functions of stratified squamous keratinized epithelium.
- Protection
- Prevent water loss while keeping surface dry
- Shield against UV damage
List 2 epithelial derivatives of the ectoderm.
- Skin epithelium
- Corneal epithelium
From which germ layer is skin epithelium derived?
Ectoderm
From which germ layer is corneal epithelium derived?
Ectoderm
List 3 epithelial derivatives of the endoderm.
- Respiratory tract epithelium
- GI tract epithelium
- Glandular epithelium (e.g., liver, thyroid, thymus, salivary glands)
From which germ layer is respiratory tract epithelium derived?
Endoderm
From which germ layer is GI tract epithelium derived?
Endoderm
From which germ layer is glandular epithelium derived?
Endoderm
List 3 epithelial derivatives of the mesoderm.
- Urogenital tract epithelium
- Blood and lymphatic vessel lining
- Pericardial, pleural, and peritoneal linings
From which germ layer is urogenital tract epithelium derived?
Mesoderm
From which germ layer is blood and lymphatic vessel epithelium derived?
Mesoderm
From which germ layer is pericardial, pleural, and peritoneal epithelium derived?
Mesoderm
Which 2 types of epithelium line the epiglottis?
Stratified squamous non-keratinized (characteristic of the esophagus)
Pseudostratified columnar ciliated (characteristic of the upper respiratory tract)
What are the 4 types of tissue?
- Epithelial tissue
- Connective tissue
- Muscle tissue
- Nervous tissue
What is a synonym for stratified epithelium?
Compound epithelium
What is mesothelium?
Simple squamous epithelium lining body cavities
What is endothelium?
Simple squamous epithelium lining blood and lymph vessels
What are epithelia?
Sheets of contiguous cells that cover the external surface of the body and line internal surfaces
What structure are epithelial cells anchored to?
Basement membrane
What are the two components of the basement membrane?
- Basal lamina
- Reticular fibres
What lays down the basal lamina of the basement membrane?
Epithelial tissue
What lays down the reticular fibres of the basement membrane?
Subtending connective tissue
What type of collagen forms the basal lamina?
Type IV
What type of collagen forms reticular fibres?
Type III
What structure prevents the spread of carcinomas?
Basement membrane
What would accelerate the renewal rate of an epithelia?
Injury
Why do different epithelia renew at different rates?
Located in environments of varying harshness
After how many days are epidermal cells replaced?
28 days
What are enterocytes?
Simple columnar epithelial cells found in the small intestine
After how many days are enterocytes (location: small intestine) replaced?
4-6 days
Why is the gut susceptible to cancer?
Quick renewal of enterocytes (4-6 days)
Which type of epithelium shields against UV damage?
Stratified squamous keratinized
What type of epithelium regulates platelet coagulation?
Endothelium
What is a carcinoma?
Cancer of epithelial origin
What percentage of all cancer cases are carcinomas?
80-90%
What are plicae circulares?
Folds of mucus membrane projecting into the small intestine
What are cilia?
Short membrane extensions that move substances such as mucus
List 2 places where you would find cilia.
- Upper respiratory tract
- Fallopian tube
What is the function of cilia in the upper respiratory tract?
Sweep out mucus and dirt
What is the function of cilia in the Fallopian tube?
Move the ovum from the ovary to the uterus
Describe the configuration of cilia.
Axonemal - 9 fused pairs of microtubules on the outside of a cylinder with 2 unfused microtubules in the center
What are villi?
Long membrane extensions that increase the surface area for absorption
Where are villi most often found?
Small intestine
What are microvilli?
Short membrane extensions that increase the surface area for absorption
Where are microvilli most often found?
Small intestine
What are stereocillia?
Very long microvilli found in the epididymis
What are thyrocytes?
Thyroid epithelial cells that synthesize thyroglobulin
What type of cells secrete calcitonin?
C-cells
What is the function of calcitonin?
Reduce blood calcium
What part of the kidney absorbs the majority (65%) of glomerular filtrate?
Proximal convoluted tubules
What part of the kidney reabsorbs sodium ions?
Distal convoluted tubules
Which hormone is responsible for the reabsorption of sodium ions by the distal convoluted tubules?
Aldosterone
What is a hypertonic solution?
Concentration of solutes is greater outside the cell than inside it
How is hypertonic urine produced?
Antidiuretic hormone secreted by the posterior pituitary increases permeability of PCT and DCT to glomerular filtrate and sodium ions
Where is bile produced?
Liver
What is the function of simple columnar epithelium of the gallbladder?
Concentrate bile by absorbing water and electrolytes
What holds cells in place?
Intercellular junctions
What is the brush border?
Microvilli-covered surface of simple cuboidal and simple columnar epithelia
What are tight junctions?
Apical barriers controlling diffusion by linking adjacent microfilaments
What are tight junctions comprised of?
Occludins
What are adherens junctions?
Belt-like barriers holding cells together by linking adjacent microfilaments
What are adherens junctions composed of?
Cadherins
What are spot junctions?
Anchoring junctions providing a continuous epithelium by linking adjacent cytoskeletons
What is another word for spot junctions?
Desmosomes
What are spot junctions composed of?
Integrins
Put the following layers in order:
- Tight junctions
- Spot junctions
- Hemidesmosomes
- Adherens junctions
Tight junctions
Adherens junctions
Spot junctions
Hemidesmosomes
How do cholera toxins increase intestinal permeability?
By disrupting junctional complexes in the gut
List 4 factors increasing the surface area of the small intestine.
- Length (4-6 m)
- Muscosa thrown into plicae circulares
- Villi
- Microvilli
What are lacteals?
Dilated lymphatic vessels in the small intestine that aid in fat absorption
Describe the mechanism by which cilia beat.
Dynein motor proteins slide along axoneme to produce rhythmic movement
What is the function of the epididymis?
Allow sperm to mature as they move from the testes to the vas deferens
What do epithelial cells of the vagina produce under the influence of estrogen?
Glycogen
What is a common substrate for lactobacilli of vagina?
Glycogen
What is the role of lactobacilli of the vagina?
Lower the pH of the vagina by producing lactic acid, preventing colonisation by pathogens
What happens to vaginal epithelium in the absence of hormonal stimulation (i.e., pre-puberty and menopause)?
Atrophy
Define gland.
An epithelial cell or collection of cells specialized for secretion
List 4 characteristics for classifying glands.
STRUCTURE of the gland (simple vs. compound)
METHOD of release (merocrine vs. apocrine vs. holocrine)
TYPE (serous vs. mucus)
DESTINATION of secretion (exocrine vs. endocrine)
Where are exocrine secretions destined?
Ducts
Where are endocrine secretions destined?
Blood and lymph vessels
Compare simple and compound glands.
Simple glands: unbranching ducts
Compound glands: branching ducts
What are the 2 types of secretion?
- Serous
- Mucus
Where would you find merocrine secretion?
Most glands
Where would you find apocrine secretion?
Mammary glands
Particularly lipid content
Where would you find holocrine secretion?
Sebaceous glands
Exocytosis is associated with what type of secretion?
Merocrine
Describe merocrine secretion.
Membrane-bound secretory vesicles fuse with the plasma membrane to release their contents
What is the fate of membranes enclosing secretory vesicles?
Recovered by the cell and reused
Name 2 areas ducts can open into.
Lumen of an organ
Surface of the skin
How does the histological appearance of proximal collecting tubules differ from distal collecting tubules?
Presence of a brush border (i.e., microvilli)
What is found in the Bowman’s capsule?
Glomerular filtrate
What type of epithelium lines blood vessels?
Endothelium (i.e., simple squamous epithelium)
What happens at the minor calyces of the kidney?
Urine collects from the renal papilla to deliver to the major calyces
Describe the structure of a thyroid follicle.
Layer of simple cuboidal epithelium enclosing colloid
What are simple cuboidal epithelium cells of the thyroid gland called?
Thyrocytes
What do thyrocytes produce?
Thyroglobulin
Which 2 hormones are produced from thyroglobulin?
- T4 (thyroxine)
- T3 (tri-iodothyronine)
What is stored in the colloid of the thyroid follicle?
Thyroglobulin
What is thyroglobulin?
A protein from which thyroid hormones are synthesized
The addition of what substance converts thyroglobulin to thyroid hormones?
Iodine
What is released by C-cells (a.k.a. perifollicular cells)?
Calcitonin
What is T4 converted to in tissues?
T3
What is the most biologically active thyroid hormone?
T3
What is the function of TSH (thyroid stimulating hormone)?
Trigger release of thyroid hormones
Where is TSH produced?
Anterior pituitary
Which organ in immediately posterior to the trachea?
Esophagus
List 2 functions of mucus secreted by goblet cells in the respiratory system.
- Keep airways moist
- Trap inhaled particles
What is the function of mucus secreted by goblet cells in the digestive tract?
Lubricate the passage of materials
How do the cilia assist in respiratory function?
Prevent accumulation of mucus in the lower respiratory tract by moving it to the oropharynx so it can be swallowed
What is the result of excessive mucus in the lower respiratory tract?
Increased infections
Why are the cartilage rings in the trachea c-shaped rather than o-shaped?
So they can deform or contract (e.g., during swallowing or coughing)
Describe the appearance of the basement membrane in respiratory epithelium.
Unusually thick
What is neoplasia?
Uncontrolled cell growth (benign or malignant)
What is dysplasia?
Abnormal development of cells
What is metaplasia?
Replacement of one cell type with another
With continued exposure to smoke, epithelial cells can begin to lose form and function. What is this process called?
Dysplasia
Why does respiratory epithelium transform to squamous epithelium in response to smoking?
To protect the airways from smoke damage
Where would you usually find the nuclei of simple columnar epithelium?
Located basally
What are the 3 layers of the small intestine, from top to bottom?
- Duodenum
- Jejunum
- Ileum
What are the 3 layers of the GI mucosa?
- Epithelium
- Lamina propria
- Muscularis mucosa
Remember: Every Lady Masturbates
What are the 4 layers of the GI tract?
- Mucosa
- Submucosa
- Muscularis externa
- Adventitia OR serosa
What type of tissue comprises the lamina propria?
Connective tissue
What type of tissue comprises the muscularis mucosa?
Smooth muscle
What type of tissue comprises the submucosa?
Connective tissue
Compare the 2 layers of the muscularis externa.
Inner: circular
Outer: longitudinal
What type of tissue comprises the adventitia?
Connective tissue
Approximately what portion of the small intestine does the jejunum comprise?
40%
Describe the structure of the mesentery.
Double fold of peritoneum that suspends the small intestine
List 4 functions of the mesentery.
- Blood supply
- Lymph supply
- Innervation
- Fat storage
Where are Paneth cells found?
Small intestine
What is the function of Paneth cells?
Release bacteria-killing compounds
What is the principal site for absorption of digestive products?
Small intestine
Why is esophageal epithelium convoluted?
To allow the lumen to expand when swallowing
What is the function of MALT (mucosa-associated lymphoid tissue)?
Immune response
Why is there a mixture of smooth and skeletal muscle in the esophagus?
Swallowing has both involuntary components (peristaltic) and voluntary components
Why does the lower 1/3 of the digestive tract contain purely smooth muscle?
Movement beyond this point is involuntary
Why would esophageal cancer lead to difficulty in swallowing?
Outgrowth of epithelium blocks the lumen
Which 5 layers of the epidermis would you find in thick skin (e.g., your palm)?
- Stratum CORNEUM
- Stratum LUCIDUM (only present on palms and soles)
- Stratum GRANULOSUM
- Stratum SPINOSUM
- Stratum BASALE
Remember: Cute Ladies Get Smart Boys
Describe the cells of the stratum basale.
Columnar or cuboidal
Describe the cells of the stratum spinosum.
Irregular polyhedral
Describe the cells of the stratum granulosum.
Squamous
Dark from granules of keratohyallin
Describe the cells of the stratum lucidum
Squamous
Clear
Which layer of the epidermis is only present on the palms and soles?
Stratum lucidum
Describe the histological appearance of the subcutis.
Light-staining due to abundant fat content
What are melanocytes?
Melanin-producing cells
Where are melanocytes located?
Stratum basale
What is an antigen?
A foreign substance that induces an immune response
In which layer of the epidermis are Langerhans cells most abundant?
Stratum spinosum
What is the function of Langerhans cells of the epidermis?
Antigen-presenting cells
Explain the process by which Langerhans cells present antigens for recognition by lymphocytes.
Invasion of antigen ->
Phagocytosis by Langerhans cell ->
Migration to lymph nodes ->
Presentation of antigen
What is a tendon?
Region of dense regular connective tissue that joins muscle to bone or muscle to muscle
What is the term for a cancer of epidermal keratinocytes?
Squamous cell carcinoma
What are umbrella cells?
Surface cells of transitional epithelium
The bladder is immediately posterior to which structure?
Pubic symphysis
Define cytotoxic.
Toxic to living cells
Contraction of which muscle empties the bladder?
Detrusor muscle
What is haematuria?
Blood in the urine
What is an ulcer?
Lesion resulting from a break in epithelial tissue
Why would urothelial cell carcinomas present with haematuria (blood in the urine)?
Ulceration of the epithelium allows blood to enter the urine
Name two risk factors for the development of bladder cancer.
- Smoking
- Chemical exposure
What is the most common cause of cystitis (inflammation of the bladder)?
Bladder infection
What is the most common source of organisms causing bladder infections?
Fecal flora
What rare type of epithelium is found in the distal urethra?
Stratified columnar
What type of glands are berry-shaped?
Acinar/alveolar glands
Remember: acai berries
What is an oligosaccharide?
A carbohydrate whose molecules are composed of a small number of monosaccharide units
Oligo = FEW
Sacchar = SUGAR
What are the 2 components of mucins?
- Carbohydrates
- Protein
What are mucins?
Glycosylated proteins produced by epithelial cells
Form mucus when hydrated
What stain reveals residual oligosaccharides in goblet cells?
Periodic acid-Schiff (PAS)
Which dye would detect glycoproteins in the basement membrane?
Periodic acid-Schiff (PAS)
What is the inheritance pattern for cystic fibrosis?
Autosomal recessive
What is the function of the CFTR?
Channel chloride ions across the cell membrane
Why does cystic fibrosis make swallowing difficult?
Sticky mucus makes it difficult to move the upper alimentary tract
Describe the chain of events that leads to sticky mucus in cystic fibrosis.
Defective CFTR ->
Buildup of Cl- in the cell ->
Increased cellular Na+ and water reabsorption ->
Poorly hydrated/sticky mucus
Why does cystic fibrosis have such systemic effects?
Affects all areas where mucus production is important (e.g., lungs, pancreas, sweat glands, vas deferens)
What is the effect of cystic fibrosis on the lungs?
Recurrent respiratory infections
List two effects of cystic fibrosis on the pancreas.
- Inflammation
- Blockage of ducts
What is meconium ileus?
An abnormally sticky first stool that blocks the small intestine
Meconium = baby’s first stool
Ileum = small intestine
What are crypts of Lieberkühn?
Any glands found in the intestine
What is the colon also known as?
Large intestine
List 2 main functions of the colon.
- Reabsorption of water and electrolytes
- Formation of feces
What are myoepithelial cells?
A thin layer of cells between the basement membrane and epithelium that contract to facilitate the transport of luminal contents
Describe the chain of events that leads to salty sweat in cystic fibrosis.
Defective CFTR ->
Poor reabsorption of Cl- by the sebaceous glands ->
Buildup of Cl- and Na+ in sweat
What is an infundibulum?
A funnel-shaped cavity or structure
What type of secretion is used by sebaceous glands?
Holocrine
Which class of hormones control the release of sebum?
Androgens
Describe holocrine secretion.
The cell disintegrates and releases its entire contents
What method of secretion provides oily sebum for the hair shaft?
Holocrine
What is fibrosis?
Thickening and scarring of connective tissue
Why does the pancreas become inflamed and fibrotic in CF?
Thick exocrine secretions accumulate and block ducts
How does cystic fibrosis cause the malabsorption of nutrients?
Mucus clogs pancreatic ducts, preventing enzymes from reaching the intestine
What percentage of cystic fibrosis patients show symptoms of insufficient pancreatic digestive enzyme secretion in the first year of life?
90%
List 3 effects of insufficient pancreatic lipase production.
- Malabsorption of vitamins A, E, D, and K
- Fatty stools (may be smelly or discolored)
- Diarrhea
What are 2 signs of fatty stools?
- Foul smell
- Discoloration (looks greasy)
Mucins are highly glycosylated polypeptides. How would they stain in H&E?
Poorly
What color do serous glands stain in H&E sections?
Pink
Why do serous glands stain pink in H&E sections?
Heavy in enzymes, which tend to be basic (i.e. high pH)
Which branch of the nervous system stimulates the release of saliva for ingestion?
Parasympathetic
What is xerostomia?
Dry mouth
What is the main type of secretion released by the parotid gland?
Serous
Which hormone acts on the milk-making tissues of the mammary gland?
Prolactin
Which hormones triggers the let-down reflex by acting on myoepithelial cells?
Oxytocin
What type of secretion involves non-membrane bound droplets (e.g., lipids) pinching off from the cell surface?
Apocrine
Describe apocrine secretion.
Non-membrane-bound droplet approaches the cell surface, where the membrane surrounds it and pinches off
Why does the plasma membrane become transiently smaller in apocrine secretion?
Surrounds droplet and pinches off from the cell
Why does the plasma membrane become transiently larger in merocrine secretion?
Membrane-bounded vesicle fuses with the plasma membrane
In what type of secretion does the plasma membrane becomes transiently smaller?
Apocrine
In what type of secretion does the cell membrane become transiently larger?
Merocrine
The lipid content of milk is released by apocrine secretion. What type of secretion releases the protein content of milk?
Merocrine
Why is the term “apocrine sweat glands” misleading?
These cells use merocrine secretion
Name 4 areas where apocrine sweat glands develop during puberty.
- Armpit
- Nipples
- Genitals
- Anus
What is the main mineralocorticoid hormone?
Aldosterone
Which mineralocorticoid hormone regulates Na+ uptake by the kidney tubules?
Aldosterone
Which glucocorticoid hormone regulates carbohydrate metabolism?
Cortisol
What is the main gonadocorticoid hormone produced by the zona reticularis?
Weak androgens
What is neuroendocrine control?
Signals from the nervous system regulating the endocrine system
Which hormone regulates the release of cortisol?
ACTH (adrenocorticotrophic hormone)
Which gland releases ACTH (adrenocorticotrophic hormone)?
Anterior pituitary
Which system controls the release of adrenalin and noradrenaline?
Sympathetic nervous system
Where are chromaffin cells found?
Adrenal medulla
What do chromaffin cells release?
Adrenaline and noradrenaline
Which cells of the adrenal medulla release adrenaline and noradrenaline?
Chromaffin cells
What type of epithelium would you find in the lower GI tract?
Simple columnar
What type of epithelium would you find in the skin?
Stratified squamous keratinized
What type of epithelium would you find in the renal calyces, ureters, bladder, and urethra?
Transitional
What type of epithelium would you find in the lining of blood vessels, mesothelium, and lining of the Bowman’s capsule?
Simple squamous
What type of epithelium would you find in the upper respiratory tract?
Pseudostratified columnar ciliated
What type of epithelium would you find in the thyroid follicles and renal collecting tubules?
Simple cuboidal
What type of epithelium would you find in the oral cavity, esophagus, vagina, and cornea?
Stratified squamous non-keratinized
What type of epithelium is best suited to protection against abrasion and water loss, keeping the surface MOIST?
Stratified squamous non-keratinized
What type of epithelium is best suited to protection against abrasion and water loss, keeping the surface DRY?
Stratified squamous keratinized
What type of epithelium is best suited to clearance of particles?
Pseudostratified columnar ciliated
What type of epithelium is best suited to absorption?
Simple columnar
What type of epithelium is best suited to distention and protection from toxins?
Transitional
What type of epithelium is best suited to secretion and gas exchange?
Simple squamous
What type of epithelium is best suited to secretion of hormones?
Simple cuboidal
What is the name of the structure separating all epithelia from underlying lamina propria?
Basement membrane
What name is given to squamous epithelium lining the chambers of the heart and blood vessels?
Endothelium
For what function are the pleura (which are serous membranes) specialised?
Secretion of lubricating fluid
For what function are the alveoli of the lungs specialised?
Gas exchange
What name is given to the simple squamous epithelium of serous membranes?
Mesothelium
Which layer of serous membranes adheres to organs?
Visceral
Which layer of serous membranes faces a body cavity?
Parietal
What cell surface specialisation discriminates proximal from distal tubules of the kidney?
Microvilli (i.e., brush border)
Place these epithelia in order of replicative capacity (highest to lowest): enterocytes, thyrocytes, keratinocytes.
- Enterocytes
- Keratinocytes
- Thyrocytes
What type of epithelium would you find in the mammary ducts?
Simple cuboidal
If histological analysis reveals that transformed ductal epithelium no longer maintains normal morphology, what process would the cells have undergone?
Dysplasia
What structure acts as a barrier to prevent malignant cells migrating from the epithelium?
Basement membrane
What cellular process recycles cellular components and provides a source of building blocks for the proliferation of malignant cells?
Autophagy
Estrogen receptor (ER) status informs treatment in women with breast cancer. List 3 tests that could be performed to confirm ER status of a biopsy.
- Immunohistochemistry
- Polymerase chain reaction
- Transcriptional profiling
In cancer cells, glycolysis is followed by lactic acid fermentation in the cytosol rather than the oxidation of pyruvate in mitochondria. Why have cancer cells undergone this switch?
Adaptation to a low oxygen environment
From what age are screening mammographies made available in England and Wales?
50
What are the 4 main macromolecules?
- Carbohydrates
- Lipids
- Proteins
- Nucleic acids
Why do many endocrine glands (e.g., adrenal gland, pituitary gland, thyroid gland) have a profuse blood supply?
To transport secretions to target cells around the body
Compare the roles of pancreatic acinar cells and islets of Langerhans.
Acinar: exocrine, synthesize digestive enzymes
Islets of Langerhans: endocrine, synthesize hormones
What is endocytosis?
Engulfing material outside the cell to form a vesicle within
What is pinocytosis?
Endocytosis of fluids
Reminder: endocytosis is engulfing material outside the cell to form a vesicle within
What is phagocytosis?
Endocytosis of solids
Reminder: endocytosis is engulfing material outside the cell to form a vesicle within
Describe transepithelial transport.
Material endocytosed at one surface ->
Transport vesicle shuttles across cytoplasm ->
Material exocytosed at opposite surface
Transepithelial transport is suited to molecules of what size?
Large
Distal swellings of the Golgi apparatus pinch off to form what structures?
Migratory vesicles
In which organelle do packaging, transport, and glycosylation occur?
Golgi apparatus
What do you call a malignant neoplasm derived from glandular epithelium?
Adenocarcinoma
Until which point do the glandular cells of the digestive, respiratory, and urinary tracts multiply? (Hint: basic functions are demanding.)
Throughout life
Until which point do the glandular cells of the liver, thyroid, and pancreas multiply? (Hint - all have hormonal functions. Think about what you associate with hormones.)
Puberty
List 3 functions impaired by the destruction of the glycocalyx. (Hint: related to specificity.)
- Adhesion
- Communication
- Mobility
Match the hormones to the mechanism of control.
Hormones: adrenaline/noradrenaline, ACTH, T3/T4, cortisol
Mechanism of control: nervous, endocrine, neuro-endocrine, negative feedback
Nervous: adrenaline/noradrenaline
Endocrine: cortisol
Neuro-endocrine: ACTH
Negative feedback: T3/T4
What is the mechanism of control for adrenaline/noradrenaline?
Nervous (SNS stimulation of adrenal medulla)
What is the mechanism of control for cortisol?
Endocrine (ACTH stimulation of adrenal cortex)
What is the mechanism of control for ACTH?
Neuro-endocrine (hypothalamic nervous stimulation of anterior pituitary)
What is the mechanism of control for T3/T4?
Negative feedback
Sympathetic nervous stimulation of which structure triggers adrenaline release?
Adrenal medulla
ACTH stimulates which structure to release cortisol?
Adrenal cortex
Nervous cells from the hypothalamus control ACTH secretion from which gland?
Anterior pituitary
What type of membrane lines internal tubes that open to the exterior (i.e., GI tract, respiratory tract, and urinary tract)?
Mucous
What type of membrane lines closed body cavities (i.e., peritoneum, pleural sac, and pericardial sac)?
Serous