EXAM PREP [MULTIPLE CHOICE] Flashcards
What is the function of the respiratory zone?
The main site of gas exchange between air and blood
What is the main function of Type I alveolar cells?
Site for gas exchange
What is the main function of Type II alveolar cells?
Secrete alveolar fluid containing surfactant
What is inspiration and expiration?
Inspiration = inhalation
Expiration = exhalation
Together this is pulmonary ventilation
Where does internal respiration take place?
In the tissues
Where does external respiration take place?
In the lungs
Main function of the conducting zone?
Filter, warm and moisten air + conduct it to the lungs
How is the majority of carbon dioxide transported?
Dissolves in plasma as bicarbonate ions
What are the two enzymes in the mouth that start chemical digestion of food?
Salivary amylase - begins starch digestion
Lingual lipase - secreted by tongue and activated in stomach to breakdown triglycerides
What is another term for swallowing?
Deglutition
What’s the main role of gastrin?
Stimulates parietal cells to secrete HCl and chief cells to secrete pepsinogen
[also contracts lower oesophageal sphincter, increases motility of stomach, and relaxes pyloric sphincter]
What is the main function of parietal cells?
Secretes HCl and intrinsic factor
What is the main function of chief cells (in gastric pits)?
Secrete pepsinogen and gastric lipase
What is the main function of G cells in gastric pits?
Secretes the hormone gastrin
What is the role of IgA in digestion?
Prevents attachment of microbes to the epithelium
What enzyme digests triglycerides into fatty acids and monoglycerides in the stomach?
Gastric lipase
What substance activates pepsinogen, denatures proteins and kills bacteria in the stomach?
HCl
Which cells allows an alkaline protective barrier to form on the inner lining of the stomach to prevent acid erosion?
Mucous cells
Name the main enzymes in pancreatic juice that help digest starch, fats and proteins.
- pancreatic amylase (starch)
- pancreatic lipase (fats)
- proteases (proteins)
What is the main role of cholecystokinin (CCK)?
Stimulates secretion of pancreatic juice to digest fats and proteins in small intestine
What feature of the small intestine forms a brush border?
Microvilli
Absorbed nutrients leave the GI tract and enter the liver via…?
hepatic portal vein
What are the three phases of digestion and their function?
- Cephalic phases - prepare the mouth and stomach for food (activated by smell, sight, thought or initial taste of food)
- Gastric phase - begins when food arrives in stomach (activated by stomach stretching) and works to promote gastric secretions and motility
- Intestinal phase - when food enter small intestines; promotes digestion of food and slows exit of chyme from stomach
What is the function of peritubular capillaries in the kidneys?
Deliver wastes to be secreted into urine and reabsorb nutrients your body needs
Nephrons are the filtering units of the kidneys. What are their 3 main functions?
- glomerular filtration (filtration of waste-laden blood in the glomerulus)
- tubular reabsorption (return of important substances to body)
- tubular secretion (movement of waste materials)
Glomerular filtration (via the filtration membrane) permits the filtration of water and small solutes. What does it prevent the filtration of?
Proteins
What is the glomerular filtration rate?
The amount of filtrate formed in all the renal corpuscles of both kidneys each minute.
What are the 3 main mechanisms that regulate the glomerular filtration rate?
- renal autoregulation
- neural regulation
- hormonal regulation
What are the 2 hormones that contribute to the regulation of glomerular filtration rate?
- ANP (atrial natriuretic peptide)
- Angiotensin II
What are the functions of ANP?
- Released from the heart in response to high blood pressure
- Results in increased secretion of Na+ (increases urine output)
- Increases glomerular filtration rate
- Reduces blood pressure
Where does the majority of tubular reabsorption happen?
Proximal tubule of the nephron
What is the function of aldosterone?
- Produced by the adrenal gland
- Increases renal reabsorption of Na+, CL- and water
- Increases blood volume and pressure
Functions of angiotensin II?
- Released in response to a decreased blood pressure
- Vasoconstriction of arterioles
- Reduces glomerular filtration rate
- Also stimulates the release of ADH
What is the function of antidiuretic hormone (ADH)?
- Released from the posterior pituitary gland
- Stimulates the insertion of water channels (aquaporin-2) to increase water reabsorption
- Decreases osmolarity of body fluids
Name the type of mucosa-associated lymphoid tissue (MALT) in the small intestine.
Peyer’s patches
There are 7 main constituents of abnormal urine. Name them.
- glucose
- proteins
- ketone bodies
- haemoglobin
- bile pigments
- erythrocytes
- leukocytes
Reduction in blood pressure stimulates the kidney to secrete what?
Renin (which, in turn, stimulates angiotensin II which raises blood pressure)
The seminal vesicles, prostate gland and bulbourethral glands are considered what…?
Accessory sex glands
In males, the system of ducts includes the ductus epididymis, ductus deferens, ejaculatory duct and urethra. What is the broad function of ducts?
Store and transport gametes
What is the function of Leydig cells?
Secrete testosterone
Seminal secretions are alkaline to help neutralise the acid in the male urethra and female reproductive tract.
What are the 3 main seminal secretions and their function?
- fructose - ATP production by sperm
- prostaglandins - sperm motility and viability, and stimulate smooth muscle contractions in female
- clotting protein semenogelin - helps semen coagulate after ejaculation
Secretions of the prostate gland include…
- citric acid - ATP production
- acid phosphatase
- proteolytic enzymes - break down clotting proteins
- seminalplasmin - decrease number of naturally occurring bacteria
Gonadotropin-releasing hormone (GnRH) controls the ovarian cycle through secretion of other hormones. Where is GnRH released from and what other hormones does it control?
Hypothalamus
Oestrogens, progesterone, relaxin and inhibin
What are the main functions of oestrogens?
- moderate levels inhibit the release of GnRH, FSH and LH
What are the main functions of progesterone?
- prepares the endometrium for implantation
- prepares mammary glands to secrete milk
- inhibits release of GnRH and LH
What are the main functions of relaxin?
- inhibits contractions of uterine smooth muscle
What are the main functions of inhibin?
- inhibits release of FSH and LH
What is the function of follicular-stimulating hormones (FSH)?
Initiate follicular growth and production of oestrogens
What is the main function of luteinising hormone (LH)?
Trigger ovulation and promote the formation of corpus luteum
Beta-estradiol, estrone and estriol are all types of what hormone?
Oestrogens
What are the phases (in order) of the reproductive cycle?
- menstrual phase (declining levels of hormones; stratum functionalis is shed; thin endometrium)
- preovulatory (new stratum functionalis produced; rising oestrogen levels; aka. proliferation phase)
- ovulation
- postovulatory (secretory phase)
If egg is fertilised, what hormone maintains the corpus luteum?
hCG
What is the hormone released from the posterior pituitary gland that stimulates the insertion of water channels to increase water reabsorption?
ADH (antidiuretic hormone)
What is the hormone produced by the adrenal glands that increases renal reabsorption of Na2+, Cl- and water resulting in increased blood volume?
Aldosterone
What is the hormone released in response to decreased blood pressure, resulting in vasoconstriction of afferent and efferent arterioles and reduced GFR?
Angiotensin II
What is the hormone released from the kidney juxtaglomerular cells in response to low blood pressure?
Renin
What is the hormone released from the heart in response to high blood pressure that results in increased excretion of sodium?
ANP (atrial natriuretic peptide)
What are the main functions of ductus (vas) deferens?
Propel, store and reabsorb sperm
What happens in the seminiferous tubules?
Sperm is produced
What is the main function of the scrotum?
Regulate temperature of the testes
What are rugae broadly (in stomach and vagina)?
Folds that allow for stretching
What are circular folds and where are they found?
In the small intestine; folds of the mucosa and submucosa that enhance absorption by increasing surface area and causing chyme to spiral
Is it the villi or microvilli that forms the brush border of the small intestine and contains digestive enzymes?
Microvilli
Baroreceptors sense what to enact change in the body?
Blood pressure change
