Flashcards in Class Test 2 Deck (96):
Why is intrinsic factor needed in the body?
Absorption of vitamin B12
What does damage to stomach mucosa cause?
What are the 3 phases of gastric secretion
Examples of gastric gland cells
What mechanisms regulate gastric secretion
Neural and hormonal mechanisms
What is stomach mucosa composed of?
Simple columnar epithelium
What type of events regulate gastric secretion
Stimulatory and inhibitory
What is the hormonal element in the intestinal phase
CCK and secretin
What is gastrin released by?
G cells of gastric glands
What does gastric lipase split?
Short-chain triglycerides into fatty acids and monoglycerides
What do hepatocytes produce?
How much bile is produced a day?
How are gallstones formed?
If bile contains insufficient salt or excessive cholesterol
What causes release of pancreatic juice
What is trypsinogen activated by?
Brush border enzymes
What does CCK induce
Enzyme rich pancreatic juice
What causes weak contractions of gallbladder?
During cephalic and gastric phases
Vagal nerve stimulation
What does pancreatic juice contain?
What form are proteases secreted in?
Inactive and activated in duodenum
Pancreas exocrine functions
Acini secrete pancreatic juice
Zymogen contain digestive enzymes
Provide optimum pH
What is the portal triad?
What does secretin release?
HCO3 rich pancreatic juice
What causes the release of CCK and secretin?
Chyme into duodenum
What does trypsin cause the release of?
Procarboxypeptidase and chymotrypsinogen
What two ways can steroid hormones be released?
Free binding proteins
What factors determine blood concentration of hormones
Rate of secretion
Rate of inactivation and excretion
What are steroid hormones based
What are the steps of hormone synthesis
What does receptor down-regulation reduce?
Target cell's responsiveness
Where is the pituitary gland?
Below the thalamus
Lies in hypophyseal fossa of the sella turcica of sphenoid bone
Six major anterior pituitary hormones?
Six hypothalamic releasing factors?
Two additional hypothalamic hormones of the posterior pituitary?
What is GnRH for?
Stimulates LH and FSH
What is FSH and LH for in male reproduction system?
FSH -> Sertoli cells -> sperm
LH -> Leydig cells -> testosterone
What's SST (somatostatin) for?
Inhibits release GH
What is the luteal phase?
Granulosa cells + thecal cells= progesterone
What is the follicular phase?
Thecal cells-> androgens-> granulosa cells
What is GH (somatotropin) for?
Insulin like growth factor and metabolic effects
Difference between osteoclasts and osteoblasts
Osteoblasts- creating bone
Osteoclasts- breaking bone
What is the parathyroid hormone?
84 a.a peptide produced by chief cells
What do C cells produce?
What does increased lusitropic effect lead to
Shorter diastolic relaxation time
What are the steps of T3 and T4 synthesis and secretion
Synthesis of thyroglobulin
Oxidation of iodide
Iodisation of tyrosine
Coupling of T1 and T2
Pinocytosis and digestion of colloid
Secretion of thyroid hormones
Transport in blood
Steps of calcitonin production
Increased plasma Ca2+
Calcitonin production increased
Decreased osteoclastic activity
Steps in parathyroid hormone
Fall in Ca2+
Parathyroid hormone production increased
PRH increased osteoclastic activity
What happens with increased chronotropic action?
What happens with increased inotropic action?
Greater force of contraction
How do liver and dietary lipoproteins enter adipocytes?
Through lipoprotein lipase action
What does the anterior pituitary hormone increase concentration of?
Glucose and fatty acids
What's insulin and glucagons role in the post-absorptive state?
Storage of nutrients
Maintenance of plasma nutrient concentrations
What are the physiological aspects of calorie buffering?
Short term osmotically active
Long term osmotically inert
What does the action of cortisol on plasma nutrients permit?
Rise in plasma glucose and fatty acids
Peripheral insulin antagonist
What do the 4 cell types in the pancreas secrete
F cells- pancreatic polypeptide
What does increased ventilation cause?
Increased alveolar PO2 (partial pressure), therefore oxygen consumption rises
What is VO2?
Measure of maximum volume of oxygen that an athlete can use
Why does HR take longer to recover after heavy exercise and faster lighter exercise?
Metabolic recovery takes longer
Repayment of O2 debt
HR remains higher for longer to get ride of lactate build up
What's mean arterial BP?
Diastolic BP + 1/3 pulse pressure
What does compliance mean?
Measure of the change in volume for a given change in pressure
What else is found when measuring the oxygen consumption
Total energy output during exercise
What does the pressure of the arterial system depend on?
How is pressure in arteries maintained when the ventricle relaxes?
What does arterial compliance depend on?
Physical properties of wall
Value of mean arterial pressure
How do fats converted to fatty acids enter the cell?
What does NKCC1 do?
Powers Cl- entry into cell down sodium ion gradient
What is linked to the sodium ion gradient?
The time taken for solutes to be absorbed
What does hydrostatic pressure do?
Aid or prevent fluid absorption
What do tight junctions allow?
What does CTFR allow?
Cl- out into the lumen
Fall in blood pressure in circulation
Renal sympathetic nerve discharge
Reduced renal blood flow and glomerular filtration
Reduced sodium chloride delivery
Increased renin release
Increased sodium chloride reabsorption
What coverts angiotensinogen from the liver to angiotensin I
What was done in Gardener's experiment?
Inflatable catheter inserted into renal artery to stimulate reduced blood pressure
Inject max stimulatory dose of aldosterone
Functions of aldosterone?
Increase Na+/K+ activity in distal tubule
Increase sodium ion reabsorption
Aim of gardeners experiment
Maximise sodium reabsorption in distal convoluted tubule
What is the function of retention of sodium ion
Maintain extra cellular volume
Fall in venous blood volume
General sympathetic discharge
Constriction of afferent arteriolar
Reduced renal blood flow
Reduced glomerular filtration
Reduced sodium chloride presented to distal convoluted tubule
Conservation of sodium chloride
What does angiotensin I in lungs and kidneys do?
Concerts enzyme ACE in lung and renal endothelium
Functions of AT1 receptors?
Effect on smooth muscle of arteries
Stimulates ADH production
What receptors receive decrease in volume of circulating blood
ANP (atrial natriuretic peptide) action
Reduced blood pressure
Inhibits ADH release
Inhibits renin release
Reduced sodium ion absorption
What are modern anatomical methods in neuroscience?
In situ hybridisation
What does in situ hybridisation detect?
mRNA sequences in neurones
What can light microscopic features determine?
6 layers of human cerebral cortex
What is immunocytochemistry?
Antibodies are used to detect molecules in CNS
What did electrical stimulation show about the brain?
Represented by maps
What are ribosomes responsible for?
How can neurons be classified?
Number of neuritites
How can axons classify neurons?
Golgi I- long axons
Golgi II- local axons
Functions of various glia
Astrocytes- mechanical and metabolic
Oligodendrocytes- make myelin
Angiotensin I converted to angiotensin II where?
How to calculate alveolar ventilation?
VA- alveolar ventilation
VE- pulmonary ventilation
VD- dead space ventilation
If you have tidal volume (VT) and respiratory rate (RR) VA can be calculated
VA= (VT x RR) - (VD x RR)
What does thirst arise from?
Increased plasma osmolality
Decreased blood volume (renin, angiotensin)
Decreased plasma osmolaity
Osmolality of blood increases with dehydration
Decreased osmolality= increase urine
Increase in ADH