Physiology sample questions Flashcards
norepinephrine is removed from the synaptic cleft by?
a. degradation via acetylcholinesterase and absorption into the presynaptic cell endings
b. reuptake into adrenergic nerve endings
c. degradation to epinephrine and absorption into postsynaptic cell endings
d. reuptake into postganglionic nerve endings
b. reuptake into adrenergic nerve endings
A mechanism of postsynaptic inhibition results from the openings of _____ channels.
a. chloride
b. sodium
c. calcium
d. magnesium
a. chloride
sodium channels opening causes an excitatory response; opening of K+ channels can also be the result of postsynaptic inhibition
The static response of muscle spindle fibers is dependent upon the direct excitation of
a. nuclear fibers
b. meissner’s corpuscles
c. merkel’s discs
d. golgi tendon organs
a. nuclear fibers
nuclear fibers or nuclear chain fibers are intrafusal fibers along with nuclear bag fibers which are responsible for detecting change in muscle length
inability to coordinate sequential movements of the vocal apparatus is characteristic of ______?
a. akinesia
b. dysarthria
c. dysdiadochokinesia
d. dysphagia
b. dysarthria- dysfunction in speech
akinesia- loss or impairment of voluntary movement
dysdiadochokiesia- impaired ability to form rapid alternating movements
dysphagia- difficulty swallowing
which of these receptor types adapts most rapidly?
a. muscle spindles
b. arterial baroreceptors
c. joint capsule receptors
d. pacinian corpuscles
d. pacinian corpuscles- (vibration and pressure)
dorsal columns
stimulation of sympathetic nervous system will cause ______.
a. bradycardia
b. bronchi dilation
c. increased peristalsis
d. pupil constriction
b. bronchi dilation
all other answers are representative of parasympathetic stimulation
which region of the brain functions in the storage of visual memory?
a. frontal
b. occipital
c. parietal
d. temporal
c. parietal- posterior parietal cortex; visual working memory and attention
visual accommodation for near vision is accomplished by ____.
a. relaxation of ciliary muscle
b. decreased refractive index of lens
c. increased parasympathetic impulses to ciliary muscle
d. increased sympathetic stimulation to ciliary muscle
b. decreased refractive index of lens
also CONSTRICTION of the ciliary muscle as well
relaxation of the muscle happens in response to visual accommodation for far vision
initial action potential of auditory conduction occurs in the
a. tectorial membrane
b. superior colliculus
c. organ of corti
d. trapezoid body
c. organ of corti- fluid waves into nerve signals; 1st step
trapezoid body- localization of sound; most nucleus fibers decussate here
tectorial membrane- cochlear amplification
superior colliculus- visual centers here, no auditory
dark adaptation of the retina requires _______.
a. activation of cones
b. X cell activation
c. rhodopsin synthesis
d. ciliary muscle relaxation
c. rhodopsin synthesis
rhodopsin- found in rods of retina; G-coupled protein receptor sensitive to light; works best in low light conditions
the primary function of cardiac muscle t-tubules is _____.
a. increase calcium concentration in sarcoplasmic reticulum
b. increase refractory period
c. counteract increased membrane permeability to potassium
d. inhibit actin and myosin movement
a. increase in calcium concentration in sarcoplasmic reticulum
same as in skeletal muscle but the mechanism is different.
t-tubules in cardiac muscle are bigger and wider and track laterally to z-discs and there are fewer t-tubules in cardiac muscle compared to skeletal muscle
which of these is a difference in the action potential of cardiac muscle when compared to the action potential of striated muscle?
a. striated muscle depends on slow calcium channels
b. cardiac muscle membrane potassium permeability decreases 5-fold
c. cardiac muscle depends only on fast sodium channels
d. striated muscle requires calcium-sodium channels
b. cardiac muscle membrane potassium permeability decreases 5-fold
I think this is the answer because in phase 0 of the cardiac action potential, the difference is a decrease in potassium permeability to open fast sodium channels
which of these is the major source of calcium ions in the excitation-contraction coupling of cardiac muscle?
a. purkinje fibers
b. sarcoplasmic reticulum
c. mitochondria
d. intercalated discs
b. sarcoplasmic reticulum
release of Ca ions from sarcoplasmic reticulum is key step of excitation-contraction coupling
which of these events detaches the myosin-actin cross bridge in skeletal muscle?
a. phosphorylation of the cross bridge
b. perpendicular positioning of the actin filament
c. binding of ATP to the myosin crossbridge
d. approximation of the contracting A bands
c. binding of ATP to the myosin crossbridge
ATP prepares myosin for binding with actin by moving it to a higher-energy state and a “cocked” position.
Once the myosin forms a cross-bridge with actin, the Pi disassociates and the myosin undergoes the power stroke, reaching a lower energy state when the sarcomere shortens.
ATP must bind to myosin to break the cross-bridge and enable the myosin to rebind to actin at the next muscle contraction.
at the neuromuscular junction botulin toxin will ____
a. inhibit the action of acetylcholinesterase
b. decrease release of acetylcholine
c. increase the end plate potential
d. inhibit the synthesis of acetylcholine
b. decrease release of acetylcholine
Calcium reacts with ____ to initiate smooth muscle contraction
a. troponin
b. tropomyosin
c. calmodulin
d. myosin
c. calmodulin
troponin binds to calcium to initiate contraction in SKELETAL muscle
the period of isovolumic relaxation occurs______.
a. immediately after systole
b. during atrial contraction
c. during aortic valve opening
d. during pulmonic valve opening
a. immediately after systole
which cardiac abnormality causes an increased P-R interval on an electrocardiogram?
a. ventricular hypertrophy
b. bundle branch block
c. sinus block
d. AV block
d. AV block
Which of these has the greatest impact on pulse pressure?
a. aortic regurgitation
b. stroke volume output
c. venous distensibility
d. patent ductus arteriosus
b. stroke volume output
the aortic bodies are sensitive to _____ changes.
a. blood pressure
b. arterial PO2
c. volume
d. temperature
b. arterial PO2
aortic bodies are a type of “peripheral chemoreceptor” which are sensory extensions of the peripheral nervous system into blood vessels where they detect changes in chemical concentrations.
which of these substances causes vasodilation?
a. endothelin
b. angiotensin
c. vasopressin
d. nitric oxide
d. nitric oxide
vasopressin, endothelin and angiotensin all cause vasoconstriction and increase in BP
A primary function of the lymphatic system is to ______.
a. control concentration of proteins in interstitial fluid
b. produce cells of the immune system
c. control concentration of lipids in circulatory system
d. induce vasomotion in capillaries
a. control concentration of proteins in interstitial fluid
not sure that this one is right because I could argue that 3 of these are primary functions so I am not sure
the function of opsonin is to ______.
a. repel macrophages
b. facilitate phagocytosis
c. stimulate cell division
d. induce autolysis
b. facilitate phagocytosis
IL-1 is released by which of these?
a. eosinophils
b. B lymphocytes
c. killer cells
d. macrophages
d. macrophages
air moves into the lungs during inspiration when the _____ pressure ______.
a. pleural; increases
b. alveolar; increases
c. alveolar; decreases
d. pleural; approximates zero
c. alveolar pressure decreases
when air isn’t moving in or out the alveolar pressure (pressure inside the lungs) is equal to the atmospheric pressure. during inspiration the increased volume of the alveoli due to lung expansion causes a decrease in alveolar pressure. At the end of inspiration, the pressure returns to zero or atm pressure
total lung capacity is calculated by which of these?
a. inspiratory reserve volume + residual volume
b. tidal volume + expiratory reserve volume
c. vital capacity + residual volume
d. tidal volume + residual volume
c. vital capacity + residual volume
An increased blood concentration of ____ stimulates the respiratory center of the medulla oblongata.
a. bicarbonate ion
b. CO2
c. albumin
d. O2
b. CO2
Pulmonary dead space is best defined as _______.
a. the air space in respiratory passages where no gas exchange occurs
b. the volume of air which cannot be released during normal expiration
c. the space of lung tissue which cannot be filled during normal inspiration
d. the volume of air exchanged during each respiration
a. the air space in respiratory passages where no gas exchange occurs
which of these primarily drives gaseous diffusion?
a. ionic interaction
b. covalent interaction
c. kinetic energy
d. particulate size
c. kinetic energy
Angiotensin II has what effect on the kidneys?
a. dilation of renal vessels
b. induces water and sodium reabsorption
c. increases urine output
d. increases glomerular filtration
b. induces water and sodium reabsorption
the absence of urine output during hemorrhagic or carcinogenic shock is principally due to ______.
a. substantial elevation in central venous pressure
b. decreased glomerular filtration rate
c. sudden rise in plasma colloidal osmotic pressure
d. exercise filtration of glucose through the glomerulus
a. substantial elevation in central venous pressure
central venous pressure= right atrial pressure= preload of right ventricle
increase in CVP can be due to several factors: decreased Cardiac output (CO) increased blood volume venous constriction arterial dilation forced expiration etc.
which of these prevents plasma protein from entering into the glomerular filtrate?
a. podocytes
b. vasa recta
c. macula densa
d. basement membrane
d. basement membrane
The basement membrane is made up of 3 layers and is fused to the endothelial membrane. Its main job is to prevent plasma proteins from being filtered out of the blood stream.
the ascending loop of henle is virtually impermeable to _____.
a. water
b. Mg++
c. Ca++
d. Na+
a. water
ascending loop= absorbs ions; impermeable to H2O
descending loop= absorb water; impermeable to ions
which of these is a potential cause of metabolic acidosis?
a. diuretic use
b. constipation
c. hyperventilation
d. diabetes mellitus
a. diuretic use
hyperventilation is the compensatory mechanism
ketosis and renal dysfunction are other common causes
Primary esophageal peristalsis is best described as ____.
a. initiated by the release of somatostatin
b. a continuation of the pharyngeal wave
c. initiated by the myenteric plexus
d. a continuation of the chewing reflex
b. a continuation of the pharyngeal wave
Lactase, maltase and sucrase are enzymes which can be found in the _______.
a. oral cavity
b. pancreas
c. stomach
d. small intestine
d. small intestine
lactase, maltase, sucrase are all brush border enzymes in the SI
somatostatin, GIP, CCK, secretin and motilin are specific to the duodenum of the SI
Most proteins are absorbed through the luminal membranes of the intestinal epithelial cells in the form of?
a. peptones
b. polypeptides
c. lipoproteins
d. dipeptides
d. dipeptides
proteins can not be absorbed as chains of AAs longer than 2-3 peptides.
what is the primary mechanism for absorption of amino acids and small peptides from the small intestine?
a. simple diffusion
b. facilitated diffusion
c. sodium co-transport
d. primary active transport
c. sodium co-transport
sodium co-transport is also known as secondary active transport
histamine stimulates the gastric secretion of ____ from the _______.
a. CCK; pancreatic alpha cells
b. CCK; pancreatic beta cells
c. HCL; chief cells
d. HCL; parietal cells
d. HCL; parietal cells
ECL (enterochromaffin-like) cells secrete histamine which stimulates HCL
Low blood concentrations of which hormones cause degeneration of the corpus luteum?
a. estrogen and luteinizing hormones
b. estrogen and progesterone
c. progesterone and follicle stimulating hormone
d. follicle-stimulating and luteinizing hormones
d. follicle stimulating and luteinizing hormones
this process is called involution of the corpus luteum; occurs around the 26th day of a normal female cycle and usually 2 days before menstruation begins
which of these hormones maintains the uterus in a condition favorable to implantation of fertilized ovum?
a. FSH
b. inhibin
c. LH
d. progesterone
d. progesterone
Angiotensin II stimulates the secretion of which of these hormones?
a. aldosterone
b. cortisol
c. epinephrine
d. glucagon
a. aldosterone
The posterior pituitary gland secretes which of these hormones?
a. vasopressin
b. growth hormone
c. corticotropin
d. luteinizing hormone
a. vasopressin aka ADH
The hormone _____ aids in lactation and is secreted from the _____ pituitary gland.
a. oxytocin; posterior
b. oxytocin; anterior
c. prolactin; posterior
d. prolactin; anterior
d. prolactin; anterior
Under normal physiologic conditions, what plays the most important role in regulating ADH secretion?
a. osmotic concentration
b. hepatic blood flow
c. blood glucose levels
d. renal blood flow
a. osmotic concentration
The majority of body heat loss at normal room temp occurs by what mechanism?
a. evaporation
b. conduction
c. radiation
d. sweating
c. radiation
a nude person sitting inside at normal room temp will have about 60% of their total heat loss by radiation
conduction by solid objects about 3%
conduction by air about 15%
evaporation cannot be controlled for purposes of temp regulation
sweating is a different mechanism
VO2 max is best described as _____.
a. the rate of oxygen use under maximum aerobic metabolism
b. oxygen consumption x total pulmonary ventilation
c. stroke volume x oxygen consumption
d. rate of oxygen use under maximal anaerobic metabolism
a. the rate of oxygen under maximum aerobic metabolism
During anaerobic exercise, the greatest amount of energy comes from ________.
a. ATP stored in muscle
b. degradation of ketones
c. conversion of glucose to pyruvic acid
d. conversion of glucose to CO2 + H2O
c. conversion of glucose to pyruvic acid
ATP stored in muscle is used up in about 3-5 seconds, phosphocreatine combined with ATP is used in about 8-10 seconds
converting glucose into pyruvic acid is called the glycogen-lactic acid system
