Physiology 101-200 Flashcards
which of the following processes will account for the excessive uncontrolled muscle rigidity seen in Malignant Hyperthermia ?
A. Increase activity of the SERCa pump
B. Delayed closure of the ryanodine receptors in the skeletal muscle
C. decrease level of voltage gated Na and K channels in the Transverse tubules
D. decrease activity of the DHPR
E. none of the above
B
prolonged opening of the ryanodine receptors will promote excessive Calcium entry in the sarcoplasm leading to stimulation of sarcoplasmic reticulum to release excessive amounts of ca for muscular contraction leadin to rigidity. The other choices will lead to decrease ca level in the sarcoplasm. Guyton 11th ed p 89-91
what kind of transport process used by non exercising skeletal muscles for glucose uptake ? A. Simple diffusion B. Secondary active transport C. Counter or exchange transport D. Facilitated diffusion E. None of the above
D
in the presence of insulin, glut 4 receptors are translocated in to sarcoplasmic membrane to promote glucose uptake via facilitated diffusion. Guyton 11th ed p 50
which of the following scenario will result to tetanic contraction of the cardiac muscle ?
A. Increased extracellular calcium ions
B. Extreme hyperthermia
C. Increase catecholamine surge
D. Increase extracellular potassium ions
E. All of the above
A
heart muscle is dependent on extracellular calcium ions for its contraction. Increasing the latter in an high proportion will lead to tetanic contraction of the heart or ventricular fibrillation. Guyton 11 th ed p 114-115
A 45 y/o male, hypertensive an diabetic went for general check up. PE was unremarkable. 12L ECG was done showing normal sinus rhythm however there were occasional inverted P waves noted after the QRS complex. What is the most likely reason for this tracing abnormality?
A. atrial fibrillation
B. supra AV nodal Premature contraction
C. premature contraction coming from the his bundle
D. atrial premature contraction
E. all of the above
C
if the origin of cardiac impulse is below the AV node, the action potential will travel towards the atria as well as to the ventricles. Since there would be much delay travelling towards the AV node than to the ventricles, inverted P waves will be seen after the QRS complex. atrial fibrillation leads to no discernible p waves with an irregularly irregular pattern of QRS complex. Supranodal premature contraction will have inverted p waves prior to QRS. Know how to read ECG and the basis of each deflections. guyton 11th ed p 150- 153
increasing the reynolds number or the turbulence in an arteriole will result in the following consequence?
A. Induction of Nitric oxide synthase
B. Decrease prostacylin release
C. Increase renin and angiotensin levels
D. Decrease cGMP
E. none of the above
A
turbulence or shear stress is one of the potent stimulus for release of Nitric oxide ( formerly known as EDRF) this is made through upregulation of NOS and increase levels of cGMP. Guyton 11th ed p 199-200
the main determinant of blood flow in a non exercising skeletal muscle is? A. Arginine vasopressin B. Angiotensin II C. Local Metabolic rate D. Autonomic nervous system E. adenosine
C
the local metabolic needs of skeletal muscle, cardiac and nervous system is the main determinant of its blood flow level Guyton 11th ed p 195-196
in which level in the vascular system wherein there is largest dissipation of arterial pressure during systole? A. Aorta B. Capillary venule junction C. arterioles D. Capillary level E. Medium size capillaries
C
arterioles are the primary determinant of arterial pressure gradient (particulary the arteriole -capillary junction). Guyton 11th ed p 162-163
which of the following scenario will lead to increased peritubular capillary fluid reabsorption?
A. Increase systolic blood pressure
B. Increase renal blood flow
C. Decrease filtration fraction
D. Intake of enalapril
E. Increase efferent arteriolar constriction
E
increasing the efferent arteriole resistance will consequently lead to decrease peritubular hydrostatic pressure resulting to increase in net fluid reabsorption. Use of ACEI will decrease the efferent arteriole constriction. Increase in BP will lead to increase in the glomerular pressure and peritubular capillary pressure. decreased filtration fraction increases the peritubular hydrostatic pressure leading to decrease reabsorption. guyton 11th ed 339-340
During Diabetic ketoacidosis, hydrogen ions actively secreted by the proximal tubule are associated with which physiologic process?
A. Excretion of ammonium ions
B. Reabsorption of bicarbonate
C. Reabsorption of potassium ions
D. reabsorption of phosphae ions E. all of the above
B
part of the compensatory response of the kidney during acidosis is to remove hydrogen ions and consequently reabsorb bicarbonate ions in the proxima tubule. ( SIMILAR TO PREVIOUS BOARD EXAM CONCEPT/PRINCIPLE) guyton 11th ed page 306-307
which of the following scenario will promote urinary calcium excretion? A. Metabolic acidosis B. Increase plasma phosphate levels C. Intravascular Volume expansion D. Squamous cell carcinoma of the lungs E. None of the above
C
calcium reabsorption is directly proportional to water and sodium reabsorption. Therefore, increase in intravascular volume will lead to a decrease in Na,Ca and H20 reabsorption. Guyton 11th ed p 372
deficiency in FXIII in the serum will lead to which of the following ? A. Prolonged PTT B. Prolonged PT C. Increase clotting time D. Decrease clot stability E. None of the above
D
polymerization of fibrin to form a clot requires the presence of fibrin stabilizing factor (FXIII). The latter is not required in the intrinsic and extrinsic pathway. Guyton 11th ed 467- 468
The increase in the alveolar ventilation during strenous aerobic exercise such as marathon is primarily due to which of the following changes?
A. cortical collateral impulses to the DRG (dorsal respiratory group)
B. Decrease in arterial pH
C. Decrease in arterial PO2
D. Decrease in venous PO2
E. All of the above
A
during prolonged aerobic exercise, the changes in the mean arterial PO2, PCO2 and pH are negligible. Venous system does not contain any pH or O2 sensors that could might affect the respiratory drive. Guyton 11th ed page 519-520
Which of the following regions in the brain uses serotonin for suppression of pain pathways? A. Ventral tegmental area of tsai B. Nucleus raphes magnus C. Periaqueductal gray region D. Inferior olivary nucleus E. None of the above
B
A- dopaminergic neurons, Cenkephalin producing neurons, Dolivary nucleus nonspecific, related to auditory system.
which is a correct pair of neurotransmitters used in fastpain and slow pain respectively at the dorsal horn synapse ? A. Glutamate/ substance P B. Acetycholine/substance P C. Acetylcholine/cGRP D. Serotonin/cGRP E. None of the above
A
refer to Guyton 11th ed p 600-601
Which of the followng occurs in rods/cones during phototransduction of light ?
A. Decrease phoshodiesterase activity
B. Increase cGMP hydrolysis
C. Decrease levels of transducin
D. Increase fraction of active voltage gated calcium channels
E. increase fraction of open voltage gated sodium channels
B
during phototransduction of light, there is an increase in the hydrolysis of cGMP leading to closure of Na channel. Failure of the Na to enter the rods leads to hyperpolarization. Guyton 11th ed page 630-631
which of the following is not part of limbic cortex? A. Orbitofrontal gyrus B. Parahippocampal gyrus C. Paracentral lobule D. Cingulate gyrus E. None of the above
C
the components of limbic cortex are the following: orbitofrontal gyrus, cingulate gyrus, parahippocampal gyrus, and subcallosal gyrus
damage to which of the following brain region leads to retrograde amnesia ? A. amygdala B. Dentate gyrus C. Hippocampus D. Subcallosal gyrus E. Thalamus
E
Guyton 11th ed p 726
Which of the following ions will increase in concentration when salivary secretion is maximally stimulated?
A. sodium
B. potassium
C. bicarbonate
D. Chloride
E. Ionic levels are constant regardless of secretion rate
A
during maximal salivary secretion, the rapid transit of saliva in the duct does not allow sufficient time for Na to be reabsorbed. Guyton 11th ed p 794
how many hours it usually takes for a body to float secondary to drowning ? A. 16 hours B. 18 hours C. 22 hours D. 24 hours E. 48 hours
C
TAG upon reconstitution inside the intestinal epithelial cells will be transported to lacteals as a chylomicron. It will then travel to lymphatic system towards the thoracic duct entering the systemic circulation via the subclavian vein. Guyton 11th ed 815-816
feeling of satiety after eating a high fat meal is secondary to which of the following changes? A. Increased cholecystokinin B. Increased ghrelin C. Decreased leptin D. Decreased peptide YY E. A and C
A
promotes sateity- increase levels of cholecystokinin, peptide YY and leptin. Promotes appetite - increase ghrelin and neuropeptide Y. Guyton11th ed p 868-870.
This statement describes the mean arterial pressure:
A. one-third of the sum of diastolic and systolic pressures
B. average of systolic and diastolic pressures
C. determined about 40% by diastolic and 60% by systolic pressure
D. average of arterial pressures measured millisecond by millisecond over a period of time
D
MAP = 1/3(S+2D). MAP is determined 40% by systolic and 60% by diastolic pressure. Guyton Medical Physiology 11th edition p.176
The following are consistent with acute control of local blood flow, except:
A. adenosine accumulation affecting blood flow regulation
B. effect of an increase in concentration of CO2 and H+ on cerebral vessels
C. stretch-induced vascular depolarization, causing vasoconstriction
D. tubuloglomerular feedback
E. development of collateral circulation
E
Collateral circulation development is a phenomenon of long-term (not acute) local blood flow regulation. Guyton Medical Physiology 11th edition pp.198-200
True regarding the baroreceptor reflex:
A. Signals from carotid baroreceptors are trasmitted through the vagus nerves.
B. Signals from aortic baroreceptors are transmitted to the tractus solitarius of the medulla.
C. The carotic baroreceptors are stimulated by pressures 0-50/60 mmHg.
D. The baroreceptors respond much more to a stationary pressure.
E. When signals have reached the brainstem, secondary signals stimulate the vasoconstrictor center
B
Signals from the carotid baroreceptors are transmitted through the Hering’s nerves to glossopharyngeal nerves. Signals from both carotic and aortic baroreceptors are transmitted to the tractus solitarius of the medulla. The carotid baroreceptors are not stimulated at all by pressures 0-50/60, as they respond progressively more rapidly above these levels and reach a max of 180 mmHg. The baroreceptors respond much more to a rapidly changing pressure. When signals have reached the brainstem, secondary signals inhibit the vasocontrictor center. Guyton Medical Physiology 11th edition pp.209-210
What causes the 4th heart sound?
A. inrush of blood into ventricles after atrial contraction
B. closure of the AV valves
C. closure of the semilunar valves
D. inrush of blood into the great valves after ventricular contraction
E. inrush of blood through stenosed valves
A
B refers to S1. C refers to S2. Guyton Medical Physiology 11th edition p.270
True of heart sounds:
A. S2 is slightly longer in duration than S1
B. S2 has a lower frequency than S1
C. S1 is caused by closure of the aortic valve
D. S2 is caused by oscillation of blood between walls of ventricles
E. AV valves are more taut than semilunar valves.
A
S2 has a higher frequency than S1, due to the more taut semilunar valves, and the great elastic coefficient of taut arterial walls. S2 is slightly longer in duration than S1. Guyton Medical Physiology 11th edition p.270
Which valve is the second most seriously damaged in rheumatic fever? A. mitral B. tricuspid C. aortic D. pulmonic
A
Mitral valve is the most seriously damaged valve in rheumatic fever, followed by aortic valve. Guyton Medical Physiology 11th edition p.271
Not true regarding the glomerular capillary membrane?
A. It is composed of 3 major layers.
B. Albumin is an example of a substance with a filterability of 1.
C. The capillary endothelium is endowed with fenestrae.
D. It is much thicker than other capillaries’.
E. Both basement membrane and podocytes have negative charges.
B
Water, sodium, glucose, and inulin are examples of substances with a filterability of 1. Guyton Medical Physiology 11th edition p.316-317
Raises GFR, except:
A. modest efferent constriction
B. increased glomerular capillary filtration coefficient
C. increased arterial pressure
D. decreased resistance of the afferent arterioles
E. none of the above
E
Guyton Medical Physiology 11th edition pp.318-320
True of intrinsic pathway for initiating clotting:
A. begins with a traumatized vascular wall
B. begins with extravascular tissues that come into contact with blood
C. begins with trauma to the blood
D. B & C
E. all of the above
C
A & B refer to the extrinsic pathway for initiating clotting. Intrinsic pathway may also be initiated by the exposure of blood to collagen from traumatized vessel wall. Guyton Medical Physiology 11th edition p.462
Not true of the sneeze reflex:
A. afferent impulses pass through CNX
B. initiating stimulus is irritation in nasal passageways
C. uvula is depressed, as opposed to the cough reflex
D. none of the above
E. all of the above
A
Afferent impulses in the sneeze reflex pass through CNV. Guyton Medical Physiology 11th edition p.480
True regarding the Haldane effect:
A. quantitatively more important in promoting CO2 transport than is Bohr’s effect in promoting O2 transport
B. increased delivery of oxygen to tissues occurs when CO2 and H+ shifts the curve
C. CO2 diffuses to the lungs, decreasing the blood PCO2 and H+ concentration, shifting the curve to the left
D. CO2 in blood increases H2CO3, shifting the curve to the right
E. When CO2 binds with hemoglobin, O2 is released.
A
The other statements are regarding Bohr’s effect. Guyton Medical Physiology 11th edition p.511
True of the ventral respiratory group of neurons:
A. participate in the basic rhythmical oscillation that controls respiration
B. functions in both inspiration and expiration
C. active during normal quiet respiration
D. A & B
E. B & C
B
It is the dorsal respiratory group of neurons that participate in the basic rhythmical oscillation that controls respiration. The ventral respiratory group is inactive during quiet respiration. Guyton Medical Physiology 11th edition p.515
The phase that contributes the most to gastric secretion: A. cephalic B. gastric C. esophageal D. intestina
B
There is no esophageal phase in gastric secretion. Cephalic phase contributes 20%, while the gastric phase is responsible for 70% of total gastric secretion. Guyton Medical Physiology 11th edition p.798
Primary bile acids are combined with what to form conjugated bile acids? A. glutamate B. glutamine C. glycine D. threonine
C
Bile acids are conjugated with glycine and taurine. Guyton Medical Physiology 11th edition p.804
The most potent stimulus for causing gallbladder contractions is: A. cholecystokinin B. secretin C. gastrin D. acetylcholine E. histamine
A
Guyton Medical Physiology 11th edition p.803
Source/s of flatus:
A. swallowed air
B. as a result of bacterial action in gut
C. diffusion from the blood into the GIT
D. A & B
E. all of the above
E
Guyton Medical Physiology 11th edition p.825
The most numerous cells of the islets of langerhans? A. alpha cells B. beta cells C. gamma cells D. pp cell
B
The following is/are factor/s that increase insulin secretion: A. leptin B. fasting C. somatostatin D. obesity E. alpha-adrenergic activity
D
Guyton Medical Physiology 11th edition p.968
True of the prostate gland: A. secretes fructose B. contributes the bulk of the semen C. secretes a slightly alkaline fluid D. secretion is mucoid
C
The seminal vesicle secretes fructose, and contributes the bulk of the semen. Prostate gland secretion is thin and milky.
The only really effective mechanism to prevent body heat control breakdown in severely cold environments is:
A. panting
B. neuronal effector mechanisms
C. behavioral control of body temperature
D. sweating
E. Piloerection
C
Guyton Medical Physiology 11th edition p.895
