Par 2 Flashcards
TR
The most common treatment for near-sightedness is with
A concave eye glass lens
The most common treatment for far sightedness is with
A convex glass lens
In the light, photoreceptors are more hyperpolarized than in the dark because CGMP
is low and Na+ and Ca2+ channels are closed
Which of the following statements is correct?
Objects in the left visual field are processed by the right visual cortex
What would be an appropriate treatment for conjunctivitis?
Antibacterial eyedrops
When a photon of light strikes rhodopsin located in the photoreceptors, the following takes place?
rhodopsin is cleaved to trans-retinol and opsin
Sodium and calcium influx is inhibited
the receptor hyperpolarizes
isomerase converts to trans-retionol cis-retinol, which binds opsin—thereby reforming rhodopsin
All the above
Which of the following describes the sequence of events leading to the photoreceptors’ activation?
Light induces receptors’ hyperpolarization, leading to a decrease in glutamate release, which activates bipolar cells which then activates ganglion cells
Which of the following statements regarding ganglion cells’ receptive fields is correct?
On centers/ off surrounds ganglion cells are stimulated when a point of light strikes the center of the receptive field and inhibits when a point of light strikes the surrounding area.
In a standing person, hair cells in the utricle are
releasing glutamate
Which cranial nerve carries sensory information from a cupula to the brain?
VIII
Which of the following statements regarding the semi-circular canal is correct?
They detect angular acceleration
Salt chemoreceptor cells detect an elevation of salt in the mouth because
Sodium ions enter the cell causing membrane depolarization that actives voltage dependent calcium channels leading to an elevation in intracellular Ca++ that stimulates neurotransmitter release.
Olfactory information is carried in
CNI
Passive stretch of skeletal muscles increase action potential firing rate of the
golgi tendon organ
Activation of a stretch reflex in muscle leads to
Contraction of the stretched muscle, contraction of the synergistic muscle, and a relaxation of the antagonistic muscle
What type of motor neurons innervate extrafusal fibers?
Only alpha
In the fast pain pathway, information is carried from nociceptors to the brain via the
Neospinothamalic tract
What fiber types carries fast pain info to the spinal cord?
A delta
Which of the following is a principal CNS neurotransmitter used in the fast pain pathway?
Glutamate
Morphine like drugs are used in the treatment of pain because they
Bind to opioid receptors in the CNS, and reduce action potential generation
Which of the flowing statements is true?
Arterioles are highly innervated and they receive both sympathetic and parasympathetic inputs from the medullary cardiovascular center
Which of the following statements is false?
There is no fundamental difference between arterial venules, aortic diameter regulates blood flow
-Arterioles are highly innervated by sympathetic and parasympathetic input
in the medullary cardiovascular center
-Alpha adrenergic receptors are more important than beta adrenergic
receptors for regulation of arteriole diameter
-Beta adrenergic receptors are more important than alpha adrenergic for
regulation of arteriole diameter only in skeletal muscle
-In skeletal muscle, epinephrine causes vasodilation
There is no fundamental difference between arterial venules, aortic diameter regulates blood flow
During a hemmorage, mean arterial pressure may fall significantly; however, cerebral blood flow is maintained relatively constant due to which of the following?
Autoregulation
Increased metabolic demand in the heart muscle can be satisfied by which of the following?
Increased blood flow
Heart muscle is very different at extracting o2 from hemoglobin, so _____________.
only an increase in the amount of blood to the heart can satisfy increased metabolic demand
A woman is brought into the ER complaining of chest pain. Examination shows that although her heart rate is elevated, her BP is normal. According to standard guidelines for the treatment of chest pain, she is immediately put on IV nitroglycerin. In a subsequent exam, her BP had decreased. Why?
Nitroglycerin generates nitric oxide, which increases CGP levels to induce vasodilation
A woman is brought into the ER complaining of chest pain. Examination shows that although her heart rate is elevated, her BP is normal. She reported sharp pain with inhalation when she lays down. After further tests, the diagnosis was acute pericartitis. Question. When the pericardial sac acutely accumulates a large amount of fluid inside it, decreasing compliance of the heart chambers, how will this initially affect venous return; and then after the body adjusts, how will it affect cardiac output?
Decreased VR, only a modest decrease in CO because her HR has increased
Activation of the sympathetic fight or flight response results in which of the following?
Cardiac output is increased due to the increased venous return and increased heart rate
Excess fluid accumulation in the extracellular space interstitium is a result of
damage to the lymph system due to obesity
increased venous hydrostatic pressure
decreased plasma oncotic pressure
damage to the capillary beds
all of the above
all of the above:
Which of the following is an effective means of identifying whether the patient is at risk for orthostatic/postural hypotension?
After removing from a supine position to an upright position, the heart rate increases significantly
Which of the following is true?
ACH induced release of bradykinin from sweat glands to non-apical skin produces vasodilation in the cutaneous capillary beds
The blood-brain barrier is the least restrictive at the __________.
circumventricular organs
Atrial blood flow to the left ventricle stops and can even reverse direction during which phase of the cardiac cycle?
Isovolumetric contraction
Which of the following acts as a vasodilator in coronary smooth muscle?
Adenosine-carbon dioxide, decrease ph, potassium, hydrogen, nitric oxide
The most important variable governing the resistance of blood vessels to blood flow is ____________.
Vessel radius
Which of the following will increase venous return?
Respiratory inspiration
Stroke volume can increase by
Atrial kick
ACE inhibitors are clinically effective anti-hypertensive agents because
They inhibit the conversion of angiotensin 1 to angiotensin 2
An increase in serum K+ will result in which of the following
Aldosterone release from the kidney
In a healthy individual, which of the following does not significantly contribute to the arterial tone?
Arginine vasopressin (ADH)
Which of the following results in vasodilation
Release of nitric oxide from endothelial cells
Which of the following is probably an abnormal finding in a resting 23 year old male?
An ejection fraction of 90% 57% SV/EDV
In cells of the SA node, what causes the rapid upstroke of the action potential that occurs?
When cells reach threshold at the end of their pacemaker potential
End of pre-potential?
Opening of Ca++ channels
The blood brain barrier protects the brain from exposure of high concentration of
CO2
If atrio-venous pressure remains constant flow through one vessel will decrease if
a vascular bed that is parallel to it opens up
During isovolumetric ventricular relaxation, the inflow and outflow valves are
Both closed
When comparing the right ventricle to the left ventricle, which of the following is false?
The right ventricle works against a greater afterload
For the whole body, the equation that expresses the relationship between cardiac output and the two factors that regulate it is:
Whole body pressure - aorta to the right atrium / TPR
The mean systemic arterial pressure is higher than the pulmonary arterial pressure because the
TPR is greater than the pulmonary vascular resistance
The plateau potential of ventricular muscle cells is largely due to
An increase in Ca++ permeability through L-type Ca++ channels.
Frank Starling behavior of ventricular muscles operate to decrease stroke volume when which of the following occurs?
A decrease in ventricular end-diastolic volume
Which of the following will increase the resistance of a blood vessel to blood flow the most?
Increasing the pressure at the end of the vessel by 20%
If a health practitioner listens carefully he/she can hear two parts of the second heart sound. These two sounds are produced by closure of two valves. The latter of these two parts are the second heart sound is delayed ___________.
more when a person takes a deep breath. Aortic closes before pulmonary
Venous return will increase by
contraction and relaxation of skeletal muscles
Which of the flowing pairs of actions or agents will both cause a decrease in heart rate?
Infusing Ach, infusing a beta blocker acetylcholine is parasympathetic
Which of the following has the slowest intrinsic firing rate?
Purkinje fibers they conduct the fastest
The QRS complex of an EKG indicates which of the following?
None of these
If the pulmonary artery develops a contradiction located shortly after it leaves the heart _______ .
Both A and B will occur. There will be increased resistance of the pulmonary vasculature as a whole at the pulmonary valve to left atrium. The right ventricular muscle will hypertrophy.
Laminar blood flow produces
Very little to no sound vs turbulent
At the start of a heart beat, the major factor resisting blood flow along the major arteries is _______.
Diastolic pressure
During vigorous exercise, a persons CO increased from 5 L/min to 13 L/min. Which of the following will happen?
Cardiac and skeletal muscle blood flow will both increase
Which of the following is closest to the MAP of a dentist having a SBP of 150mm Hg and a pulse pressure of 90mm Hg
90 mm Hg
Shaun White (aka the Flying Tomato) was born with a hole between his
right and left ventricles (septal defect)
What type of cell produces cerebro-spinal fluid?
Choroid plexus epithelium
Which statement is correct regarding cells that produce the myelin sheath surrounding neuronal axons?
Oligodendrocytes can simultaneously form myelin on the axons of many different neurons whereas Schwann cells can only form myelin on axon of one neuron
Which properties accurately describe Ruffini endings?
They are found in the skin and have a large receptive field
Meissner’s corpuscles are?
Located shallow in the ridges of glabrous skin
Information from vibration or joint receptors ascends to the higher centers of the brain in the dorsal tract. One characteristic of the pathway of the dorsal tract is that these?
Ascend ipsilaterally in the spinal cord and cross over in the brain stem
Temperature receptors in the body contain which ion channels?
TRPV, TRPM, and TRPA
In hair cells of the organ of Corti, __________ ion channels open in response to stretch and therefore cause ___________ in the membrane potential.
K+ channels, depolarization
In the auditory system, the round window performs what function?
Maintaining the middle ear cavity at atmospheric pressure
Conduction deafness occurs in?
Transmission of sound waves from middle ear to oval window is impaired
Which of the following is not a significant contributor to arteriole tone in a healthy individual?
Arginine vasopressin
Endothelial cell derived nitric oxide system
Adrenergic system
Cholinergic system
Renin/angiotensin system
Arginine vasopressin
The baroflex is most important for
Responding to acute changes in blood pressure
Which of the following vascular segments represents the greatest general area of the circulatory system?
Capillaries
Which of the following portions of the cardiovascular system is the velocity of blood flow the highest?
Aorta
The blood brain barrier is impermeant to passive diffusion of
Glucose
Which of the following will facilitate diffusion of oxygen from arterial blood into tissue?
An increase the number of open pre capillary sphincters
Which one of the following factors would increase pre load?
Increase in diastolic volume
Increased metabolic demand in heart muscle is mainly satisfied acutely by which of the following?
Increase in blood flow since the heart is very efficient in extracting O2 from hemoglobin only increasing the amount of blood to the heart can accommodate an increase in cardiac demand
Low of concentrations of epinephrine will have which of the following effects?
Vasodilation of skeletal muscle arterioles because of preferential activation of adrenoreceptors
During which phase of the cardiac cycle is the coronary blood flow maximum?
Isovolumetric ventricular relaxation
During exercise, which of the following occurs?
Blood flow to skeletal muscle and skin increases
A decrease in venous compliance will result in
Increase venous return
Which of the following will increase cardiac output?
Increase venous return
Scenario: A woman is brought into the emergency room complaining of chest pain. Examination shows that although heart rate is elevated, her blood pressure is normal. The standard guideline for treatment of chest pain is that she is immediately put on nitroglycerin. In a subsequent exam, it is found that her blood pressure has dramatically dropped. Question: Why did her blood pressure drop?
Nitroglyceran generates nitric oxide which is a potent vasodilator
Scenario: A woman is brought into the emergency room complaining of chest pain. Examination shows that although heart rate is elevated, her blood pressure is normal. She reported sharp pain with each inhalation which lead to a diagnosis of acute pericarditis. Question: When the pericardial sac accumulates large amounts of fluid inside of it, decreasing compliance of the heart’s chambers, how will this initially affect venous return and then after the body adjusts, how will it affect cardiac output.
Decrease venous return only a modest decrease in cardiac output because heart rate would have increased
If the pulmonary artery develops a constriction shortly after it leaves the heart
a. resistance of the pulmonary vasculature would increase
b. the right ventricular muscle would hypertrophy
c. both a and b would occur
d. none of the above
C
Laminar blood flow
Produces little to no sound
At the start of a heart beat a major factor resisting blood along the major arteries is?
Diastolic pressure
Which of the following probably isn’t an abnormal finding in a resting 23 year old female?
• Hematocrit =50%
In cells of the SA node what causes the rapid upstroke of the action potential that occurs when cells reach threshold at the end of their pacemaker potential?
Opening of calcium channels
If the arteriole venous pressure gradient remains constant flow through a single vessel will decrease?
If a vascular bed that is parallel to it opens up
During isovolumetric ventricular contraction?
Inflow and outflow valves are both closed
When comparing the right ventricle to the left ventricle, which of the following is false?
The right ventricle works against a greater afterload
Muscle mass is less in the right ventricle
Pressure generated in the left ventricle is greater
The right ventricle does less work
The left ventricle consumes more oxygen
The right ventricle works against a greater afterload
The equation that expresses the relationship between cardiac output and the two factors that regulate it is?
Whole body pressure difference/TPR
The mean systemic arterial pressure is higher than the mean arterial pressure because the
TPR is greater than cardiovascular resistance
The plateau potential for the reticular muscle cells is largely due to there?
Increase in calcium permeability through L type calcium channels
Frank Starling behavior of ventricular muscle operates to decrease stroke volume. Which of the following occurs?
A decrease in ventricular end diastolic volume
Which of the following will increase the resistance of blood vessel to blood flow the most?
Increasing the viscosity of the blood by 10%
