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)