Old Material Flashcards
An increase in parasympathetic tone causes
bronchoconstriction
The adrenal medulla releases
Mostly epinephrine, a smaller amount of norepinephrine
Which is characteristic of the “fight or flight” response?
Vasodilation of vessels supplying skeletal muscle
What type of receptor is found on the pacemaker cells of the heart?
beta 1 adrenergic
Which of the following causes an increase in heart rate?
Norepinephrine at beta 1 adrenergic receptors of the SA node
Plasma and interstitial fluid contain higher _____ and lower _____ compared with intracellular fluid.
Na+; K+
Oxygenated blood is found in the
pulmonary vein
What are the predicted effects of a muscarinic cholinergic agonist?
Decreased heart rate
Which of the following stimulates increased release of erythropoietin?
All of the above
tissue hypoxia, low blood oxygen, anemia
In erythrocyte recycling by the liver and spleen, the heme group of hemoglobin is metabolized into
bilirubin and bile
Blood cells form from stem cells located in
bone marrow
Males generally have a higher hematocrit than females. Thus males have
Higher amount of erythrocytes than females
An excess of white blood cells is associated with
leukemia
Which accurately describes the sequence of activation in the common pathway of clotting?
Factor X/prothrombin/thrombin/fibrin
Platelets aid in clotting by
All of the above
secreting vasoconstrictors; activating clotting factors; aggregating at a vessel injury
A blood clot is the combination of erythrocytes, platelets and
fibrin
A traveling blood clot is called
embolus
The mitral valve is located between the
Left atrium and left ventricle
What allows electrical signals to travel throughout the heart muscle?
Gap junctions
The right side of the heart contains _____ blood. The left side of the heart contains _____ blood.
Deoxygenated; oxygenated
The heart is contained in the
pericardial cavity
Acetylcholine is a
negative chronotropic agent
The plateau phase in the action potential of the cardiac myocyte
All of the above
An increase in vagal (parasympathetic) tone results in
Hyperpolarization of pacemaker cells
Which sequence accurately describes the order of the Cardiac electrical conduction pathway?
SA node/atrial myocardium/AV node/AV bundle/Ventricular myocardium
Sympathetic stimulation of the pacemaker cells of the heart causes
Calcium influx through L-type calcium channels
Semilunar valves open during
ventricular systole
In order to eject blood from the heart, ventricular pressure must
exceed aortic pressure
Increased preload (End Diastolic Volume) causes
increased stroke volume
epinephrine is a
Positive chronotropic and inotropic agent
What type of agent will block (prolong) phase 3 of the action potential of cardiac myocytes?
Potassium channel blocker
Stroke volume=
End diastolic volume (EDV) - End systolic volume (ESV)
The average cardiac output in a resting individual is
5L/min
Heart rate=
cardiac output/ stroke volume
Which statement accurately describes Starling’s Law of the Heart?
Increased filling of the heart stretches the ventricular wall, causing cardiac muscle to contract more forcefully
Ventricular systole involves all of the following EXCEPT
atrial contraction
What does an ECG measure?
Electrical activity of the heart
A resting heartbeat above 100 beats per minute is known as?
Tachycardia
Atrial depolarization on an ECG is represented as
P wave
The ‘Ectopic foci’ that can cause premature beats (PACs, PVCs) are actually
Cardiac myocytes that take over as pacemaker cells
Bradycardia is a common side-effect of which agent?
beta blocker
Large lumens, low pressure, blood storage are features of which vessels?
veins
In atrial fibrillation and atrial flutter, the inefficient emptying of the blood from the atria makes what event more likely?
clot formation
Systolic blood pressure is generated by
Ventricular contraction
The most significant influence on vascular resistance is
vessel radius
Dilation of an arteriole to twice its radius will have what effect on blood flow
16-fold increase in flow
An L-type calcium channel blocker has what effect on blood vessels?
vasodilation
vascular compliance is
The increase in vessel volume compared to the increase in vessel pressure
Which blood vessels play a key role in regulating blood distribution and pressure because their diameters may be easily and rapidly adjusted?
arterioles
the slowest movement of blood occurs in
capillaries
The vessels that supply the neck and head on each side
carotid arteries
Relatively thick muscular walls and elastic properties refers to
large artery
What is the MAP of a person with a systolic/diastolic blood pressure reading of 100/60 mm Hg?
73 mmHg
An increase in sympathetic tone causes veins to
all of the above
The volume of blood flowing back to the heart through the systemic veins is known as
venous return
Given these blood vessels: 1. aorta 2. inferior vena cava 3. pulmonary arteries 4. pulmonary veins Which vessels carry oxygen-rich blood?
1,4
The rate of blood flow in pulmonary circulation is _____ the rate of blood flow in systemic circulation.
equal to
To return blood back to the heart, _____ must exceed that of _____.
Venous pressure; Right atrial pressure
The flow of blood into an individual capillary is regulated by a/an
precapillary sphincter
The parasympathetic nervous system can influence MAP by altering
heart rate
In response to cold (decreased metabolism), an organ will do what to keep it’s local blood flow constant?
Constrict precapillary sphincters
Baroreceptors are located in the _____.
aorta and carotid sinus
Loss of sympathetic tone at systemic arterioles results in
Decreased total peripheral resistance (TPR)
Loss of sympathetic tone at systemic veins results in
Decreased venous return
Which plasma protein circulates in the blood in an inactive state?
angiotensinogen
Long-term regulation of blood pressure is primarily accomplished by altering
blood volume
Atrial natriuretic peptide (ANP) is secreted from the _____ when blood pressure _____.
Atria; rises
Angiotensin II raises blood pressure by all of the following mechanisms EXCEPT
Promoting water excretion by the kidney
A blood pressure of 140/80 is categorized as
Stage I Hypertension
Why is hypertension associated with higher myocardial oxygen demand?
The heart has to work harder to eject blood
When blood pressure rises, baroreceptors signal the brainstem to decrease sympathetic output, resulting in all of the following EXCEPT
Vasoconstriction
The crushing pain associated with angina pectoralis is an indication that
The heart is ischemic
In heart failure, the kidneys
Increase blood volume
The release of renin is directly stimulated by?
Decreased blood flow to kidneys
A sudden drop in blood pressure and loss of consciousness is known as
shock
What causes reabsorption of fluid at the venous end of an idealized capillary bed?
C. Low capillary hydrostatic pressure and high capillary colloidal osmotic pressure
The endothelium (lining of capillaries) is
Simple squamous epithelium
What type of substance would you NOT expect to find in urine?
mitochondria
What is the osmolarity of lymph?
300 mosmol/L
What happens to lymph?
It returns to the blood at subclavian veins
What type of capillaries form the glomerulus of the nephron?
fenestrated
the neural control of micturition, which efferent pathway is under-developed in infants?
somatic- from brain
What sort of receptors are most important in the contraction of the detrusor muscle?
muscarinic cholinergic
Urine flows from a kidney to the urinary bladder via a
ureter
What is the name of the long capillary loops that parallel the loop of Henle of juxtamedullary nephrons?
vasa recta
In ultrafiltration in a typical capillary bed, the ultrafiltrate moves from
The vascular lumen to the interstitium
Which vessels receive blood directly from the efferent arteriole?
Peritubular capillaries
What are the characteristics of inulin that make its clearance = GFR?
Freely filtered, not reabsorbed, not secreted
What structures are located on the apical surfaces of proximal convoluted tubule cells that increase the surface area available for reabsorption?
microvilli
In the nephron, ultrafiltration occurs at the _____ and reabsorption at the _____.
glomerulus; peritubular capillaries
How does dilation of the afferent arteriole produce an increase in GFR?
Increased blood pressure and increased blood flow
The tubular transport maximum for glucose measures the maximum rate of glucose ____ by the renal tubules.
reabsorption
Which of the following will most definitely cause an increase in the GFR even when MAP is very low?
constriction of the efferent arteriole
About how much fluid is filtered into the renal tubules each minute?
125 mL
Average creatinine clearance for a young adult male is _____.
125 ml/min
Where does most reabsorption occur?
proximal convoluted tubule
Substances with high clearances are actively
secreted
In the first step of glucose reabsorption, what moves “downhill” to allow glucose to move “uphill” across the apical membrane?
Na+
