Test #4 Flashcards
Which of the following statements is true concerning the depolarization of a cell in the SA node?
The cell will not depolarize until it receives sympathetic stimulation
The aortic semilunar valve
Prevents the backflow of blood into the left ventricle during ventricular relaxation
Which of the following will DECREASE systemic arterial blood pressure
Vasodilation
With regard to the regulation of heart rate
a. Stimulation of parasympathetic nerves to the heart causes a slowing of heart rate
b. Stimulation of the sympathetic nerves to the heart causes an increase in heart rate
c. A person whose heart lacks all autonomic innervation has a faster heart rate at rest than a person with a normally innervated heart
The carotid sinus baroreceptor reflex
a. Regulates blood pressure to the brain
b. Responds to low blood pressure by activating the sympathetic nervous system
c. Responds to high blood pressure by activating the parasympathetic nervous system
If an increase in blood pressure is detected in the right atrium, which of the following would occur?
Sympathetic increase of heart rate
Increased vasoconstriction
Which of the following would directly add to vessel resistance?
a. Increased vessel length to due weight gain
b. Atherosclerosis
c. Dehydration leading to added viscosity
Put the following events in the cardiac cycle in order, beginning immediately after atrial contraction:
i. Isovolumetric ventricular relaxation
ii. Isovolumetric ventricular contraction
iii. Ventricular filling
iv. Ventricular ejection
b. 4,3,2,1
Which of the following would cause an increase in cardiac output, if detected in the aortic arch?
High systemic arterial CO2
Which of the following will increase stroke volume?
a. Increased afterload
b. Increased preload
c. Increased venous return
Inspiration occurs as a result of
Increase in size of the thoracic cavity due to contraction of the inspiratory (external) intercostal muscles
A downward movement of the diaphragm
Oxygen is carried in blood
a. Bound to hemoglobin
b. Dissolved in the plasma
c. On the albumin
Afferent arteriole vasoconstriction ____ blood flow into the glomerulus, which causes the glomerular capillary blood pressure to ______, leading to a(n) ______ in the net filtration pressure and a resultant ______ in the GFR.
Non of the above
As resistance increases, systemic arterial blood flow will ______. As the change in P increases, blood flow tends to __________.
Decrease, decrease
The right atrial reflex
Responds to systemic venous pressure
Activated the sympathetic nervous system in response to stretching
Which of the following would cause deoxyhemoglobin to form?
Increased temperature of the blood
Basic renal processes include
Filtration from Bowman’s capsule into the glomerulus
The amount of a substance that is excreted in the urine is equal to the amount that is ______ plus the amount that is ______ minus the amount that is ______
Reabsorbed…..secreted……filtered
Each of the following substances is initially present in filtrate in the PCT in the kidney. Which one is not normally present in urine?
Phosphate ion
Which of the following substances undergo renal secretion?
Calcium ion
The myogenic regulation response in the kidney to high systemic blood pressure would be:
None of the above
Which of the following would cause an increase in Na reabsorption at the proximal convoluted tubule?
a. Decreased blood volume
b. Decreased blood pressure
c. Decreased cardiac output
In order for water to be absorbed at the distal convoluted tubule, _____ must be present
ADH
Which of the following is composed of inspiration and expiration?
Internal respiration
Contraction of which of the following muscles is involved in normal expiration?
External Intercostals
The opening and closing of the AV and semilunar valves is driven by
Differences in pressure across the valve
Which of the following is the correct conduction pathway through the heart?
SA node, AV node, bundle of His, bundle branches, Purkinje fibers
What is occurring during ventricular ejection?
The AV valves are closed and the semilunar valves are open as blood is leaving the ventricles.
During which phase of the cardiac cycle are all four heart valves open?
none
Which of the following describes the effect of end-diastolic volume on stroke volume? (Starling’s Law)
An increase in end-diastolic volume stretches ventricular muscle cells to lengths closer to optimum, increasing the strength of contraction and thereby increasing stroke volume.
During myogenic (local) regulation of glomerular filtration rate, an increase in mean arterial pressure will cause the
Afferent arterioles to constrict and thereby maintain a relatively constant glomerular filtration pressure
How does the sympathetic nervous system decrease glomerular filtration rate?
Stimulates constriction of the afferent arteriole only
In diabetes mellitus, why does polyuria occur?
Lack of insulin decreases water reabsorption
Most reabsorption occurs in the _____ and is ______
Proximal tubule: not regulated
Increasing the GFR will increase the loss rate of sodium into the urine
True
The SA node is normally the heart’s pacemaker because it has the fastest spontaneous rate of depolarization
False
Aldosterone causes sodium secretion and potassium reabsorption
True
The respiratory system and the urinary system both have mechanisms of regulating blood pH
True
During inspiration, the diaphragm contacts and the alveolar pressure is less than atmospheric pressure; during expiration, the diaphragm relaxes and the alveolar pressure is greater than atmospheric pressure
True
In the systemic circulation, the PO2 of arterial blood exceeds the PO2 of venous blood, while the reverse is true for the pulmonary circulation
True
Contraction of the atria causes the opening of the atrioventricular valves
False
