Physiology Exam 2 Flashcards
(194 cards)
What about veins allows them to accommodate high volumes with little change in pressure.
Large Compliance
What is Venous return?
Venous return is the volume of blood returning to the central venous compartment (i.e., thoracic venae cavae and right atrium) per minute.
What promoted Venous return? High or Low CVP?
Low CVP promotes venous return into the central venous compartment.
What inhibits Venous return? High or Low CVP?
High CVP inhibits venous return into the central venous compartment.
If a 20-year-old and a 60-year-old male had the same body mass, cardiac output, heart rate, and mean arterial pressure, which of the following would characterize the circulatory system in the 60year-old as compared to that in the 20-year-old?
A. The 60-year-old man would have a lower systolic pressure.
B. The 60-year-old man would have a higher diastolic pressure.
C. The 60-year-old man would have a higher cardiac workload.
D. The 60-year-old man has elevated arterial resistance.
C. The 60-year-old man would have a higher cardiac workload.
Which of the following will be seen when both heart rate and stroke volume are increased? A. Increased mean arterial pressure B. Increased central venous pressure C. Increased pulse pressure D. Decreased diastolic pressure
C. Increased pulse pressure
Which of the following is true of the relationship between cardiac output (CO) and central venous pressure (CVP)?
A. Increased CVP increases CO
B. Equal CO to CVP results in increased flow (L/min)
C. Increased CO increases CVP
D. Decreased CVP increases CO
D. Decreased CVP increases CO
Autoregulation of blood flow in organs such as the heart and brain allows:
A. changes in arterial pressure to cause proportional changes in organ blood flow.
B. their oxygen supply to remain stable in spite of fluctuations in arterial pressure.
C. constriction of their arterioles when arterial pressure decreases.
D. neurogenic reflexes to control vascular resistance in those organs.
B. their oxygen supply to remain stable in spite of fluctuations in arterial pressure.
If blood flow to an organ is 100 mL/minute when the mean arterial pressure in the main artery supplying the organ is 100 mm Hg, which of the following flow conditions is inconsistent with the properties of autoregulation of blood flow when the mean arterial pressure in the supplying artery is reduced to 80 mm Hg? (For this question, do not consider any effects of activation of blood pressure reflexes in the response.) A. Blood flow = 75 mL/minute B. Blood flow = 85 mL/minute C. Blood flow = 90 mL/minute D. Blood flow = 99 mL/minute
A. Blood flow = 75 mL/minute
If mean capillary hydrostatic pressure = 30 mm Hg, interstitial hydrostatic pressure = 0 mm Hg, plasma oncotic pressure = 25 mm Hg, and interstitial oncotic pressure = 2 mm Hg, which of the following will create a situation in the capillary where there is no net reabsorption or filtration of fluid across the capillary?
A. Reducing plasma oncotic pressure to 22 mm Hg
B. Decreasing interstitial oncotic pressure to –4 mm Hg
C. Increasing interstitial hydrostatic pressure to 7 mm Hg
D. Increasing plasma oncotic pressure to 30 mm Hg
C. Increasing interstitial hydrostatic pressure to 7 mm Hg
What will occur in a person with intact cardiovascular neural reflexes when a sudden drop in mean arterial pressure from a normal value of 95 mm Hg to 70 mm Hg?
A. Constriction of cutaneous arterioles
B. Maximized carotid baroreceptor nerve firing rate
C. Contraction of cerebral arteries
D. Stimulation of the vasodepressor center in the medulla
A. Constriction of cutaneous arterioles
Heart rate is \_\_\_\_\_\_\_\_\_ in response to \_\_\_\_\_\_\_ firing rate of arterial baroreceptor nerves. A. increased; increased B. decreased; decreased C. increased; decreased D. decreased; zero
C. increased; decreased
If an individual’s resting heart rate is 75 beats/minute (bpm), complete blockade of the parasympathetic and sympathetic nerve activity to the heart will result in which of the following heart rates?
A. >75 bpm because of elimination of sympathetic activity to the heart
B. < 75 bpm because the parasympathetic nerves dominate heart rate at rest
C. >75 bpm because sympathetic nerves dominate heart rate at rest
D. >75 bpm because acetylcholine hyperpolarizes the SA node
D. >75 bpm because acetylcholine hyperpolarizes the SA node
What are receptors specific for?
Specific for stimulus
What is a slow adapting receptor also known as?
Tonic
what is a fast adapting receptor also known as?
Phasic
What are the 4 cutaneous sensory modalities?
Pain, Touch, Vibration, Temp
Final destination of the somatosensory system?
Post central Gyrus in the parietal lobe
Talk about Ruffinis’s endings
Contribute to the sensation of touch Have large receptor fields Slow adapting Skin stretch Slightly deeper than meissners and merkles but more superficial than pacianian
Talk about Pacinian corpuscles
Very rapidly adapting
Rapidly changing stimuli
VIbration
Deepest
Talk about Merkle’s Discs
Small receptor fields These allow for fine discrimination Slow adapting Detect steady pressure Most superficial
Talk about Meissner’s corpuscles
Small receptor fields These allow for fine discrimination Fast adapting Detect rapid changes Most superficial
What is the area of the skin supplied with afferent nerve fibers called?
Dermatomes
Talk about hair follicles
These have a nerve plexus that senses hair displacement.