Exam 1 Flashcards
(27 cards)
T/F
Spontaneous diastolic depolarization features the change in resting membrane potential toward a critical threshold potential for depolarization and is a characteristic of pacemaker tissue
True
T/F
Efferent outflow from central command can override the extrinsic control exerted on the heart by the cardioregulatory center in the medusa oblongata
True
During low to moderate intensity exercise, heart rate is increased mainly by:
A) Inhibition of sympathetic stimulation
B) Activation of parasympathetic stimulation
C) Activation of sympathetic stimulation
D) Inhibition of parasympathetic stimulation
D) Inhibition of parasympathetic stimulation
The opening of dormant capillaries in exercise does all of the following except:
A) Increase the effective surface for gas and nutrient exchange
B) Decrease heart rate
C) Deliver a large blood volume with only a minimal increase in blood flow velocity
D) Increase total muscle blood flow
B) decrease heart rate
The cardiac transplant patient demonstrates all of the following hemodynamic responses to exercise except
A) Chronotropic response due only to blood Bourne epinephrine
B) Impaired exercise capacity compared to normal subjects
C) No training effects
D) No plateau of stroke volume
E) No autonomic neural control
C) no training effect
T/F
Sympathetic stimulation affects blood flow throughout the body by a-adrenergic receptor causing vasodilation
False
T/F
Increases in systolic and mean arterial blood pressures during exercise are explained by overriding the normal operating range of baroreceptor loop at rest to a higher operating range with the same sensitivity
True
Stimuli within active muscle that promote vasodilation include: A) Increased tissue PCO2 B) Increased NO C) Decreased pH D) All of the above
D) All of the above
T/F
Constriction and dilation large arteries provide the critical mechanism for regulation flow to capillary beds
False
Functions of the cardiovascular system:
- Transport of O2 to _______
- Transport of CO2 _____ tissues
- Transport of energy substrate
- _________ of hormones
- ____________ of arterial blood pressure
- Thermoregulation
Tissues
From
Transport
Maintenance
Cardiovascular 4 components:
Heart
arteries
capillaries
veins
T/F
No gaseous exchange occurs between arterial blood and surrounding tissues
True
Arterioles branch and form smaller and less muscular vessels called ___________, which are _ -20 micrometers in diameter
Metarterioles
10
Metarterioles end in microscopically small blood vessels called __________ that contain 6% of total blood volume
Capillaries
The pre capillary sphincter consists of a ring of ______ muscle that encircles the capillary
Smooth
T/F
Sphincter constriction and relaxation provide a means for blood flow regulation within a specific tissue to meet metabolic requirements
True
2 factors trigger pre capillary sphincter relaxation to open more capillaries:
- Driving force of increased local BP plus ________ neural control
- Local __________ produced in exercise
Intrinsic
Metabolites
T/F
Cardiac muscle cells are no more than 8 microns(the width of a typical red blood cell)from a capillary
true
Inferior vena cava
Veins in the lower body eventually returns blood to right atrium from abdomen, pelvis, and lower extremities
Venous blood from vessels in head, neck, shoulder region, thorax, and abdominal walls flow into the ________ vena cava to join inferior vena cava at the heart
Superior
Mixed ______ blood enter right atrium, then through the tricuspid valve to the right ventricle
Venous
_______ within veins allow blood to flow in only one direction toward the heart
Vales
Venous pooling benefits
- enhance post exercise lactate clearance
- offsetting possible syncope to post exercise catecholamine induced vasodilatiion
High blood pressure is also known as
hypertension
