Regulation of Blood Flow Flashcards
Cardiac Output
- Amount of blood flowing from the heart each minute
- Affected by stroke volume and heart rate
- stroke volume x heart rate
Stroke Volume
- Quantity of blood pumped with each heart beat
- weaker=more beats
Heart rate
-beats per minute (normal, 70)
Blood Pressure
- Measure of force that blood pushes against the arteries
- depends on Cardiac output and Arteriolar resistance
Increased cardiac output=?
increased pressure
Contraction of smooth muscle =
increased BP
Relaxation of smooth muscle =?
decreased BP
BP measured with ______
sphygmomanometer (BP cuff)
Systolic BP
ventricular contraction
normal = 120mmHg
Diastolic BP
Ventricular relaxation
Normal = 70mmHg
Hypertension
- high BP
- causes blood vessels to weaken or rupture
- connective tissue builds up bcs of body repairing itself, making arteries hard and less elastic
- 140/90
- Cause chest pains, strokes, heart attacks
Regulating High BP
BP receptors > medulla oblongata > arteries dilate > increase of outflow from artery > cardiac output decreases > slows movement of blood into arteries > lowers BP
Hypotension
- Low BP
- 90/60
- Reduces ability to transport blood
- Cause heart attacks, shock, stroke
Regulating Low BP
- BP receptors > medulla oblongata > arteries constrict > increase blood flow into artery > cardiac output increased > decreased outflow of blood > increases BP
Regulating Body Temperature
Thermoregulation: maintenance of body temperature within a range that allows cells to function efficiently
Temperature rises Pathway
- Nerve impulse > hypothalamus
- stimulated sweat glands
- Dilated blood vessels
- Blood flow to skin increases
- Heat loss (sweating)
Temperature drops pathway
- Nerve impulse > hypothalamus
- Skeletal muscles contract > shiver
- Blood vessels constrict
- Reduced heat loss
Filtration
- Water moves from capillary > ECF (Extracellular Fluid)
Absorption
Water moves from ECF > capillary
What is the effect of loss of blood
Cause low BP which increases the heart rate, the heart will beat faster to help the blood loss, blood vessels constrict to increase blood flow into artery
