Lecture 14- Blood Pressure

Question 1

Sphygmomanometer

Answer 1

Blood pressure cuff

Measures blood pressure

Question 2

What are the three adaptations critical to venous return?

Answer 2

1. Contraction off skeletal muscles creates a muscular pump to move blood back toward heart while venous valves prevent back flow
2. Pressure changes during breathing create a respirator pump to move blood by squeezing addominal veins as thoracic veins expand
3. Under sympathetic control, smooth muscles undergo sympathetic vena contraction pushing blood back toward the heart

Question 3

Varicose vein

Answer 3

A vein that has become enlarged or twisted

Most common in the legs because of gravity

Question 4

Difference between arteries and veins

Answer 4

Arteries run deep and are well protected
Veins can run deep and parallel to arteries or superficial

Artery pathways are relatively straight
Venous pathways often have interconnections

Question 5

Where does venous drainage not run parallel to arterial supply?

Answer 5

Dural sinuses draining the brain

Hepatic portal system draining from digestive organs to liver before entering main systemic circulation

Question 6

What three factors maintain blood pressure?

Answer 6

Cardiac output

Peripheral resistance

Blood volume

Question 7

What forms the cardiovascular centre?

Answer 7

Clusters of neurons in the medulla oblongata, Cardioacceleratory, cardioinhibitory and vasomotor centres

Question 8

Baroreceptors (pressure sensors)

Answer 8

Located in carotid sinus (side of neck) an aortic arch (just above heart) detect stretch and send impulses to vasomotor centre, inhibiting its activity and promoting vasodilation of arterials and veins

Question 9

What is the gas exchange in blood monitored by?

Answer 9

Detecting carbon dioxide

Question 10

Chemoreceptors

Answer 10

Detect rise in carbon dioxide levels of blood and stimulate the cardioacceleratory and vasomotor centres, which increases cardiac output and vasoconstriction.

Question 11

How do hormonal controls influence blood pressure?

Answer 11

By acting on vascular smooth muscle or vasomotor centre of the brain

Question 12

Norepinephrine and epinephrine

Answer 12

Neurotransmitters and hormones that produce body’s fight or flight response

Both increase heat rate and blood sugar

Question 13

Renin angiotensin aldosterone system

Answer 13

Hormone system that regulates blood pressure, fluids and electrolytes

Question 14

Renin

Answer 14

Enzyme activate din kidneys and released in blood plasma

Liver secretes a protein that Erin activates as angiotensin I and vascular endothelial cells convert to angiotensin II

Question 15

Angiotensin II

Answer 15

Is a vasoconstrictor and increases salt rentention in kidneys

Also stimulat the relates of aldosterone and anti diuretic hormone

Question 16

Aldosterone

Answer 16

From adrenal glands stimulates kidneys to retain more salt and water in blood

Increases blood volume and therefore blood

Question 17

Antidiuretic hormone

Answer 17

From pituitary gland promotes water reabsorption by kidneys, resulting in an increase in blood volume and blood pressure

Question 18

Atrial natriuretic peptide

Answer 18

is a vasodilator that increases sodium and water excretion in the kidneys, resulting in a drop in blood volume and blood pressure.

Inhibit srelease of renin aldosterone and ADH by organs that make those hormones

Released by cardiac muscle cells in response to high blood pressure in cardiac atria

Question 19

Direct renal mechanism

Answer 19

counteracts changes in blood pressure by altering blood volume, through adjustments in the rate of kidney filtration, resulting in an increased or decreased loss of fluids and solutes in the urine.

Question 20

Indirect renal mechanism

Answer 20

the renin- angiotensin-aldosterone system, which counteracts a decline in arterial blood pressure by releasing aldosterone and ADH, triggering thirst and salt cravings and promoting vasoconstriction.