Regulation of Circulation

Question 1

Fairly constant

Answer 1

brain, liver, heart

Question 2

Needs/supply change

Answer 2

skin, muscles, gut

Question 3

Systemic circuit

Answer 3

rest of body

Question 4

Pulmonary circuit

Answer 4

flow to lungs

Question 5

NO

Answer 5

paracrine hormone

Question 6

Muscle contraction proteins

Answer 6

actin and myosin

Question 7

Intracellular Ca2+

Answer 7

needed to enable myosin to bind to actin, normally low levels
electrical signal receieved by muscle fiber releases stores of Ca into muscle fiber cytosol

Question 8

Action potential

Answer 8

electrical signal that is a self sustaining wave of membrane depolarization, results from the movement of ions across the plasma membrane

Question 9

Influences on cardiac cycle

Answer 9

electrical, chemical

Question 10

Cardiac cycle

Answer 10

1) SA node
2) AV node
3) bundle branches
4) Purkinje fibres

Question 11

Cardiac output

Answer 11

heart rate x stroke volume

Question 12

Acetylcholine

Answer 12

neurotransmitter, released by nerves to cells of SA ndoe, opens K channels and efflex of K from cells, lowers resting potential of cells

Question 13

Norepinephrine

Answer 13

released by nerves to cells of SA node, increases Ca2+ and Na influx

Question 14

Adrenaline

Answer 14

epinephrine. blood borne hormone, nervous stimulation of cardiac output. increases release of Ca into cytosol of ventricular cells and faster removal of these ions. stronger/briefer contractions