chapter 18 and 19 preparation

Hypocalcemia

Low blood calcium, decreases HR

Hypercalcemie

High blood calcium, increases HR and contracibilty

End systolic volume

Volume of blood remanning in ventricles after contraction

End diastole volume

Amount of blood that collects in ventricle Donna diastole

Stroke volume

Volume of blood pumped out

Cardiac output

Volume of blood pumped out in 1 minute

3 factors that affect Sv

Preload, contractibility afterload

Preload

Degree to which cardiac muscle cells are stretched

Contractility

Contractile strength @given muscle length

Afterload

Back pressure exerted by arterial blood

Blood vessels

Delivery system of dynamic structures that begins and ends @ heart

Arteries

Carries blood from heart - oxygenated

Capillaries

Direct contact with tissue cells; directly serve cellular needs

Veins

Carry blood toward heart; deoxygenated

Structure of blood vessel wall

Tunica intimate, tunica media, tunica external

Arteries 3 groups:

Elastic arteries, muscular arteries, arterioles

Peripheral resistance

Blood viscosity, total blood vessel length blood vessel diameter

Sequence of excitation

Sinoatrial nodes

Atrioventricular node

Atrioventricular bundles

Bundle branches

Subendocardial conducting network

Intrinsic

Pacemaker potential: K closed, Na open POSITIVE

Depolarization: Ca channels huge influx

Depolarization: K open and enter NEGATIVE

Venous blood pressure return

Muscular pump, respiratory pump, sympathetic venoconstriction

What is pericardium?

Outer protective layer of the heart

Elastic arteries

Largest _ thick walled, large lumen inactive vasoconstriction

Muscular arteries

Distribute blood to organs mare smooth muscle

Arterioles

Lead to capillary beds