(B2) E1, Q2 physiology

Cardiac output (CO)

Blood volume pumped by heart per unit time

Venous return (VR)

Blood volume in veins

Capacitance vessels

Veins

Resistance vessels

Arterioles

In steady state, compare CO and VR

CO = VR

Blood flow is proportional to

Radius ^4

Conductance

1/ resistance

Blood flow in cardiovascular system is

Laminar

Which flow type requires more energy

Turbulent

Reynolds number (Nr)

Predicts if blood flow is laminar (<2000) or turbulent (>3000)

Pressure is highest in

Aorta/ arteries

Law of Laplace

Explains why small blood vessels do not rupture under pressure of blood flow

MAP (mean arterial pressure)

Diastolic pressure + 1/3 pulse pressure

Compliance

Blood vessel elasticity

Capacitance

Total volume of blood a vessel can hold

Which vessel releases NO, a regulator of blood flow

Capillaries

A1 receptors

Cause blood vessels to constrict, increasing BP

Name 3 A1 receptor drugs

Phenylephrine, oxymetazoline, midodrine

sarcolemma

Muscle membrane

Sarcoplasm contains

A large number of mitochondria

Sarcoplasmic reticulum

Store/ release Ca2+

Myofibrila

Divided into sarcomeres, made of actin, myosin, and titin

Sarcomere mnemonic

Zach is a hungry man

Tropomyosin

Cover actin so myosin cannot bind

F actin

The double stranded actin polymer

troponin complex

Binds calcium to move tropomyosin to expose binding sites

Troponin T

Binds tropomyosin

Troponin I

Inhibits myosin, binds actin

Troponin C

Binds calcium

Myosin

Thick filament

Myosin head does what

Binds and hydrolyzes ATP

Where are t tubules found

Between SRs

What is a triad

A t tubule and 2 terminal cisternae (SR ends)

Electrical synapse

No delay, bidirectional

Chemical synapse

Delay, unidirectional

Ionotropic receptor

Ligand gated ion channels

Metabotropic receptor

GPCR

What does titin do

TMZ: links myosin to Z line