Cardio phys book stuff and notes

The volume of blood ejected from the LV per unit of time is

cardiac output

The rate at which blood is returned to the atria from the veins is called?

venous return

Parallel arrangement means

that total systemic blood flow must equal cardiac output

Where is pressure highest, the vena cava or the right atrium ?

the vena cava

What happens in the capillary beds?

O2 is added to remove CO2

The volume of blood in the arteries is

stressed volume

What is the site of highest resistance to blood flow?

arterioles

What arterioles have B2 adrenergic receptors?

skeletal muscle

The volume of blood contained in the veins is the

unstressed volume

What do a1 receptors do to unstressed volume?

reduce it

What factors determine blood flow through blood vessels?

pressure difference between ends and resistance of the vessel to blood flow

Where does the greatest decrease in pressure occur?

in the arterioles

What holds the largest percentage of blood in the body?

Veins (60-70)

What holds the second highest percentage of blood in the body?

arteries and capillaries (5-10)

Describe mean arterial pressure in terms of the aorta

mean arterial pressure is high in the aorta and drastically drops when it reaches the arterioles

What pressures are greater in the large arteries relative to the aorta?

pulse pressure and systolic pressure

compliance in vessels is

change in volume for a given change in pressure.

How would you describe compliance in veins at low pressures?

very compliant

What is capacitance?

the total vessel can hold at a given pressure

Why is MAP highest in the aorta and large arteries?

Elasticity of the aorta and large arteries

Why do the arterioles have a strong drop in MAP?

have a high resistance to flow

What is the lowest pressure measured in a cardiac cycle?

diastolic pressure

What is the highest pressure in the cardiac cycle?

Systolic

What is pulse pressure?

the difference between systolic and diastolic pressure

How is mean arterial pressure calculated?

diastolic pressure +1/3 pulse pressure

What is pulmonary vascular resistance compared to systemic vascular resistance?

much lower

Where are contractile cells?

A/V cells, working cells

What are contractile cells?

SA node, AV nodes, perkunje, his, etc. rapidly spread APs

What is the first step of the complete circuit in mammals?

oxygenated blood fills the left ventricle

What is the second step in circulation?

blood is ejected from left ventricle to aorta

The third step of the complete circuit?

cardiac output is distributed among various organs

what is the fourth step of the complete circuit?

blood flow from organs is collected in veins

What is the fifth step of the complete circuit?

venous return to right atrium

What is the 6th step of the complete circuit?

mixed venous blood fills the right ventricle

What is the 7th step of the complete circuit ?

blood is ejected from the right ventricle into pulmonary artery

What is the 8th step of the complete circuit?

blood from lungs is returned to the heart via pulmonary vein

What is the job of blood vessels?

delivers blood to tissues for nutrients and waste exchange and regulates blood flow to organs

arteries deliver

O2 to organs

How would you describe the aorta?

largest artery, greatest elasticity

What are the distinctive parts of veins?

veins have minimal elasticity and high capacitance, low pressure, carry most blood volume

What is lymph

plasma ultrafiltrate

What does increased viscosity do to resitance

increases resistance

What does length do to resistance

increased length increases resistance

What does decreased radius of vessel do to resistance?

increases the resistance

If blood flow is less than 2000 it is considered

laminar

If blood flow is greater than 2000 it is considered

turbulent

What is the MAP of the aorta?

80-100 mmHg

What is the MAP of the right atrium?

0-5 mmHg

What is the main determinant of Packed Cell volume?

viscocity

What are the four phases of an AP in the heart

1. Na comes into the heart rapidly

2. Ca comes in slowly K leaves (plateau phase)

3. K leaves rapidly

4. Na and Ca enter cell and K leaves

The P wave is

depolarization of the atria

What sound is the P wave?

4th heart sound

What is the PR interval?

time from initial depolarization to initial depolarization to ventricles

QRS duration is the

depolarization of the ventricles

What heart sound is the QRS?

1st heart sound

The T wave is the

repolarization of ventricles

The QT interval is

ventricular depolarization to the last ventricular repolarization

What maintains the Na gradient and RMP in cardiac muscle contraction

Na/ATPase

What is the Frank-starling relationship?

volume of blood ejected from ventricle depends on volume present at the end of diastoe, increases EDV and increases CO

sympathetic activation via B1 causes

increases HR, increases contractility, increases vasoconstriction

What does baroreceptor reflex do?

increases blood pressure, decreases HR

What do chemoreceptors do?

periphreal- O2

Central-Co2 and pH

What does RAAS do?

vasocontriction, Na+ and H2O absorption, increases thirst

Aldosterones job is

Na+ H2O absorption

Atrial natriuretic peptide does

increased renal excretion of salt water, vasodilation, and increased vascular permeability

ADH does

increases H2O