blood vessels test

Arteries/arterioles function

Carry blood away from heart to capillaries

Capillaries function

Exchange of substances between tissues and blood

What color is oxygenated blood

Red

Vein/venule function

Carry blood to heart

What do blood vessels need

Oxygen/nutrients, bigger ones have own blood supply

What has lowest BP in whole body

Veins/venules

Inner layer of blood vessel name

Tunica intima (made of simple squamous epithelium)

Middle layer of blood vessel name

Tunica media (made of smooth muscle)

Name for outer layer of blood vessel

Tunica adventitia (connective tissue)

Middle layer function

Controls BP in arterioles

Largest artery in body and location

aorta (in heart)

What do capillaries do

Joins arterioles to venules

What substances are exchanged in capillaries

Oxygen, carbon dioxide, nutrients, wastes

Are all capillary beds open at same time

Never

Arteriovenous shunt

Allows capillaries to be bypassed

What closes off capillaries

Precapillary sphincter

Are veins stiff or elastic

Elastic; can stretch/expand to hold more blood

What is maximum % of blood in venous side of circulation at any one time

70%

Function of veins’ valves

Prevent backflow of blood

How do valves prevent backflow

Skeletal muscle action squeezes blood upward through valves

Largest veins

Vena cavae

Two types of vena cavae

Superior and inferior

How many chambers does the heart have

4 chambers

What are the 2 upper chambers called

Atria

What do 2 upper atrias do

Receiving chamber for blood from body/lungs

Name of two lower chambers

2 lower ventricles

What do ventricles do

Pump blood back into body/lungs

What is a septum

Separates each pair of chambers

Why does septum separate?

To keep oxygenated and deoxygenated blood separate. Right atrium = deoxygenated, left atrium = oxygenated

What is major portion of heart wall

Myocardium-cardiac muscle

what are inner surfaces of the heart wall lined with

Endocardium

Outer surfaces of heart wall are lined with)

Epicardium

what kind of tissue is endocardium

Epithelial

What kind of tissue is epicardium

Connective tissue

How many heart valves per chamber

One valve per chamber

What are heart valves called

Atrioventricular valves

Where are atrioventricular valves located

Between atrium and valve on each side

Where is mitral valve located

Between left atrium and left ventricle

Where is tricuspid valve located

Between right atrium and right ventricle

what are semi lunar valves

Aortic and pulmonary valve

Aortic valve location

Between left ventricle and aorta

Pulmonary valve location

Between right ventricle and pulmonary artery

What do all valves in heart do

Control blood flow through the heart

What do superior/inferior vena cavae do

Bring oxygen-lacking blood to right atrium

how is de-oxygenated blood oxygenated

Blood flows: superior/inferior VC → right atrium → tricuspid valve → right ventricle → pulmonary valve → pulmonary artery → lungs → pulmonary veins → left atrium → mitral valve → left ventricle →aortic valve → body.

Which side is pulmonary pump on

Right side

What does pulmonary pump do

Pump deoxygenated blood to pulmonary circuit/lungs

Which side is systemic pump

Left side

What does systemic pump do

Pumps oxygenated blood out to systemic circulation

What type of blood pressure is required for ventricle pumps to work

Higher BP

How long is cardiac cycle

0.8 seconds

How does each heartbeat occur

Both atria contract together, then both ventricles contract together. NEVER AT SAME TIME

Systole definition

Contraction of heart muscle

Diastole definition

Relaxation of heart muscle

Normal HR

60-80 BPM

What produces “lub dup” heart sounds

Turbulence/tissue vibration as valves close

When does “lub” sound occur

When Atrioventricular valves close

When do “dups” occur

When semilunar valves close

What are heart murmurs

Leaky valves producing abnormal heart sounds

What is autorhymicity

Cardiac muscle contracting w/out neural stimulation

what are nodal tissues

2 areas in heart that have both muscular/nervous properties

What do nodal tissues do

Generate action potentials to cause contractions

What does SA node do

Produces electricity

What is normal conduction pathway

SA node in right atrium starts impulse → spreads through atria → AV node delays and sends it down AV bundle → through septum → Purkinje fibers spread it through ventricles.

What happens if AV fails

Ventricles can contract alone (20-40 BPM)

How to have extrinsic control of heartbeat

Parasympathetic stimulation decreases HR, then sympathetic increases HR and contractility.

Can hormones control heart rate

Yes

What two chemicals cause increased HR

Epinephrine and norepinephrine

When do epinephrine and norepinephrine increased HR occur

Exercise, fight/flight

What does electrocardiogram do

measures electrical activity of heart

What is P-wave

Atrial depolarization (contraction)

What is QRS complex

Ventricular depolarization

What is T-wave

ventricular depolarization -relaxing

Tachycardia

Pulse at rest over 100 BPM

Bradycardia

Pulse at rest under 60 BPM

Sinostrial block

Signal from SA node doesn’t reach atria, no p-wave

Atrioventricular block

Signal gets delayed too much going to ventricles, P-R interval too long

Ventricular fibrillation

Erratic quivering of ventricles, constant small movements but no pumping occurs. Lethal

Cardiac arrest

Flatline

Atrial fibrillation

No meaningful P-wave, atria isn’t fully contracting. Not lethal because ventricles still contract

Is sinoatrial block lethal

No; 70% of blood still goes through

Pulmonary circuit locations

Right ventricle pumps deoxygenated blood to lungs via pulmonary arteries → gas exchange in alveolar capillaries →oxygenated blood returns to left atrium via pulmonary veins.

Systemic circuit locations

Left ventricle pumps oxygenated blood into aorta → systemic arteries → capillaries (O2 dropped, CO picked up) - venules/veins → superior/inferior vena cava → right atrium.

What does coronary circulation do

Supply heart muscle

what are coronary arteries

First branches off aorta, located on heart surface, distribute blood to heart muscle

Where is blood collected in coronary circulation

Collected in venules, then opened into coronary veins

What atrium do coronary veins enter into

Right atrium

Hepatic portal system cleaning process

Carries nutrient-rich blood from digestive tract to liver via hepatic portal vein. Liver absorbs nutrients, detoxifies blood, and sends clean blood to inferior vena cava via hepatic veins.

Where is highest blood flow

Aorta

Where is lowest blood flow

Vena cavae

What is blood pressure

Pressure of blood against vessel walls

What has highest pressure

Systolic pressure

What has lowest pressure

Diatomic pressure

What does blood pressure account for

Flow through arteries and arterioles

When does blood pressure decrease

As blood flows throughout your body, spreads out

What is the normal blood pressure

110/70

What does 110/70 represent in BP

Systolic/diastolic

Function of papillary muscle

To help close valves