Cardiovascular System

REMEMBER!!!

pulmonary = to lungs, systemic = to the body, coronary= to the heart

diagrams DO NOT show your left and right → shows patients so everything is flipped

Coverings of the Heart

Acronym: FSPVME

Pericardium: sac that encloses heart composed of

• fibrous pericardium

• serous pericardium

• visceral pericardium (epicardium)

• parietal pericardium

• fibrous pericardium (tough and dense connective tissue)

Pericardial cavity contains serous fluid to reduce friction

Wall of the Heart:

epicardium- connective tissue with epithelium

• capillaries and nerve fibers, fat along coronary arteries and cardiac veins

myocardium- cardiac muscles that pumps blood out of heart chambers

endocardium- epithelium and underlying connective tissue

Purkinje Fibers

• Specialized cardiac muscle fibers that conduct electrical impulses in the heart

• Play a significant role in the coordinated contraction of heart chambers

• Located in the inner ventricular walls of the heart to facilitate synchronized heartbeats.

Heart Chambers & Valves

Atria

upper chambers → atria (thin walls and receive blood returning)

auricles: ear like projections that extend from atrioventricular orifice and guarded by A-V valve

Ventricles

Valves of the Heart

• tricuspid valve (right atrioventricular orifice) - prevents blood from moving from right ventricle into right atrium during ventricular contraction

• pulmonary valve (entrance to pulmonary valve) - prevents blood from moving from pulmonary trunk into right ventricle during ventricular relaxation

• mitral valve (left atrioventricular orifice) - prevents blood from moving from left ventricle into left atrium during ventricular contraction

• aortic valve (entrance to aorta) - prevents blood from moving from aorta into left ventricle during ventricular relaxation)

Blood Flow Circulation

1. deoxygenated blood enters right atrium through superior and inferior vena cava

2. blood passes tricuspid valve into right ventricle

3. right ventricle contracts and pushes through pulmonary valve

4. pulmonary arteries

5. pulmonary arteries then sends to lungs where blood receives oxygen

6. then goes through pulmonary veins back to left atrium

7. mitral (bicuspid ) valve opens for left atrium contraction and flows into left ventricle

8. left ventricle contracts and blood is pushed into aortic valve

9. oxygenated blood enters aorta and sent out to body

Blood Vessels

veins → to heart, arteries → to body

• arteries and arterioles

  • strong and elastic

  • 3 layers

    • Tunic Interna (innermost simple squamous with smooth surface)

    • Tunic Media (tube of smooth muscle fibers)

    • Tunica Extrema (thin connective tissue of collagen and elastin)'

• capillaries

  • connects to arterioles (extension of inner lining) and venules

  • semipermeable layer allows exchange of oxygen, carbon dioxide, metabolites, and nutries

• venules and veins

  • parralllels arteries back to heart

  • 3 layers like arteries but

    • thinner middle layer

    • less elastic

    • lumen has greater diameters and contains flaplike valves to stop blood backing up

Heart Actions (Cardiac Cycle + Sounds)

What is a cardiac cycle versus blood circulation?

cardiac cycle : events that occur during one complete heartbeat

blood circulation: continuous movement of blood

systole: contraction

diastole: relaxation

atrial systole while ventricular diastole and ventricular systole while atrial diastole

heart sound: lubb - dupp, causes by vibrations of heart tissues and opening and closing of the valves

lubb- ventricular systole

dupp- ventricular diastole

murmur: abnormal sound and can be detected using a stethoscope

Cardiac Conduction System

cardiac conduction system: A network of specialized muscle cells is found in the heart's walls. These muscle cells send signals to the rest of the heart muscle causing a contraction

a "node" refers to a specialized area of tissue within the heart that generates and conducts electrical signals

S-A Node (sinoatrial node)- small specialized cardiac muscle below epicardium in right atrium, near opening of superior vena cava

• decrease in potassium permeability

• over 80 times in a minute (rhythmic)

• known as the “pacemaker”

A-V Node (atrioventricular node)- inferior portion of septum and beneath endocardium

(gatekeeper between atria and ventricles)

• only normal conduction between atrial and ventricular syncytia

• impluse delayed as moved away from A-V node

A-V Bundle (aka. Bundle of His)- large fibers and divides right and left bundle branches

Purkinje Fibers- carry impluses to distant regions

Electrocardiograms, Pulse Rate, and Blood Pressure

Electrocardiogram

an electrocardiogram is a recording of the electrical changes that occur in the myocardium during a cardiac cycle using electrodes placed on skin

How it works?

1. the S-A node triggers a cardiac impulse

2. the atrial fibers depolarize → produces electrical change

3. pen moves producing a P wave → represents depolarization of atrial fibers that will lead to contraction of the atria

4. when reaches ventricular fibers, depolarization of ventricular fibers→ QRS complex

5. depolarization of ventricular walls (contraction) → T wave

Lab on Pulse and Blood Pressure

• blood pressure is the force exerted against the walls of the arteries

• blood pressure refers too systemic arterial pressure

• maximum pressure achieved during ventricular contraction is called systolic pressure

• lowest pressure that remains in arterial system during ventricular relaxation is called diastolic pressure

• a pulse is caused by the closing of the aortic valve

• the brachial artery in the arm is the standard systemic artery in which we measure blood pressure

• the first sound of the cardiac cycle occurs when the atrioventricular valves are closing

• the second sound of the cardiac cycle occurs when the semilunar valves are closing

Reading blood pressure:

top number - systolic pressure (contraction)

lower number - diastolic pressure (relaxation)

Heart Issues & Concerns

Endocarditis- inflammation of the endocardium

Hypertension- high blood pressure

• potential

• causes: kidney disease, sodium, obesity, stress, arteriosclerosis, essential, primary or idiopathic hypertension

• enlargement and weakening of heart due to increased leftt venricle pumping

Atherosclerosis- build up of fats or cholesterol around artery walls

• can be developed from coronary thrombosis, coronary embolism,s troke

Extra Quizizz Review!!

1. blood pressure is lowest in vena cava

2. the valve between the left ventricle and aorta is the aortic

3. capillaries is smallest vessel

4. EKG= PQRST

5. coronary is the circulation that brings blood from aorta to myocardium and back to right atrium through coronary sinus

6. ventricular fibrillation refers irregular contraction of the ventricle, heartbeat fast and ineffective heart rhythm that may result in death

7. tachycardia refers to heart rate that is fast

8. heat may cause vasodilation

9. angina is spasm of chest pain due to decrease in blood flow to myocardium

10. medical term for heart attack is myocardial infraction

11. renin regulated blood