ANATOMY AND PHYSIOLOGY - HEART

Regulates blood supply, Generates blood pressure, Routes blood, Ensures 1 way blood flow

The Functions of the Heart

fist size, less than 1 lb

Size and weight of the Heart

between lungs in thoracic cavity

Location of the Heart

apex towards the left side

Orientation of the heart

Pericardium

double-layered sac that anchors and protects heart

Parietal Pericardium

membrane around heart’s cavity

Visceral Pericardium

membrane on heart’s surface

Pericardial Cavity

space around heart

Epicardium

surface of heart (outside)

Myocardium

thick, middle layer composed of cardiac muscle

Endocardium

smooth, inner surface

1, nucleus

Cardiac Muscle has ___ centrally located __________

F, rich

T OR F:

Cardiac Muscle is poor in Mitochondria.

F, branching

T OR F:

Cardiac Muscle have pumping cells.

actin and myosin

The Cardiac Muscle is striated by

LA, RA, LV, RV

The 4 Chambers of the Heart

Coronary Sulcus

separates atria from ventricles

Atria

Located at the Upper Portion

Atria

Holding Chambers

Atria

Contract minimally to push blood into ventricles

minimally, ventricles

Atria contract ____________ to push blood into ____________

Atria

Small, thin-walled

Interatrial Septum

separates right and left atria

Ventricles

Located at the Lower Portion

Ventricles

Pumping Chambers

forcefully

Ventricles contract ____________ to propel blood out of heart

Ventricles

Contract forcefully to propel blood out of heart

Ventricles

Thick, strong-walled

Interventricular Septum

separates right and left ventricles

Valves

structures that ensure 1 way blood flow

Atrioventricular Valves

between atria and ventricles

Tricuspid Valve

AV valve between RA and RV

Right Atrium and Right Ventricle

The Tricuspid Valve is an Atrioventricular Valve between

Bicuspid Valve

AV valve between LA and LV

Left Atrium and Left Ventricle

The Bicuspid Valve is an Atrioventricular Valve between

Papillary Muscles

cone-shaped, muscular pillars

Chordae Tendineae

attached to AV valve flaps

Chordae Tendineae

supports valves

Pulmonary Semilunar Valve

base of pulmonary trunk

Aortic Semilunar Valve

Base of aorta

LA into LV

If the Bicuspid Valve is open, blood flows from

closed

If the Bicuspid Valve is open, the Aortic Semilunar Valve is

open

The tension on chordae tendineae is low if the Bicuspid Valve is

LV into Aorta

If the Bicuspid Valve is closed, blood flows from

open

If the Bicuspid Valve is closed, the Aortic Semilunar Valve is

closed

The tension on chordae tendineae is high if the Bicuspid Valve is

Cardiac Skeleton

plate of connective tissue

Cardiac Skeleton

fibrous rings

Atrioventricular and Semilunar Valve

Cardiac Skeleton surround the

Pulmonary Circuit

carries blood from heart to lungs

Pulmonary Circuit

blood is O2 poor, CO2 rich

Superior and Inferior Vena Cava, Coronary Sinus

The Right Atrium receives blood from:

Superior Vena Cava

drains blood above diaphragm

Inferior Vena Cava

drains blood below diaphragm

Coronary SInus

drains blood from myocardium

Right Ventricle

opens into pulmonary trunk

Pulmonary Trunk

splits into right and left pulmonary arteries

Pulmonary Arteries

carry blood away from heart to lungs

Systemic Circuit

carries blood from heart to body

Systemic Circuit

blood is O2 rich, CO2 poor

Left Atrium

4 openings (pulmonary veins) that receive blood from lungs

Left Ventricle

opens into aorta

Left Ventricle

thicker, contracts more forcefully, higher blood pressure than right ventricle has to get to body

Aorta

carries blood from LV to body

RA, TV, RV, PSV, PT, PA, L, PV, LA, BV, LV, ASV, A, B

Blood Flow to the Heart

Coronary Arteries

supply blood to heart wall

Coronary Arteries

originate from base of aorta (above aortic semilunar valve)

Left Coronary Artery

has 3 branches

Left Coronary Artery

supply blood to anterior heart wall and left ventricle

Right Coronary Artery

originates on right side of aorta

Right Coronary Artery

supply blood to right ventricle

Pacemaker Potential

Changes in membrane channels’ permeability are responsible for producing action potentials and are called

Depolarization Phase

Na+ channels open, Ca2+ channels open

Plateau Phase

Na+ channels close, Some K+ channels open, Ca2+ channels remain open

Repolarization Phase

K+ channels are open, Ca2+ channels close

Coronary System of the Heart

contraction of atria and ventricles by cardiac muscle cells

SA Node

in RA

SA Node

where action potential originates

SA Node

functions as pacemaker

SA Node

large number of Ca2+channels

SA Node, AV Node, AV Bundle, RL Bundle Branches, Purkinje Fibers

Path of the Action Potential to the Heart

Electrocardiogram

record of electrical events in heart

Electrocardiogram

diagnoses cardiac abnormalities

Electrocardiogram

uses electrodes

Electrocardiogram

contains P wave, QRS complex, T wave

P Wave

depolarization of atria

QRS Complex

depolarization of ventricles

QRS Complex

contains Q, R, S waves

T Wave

repolarization of ventricles

Right and Left

Heart is 2 side by side pumps:

Atria

Primers for Pumps

Ventricles

Power Pumps

Cardiac Cycle

repetitive pumping action which includes contraction and relaxation

Cardiac Muscle Contractions

produce pressure changes within heart chambers.

Pressure Changes

are responsible for blood movement.

T

T OR F:
Blood moves from areas of high to low pressure.

Atrial Systole

Contraction of Atria

Ventricular Systole

Contraction of Ventricles

Atrial Diastole

Relaxation of Aorta

Ventricular Diastole

Relaxation of Ventricles