Anatomy and Physiology: Chapter 17 The Cardiovascular System

Pulmonary Circuit

Right Side: Receives oxygen poor blood from body and pumps it to the lungs

Systemic Circuit

Left Side: Receives oxygen rich blood from the lungs and pumps it to the rest of the body

Receiving Chambers

Atria

Pumping Chambers

Ventricles

Apex of the Heart

bottom point(points left)

Base of the Heart

top part(points right)

Pericardium

double-walled sac that surrounds the heart

2 Layers of the Pericardium

1. Fibrous Pericardium(protects and anchors the heart, prevents overfilling)

2. Serous Pericardium(2 layers: parietal layer, visceral layer)

3 Layers of the Heart Wall

1. Epicardium(visceral layer of serous pericardium)

2. Myocardium(circular/spinal bundles of contractile cardiac muscle cells)

3. Endocardium(innermost layer, continuous with endothelial lining of blood vessels)

Coronary Sulcus

atrioventricular groove, encircles junction of atria and ventricles

Interatrial Septum

separates atria

Interventricular Septum

separates ventricles

Atria

receiving chambers, thin walled

Auricles

flappy appendages on atria that increase volume

Ventricles

Discharging/Pumping cambers, thicker walls

2 Major Types of Heart Valves

1. Atrioventricle valves(between atria and ventricles)

2. Semilunar valves(between ventricles and major arteries)

Tricuspid Valve

The atrioventricle valve between right atrium and right ventricle. Has 3 cusps.

Mitral(Bicuspid) Valve

The atrioventricle valve between the left atrium and ventricle, Has 2 cusps.

Pulmonary Semilunar Valve

between right ventricle and pulmonary trunk

Aortic Semilunar Valve

between left ventricle and aorta

Coronary Circulation

Blood supply for the heart itself

Left Coronary Artery

Supplies interventricular septum, anterior ventricular walls, left atrium, and posterior wall of left ventricle

Right Coronary Artery

Supplies right atrium and most of right ventricle.

Cardiac Veins

Collects blood from capillary Veins

Coronary Sinus

Formed by the merging of the great cardiac vein, middle cardia vein, and small cardiac vein then empties into the right atrium.

Cardiac Muscles (features)

striated, short, branched, interconnected, one(sometimes 2) nulceus, LOTS of mitochondria

Differences between Cardiac and Skeletal Muscles

1. cardiac cells are self-excitatory

2. heart contracts as a unit

3. tetanic contractions only occur in skeletal muscles

4 cardiac muscles are almost exclusivly aerobic

5. cardia has gap junctions

4 Major Macromolecules

Complex Carbohydrates

Complex Lipids

Nucleic Acid

Proteins

Action Potential(3 stages)

1. Depolarization

2. Repolarization

3. Hyperpolarization

Myocardial Cells

has plateau on chart, resting membrane potential is -90mV

Intrinsic Conduction Cells

Looks like weird W, resting membrane potential is -60mV

Types of Proteins(3)

1. Channels- passive

2. Pumps- active(requires ATP)

3. Contractile- Actin(thin) and Myosin(thick)

Systole

Period of heart contraction

Diastole

Period of heart relaxation

Cardiac Cycle

Blood flow through the heart during one complete heartbeat

End Diastolic Volume(EDV)

volume of blood in each ventricle at the end of ventricular diastole

End Systolic Volume(ESV)

volume of blood remaining in each ventricle after systole

Stroke Volume(SV)

Amount of blood pumped each beat/ EDV-ESV

Cardiac Output(CO)

CO=Heart Rate(HR) x Stroke Volume(SV) (normal=5.25 L/min)

Heart Rate(HR)

Number of beats per minute

Cardiac Reserve

Difference between resting and maximal cardiac output(CO)

3 Main factors that affect SV

1. preload(stretch of the heart muscle)

2. contractility

3. afterload(back pressure exerted by arterial blood)

What can regulate Heart Rate

1. Autonomic Nervous System

2. Chemicals

3.Other Factors

Atrial Brainbridge Reflex

sympathetic reflex initiated by increased venous return, hence increased atrial filling