Chapter 13: Heart and Circulation

These flashcards cover key vocabulary and concepts related to the heart and circulation as discussed in the lecture.

Functions of the circulatory system

Transporting nutrients, oxygen, hormones, and waste products throughout the body.

Pulmonary circuit

The system of blood vessels that carries blood between the heart and the lungs.

Side of heart that pumps for pulmonary circuit

The right side of the heart.

Systemic circuit

The system of blood vessels that carries blood between the heart and the rest of the body.

Side of heart that pumps for systemic circuit

The left side of the heart.

AV valves eversion prevention

The chordae tendineae and papillary muscles prevent eversion.

Flow of blood through heart and great vessels

Blood flows from the body into the right atrium, through the right ventricle to the lungs, and returns to the left atrium and left ventricle to be pumped to the body.

Three layers of blood vessels

Tunica intima, tunica media, and tunica externa.

First heart sound S1 (Lub) cause

Closure of the AV valves during ventricular contraction.

Second heart sound S2 (Dub) cause

Closure of the semilunar valves during ventricular relaxation.

Causes of valve closure

Pressure changes in the heart chambers.

Heart murmur

An abnormal heart sound often due to turbulent blood flow.

Term for a leaky valve

Regurgitation.

Term for a narrowed or stiff valve

Stenosis.

Cardiac cycle

The sequence of events in one heartbeat, including systole and diastole.

Systole

The phase of the cardiac cycle when the heart contracts and pumps blood.

Diastole

The phase of the cardiac cycle when the heart relaxes and fills with blood.

End-diastolic volume (EDV)

The volume of blood in a ventricle at the end of diastole.

End-systolic volume (ESV)

The volume of blood in a ventricle at the end of systole.

Connection of myocardial cells

Intercalated discs connect all myocardial cells.

Functional syncytium

A network of interconnected cells that function as a single unit.

Pacemaker of the heart

The sinoatrial (SA) node located in the right atrium.

Sequence of conductive tissues in the heart starting with SA node

SA node → atrioventricular node (AV node) → bundle of His → Purkinje fibers.

Secondary pacemakers

Atrioventricular (AV) node andbundle branches.

Pacemaker potential in SA node cause

Gradual depolarization due to sodium influx.

Three electrical events of cardiac muscle action potentials

Phase 0: rapid depolarization, Phase 1: initial repolarization, Phase 2: plateau phase.

Long refractory period in myocardial cells cause

Calcium influx during the plateau phase prevents premature contraction.

Importance of long myocardium refraction

Prevents tetany and allows effective pumping; seen as the baseline on EKG.

EKG definition

Electrocardiogram; measures the electrical activity of the heart.

P wave representation

Atrial depolarization.

QRS wave representation

Ventricular depolarization.

ST segment representation

The period between ventricular depolarization and repolarization.

T wave representation

Ventricular repolarization.

Cause of heart attack

Coronary artery blockage; ST elevation is a common indicator on EKG.

ST depression significance

May indicate ischemia or myocardial infarction.

ST elevation significance

May indicate acute myocardial infarction.

Layers of blood vessels

Tunica intima, tunica media, and tunica externa; tunica media is influenced by the autonomic nervous system.

Elastic arteries

Large arteries with high elasticity, found near the heart.

Capillaries

Tiny blood vessels that allow exchange of oxygen, nutrients, and waste.

Bulk of blood volume location

Primarily in the venous system.

Help veins return blood to heart

Skeletal muscle pump and respiratory pump.

Functions of lymphatic system

Transport lymph, provide immune responses, and return fluid to blood circulation.

functional syncytium

Atherosclerosis

A condition characterized by the buildup of plaque in arteries, leading to potential blockages.

LDL and HDL cholesterol

LDL (low-density lipoprotein) is 'bad' cholesterol; HDL (high-density lipoprotein) is 'good' cholesterol.

Ischemia definition

Insufficient blood flow to tissue due to blockage.

Infarction definition

Tissue death due to lack of blood supply.

Chest pain symptom

Angina.

Myocardial infarction (MI) cause

Plaque rupture followed by thrombosis at an atherosclerotic site.

Atherosclerotic process in vessel wall

Formation of fatty streaks that develop into plaques.

Arrhythmia definition

Irregular heart rhythm.

Bradycardia definition

Abnormally slow heart rate.

Tachycardia definition

Abnormally fast heart rate.