Med-tech Cardiac Test

Gap Junctions

Specialized connections between cells allowing direct electrical and chemical communication; found in cardiac and smooth muscle.

Desmosomes

Anchoring junctions that hold cells together, providing structural integrity; prevalent in cardiac muscle and skin.

SA Node (Sinoatrial Node)

 Located in the right atrium; the heart's natural pacemaker, initiating electrical impulses.

AV Node (Atrioventricular Node)

Located near the septal wall of the right atrium; delays and relays impulses from the atria to the ventricles.

Papillary Muscles

Located in the ventricles; contract to prevent prolapse of atrioventricular valves during systole.

Chordae Tendineae

String-like structures connecting papillary muscles to valve leaflets; prevent valve backflow

Pulmonic Valve

Located between the right ventricle and pulmonary artery; prevents backflow of blood into the right ventricle

Aortic Valve

 Located between the left ventricle and the aorta; prevents backflow into the left ventricle.

Mitral Valve

Between the left atrium and left ventricle; prevents backflow into the atrium.

Cardiac Auscultation Locations:

1) Aortic Area:

2) Pulmonic Area:

3) Erb’s Point:

4) Tricuspid Area:

5) Mitral Area (Apical):

1) 2nd intercostal space, right sternal border

2) 2nd intercostal space, left sternal border

3) 3rd intercostal space, left sternal border)

4) 4th-5th intercostal space, left sternal border

5) 5th intercostal space, midclavicular line

Syncytium

A multinucleated cell-like structure enabling synchronized contraction; key in cardiac muscle

Bruit

An abnormal sound caused by turbulent blood flow, often indicative of vascular abnormalities

 Innocent Murmur

A harmless heart murmur without underlying pathology, common in children

Aneurysm

A localized dilation or bulge in a blood vessel wall due to weakness

Arrhythmia

 An abnormal heart rhythm caused by electrical disturbances.

 Atrial Fibrillation (AFib)

Irregular atrial rhythm; increases stroke risk

Ventricular Tachycardia (VT)

Rapid ventricular rhythm; potentially life-threatening

Bradycardia

Abnormally slow heart rate; may require pacemaker

Superior Vena Cava location and function

• Location: drains the upper body into the right atrium

• Function: Return deoxygenated blood to the heart.

Inferior Vena Cava location and function

• Location: drains the lower body.

• Function: Return deoxygenated blood to the heart.

Myocardial Infarction Causes:

Blockage of coronary arteries due to plaque rupture, thrombus, or vasospasm.

Atrial Fibrillation Side Effects:

Palpitations, fatigue, and increased risk of embolic stroke

Arterial Layers:

1. Intima:

2. Media:

3. Adventitia:

1. Innermost endothelial layer

2. Middle muscular and elastic layer

3. Outer connective tissue layer

Cardiomyopathy Causes and Effects:

• Causes: Genetic factors, hypertension, alcohol, infections.

• Effects: Impaired cardiac function, heart failure.

Types of Cardiomyopathy:

1. Dilated:

2. Hypertrophic:

3. Restrictive:

1. Enlarged ventricles with weakened contraction

2. Thickened ventricular walls obstructing blood flow

3. Stiffened ventricles reducing filling

Congestive Heart Failure Signs and Symptoms:

Shortness of breath, edema, fatigue, weight gain, and jugular vein distension.

Pressures in the Heart:

Highest in the left ventricle during systole due to systemic circulation demand.

First Heart Sound (S1):

Created by closure of mitral and tricuspid valves during systole

Second Heart Sound (S2):

Created by closure of aortic and pulmonic valves during diastole.

Blood Flow Through the Heart:

1. Vena cava → Right atrium → Tricuspid valve → Right ventricle → Pulmonic valve→ Pulmonary artery → Lungs.

2. Pulmonary veins → Left atrium → Mitral valve → Left ventricle → Aortic valve →Aorta → Body.

Purpose of an EKG:

Records the heart’s electrical activity to diagnose arrhythmias, ischemia, or conduction abnormalities.

P Wave:

Represents atrial depolarization (electrical) and atrial contraction (mechanical).

QRS Complex:

Represents ventricular depolarization (electrical) and ventricular contraction (mechanical).

T Wave:

Represents ventricular repolarization (electrical) and ventricular relaxation (mechanical)