HEART and BV

What are the main parts of cardiac circulation?

Aorta, Pulmonary trunk (arteries), Pulmonary veins, Left Atrium, Right Atrium, Left Ventricle, Right Ventricle, Tricuspid valve, Bicuspid (Mitral) valve, Pulmonic valve, Aortic valve, Pulmonary capillaries, Systemic capillaries.

What is the function of the pulmonary circuit?

ADD OXYGEN Carries deoxygenated blood from the right ventricle to the lungs and returns oxygenated blood to the left atrium.

What is the function of the systemic circuit?

Carries oxygenated blood from the left ventricle to body tissues and returns deoxygenated blood to the right atrium.

Why are there valves in the heart?

To prevent backflow of blood and ensure one-way blood flow.

What is vascular incompetence?

A failure of a valve to close completely, causing backflow of blood.

What is stenosis?

A narrowing of a heart valve that restricts blood flow.

What are the layers of the heart from outside to in?

1. Fibrous Pericardium

2. Parietal layer of Serous Pericardium

3. Pericardial cavity

4. Epicardium (Visceral Pericardium)

5. Myocardium

6. Endocardium.

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What distinguishes cardiac muscle from smooth and skeletal muscle?

Cardiac muscle is autorhythmic or involuntary, contracts as a functional syncytium, has a longer contraction period, is striated, involuntary, and contains intercalated discs.

Smooth non-striated, involuntary, and lines hollow organs.

Skeletal striated, voluntary, and attached to bones for movement.

What blood vessels supply oxygen-rich blood to the myocardium?

Coronary arteries.

What is a myocardial infarction?

Death of a portion of cardiac muscle due to prolonged ischemia, usually from blockage of a coronary artery.

What is the treatment for coronary artery disease?

CABG (coronary artery bypass graft), coronary stent placement, angioplasty.

What is the role of the AV node in the heart?

Acts as a delay center and secondary pacemaker (40-60 bpm), allowing ventricles time to fill before contracting.

What is the role of the SA node in the heart?

The primary pacemaker (60-100 bpm); initiates impulses that cause atrial depolarization.

Which side of the heart is more muscular and why?

The left ventricle is more muscular because it pumps blood to the entire systemic circulation.

What electrical events occur during the P wave of an EKG?

Atrial depolarization.

What electrical events occur during the QRS complex of an EKG?

Ventricular depolarization (atrial repolarization occurs but is hidden).

What electrical events occur during the T wave of an EKG?

Ventricular repolarization.

What is bradycardia?

A heart rate less than 60 bpm.

What is tachycardia?

A resting heart rate greater than 100 bpm.

What is ventricular fibrillation?

Chaotic ventricular electrical activity resulting in no effective cardiac output.

What is a normal ECG?

Normal sinus rhythm; impulses originate from the SA node at a regular rate.

What is junctional rhythm?

Impulses originate from the AV node; absent or inverted P waves; usually bradycardic.

What is heart block?

Impaired conduction between atria and ventricles (e.g., prolonged PR interval or dropped QRS complexes in 2nd degree block).

What happens during atrial systole?

AV valves open, semilunar valves closed; atria contract and complete ventricular filling (adds ~20-30% of EDV).

What occurs during isovolumetric contraction of ventricles?

All valves closed; ventricular pressure rises rapidly with no change in volume.

What happens during ventricular ejection?

AV valves closed, semilunar valves open; blood is expelled (~70 mL stroke volume).

What occurs during isovolumetric relaxation of ventricles?

All valves closed; ventricular pressure falls with no change in volume.

What happens during ventricular filling?

AV valves open; blood flows passively from atria into ventricles.

What is stroke volume?

The volume ejected per beat from each ventricle (about 70 mL at rest).

How is stroke volume calculated?

Stroke Volume = EDV − ESV.

What is cardiac output?

The volume of blood ejected by one ventricle per minute. (

How is cardiac output calculated?

Cardiac Output = Stroke Volume × Heart Rate.

What is cardiac reserve?

The difference between maximum cardiac output and resting cardiac output. (5-6 liters/min)

What is preload?

The degree of ventricular muscle stretch at the end of diastole (related to EDV). increased by increase venous return to right atrium

What is afterload?

The pressure the ventricles must overcome to eject blood (arterial pressure).

What is contractility?

The strength of ventricular contraction at a given preload.

What type of stimulation increases heart rate?

Sympathetic stimulation increases heart rate and contractility.

What type of stimulation decreases heart rate?

Parasympathetic stimulation (via vagus nerve) decreases heart rate.

What effect do catecholamines have on heart rate?

Increase heart rate and contractility.

What effect does acetylcholine have on heart rate?

Mimics Parasympathetic effects; decreases heart rate.

What are the 'good' and 'bad' types of cholesterol?

HDL (good) removes excess cholesterol; LDL (bad) contributes to plaque formation.

What is the function of the foramen ovale during fetal circulation?

Allows blood to bypass the fetal lungs by flowing from right atrium to left atrium.

What happens to the foramen ovale after birth?

It normally closes and becomes the fossa ovalis.

What is patent foramen ovale (PFO)?

A condition where the foramen ovale fails to close after birth.

What causes patent ductus arteriosus?

Failure of the ductus arteriosus to close after birth.

What are the signs of left-sided congestive heart failure (CHF)?

Persistent cough in the evenings, pulmonary edema; blood backs up into lungs as pulmonary edema, suffocation and lack of oxygen to the tissues

What are the signs of right-sided CHF?

fluid builds up in tissue = swollen ankles, peripheral edema, ascites, jugular venous distention.

What are the three layers of arteries?

Tunica interna, Tunica media, Tunica externa.

What is the function of the tunica interna?

Provides a smooth surface to reduce friction and prevent clot formation.

What is the function of the tunica media?

Regulates vessel diameter to control blood pressure and flow.

What is the function of the tunica externa?

Provides structural support and prevents overexpansion.

How many tissue layers do arteries have?

Three layers.

Do arteries operate under high or low pressure?

High pressure.

What are some special features of arteries?

Thick elastic walls, high compliance, adjustable diameter.

What is the primary function of arteries?

Carry blood away from the heart.

How many tissue layers do veins have?

Three layers, but thinner walls than arteries.

Do veins operate under high or low pressure?

Low pressure.

What special feature do veins have?

One-way valves.

What is the primary function of veins?

Carry blood toward the heart.

What are capillaries?

Microscopic vessels where exchange of gases, nutrients, and wastes occurs.

What are the three types of capillaries?

Continuous, fenestrated, sinusoidal.

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Where are continuous capillaries found?

Skin, muscle, lungs, and brain;  he least permeable and most common capillary in the human body, skin, muscle; have a nice covering with no breaks; made up of endothelial cells; areas in the body where we want to regulate what moves out and in

Where are fenestrated capillaries found?

Kidneys, small intestine, endocrine glands; large (pores) increase permeability; Occurs in areas of active absorption or filtration

Where are sinusoidal capillaries found?

Liver, bone marrow, spleen; Most permeable; have an incomplete membrane with large pores and breaks in between the cells that allow transport of nutrients or substances

What is the function of precapillary sphincters?

Regulate blood flow into capillary beds.

What does BHP stand for?

Blood hydrostatic pressure.

What does IFOP stand for?

Interstitial fluid osmotic pressure.

What does BCOP stand for?

Blood colloid osmotic pressure.

What is the net filtration pressure (NFP) if BCOP = 15, IFOP = 10, and BHP = 50?

NFP = (BHP + IFOP) − BCOP = (50 + 10) − 15 = 45 mmHg.

What condition could result from insufficient albumin production?

Edema; swelling caused by excess fluid trapped in body tissues, commonly affecting legs, feet, and ankles.

What force pushes blood through arteries?

Ventricular contraction.

What force pushes blood through veins?

Skeletal muscle pump and respiratory pump.

What are the four factors that affect blood flow?

Blood pressure, vascular resistance, venous return, and vessel diameter.

What factors increase systemic vascular resistance?

Decreased lumen diameter, increased blood viscosity, increased vessel length.

What is systolic pressure?

Arterial pressure during ventricular contraction (~120 mmHg).

What is diastolic pressure?

Arterial pressure during ventricular relaxation (~80 mmHg).

What is pulse pressure?

Systolic minus diastolic pressure (e.g., 120 − 80 = 40 mmHg).

What is mean arterial pressure (MAP)?

Diastolic pressure + ⅓ (pulse pressure).

Why do we monitor MAP during surgical procedures?

It reflects tissue perfusion.

What anatomical features assist with venous return?

One way valves, Skeletal muscle pump and respiratory pump.

What is the skeletal muscle pump?

Muscle contractions compress veins and move blood toward the heart.

What is the respiratory pump?

Pressure changes during breathing that promote venous return.

What factors does the body modify to maintain or change blood pressure?

1. Heart rate

2. Stroke volume

3. Vessel diameter

4. Blood volume.

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What is shock?

Inadequate tissue perfusion due to circulatory failure.

What are the signs and symptoms of shock?

Systolic BP < 90 mmHg, tachycardia, weak rapid pulse, pale cool skin, altered mental status.

What are the different types of shock?

Hypovolemic, cardiogenic, distributive (vascular), and obstructive.

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What causes hypovolemic shock?

Severe blood or fluid loss.

What causes cardiogenic shock?

Failure of the heart to pump effectively.

What causes vascular (distributive) shock?

Occurs when blood vessels in the body inappropriate dialate or enlarge; anaphylactic shock (allergy) , neurogenic schock (damnge to nervous system), septic shock (release toxin)

What causes obstructive shock?

Physical obstruction to blood flow (e.g., pulmonary embolism, cardiac tamponade).

How does the body prevent passing out when standing up?

Baroreceptors detect decreased BP and activate sympathetic responses to increase HR and vasoconstriction.

What is hypertension?

Chronic elevation of blood pressure (≥130/80 mmHg).

What are the primary causes of hypertension?

Obesity, smoking, atherosclerosis, kidney disease, endocrine disorders, genetics.

What is hypotension?

Abnormally low blood pressure.

What lifestyle changes can help stabilize blood pressure?

Regular exercise, healthy diet, reduced sodium, weight control, stress management.

What is the role of ADH in blood pressure regulation?

Promotes water reabsorption in kidneys, increasing blood volume and BP.

What does the renin-angiotensin-aldosterone system do?

Increases blood volume and vasoconstriction to raise blood pressure.

What is the function of ANP (Atrial Natriuretic Peptide)?

Promotes sodium and water excretion, lowering blood volume and BP.

What effect does epinephrine have on blood pressure?

Increases heart rate, contractility, and vasoconstriction, raising blood pressure.

List the structure according to the sequence of fluid flow

Blood capillaries, interstitial spaces, lympathic capillaries, lympathic vessels, lympathic ducts, subclavian nerves