cardiovascular

What is the cardiovascular system?

A closed system consisting of the heart and blood vessels.

What is the primary function of the heart?

To pump blood.

What is the role of blood vessels?

To allow blood to circulate to all parts of the body.

What are the main functions of the cardiovascular system regarding delivery and removal?

To deliver oxygen and nutrients, and to remove carbon dioxide and other waste products.

Where is the heart located?

In the thorax, between the lungs.

Which way does the apex (pointed end) of the heart point?

Toward the left hip.

What is the approximate size and weight of the human heart?

About the size of a fist and less than 1 lb.

What is the double serous membrane covering the heart called?

The Pericardium.

What is found in the space between the layers of the pericardium?

Serous fluid.

How many layers make up the heart wall? Name them from outside to inside.

Three layers: Epicardium (outside), Myocardium (middle), Endocardium (inner).

Describe the Epicardium based on the text.

The outside layer of the heart wall, identified as the parietal pericardium (visceral layer), and a connective tissue layer.

Describe the Myocardium.

The middle layer of the heart wall, composed mostly of cardiac muscle.

Describe the Endocardium.

The inner layer of the heart wall, made of endothelium.

How do the right and left sides of the heart function relative to each other?

They act as separate pumps.

How many chambers are in the heart?

Four chambers.

What are the receiving chambers called? Name them.

Atria (singular: atrium). Right atrium and Left atrium.

What are the discharging (pumping) chambers called? Name them.

Ventricles. Right ventricle and Left ventricle.

What is the primary function of heart valves?

To allow blood to flow in only one direction and prevent backflow.

How many valves are in the heart?

Four valves.

What are the valves located between the atria and ventricles called?

Atrioventricular (AV) valves.

What is the name of the left AV valve?

Bicuspid valve (also called Mitral valve).

What is the name of the right AV valve?

Tricuspid valve.

What are the valves located between the ventricles and the major arteries called?

Semilunar valves.

Name the two semilunar valves.

Pulmonary semilunar valve and Aortic semilunar valve.

What structures hold the AV valves in place and prevent them from inverting?

Chordae tendineae ('heart strings').

Which major vessel leaves the left ventricle?

Aorta.

Which major vessels leave the right ventricle?

Pulmonary arteries.

Which major vessels enter the right atrium?

Vena cava (Superior and Inferior).

Which major vessels enter the left atrium?

Pulmonary veins (four of them).

Does the blood flowing through the heart chambers nourish the heart muscle itself?

No.

What system provides the heart muscle (myocardium) with its own blood supply?

The coronary circulation system.

What vessels supply blood TO the myocardium?

Coronary arteries.

What vessels drain blood FROM the myocardium?

Cardiac veins.

Where do the cardiac veins ultimately empty their blood?

Into the right atrium via the coronary sinus.

What condition is described as chest pain resulting from inadequate blood supply to the heart, potentially linked to a rapid heartbeat?

Angina Pectoris.

What system allows the heart muscle to contract regularly without external nerve impulses?

The intrinsic conduction system (nodal system).

What is the primary pacemaker of the heart and where is it located?

The Sinoatrial (SA) node, located in the right atrium.

List the structures of the intrinsic conduction system in the order the impulse travels.

SA node -> Atrioventricular (AV) node -> Atrioventricular bundle (Bundle of His) -> Bundle branches (right and left) -> Purkinje fibers.

Where is the Atrioventricular (AV) node located?

At the junction of the atria and ventricles.

What does the P wave on an EKG/ECG represent?

The impulse spreading across the atria (atrial depolarization).

What does the QRS complex on an EKG/ECG represent?

The spread of the impulse down the septum and through the ventricles via the Purkinje fibers (ventricular depolarization).

What does the T wave on an EKG/ECG represent?

The end of electrical activity in the ventricles (ventricular repolarization).

Describe the sequence of contraction/relaxation in the cardiac cycle.

Atria contract simultaneously, then relax; then ventricles contract simultaneously.

What term means heart muscle contraction?

Systole.

What term means heart muscle relaxation?

Diastole.

Define Cardiac Output (CO).

The amount of blood pumped by each side (ventricle) of the heart in one minute.

What is the formula for Cardiac Output?

CO = Heart Rate (HR) x Stroke Volume (SV).

Define Stroke Volume (SV).

The volume of blood pumped by each ventricle in one contraction (beat).

What is a normal resting Cardiac Output value mentioned?

Approximately 5000 ml/min (or 5.25 L/min based on the example).

How frequently does the entire blood supply pass through the body at rest?

About once per minute.

What does Starling's law of the heart state?

The more the cardiac muscle is stretched (up to a point), the stronger the contraction will be.

What is the most common way the body changes cardiac output?

By changing the heart rate (HR).

List factors that can INCREASE heart rate.

Sympathetic nervous system stimulation, crisis/stress, low blood pressure, hormones (epinephrine, thyroxine), exercise, decreased blood volume.

List factors that can DECREASE heart rate.

Parasympathetic nervous system stimulation, high blood pressure or blood volume, decreased venous return.

What condition involves a "worn out" heart pumping weakly?

Congestive Heart Failure (CHF).

What effect does Digitalis have on the heart, often used for CHF?

It provides a slower, steady, but stronger beat.

List the types of blood vessels in order, starting from those leaving the heart.

Arteries -> Arterioles -> Capillaries -> Venules -> Veins.

How many layers (tunics) typically make up the walls of larger blood vessels (arteries/veins)? Name them from inner to outer.

Three layers: Endothelium (inner), Smooth muscle (middle), Fibrous connective tissue (outer).

Which nervous system controls the smooth muscle layer in blood vessels?

Sympathetic nervous system.

Which type of blood vessel has the thickest walls?

Arteries.

Which type of blood vessel generally has a larger lumen (internal diameter)?

Veins.

How is blood helped to move back towards the heart in veins, especially from the limbs?

By the "milking action" of surrounding skeletal muscles.

How thick are capillary walls, and why is this important?

Only one cell layer thick, which allows for efficient exchange of gases, nutrients, and wastes between blood and tissues.

What primarily drives blood flow in arteries?

The pumping action of the heart.

What are the two types of vessels found in a capillary bed?

1. Vascular shunt (a direct connection between arteriole and venule) 2. True capillaries (exchange vessels).

What structures control blood flow into the true capillaries?

Precapillary sphincters.

What substances typically move from the blood into the tissue cells at the capillaries?

Oxygen and nutrients.

What substances typically move from the tissue cells into the blood at the capillaries?

Carbon dioxide and metabolic waste products.

List four vital signs mentioned that indicate cardiovascular efficiency.

Arterial pulse, Blood pressure, Respiratory Rate, Body Temperature.

What is the arterial pulse?

The pressure wave of blood traveling through the arteries, generated by each heartbeat.

Where is the pulse typically monitored?

At "pressure points" where arteries are close to the surface (e.g., radial, carotid, brachial, facial, posterior tibial arteries).

What does systolic blood pressure measure?

The pressure in the arteries at the peak of ventricular contraction.

What does diastolic blood pressure measure?

The pressure in the arteries when the ventricles are relaxed (in diastole).

How does blood pressure generally change as distance from the heart increases?

It decreases.

Name three major categories of factors that affect blood pressure.

Neural factors (autonomic nervous system), Renal factors (kidneys/volume/hormones like renin), Temperature, Chemicals, Diet.

How does heat generally affect blood vessels?

It has a vasodilation effect (widening).

How does cold generally affect blood vessels?

It has a vasoconstricting effect (narrowing).

What is a general normal range given for systolic pressure?

110-140 mm Hg.

What is a general normal range given for diastolic pressure?

75-80 mm Hg.

What is Hypotension? Provide the systolic value mentioned.

Low blood pressure, often associated with illness. Systolic below 110 mm Hg.

What is Hypertension? Provide the systolic value mentioned.

High blood pressure, which can be dangerous if chronic. Systolic above 140 mm Hg.