The Heart

How much is the average CO for humans?

5 Liters per minute

How many bpm does the SA node generate?

60-100 BPM

Cardiac output is the product of two variables, which is the equation for CO

CO = HR x SV

True or false: arteries always carry oxygenated blood

FALSE. Arteries are blood vessels that go AWAY from the heart. The pulmonary arteries leave the right ventricle and carry deoxygenated blood AWAY from the heart and to the lungs where they pick up oxygen and carry oxygenated blood through the pulmonary veins

The heart muscle cells are connected by ________ discs

Intercalated discs, which contain may gap junctions connecting the cytoplasm of adjacent cells, allowing for coordinated ventricular contraction

Cardiac muscle has myogenic activity. What does this mean?

It can contract without any neurological input

What tissue is the outer/inner pericardium made up of?

Outer: fibrous proteins that attach the heart to the rest of the body Inner: Serious layer that contains the visceral and parietal pericardium

What is is a major vessel of the human heart that originates from the right ventricle. It branches into the right and left pulmonary arteries, which lead to the lungs.

Pulmonary trunk

Lub Dub are the heart sounds. Lub is S1 and is the sound of which valves? Dub is S2 and is the sound of which valves?

S1: T&M (tricuspid and mitral) S2: A&P (aortic and pulmonary)

When the heart contracts, which two valves are open? Which two valves are closed?

Semilunar valves are open to pump blood to lungs and systemically Atrioventricular valves are closed to allow for filling of the chambers

What circulation system do the lungs get oxygen from? What are they called?

Systemic circulation (with mixing from pulmonary circulation), bronchial vessels

What circulation system does the heart get blood from? What are they called?

Systemic circulation, coronary vessels

During periods of rest or exercise, which system will increase or decrease CO?

The autonomic nervous system. Sympathetic and parasympathetic, respectively.

What keeps the valves from flipping backwards?

The chordae tendineae (tendinous cords), colloquially known as the heart strings, are tendon-resembling fibrous cords of connective tissue that connect the papillary muscles to the tricuspid valve and the bicuspid valve in the heart.

Cardiac Output (CO)

The total blood volume pumped by a ventricle in 1 minute

Why are beta blockers given to people who've suffered an MI?

They block the sympathetic stimulation of the heart, resulting in lower heart rate and lower contractility. Thusly, the heart does not have to work as hard, so its oxygen demand is diminished, which helps to prevent further damage to cardiac tissue

What is the name of the two atrioventricular valves?

Tricuspid and mitral

Define Stroke Volume

Volume of blood pumped per beat

What are the 3 layers of the heart from inside to outside?

endocardium, myocardium, epicardium (pericardium)

Name the two semilunar valves

pulmonary valve and aortic valve

What are the two layers of the pericardium? (from inside to outside)

visceral and parietal

Atrial kick is caused by what? What percentage of cardiac output does it account for?

- additional volume of blood in ventricles causes by atrial systole -accounts for 5-30% of cardiac output

After the SA node, where does the impulse go next in order?

AV node --> Bundle of his --> Interventricular septum wall --> purkinje fibers

The intraventricular septum has two different parts, what are they?

The membranous part between the atrias The muscular part between the ventricules The membranous part is where Ventricular Septal Defect VSD can happen

Peripheral neuropathy is the most common type of diabetic neuropathy, but some patients also experience autonomic neuropathy. Which of the following symptoms is associated with autonomic neuropathy? a) sharp decreases in blood pressure when standing b) loss of feelings in arms c) inability to focus the eye d) flat affect

a) sharp decreases in blood pressure when standing Autonomic neuropathy does not impact a person's affective state. Loss of feeling in arms is associated with peripheral nerve damage, or peripheral neuropathy. Inability to focus the eye is associated with focal neuropathy, or damage to one specific nerve. Autonomic neuropathy affects the autonomic nervous system; it affects heart and blood vessels, the urinary tract, sex organs, sweat glands, the eyes, and lungs.