Circulation

Question 1

Describe the function of Arteries

Answer 1

Carry oxygenated blood away from the heart unless its carrying blood to the lungs, then the blood is deoxygenated.

Question 2

Describe the function of Capillaries

Answer 2

connect arteries and veins (more correctly, arterioles and venules), they are blood vessels in the alveoli (part of the lungs) and other organs. In the lungs they release carbon dioxide and allowed oxygen to enter, in the small intestine they absorb most of the end products of digestion.

Question 3

Describe the function of Veins

Answer 3

Carry deoxygenated blood towards the heart unless its getting blood from the lungs, then the blood is oxygenated.

Question 4

Describe the function of Leukocytes

Answer 4

White blood cells (leukocytes) fight infection

Question 5

Describe the function of Erythrocytes

Answer 5

Specialize in transporting oxygen through the body with the help of hemoglobin, they also carry CO2 in small amounts for waste removal. Mature erythrocytes do not have nuclei.

Question 6

Describe the function of blood plasma

Answer 6

Plasma maintains fluid balance in cells and between cells.

Question 7

Describe the function of Platelets

Answer 7

Platelets help with blood clotting.

1) A damaged blood vessel releases chemicals that attract platelets.
2) Platelets rupture, release chemicals, and form thromboplastin.
3) Calcium + thromboplastin + prothrombin produces thrombin
4) Thrombin reacts with fibrinogen to produce Fibrin, an insoluble protein that forms a mesh (clot) over the injury.

Question 8

Describe the function of blood

Answer 8

Blood absorbs and transports essential nutrients and chemicals and also transports and removes waste products and also regulates the bodys temperature, they can change the volume of blood flowing near the skin. Blood vessels can either expand (vasodilation) to release heat or contract (vasoconstriction) to conserve heat.

Question 9

How does blood flow through the body?

Answer 9

Humans have a closed circulatory system which keeps blood within the vessels. The blood follows a continuous fixed path of circulation and is confined to a network of vessels that keeps the blood separate. Veins have one-way valves to keep blood moving backward (think of gravity pulling blood towards your feet).

Question 10

Which leukocytes are g̶a̶y f̶a̶g̶s̶ phagocytes

Answer 10

monocytes and macrophages, granulocytes (not including basophils)

Question 11

What are the three granulocytes and which one is not a phagocyte

Answer 11

Neutrophil, eosinophil and basophil. Basophil is not a phagocyte.

Question 12

How does blood help regulate body tempurature

Answer 12

Deep arteries and veins entering and leaving the body’s extremities lie adjacent to one another, so warmer blood that flows from the body core/from inside the body to the extremities exchanges heat with the cooler blood returning from the extremities to the body core.

Question 13

What is a cardiomyocyte?

Answer 13

Cardiomyocytes are the cells responsible for generating contractile force in the intact heart (pumping/beating).

Question 14

What is the Sinoatrial node?

Answer 14

The SA (sinoatrial) node generates an electrical signal that causes the upper heart chambers (atria) to contract. The SA node is considered the pacemaker of the heart as it controls how fast the heart beats.

Question 15

What is the Atrioventricular node?

Answer 15

The atrioventricular node transmits electrical signals to the His bundle and purkinje fibers which then take those signals to make the ventricles contract.

Question 16

Systole vs diastole?

Answer 16

Systole is when the heart contracts and blood is pumped through the body. Diastole is the relaxation phase where the heart fills up with blood (the filling process takes longer that systole).

Question 17

Where are the different nodes and nerves loaced?

Answer 17

The SA node is located in the right atrium, below the superior vena cava. The AV node is located beside the opening of the coronary sinus or by the tricuspid valve. The His bundle is located between the atria and the ventricles (in the interartial septum). The purkinje fibers are located in the inner ventricular walls of the heart.

Question 18

When do the “lub-DUB” sounds occur?

Answer 18

• “lub” is the closing of the atrioventricular valves that occurs at beginning of systole to prevent backflow of blood into atria
• “DUB” is the closing of the semilunar valves that occurs after systole/before diastole to prevent the backflow of blood into the ventricles.

Question 19

Different parts of the EKG

Answer 19

• P wave = SA Node fires and atria contract
• Between P and Q = signal pauses at AV Node as ventricles fill
• QRS wave = ventricular contractions (lub occurs at Q)
• T wave = ventricle relaxes/recovers (DUB occurs here)

Question 20

What is cardiac output?

Answer 20

Cardiac output: the volume of blood pumped by the heart, expressed as mL per minute.

Question 21

How to calculate cardiac output with heart rate and stroke volume

Answer 21

Heart rate x stroke volume = cardiac output

H x S = C