Lecture Exam 1 Study

Question 1

What sequence does blood flow through the heart?

Answer 1

Watch more videos on it!!!!!!!!! don’t be dumb.

Question 2

How does contraction occur in cardiac contractile cells?

hint: describe actions of actin/myosin

Answer 2

the binding of the myosin head to ATP, pulls the actin filaments to the center of the sarcomere, the mechanical force of contraction.

Question 3

What occurs at the sarcolemma?

Answer 3

Site where calcium enters and leaves a cell

Question 4

What occurs during mid-late diastole

Answer 4

the ventricles become fully dilated, the atria begin to contract, pumping blood to the ventricles.

Question 5

What occurs during early ventricular diastole

Answer 5

during ventricular diastole–early, the heart relaxes and expands while receiving blood into both ventricles through both atria

Question 6

Explain the extrinsic innervation of the heart

sympathetic/parasympathetic

Answer 6

The extrinsic supply is from parasympathetic (from the vagus nerve) and sympathetic nerves from both the superficial and deep cardiac plexuses, which provide post-ganglionic fibers to the (SA) and (AV) nodes

Question 7

What are the characteristics of elastic arteries?

Answer 7

contain larger numbers of collagen and elastin filaments in their tunica media than muscular arteries do, giving them the ability to stretch in response to each pulse

Question 8

What are the characteristics of muscular arteries?

Answer 8

the tunica media is composed almost entirely of smooth muscle

Question 9

What are the characteristics of arterioles?

Answer 9

have muscular walls (usually only one to two layers of smooth muscle cells) and are the primary site of vascular resistance.

Question 10

What are the characteristics of continuous capillaries?

Answer 10

Continuous capillaries are generally found in the nervous system, as well as in fat and muscle tissue

Question 11

What are the characteristics of fenestrated capillaries?

Answer 11

can be found in tissues where a large amount of molecular exchange occurs, such as the kidneys, endocrine glands, and small intestine.

Question 12

What are the characteristics of sinusoidal capillaries?

Answer 12

found in the liver, spleen, lymph nodes, bone marrow and some endocrine glands

Question 13

What are venules?

Answer 13

Very small branches that collect the blood from the various organs and parts to return to the heart

Question 14

What are veins?

Answer 14

blood vessels that carry blood low in oxygen from the body back to the heart

Question 15

Describe blood pressure regulation

Answer 15

blood pressure is regulated by baroreceptors which act via the brain to influence the nervous and the endocrine systems.

Question 16

How are RBC’s produced?

Answer 16

are formed in the red bone marrow of bones through a process called Erythropoiesis.

Question 17

What is meant by antigens in reference to RBC’s?

Answer 17

any substance to which the immune system can respond

Question 18

What is meant by antibodies in reference to RBC’s?

Answer 18

proteins made by your body to attack foreign substances such as viruses and bacteria.

Question 19

Describe what causes hemolytic disease of newborns

Answer 19

when the immune system of the mother sees a baby’s RBCs as foreign. Antibodies then develop against the baby’s RBCs. These antibodies attack the RBCs in the baby’s blood and cause them to break down too early. HDN may develop when a mother and her unborn baby have different blood types

Question 20

How are systemic and pulmonary circuits similar?

Answer 20

They both move blood from the heart to another system

Question 21

What does auto rhythmic mean?

Answer 21

the heart produces its own pulses through electrochemical stimuli originating from a small group of cells in the wall of the right atrium, known as the sinoatrial node (or SA node).

Question 22

What is an ECG?

Answer 22

means of measuring heart membrane potential during the cardiac cycle by measuring the electric current conducted through body fluid to the skin

Question 23

What does the P wave represent?

Answer 23

depolarization of the atria

Question 24

What does the QRS wave represent?

Answer 24

depolarization of the ventricles

Question 25

What does the T wave represent?

Answer 25

repolarization of the ventricles

Question 26

What things are measured in an ECG?

Answer 26

heart rate (intervals between cycles)
contraction force (amplitude of waves)
rhythm (intervals between waves)

Question 27

What does abnormally long P-Q interval indicate?

Answer 27

AV conduction problem

Question 28

What do ectopic beats indicate?

Answer 28

an AP is being generated independently of the SA node

Question 29

What is pulmonary circulation?

Answer 29

movement of blood between the heart and lungs

Question 30

What is systemic circulation?

Answer 30

Movement of blood from the heart to the rest of the body

Question 31

What causes the first heart sound?

Answer 31

The first heart sound represents closure of the atrioventricular (mitral and tricuspid) valves

Question 32

What occurs during an action potential in cardiac autorythmic cells?

Answer 32

slow influx of sodium ions until the threshold is reached followed by a rapid depolarization and repolarization. The prepotential accounts for the membrane reaching threshold and initiates the spontaneous depolarization and contraction of the cell.

Question 33

The _____ supply is from _______ (from the vagus nerve) and sympathetic nerves from both the superficial and deep cardiac plexuses, which provide post-ganglionic fibers to the (SA) and (AV) nodes

Answer 33

Extrinsic

Parasympathetic