Heart/Blood Vessels/Immune/Lymph

Question 1

How big is the heart?

Answer 1

About the size of a fist. Weights 9-12 oz.

Question 2

How many times does the heart beat per day?

Answer 2

100,000 beats per day

Question 3

How much blood does the heart pump?

Answer 3

About 7,000 liters per day

Question 4

Where is the heart located?

Answer 4

Above the diaphragm between the lungs in the mediastinum.

Question 5

How much pericardial fluid is in the heart?

Answer 5

15 mL

Question 6

What is the pericardium?

Answer 6

The outer cover of the heart. Has a parietal cover which is outside and a visceral cover which is on the inside and consists of 2 layers. Pericardial fluid is in between the two layers.

Question 7

What are the 3 layers of the heart wall?

Answer 7

The outer is epicardium. The middle layer is myocardium ((striated, involuntary, branched)). The inner layer is endocaridum (connective tissue, covers valves).

Question 8

Describe the myocardium.

Answer 8

One nucleus per cell, short, many mitochondria, best blood supply, locked together at intercalated discs, twitches all the time with long refractory periods, lipids have more energy potential, aerobic even when active.

Question 9

What is systole and diastole?

Answer 9

Systole is contraction of the chambers, diastole is relaxing of the chambers. Happens at the same time in atria and ventricles.

Question 10

What does the SA node do?

Answer 10

Also called the pacemaker, it initiates the stimulus for the heart to contract.

Question 11

What is the P portion of a PQRST wave?

Answer 11

Represents the depolarization in the sinus node and subsequent atrial contraction. Small due to small mass of the atrium

Question 12

What is the QRS complex?

Answer 12

Represents the conductance and sequential depolarization of the ventricles. Large due to large mass of the ventricles.

Question 13

What is the T portion of a PQRST wave?

Answer 13

Represents the repolarization of the ventricles.

Question 14

Define cardiac arrhythmia

Answer 14

It is an irregular heartbeat. More common as one gets older.

Question 15

What is atrial fibrillation?

Answer 15

An irregular and often rapid heart rate that commonly causes poor blood flow to the body. Happens when the two atrial chambers have an irregular beat.

Question 16

What is premature atrial contraction?

Answer 16

An atrial contraction that happens earlier than the next regular beat should have happened.

Question 17

What is premature ventricular contraction?

Answer 17

Extra, abnormal heartbeats that begin in one of your heart’s two lower pumping chambers (ventricles).

Question 18

What is ventricular fibrillation?

Answer 18

When the heart’s electrical activity becomes disordered and the ventricles contract in a rapid unsynchronized way. Heart pumps little or no blood.

Question 19

What happens if the SA node malfunctions?

Answer 19

The AV node sets the pace of the heart which is about 40-60 bpm. Less blood gets circulated to the body.

Question 20

What is the pace when the hearts conductive system is normal?

Answer 20

About 70 bpm

Question 21

What is bradycardia?

Answer 21

A slower than normal heart rate.

Question 22

What is tachycardia?

Answer 22

A faster than normal heart rate.

Question 23

What are the two phases of the cardiac cycle?

Answer 23

Systole and diastole.

Question 24

What are the average times for the cardiac cycle?

Answer 24

Atrial systole happens at 100ms. Ventricle systole happens between 100-360ms. Early ventricular diastole happens around 360-800ms.

Question 25

What terms describes the ability to listen to heart sounds?

Answer 25

Auscultation.

Question 26

What sounds are we listening for when using a stethoscope?

Answer 26

Listening for turbulence when blood sloshes around when valves close (lubbdupp sound)

Question 27

What is the first sound heard (lubb)?

Answer 27

The closing of the AV valve.

Question 28

What is the second sound heard?

Answer 28

the “dupp” is the closing of the semilunar valve (aortic and pulmonary)

Question 29

What are heart murmurs?

Answer 29

Any abnormal sound before or after the valves close.

Question 30

What is the formula for cardiac output?

Answer 30

Stroke Volume (mL/beat) x BPM (beats/minute) = Cardiac Output (mL/minute)

Question 31

What is stroke volume?

Answer 31

The amount of blood per beat ejected into the aorta and pulmonary artery.

Question 32

What is end-systolic volume (ESV)?

Answer 32

The volume of blood in a ventricle at the end of contraction (systole). Lowest volume of blood in the ventricle at any point in the cardiac cycle.

Question 33

What is end-diastolic volume (EDV)?

Answer 33

The volume of blood in the right and/or left ventricle at the end of diastole.

Question 34

What is Starling’s Law?

Answer 34

The strength of the heart’s systolic contraction is directly proportional to its diastolic expansion with the result that under normal physiological conditions the heart pumps out of the right atrium all the blood returned to it without letting any back up in the veins

Question 35

What is cardiac reserve?

Answer 35

The work that the heart is able to perform beyond that required under the ordinary circumstances of daily life.

Question 36

What are some factors that influence heart rate?

Answer 36

Temperature, body position, age, emotions, sex of individual, hormones (epinephrine), potassium decrease, calcium increase.

Question 37

What are baroreceptors?

Answer 37

Pressure sensors in arteries that regulates the blood pressure throughout the body. Located on the aorta, carotid and atrial arteries.

Question 38

What is Marey’s Law?

Answer 38

The pulse rate varies inversely with the blood pressure (pulse is slow when the pressure is high).

Question 39

What is the brainbridge reflex?

Answer 39

Acceleration of the heart rate results in increased blood pressure. Prevents pooling of the blood in veinous system.

Question 40

How many blood vessels do we have?

Answer 40

Enough to go around the globe twice. About 65,000 miles of blood vessels

Question 41

How does blood move through the vessels?

Answer 41

Arteries take blood away from the heart and veins bring the blood back to the heart. In between arteries and veins are capillaries. Arterioles take blood from the arteries to the capillaries and venules take blood from the capillaries to the veins.

Question 42

What are the 3 layers of blood vessels?

Answer 42

Tunica intima (interna), tunica media, tunica externa (adventitia). They are the same for arteries and veins.

Question 43

Describe the tunica intima

Answer 43

Made up of a thin layer of endothelial cells and lines the entire circulatory system. Capillaries only have a tunica intima

Question 44

Describe the tunica media

Answer 44

The muscular, middle layer of arteries and veins. Bigger in arteries than veins. Made of elastic and collagenous fibers.

Question 45

Describe the tunica externa

Answer 45

The outside layer composed of elastic and collagenous fibers. Protect the vessel from over expansion. Vasa Vasorum are found on this level that supplies blood to the vessels.

Question 46

Describe elastic arteries.

Answer 46

Receives blood directly form the heart. They are thin in order to stretch and accommodate the blood surge.

Question 47

Describe muscular (distributing) arteries

Answer 47

Further away from the heart. Goes to specific organs. Smaller than elastic.

Question 48

What are arterioles?

Answer 48

Small vessels that moves blood from arteries to capillaries. May have only smooth muscle cells in tunica externa. Can dilate to affect blood pressure.

Question 49

What are venules?

Answer 49

Carries blood from capillaries to veins. Has three layers: Inner endothelium, middle later of muscle and elastic tissue, outer layer of fibrous connective tissue. Comes from individual organs.