Cardiovascular system

Question 1

what is the pulmonary circuit

Answer 1

from the hear to the lungs back to the heart

Question 2

systemic circuit

Answer 2

from heart to body back to the heart

Question 3

coverings of the heart

Answer 3

1. Pericardium
   - Fibrous (outside layer) very tough/fibrous
   - parietal: outside layer of a double edged sac, beneath fibrous
2. Pericardial cavity: serous fluid and this is where the heart is housed
3. visceral pericardium
   - innermost

Question 4

3 layers of the wall of the heart

Answer 4

1. epicardium- outermost, connective tissue, epithelial
2. myocardium-muscle, middle layer of the heart, responsible for contraction
3. endocardium: epithelial tissue, inner most, blood vessels join here
   - purkinje fibers: complete contraction

Question 5

what is special about the pulmonary artery

Answer 5

only artery that carries deoxygenated blood

Question 6

where does the neural impulse go through

Answer 6

interventricular septum

Question 7

Cardiac Cycle

Answer 7

atrial systol- ventricular diastole

ventricular systole- atrial diastole

Question 8

heart sounds

Answer 8

First Sound: tricuspid and mitral valve closing

second sound: pulmonary and aortic valves

Question 9

SA node

Answer 9

pacemaker for the heart

initiates impulse

Question 10

AV node

Answer 10

a light pause happens here so ventricles can fill completely
-when impulse moves from SA node to AV node the atria contraction happens

Question 11

Bundle of HIS

Answer 11

divides into 2 bundle branches and moves into the purkinje fibers

Question 12

ECG

Answer 12

recording of the electrical changes that occur during a cardiac cycle

Question 13

P wave
QRS complex
T wave
U wave

Answer 13

P: small atrial depolarization, atrial contraction
QRS: ventricular contraction
T: ventricular repolarization
U: doesnt always happen, final repolarization of perkinje fibers

Question 14

Types of blood vessels

Answer 14

1. Arteries: blood away from heart, largest, muscular
2. arterioles: muscular, control where the blood goes
3. capillaries: gas exchange happens here, not muscular, smallest
4. venules: smaller vessels in the venus system
5. veins: blood to heart

Question 15

vasoconstriction

Answer 15

constriction at arterioles thats going to lessen the blood flow to an area

Question 16

vasodilatation

Answer 16

dilation at arterioles to increase blood flow to an area

Question 17

capillaries

Answer 17

smallest vessels
permeability varies
-brain is the least permeable

density varies
-high density in the brain and muscles

pre-capillary sphincters: regulate amount of blood entering capillary bed

Question 18

blood pressure

Answer 18

Systolic: pressure during contractions of the ventricles in the arteries

Diastolic: pressure during the relaxation of ventricles in the arteries

Question 19

5 factors that affect blood pressure

Answer 19

1. blood volume increases
2. heart rate increases
3. stroke volume
4. blood viscosity
5. peripheral resistance: friction that is exerted by the blood on the vessel walls, more friction means higher BP

Question 20

Cardiac Output

Answer 20

product of heart rate times stroke volume

how much blood pumped by the heart each minute

Question 21

Regulation of HR

Answer 21

Decrease Heart Rate (parasympathetic)
-SA node will slow the HR to decrease BP

Increase HR: Sympathetic

• cardiac control center in the medullar oblongata
• stimulates SA node

Question 22

Regulation of Stroke volume

Answer 22

• End Diastolic Volume (EDV)
• Preload venous return: volume that is pumped from left ventricle is the same as the volume coming into right atrium
• Average Aortic Blood Pressure: afterload

-Strength of ventricular contraction

Question 23

Venous Blood Flow (3 parts)

Answer 23

1. Skeletal Muscle Pump
   - rhythmic skeletal muscle contractions
   - one way valves
2. respiratory pump
   - as we breath we squeeze diaphragm which pushes down onto organs, and muscles to open up ribs in thoracic cavity creating high pressure in low abdominal cavity and low pressure in the thoracic cavity
3. Venoconstriction: constrict at venules forces blood out of veins towards heart

Question 24

Average Aortic Pressure

Answer 24

inversely related to stroke volume

• high afterload: volume of blood in left ventricle
• reducing aortic pressure results in higher stroke volume

Question 25

Ventricular contractility

Answer 25

• increase contractility results in high stroke volume

Frank Starling Law
-relation between the length of cardiac muscle fibers as a result of the stretch, more stretch the greater the force it can generate