14

Question 1

structure of veins

Answer 1

low pressure blood
thinner walls
larger interior diameters
blood flow increased by skeletal muscle activity

Question 2

Capillaries structure and function

Answer 2

-walls one cell layer thick
-blood pressure drops as blood passes into capillaries
- gas, nutrients, and waste exchange

Question 4

Arterioles has _____ _____ that allow

Answer 4

-muscle fibres
- contraction to decrease blood fliw

Question 5

Aorta receives blood from ______ has _____ ______ in its wall allowing it to:

Answer 5

heart, elastic fibres, allows it to expand when blood enters it under high pressure and propel blood forward through elastic recoil

Question 6

how is blood flow to specific tissues regulated by signals from the NS

Answer 6

NS sends signal for muscle fibres in arteriole to contract or relax

Question 7

difference between the structure of artery and vein

Answer 7

artery has elastic tissues

Question 8

thin flaps of tissue in larger veins that prevent backflow of blood are called

Answer 8

one way valves

Question 9

skeletal muscle contraction and negative thoracic pressure assists in:

Answer 9

venous returns

Question 10

interstitial fluid builds up because of two forces

Answer 10

1. an outward directed hydrostatic force in capillaries, created by the pressure generated by the heart
2. an inward directed osmotic force in capillaries, created by the higher conc of solutes in blood.

Question 11

the mechanism to drain excess fluid is carried out by the _____ ______

Answer 11

lymphatic system

Question 12

the lymphatic system is composed of

Answer 12

thin walled branching tubules called lymphatic ducts.

Question 13

interstitial fluid that enters the lymphatic ducts is called

Answer 13

lymph

Question 14

lymphatic fluid is returned to the general circulation via the:

Answer 14

left and right subclavian veins

Question 15

the ___ recieves blood returning from circulation

Answer 15

atria

Question 16

the _______ generate force to propel the blood out of the heart and through the circulatory system.

Answer 16

ventricles

Question 17

atria are separated from ventricles by

Answer 17

atrioventricular valves

Question 18

A ______ ________ carries blood to the lungs, and _________ _______ carries oxygenated blood to the heart

Answer 18

pulmonary artery, pulmonary veins

Question 19

ciculation is split into two circuits:

Answer 19

1. pulmonary circuit
2. systemic circuit

Question 20

thr pulmonary circuit take blood to the

Answer 20

lungs

Question 21

the systemic circuit takes blood to the:

Answer 21

body

Question 22

two separate circuits allow for a

Answer 22

high pressure systemic circuit and a low pressure systemic circuit

Question 23

the human. circulatory system returns blood low in oxygen to the right atrium through the:

Answer 23

inferior and superior venae cavae

Question 24

steps in pulmonary circulation

Answer 24

1. blood enters right atrium
2. blood enters right ventricle
   3 blood is pumped to lungs

Question 25

steps in systemic circulation

Answer 25

1. blood returns to left atrium from lungs through pulmonary vein 2. left atrium contracts and pushes the blood into the left ventricles 3. the muscle of left ventricle contracts and sends oxygenated blood at high pressure through the aorta and into the arteries of the systemic circulation.

Question 27

heart murmur is caused by

Answer 27

damage to the heart valves

Question 28

two pumps that assist in moving blood back to heart

Answer 28

skeletal muscle contraction respiratory pumps

Question 29

cardiac muscle makes up -1- and is responsible for -2-

Answer 29

the walls of the heart pumping blood throughout the body

Question 30

cardiac muscle cell structure

Answer 30

- intercalated discs - striated - branched, intercalated discs form direct cytoplasmic connections between cells - contains sarcomeres - involuntary, motor neuron is not required

Question 31

_____ in intercalated discs connect cytoskeletons together

Answer 31

desmosomes

Question 32

____ _____ in intercalated discs act as channels between cardiac muscle cells

Answer 32

gap junctions

Question 33

electrical signals are rapidly conducted between _______ in cardiac muscle through ____ _____

Answer 33

cardiomyocytes, gap junctions

Question 34

why is the action potentials of cardiomyocytes more prolonged than those of skeletal muscle

Answer 34

cardiomyocytes have an extended plateau phase mediated by calcium influx

Question 35

the cells in the heart that initiate contraction are called

Answer 35

pacemaker cells

Question 36

pacemaker cells are located in a region in the ____ ______ called ______ _____

Answer 36

right atrium, sinoatrial node (SA)

Question 37

electrical impulses are directed through the heart on pathways composed of _____ _______

Answer 37

modified cardiomyocytes

Question 38

characteristics of modified cardiomyocytes

Answer 38

-elongated -do not contract -spread action potentials rapidly throughout myocardium -undergoes depolarization

Question 39

electrical activation of the heart can be recorded with an

Answer 39

electrocardiogram(ECG)

Question 40

How is ECG generated?

Answer 40

by amplifying the overall electrical signal conducted from the heart to the chest wall through the tissues of the body.

Question 41

P wave shows

Answer 41

atrial depolarization

Question 42

QRS complex

Answer 42

shows ventricular depolarization

Question 43

T wave

Answer 43

shows ventricular repolarization

Question 44

steps in heart electrical activity

Answer 44

1. signal originates in the sinoatrial node, 2. SA signal spreads and atrial muscles contract pushing blood into ventricles. 3. signal reaches the AV node and is delayed before spreading along conducting fibres in the ventricular walls 4. signal from AV spreads along conducting fibres to bottom and then to top of ventricles after all blood has pooled into the ventricles 5. ventricles relax

Question 45

At rest, ______ neurons slows down heart rate

Answer 45

parasympathetic

Question 46

parasympathetic neurons secrete _____ to slow down heart rate

Answer 46

acetylcholine

Question 47

_______ slows the rate of depolarization of cardiac cells

Answer 47

acetylcholine

Question 48

_______ neurons speed up heart rate and increase force of cardiac muscle contraction

Answer 48

sympathetic

Question 49

sympathetic neurons release ______ and ________ to speed up heart rate

Answer 49

epinephrine, norepinephrine

Question 50

the contraction phase of the atria and ventricles is called

Answer 50

systole

Question 51

the the relaxation phase of the atria and atrium is called

Answer 51

diastole

Question 52

a complete cardiac cycle consists of

Answer 52

one complete systole and diastole

Question 53

blood pressure measured in the systemic arterial circulation at the peak of ventricular ejection into the aorta is called

Answer 53

systolic blood pressure

Question 54

blood pressure measured just before ventricular ejection is called

Answer 54

diastolic blood pressure

Question 55

blood pressure sensed by ______ are found in major arteries

Answer 55

baroreceptors

Question 56

when baroreceptors detect changes in blood pressure, they trigger _______ or _______ signals that change the heart’s output

Answer 56

parasympathetic, sympathetic

Question 57

cardiac output can be changed by adjusting both ____ _____ and _____ _____ ______

Answer 57

heart rate, force of contraction

Question 58

another name for heart attack

Answer 58

myocardial infarction