Cardiovascular System

Question 1

Components of Circulatory System

Answer 1

Blood
Blood Vessels
Heart

Question 2

Types of Blood Vessels

Answer 2

Arteries/Capillaries/Veins
Arterioles/Venules

Question 3

2 Circuits of Cardiovascular System

Answer 3

Pulmonary Circuit - Blood to and from lungs
Systemic Circuit - Blood to and from rest of body

Question 4

Blood states across the body

Answer 4

Arteries carry oxygenated blood
Veins carry deoxygenated blood
Pulmonary Vein has oxygenated blood
Pulmonary Artery has deoxygenated blood

Question 5

Location of heart

Answer 5

Thoracic Cavity
Near anterior chest wall
Posterior to sternum

Question 6

Factors heart size

Answer 6

Biological sex
Age
Size of individual
Exercise

Question 7

General Structure of the Heart

Answer 7

4 chambers acting as a double pump
2 Atria, 2 Ventricles

Question 8

Atria and Ventricles (Pathway through the Heart)

Answer 8

Right Atrium receives blood from systemic circuit and passes it to right ventricle
Right Ventricle receives blood from right atrium and pumps it into the pulmonary circuit
Left Atrium receives blood from pulmonary circuit and passes it to the left ventricle
Left Ventricle receives blood from left atrium and passes it to the systemic circuit

Question 9

Heart Wall Muscle Structure

Answer 9

Pericardium - Outer Wall
Epicardium - Middle Wall
Myocardium - Inner Wall

Question 10

Pericardium Structure and Function

Answer 10

Contains fibrous tissue (collagen)
Stabilizes heart position
Provides lubrication (using pericardial fluid)

Question 11

Myocardium Structure

Answer 11

Thick muscle layer between epicardium/endocardium
Highest thickness at Left Ventricle
Thickness changes based on what chamber needs to create more pressure
Myogenic
Interacts with ANS and endocrine system

Question 12

Intercalated Disks in the Heart

Answer 12

Junction between cardiac cells
Contains gap junctions and desmosomes

Question 13

Gap Junction Definition

Answer 13

Junction allowing for depolarisation to pass between cells, synchronising muscle contraction

Question 14

Desmosome Definition

Answer 14

Bind adjacent myocytes together

Question 15

Endocardium Definition

Answer 15

Covers all inner surfaces of the heart
Consists of epithelial tissue
Continuous with epithelium of vessels

Question 16

Ventricular Wall differences

Answer 16

LV = thick wall, higher blood pressure needed to pump blood to rest of the body
RV = thin wall

Question 17

Blood Pressures in Ventricles

Answer 17

LV = 80-100mmHg
RV = <15mmHg
Systemic Circuit blood pressure 4-6x higher than pulmonary circuit

Question 18

Why is pulmonary circuit blood pressure low

Answer 18

Lungs are delicate, so low blood pressure needed. If higher, would damage blood vessels and lungs

Question 19

Order of structures in cardiovascular system

Answer 19

Vena Cava, Right Atrium, Tricuspid Valve, Right Ventricle, Pulmonary Valve, Pulmonary Artery, Pulmonary Vein, Left Atrium, Bicuspid Valve, Left Ventricle, Aortic Valve, Aorta

Question 20

Chordae Tendineae Definition

Answer 20

Tendinous Strings attached to valves
Tether Valves to ventricular walls
Stops valves from opening the wrong way from ventricular systole

Question 21

Papillary Muscle Definition

Answer 21

Muscles attached to valves

Question 22

Heartbeat Definition

Answer 22

A single contraction of the heart muscle
Contracts in series: Atria First, Ventricles Second

Question 23

2 Types of Cardiac Muscle

Answer 23

Contractile - Produces contractions
Cardiac Pacemaker cells - conducting cells

Question 24

3 Types of pacemaker cells

Answer 24

Sino Atrial Node
Atrio Ventricular Node
Purkinje Fibres

Question 25

Replacing SAN

Answer 25

Artificial Pacemaker replaces SAN if it becomes dysfunctional

Question 26

Cardiac Cycle

Answer 26

SA Node activity/atrial activation begins (t=0) Stimulus spreads across atrial surfaces and reaches the AV Node (t=50msec) (P) 100msec delay at the AV Node, atrial contraction begins (t=150msec) Impulse travels along interventricular septum within AV bundle, bundle branches to Purkinje fibers and to papillary muscles of RV (t=175msec) (Q) Impulse distributed by Purkinje fibers and relayed through ventricular myocardium, Atrial contraction is completed, ventricular contraction begins (t=225msec) (QRS)

Question 27

Waves on a ECG

Answer 27

P Wave - Atria depolarization QRS Complex - Ventricle depolarization T Wave - Ventricle Repolarization

Question 28

When does heartrate change?

Answer 28

Fight/Flight System Training/Exercise Rest

Question 29

Factors affecting Heart Rate

Answer 29

ANS Catecholamines Changes in O2/CO2 Levels Changes in blood pressure Changes in pH

Question 30

ANS Control of Heart Rate

Answer 30

Sympathetic pathway increases heart rate Parasympathetic pathway decreases heart rate Both intervene at SAN

Question 31

Types of Catecholamines

Answer 31

Endocrine Response from ANS Epinephrine Norephinephrine (Noradrenalin)

Question 32

Epinephrine Features

Answer 32

Released by adrenal medulla from activation of sympathetic nerves innervating this tissue Increases heart rate and contractility Works by binding adrenergic receptors on the heart

Question 33

Norephinephrine Features

Answer 33

Initially increases heart rate and contractility, but longer exposure results in decreased heart rate and contractility Released by adrenal medulla, mostly from spillover from sympathetic nerves innervating the heart Works by binding adrenergic receptors on the heart

Question 34

Chemoreceptors in Cardiovascular System

Answer 34

Peripheral = Carotid Bodies and aortic bodies Central = Medulla

Question 35

Effects of pH on heart rate

Answer 35

Low pH = increased heart rate = activates sympathetic ANS High pH = decreased heart rate = activates parasympathetic ANS

Question 36

Effects of CO2 levels on heart rate

Answer 36

High CO2 = increased heart rate = activates sympathetic ANS Low CO2 = decreased heart rate = activates parasympathetic ANS

Question 37

Baroreceptors in Cardiovascular System

Answer 37

Mechanoreceptors sensing changes in blood pressure on a beat by beat basis Carotid Sinus = Senses increases/decreases Aortic Arch = Senses increases only

Question 38

Effect of Blood Pressure on Heart Rate

Answer 38

Low BP = less stretch of receptor = increased sympathetic ANS activation = increased heart rate High BP = more stretch of receptor = increased parasympathetic ANS activation = decreased heart rate