Cardiac

Question 1

What are intercalated discs

Answer 1

Sites of end to end attachments between adjacent cells

Maintain mechanical integrity

Question 2

What is a dyad

Answer 2

The t tubule and its communication to sarcoplasmic reticulum is a dyad unlike skeletal muscle has triad

Question 3

What are cardiac myocytes

Answer 3

Intrinsic rhythmic contraction
Gap junctions in intercalated discs allow for synchornisation of contraction between cells and allow waves of excitation to sweep through tissue
Rhythm is indept of autonomic nervous system but modulated by it

Question 4

What is the overall contraction coordination of the heart

Answer 4

Controlled by
Pacemaker cells sinoatrial node which pass impulse to atrioventricular node and then to base of ventricles and modified bundles of his to purkinje fibres making a contraction

Question 5

What are the regenerative cells in the cardiac muscle

Answer 5

Satellite cells

Question 6

What is the role of the circulatory system in relation to cardiac muscle

Answer 6

Transport of oxygen Nd nutirents to tissue
Transport carbon dioxide and other metabolic waste form tissue
Temp reg
Distribution of hormones and immune cells
Reproductive function in males

Question 7

What are the components of the circulatory system

Answer 7

The heart 
Arterial system 
Capillaries
Venous system 
Lymph vascular system

Question 8

What are the layers of blood vessels

Answer 8

Tunica Intima - inner layer endothelial cells

Tunica media - Middle miscle

Tunica externa - outer supporting connective tissue

Question 9

What are the three layers of the heart

Answer 9

Endocardium - inner layer
Myocardium - Middle
Epicardium - outer

Question 10

Explain the endocardium

Answer 10

Lines entire inner surface of the heart including valves
Endothelial cells rating on basal lamina thin collagen thicker dense ct
Sub endocardium when loose ct

Question 11

What is myocardium

Answer 11

Thick muscular layer of the heart made up almost entirely of bundles and layers of contractile cardiac muscle fibres

Question 12

What is epicardium

Answer 12

In outer surface mesothelium

Layer is backed by fibroelastuc connective tissue

Question 13

What is the pericardial sac

Answer 13

Surrounds the heart made up of fibrocollagenous tissue that contains elastic tissue
Lined by mesothelium
Pericardial cav has some fluid

Question 14

What is cardiac tamponade

Answer 14

When there is an excessive production of pericardial fluid

Question 15

Explain the fibrous Skelton of the heart

Answer 15

Fibrous skeleton fo red by thick bands of connective tissue around heart valves, between atria, between ventricles

Question 16

What is the composition of the heart valves

Answer 16

Outer endothelial layer and a layer of collagen and elastin around a core of dense connective tissue called lamina fibrosa which is continuous with fibrous skeleton

Valves held by papillary muscles, chordae tendinae

Question 17

What are the three types of cardiac cell muscle

Answer 17

Contractile cell
Pacemaker cell
Conducting cell

Question 18

How does a pacemaker cell create an impulse

Answer 18

Such as sinoatrial node
Undergoes spontaneous depolarisation
Causing depo of nearby cells spreading like a wave
Know the porgression

Question 19

What is the modulation of heart rate

Answer 19

Efferent nerve fibres of autonomic nervous system innervate heart moderate via sinoatrial node

Symp nerve fibres originate in symp chain ganglia of chest and release noradrenaline whic increases heart rate

Preganglionic parasymp fibres reach heart via vagus

Adrenaline released by adrenal medulla also increases heart rate

Question 20

What are the three forms of capillaries

Answer 20

Continuous most common
Fenestrated - pores
Sinusoidal - lack basal lamina and have large gaps

Question 21

What does cardiac muscle form

Answer 21

Heart and its four chambers and origins of great vessels