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Flashcards in Anatomy of the Heart Deck (58)
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1
Q

What shape is the heart and where is it located?

A
  • cone shaped muscular pump
  • located in the thorax between the lungs
  • Protected by the ribs and sternum
  • Lies between ribs 2-5 of the left of the midline
  • apex lies in the 5th intercostal space in the midclavicular line
2
Q

What layers is the pericardium made up of?

A
  • outer fibrous layer

- inner serous pericardium

3
Q

Give features of the fibrous pericardium

A
  • Inelastic, made of dense connective tissue

- Fuses inferiorly with the diaphragm and superiorly with the great vessels

4
Q

What parts is the serous pericardium made up of?

A

Double layered serous membrane - made up of parietal and visceral layers

5
Q

Give features of the parietal layer of the serous pericardium

A
  • lines the inner surface of the fibrous pericardium
  • dense fibrous layer
  • made up of areolar tissue and mesothelium
6
Q

Give features of the Visceral layer of the serous pericardium

A
  • also called visceral epicardium
  • adheres to the surface of the heart
  • Made up of mesothelium and areolar tissue
7
Q

What is the pericardial cavity?

A

potential space between the parietal and visceral layers, contains pericardial fluid and prevents friction

8
Q

What is the heart wall made up of?

A

Three layers:

  • Endocardium: inner layer - endothelium and areolar tissue
  • Myocardium: middle layer- cardiac muscle cells and connective tissue
  • Epicardium: outer layer - visceral pericardium
9
Q

What is the trabeculae carnae?

A

ridges in the inside heart walls which are made up of muscle

10
Q

What are the Chambers of the heart?

A
  • right and left atria

- right and left ventricles

11
Q

What is the structural difference between the two ventricles?

A

The left has a much thicker wall

12
Q

What are the inter-atrial septum and the inter-ventricular septum?

A
  • separates right and left atrium

- Separates right and left ventricles

13
Q

What are the different great vessels and what do they do?

A
  • Superior and inferior vena cavae bring blood into the right atria
  • The pulmonary trunk comes out of the right ventricle and splits into two to form the right and left pulmonary arteries which deliver deoxygenated blood to the lungs
  • the four pulmonary veins lead into the left atrium carrying oxygenated blood to the heart
  • the aorta leaves the left ventricle carry oxygenated blood around the body
14
Q

What is the fibrous skeleton of the heart and what does it do?

A
  • Fibrous connective tissue between the atria and ventricles
  • Electrically separates the atria from the ventricles
  • Encircles the pulmonary trunk and aorta
  • Heart valves suspended from it
15
Q

What two types can the heart valves be categorised into?

A

Atrioventricular (AV) valves and Semilunar valves

16
Q

What are the two types of atrioventricular valve and where are they located?

A
  • Tricuspid (right AV valve)

- Bicuspid/ mitral (left AV valve

17
Q

What are the two types of semilunar valves?

A
  • pulmonary

- aortic

18
Q

Give features of AV valves

A
  • Located between the atria and ventricles
  • Opened by the blood flowing from atria to the ventricles
  • Anchored by chordae tendinea to papillary muscles
  • Contraction of the papillary muscles prevents eversion of the valves and therefore backflow of blood into the atria
  • Valves are open when ventricular pressure is less than atrial pressure
  • Valves are closed when ventricular pressure is greater than atrial pressure
19
Q

Give features of semilunar valves

A
  • Guard the entrances of the aorta and pulmonary trunk
  • Opened by force of blood as the ventricles contract (as ventricle pressure gets high)
  • Blood flows backwards in the aorta and pulmonary trunk during ventricular relaxation, this pools in the cusps and pushes the valves shut
  • Opened when pressure in ventricles is higher than the pressure in the aorta
  • Prevents backflow of blood into ventricles
20
Q

When is blood delivered to the myocardium?

A

During ventricular relaxation

21
Q

What is the coronary circulation system made up of?

A
  • Left Coronary artery (LCA)
  • Right Coronary artery
  • great, middle and small cardiac veins
22
Q

What does the Left coronary artery split off into?

A
  • anterior interventricular - goes down through the ventricles
  • circumflex - wraps around the heart to get to the back
23
Q

What does the right coronary artery split into?

A
  • Marginal artery - runs along lower border of the right ventricle
  • Posterior interventricular - runs down the ventricle at the back
24
Q

What do the great middle and small cardiac veins do?

A
  • All drain into the coronary sinus which empties into the right atrium
  • Great: runs in the same region as the anterior interventricular artery
  • Middle: runs with the posterior interventricular artery
  • Small: runs with the marginal artery
25
Q

What does the anterior cardiac vein do?

A

drains directly into the right atrium

26
Q

How can the patency (how much they are open) of coronary vessels be examined?

A

by angiography

27
Q

What is the cardiac conducting system?

A

Effective heart contraction coordinated by the cardiac conducting system. It consists on non-contractile cells that initiate electrical impulses

28
Q

What are the different components of the cardiac conducting system?

A
  • Sinoatrial (SA) node
  • Atrioventricular (AV) node
  • AV bundle (bundle of His)
  • Right and left bundle branches
  • Purkinje fibres
29
Q

How can cardiac impulses be measured?

A

Using an electrocardiogram (ECG)

30
Q

Why is foetal circulation different from normal circulation?

A

Because:

  • Oxygen and nutrients are received from the placenta via the umbilical vein
  • Need to bypass non functional lungs
31
Q

What are the three circulatory shortcuts in foetal circulation?

A
  1. Foramen ovale connects the right to the left atria – bypassing the right ventricle and pulmonary system
  2. Ductus arteriosus connects the pulmonary trunk to arch of aorta – bypassing pulmonary system and left side of heart
  3. Ductus venosus connects the umbilical vein to inferior vena cava – bypasses the liver
32
Q

How does the foramen ovale stay open in foetal circulation?

A

Because of the high pressure in the right side of the foetus’ heart

33
Q

What happens when both oxygenated and deoxygenated blood enter the right atrium in foetal circulation?

A
  • Some goes to left atrium
  • Some goes to right ventricle and goes to pulmonary trunks:
     Little bit of blood goes from pulmonary trunks to lungs
     Most of blood passes over ductus arteriosus into aorta. Blood that’s returned to heart and blood that’s come from right atrium will also go into the aorta.
34
Q

What happens at birth?

A
  • Baby takes it’s first breath -> lungs expand -> blood rushes into pulmonary circulation -> O2 levels rise -> constricts ductus arteriosus
  • Baby takes first breath -> left atrium pressure increases -> foramen ovale closes to become fossa ovalis
  • Baby takes first breath -> umbilical cord tied -> umbilical vessels close -> ductus venosus fibroses (closes)
35
Q

what are the changes when a baby is born in terms of their circulatory system?

A
  • Ductus venosus becomes ligamentum venosum in adult
  • Foramen ovale becomes fossa ovalis in adult
  • Ductus arteriosus becomes ligamentum arteriosum in adult
36
Q

Why are capillaries called exchange vessels?

A

their thing walls permit the exchange of substances between blood and the surrounding tissues

37
Q

Where are the great vessels connected to the heart?

A

at the superior end of the heart at it’s base

38
Q

What is the inferior pointed tip of the heart called?

A

it’s apex

39
Q

What is the mediastinum?

A

The region between the two pleural cavities. The heart sits at it’s anterior portion

40
Q

What is pericarditis?

A

is when pathogens infect the pericardium producing inflammation. The inflamed pericardial surfaces rub against one another, making a distinctive scratching sound (a friction rub) that can be heard through a stethoscope that is placed on the chest.

41
Q

What does pericardial inflammation commonly result in?

A

Increased production of pericaridal fluid. Fluid then collects in the pericardial cavity restricting movement of the heart. This condition (cardiac tamponade) can also result from traumatic injuries that produce bleeding into the pericardial cavity

42
Q

What are the features of the atrium walls?

A

The atria have relatively thin muscular walls and are highly expandable

43
Q

What is the coronary sulcus?

A

is a deep groove that marks the border between the atria and ventricles

44
Q

What are the anterior interventricular sulcus and the posterior interventricular sulcus?

A

shallower depressions that mark the boundary between the left and right ventricles

45
Q

What four things does the connective heart tissue do?

A
  1. Provides physical support for the cardiac muscle fibres, blood vessels and nerves of the myocardium
  2. Help distribute the forces of contraction
  3. Add strength and prevent overexpansion of the heart; and
  4. Provide elasticity that helps return the heart to its original size and shape after a contraction
46
Q

Where do the superior and inferior cavae deliver blood from?

A
  • The superior vena cava delivers blood to the right atrium from the head, neck, upper limbs and chest
  • Inferior vena cavae delivers it from the rest of the body
47
Q

Where in the heart aren’t there any valves?

A

Between the vena cava and right atrium

48
Q

What’s the differences between the bicuspid and tricuspid valves?

A

The bicuspid valve contains two cusps and the tricuspid valves contain 3 cusps

49
Q

What’s adjacent to each cusp of the aortic valve?

A

Saclike expansions of the base called aortic sinuses

50
Q

What is the ligamentium arteriosum?

A

A fibrous band left over from the ductus arteriosus. It attached the pulmonary trunk to the aortic arch

51
Q

How do the AV valves open and close?

A

When the ventricles are relaxed, the chordae tendineae are loose, and the AV valves offer no resistance as blood flows from the atria into the ventricles. When the ventricles contract, blood moving back toward the atria swings the cusps together, closing the valves. At the same time, the con-traction of the papillary muscles tenses the chordae tendineae, stopping the cusps before they swing into the atria.

52
Q

When do valvular heart disease symptoms appear?

A

If valve function deteriorates to a point where the heart can’t maintain adequate circulatory flow

53
Q

What is an important cause of carditis (inflammation of the heart)?

A

Rheumatic rever

54
Q

Where do the right and left coronary arteries originate?

A

At the right and left aortic sinuses

55
Q

What is coronary artery disease characterised by?

A

interrupted blood flow to the myocardium. This is usually caused by a fatty deposit/ atherosclerotic plaque. You can get angina which is characterized by pain down your left arm when exercising

56
Q

When does a myocardial infraction (heart attack( occur?

A

when part of the coronary circulation becomes blocked and cardiac muscle cells die from lack of oxygen.

57
Q

What is a coronary thrombosis?

A

when a vessel already narrowed by a plaque formation may become blocked by a sudden spasm in the smooth muscles of the vascular wall

58
Q

What is the pericardium?

A

The sac the heart lies in