Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Gross anatomy > The heart and mediastinum > Flashcards

The heart and mediastinum Flashcards

1
Q

Describe pulmonary circulation

A

Low resistance

pressure 20/10mmHg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Describe the systemic circulation

A

High variable resistance

120/80mmHg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the 3 layers of the heart wall?

A

3 layers of the heart wall
Epicardium (also visceral/serous pericardium)
Muscular myocardium
Endocardium (monolayer endothelial cells)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What’s the function of pericardial cavity?

A

Heart sits in it and allows friction free contraction within chest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Two layers of pericardium?

A

Outer fibrous layer (continuous with central tendon of diaphragm)
Serous layer inside

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the pericardial sac?

A

Double layered sac, sealed to diaphragm which surrounds heart apart from where great vessels enter/leave

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are some abnormalities that arise of the pericardium?

A

Pericarditis: inflammation of pericardium, people complain with chest pain due to friction (heart beats and it rubs)

Tamponade: effusion of pericardium (e.g. post viral infection or shot in heart ), fluid builds up between 2 pericardial layers and insults pumping action of the heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is meant by pericardial sinus?

A

Cavities produced by pericardium around the heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Two types of pericardial sinuses?

A

Oblique sinus between heart and great vessels

Transverse sinus: around aorta and pulmonary trunk posterior to heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How is transverse sinus formed?

A

Dorsal mesocardium breaks down

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe orientation of heart in thorax

A

Lies obliquely, RV and RA face anteriorly, LV and LA posterior

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe the surface borders of the heart

A

Superior border: line following 2nd left costal cartilage to 3rd right costal cartilage

Right border: 3-6 right intercostal cartilage

Apex (left border): in 5th intercostal space in mid clavicular line

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What happens in situs inversus

A

Mirror image positioning of all organs (compatible with life)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is situs solitus?

A

Normal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is fibrous skeleton formed of?

A

Cartilaginous ring at level of membranous ventricular septum (connective tissue frame which functions to electrically isolate the atria from the ventricles)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the function of fibrous skeleton of heart?

A

Non conducting separation of atria and ventricles, electroinsulation so impulses must pass through AVN

Support for valves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the principal venous structures draining to heart?

A

SVC, IVC (drain into right atrium)
Pulmonary veins
Coronary sinus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the coronary sinus?

A

A collection of veins joined together to form a large vessel (coronary sinus) that empties blood into right atrium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Where does coronary sinus run and which veins does it receive?

A

Runs in AV groove

Receives, great, middle and small cardiac vein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the name of the right AV valve?

A

Tricuspid valve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What does fibrous skeleton contain?

A

AV, aortic and pulmonary valve orifices

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are 3 cusps of tricuspid valve attached to?

A

Fibrous ring surrounding AV orifice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Structure of pulmonary/aortic valves?

A

3 semi lunar cusps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What veins does the left atrium receive?

A

4 pulmonary veins (2 inferior, 2 superior 2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Why does left atrium have smooth walled interior?

A

Formed by incorporation of primitive pulmonary veins in development

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the left AV valve?

A

Mitral valve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Describe structure of mitral valve?

A

2 cusps and papillary muscles larger than counterparts on right side

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What are aortic sinuses?

A

Formed behind cusp of each valve as a bulge in aortic wall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What do left, right posterior and anterior aortic sinuses supply?

A

Left Posterior - origin of left coronary artery
Right anterior: origin of right coronary artery
Right posterior: no artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What happens to blood supply to ventricular wall in systole, why, therefore, when does most coronary perfusion occur?

A

High pressure generated shuts off coronary circulation

Most coronary perfusion in diastole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

How does heart blood supply show end organ circulation?

A

Branches of coronary artery are functional end structures (anastomoses between LCA and RCA rare and inefficient) and sensitive to obstruction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

In terms of coronary arteries, why can myocardial infarctions/angina be caused?

A

Occlusion of major coronary arteries and inefficienct anastomoses between RCAs and LCAs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Where does coronary circulation originate from?

A

RCA and LCA arise above aortic valve at left/right aortic sinuses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Which layers of heart do coronary arteries supply?

A

Myocardium and epicardium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What do LCA and RCA supply generally?

A

LCA: left ventricles, atria and IV septum
RCA: right ventricles, atira and septum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

How does the RCA branch?

A

The right coronary artery passes from the right aortic sinus and branches to form the right marginal artery (RMA) anteriorly.

In individuals who have right dominant circulation (~80% of individuals), it also branches into the posterior descending/interventricular artery.

37
Q

How does the LCA branch?

A

Emerges from the left coronary sinus, initially branches to yield the left anterior descending (LAD) artery.

It also gives off the left marginal artery (LMA) and the left circumflex artery.

In ~20 of individuals, the left circumflex artery contributes to the posterior descending artery, these individuals are left dominant.

38
Q

What does marginal branch of RCA supply?

A

RV and apex

39
Q

What does the RCA supply?

A

SAN and RA

40
Q

How does blood pooling help close SL valves in diastole?

A

Turbulence of blood as aortic pressure decreases, blood pools in aortic sinuses (then can travel through coronary arteries)

41
Q

Which is the more important coronary artery and why?

A

Left, has 3 main branches instead of 2.

42
Q

What does the LAD supply?

A

LV and septum

43
Q

What does the LCA supply?

A

LA and LV anterior 2/3 of the interventricular septum

44
Q

What does the LMA supply?

A

LV

45
Q

Where is the SAN?

A

In cristae terminalis (separates the smooth and rough walls of the RA)

46
Q

What happens to the bundle of his?

A

Divides into posterior and anterior left and right bundle branches which transmit impulses to endocardial regions on left and right ventricles.

47
Q

What do branches of left and right branches of Bundle of His do?

A

Transmit impulses to Purkinje fibres

48
Q

Why do many fibres innervating cardiac plexus arise in the neck?

A

Heart develops in cervical region of embryo

49
Q

Why is there referred pain to chest arm and neck in myocardial infarction?

A

Cardiac sensory pain fibers follow the sympathetic back to the spinal cord and have their cell bodies located in thoracic dorsal root ganglia 1-4.

The central nervous system (CNS) perceives pain from the heart as coming from the somatic supplied by the T1-4 (dermatomes arising from this dorsal root ganglia (T1-5) are in the upper limb and up to the neck).

50
Q

What is the inner wall of the right atrium like?

A

Lateral rough walled part consisting of pectinate muscle.

Smooth walled part

51
Q

Why is there a smooth and rough wall of the right atrium?

A

Different embryological origin
Rough wall from primitive atrium
Smooth wall from sinus venosus and interatrial septum

52
Q

Why is the right ventricle wall much thinner than the left ventricle wall?

A

Less force is required to pump the blood to the lungs. Pulmonary circulation has 6x lower resistance so 6x lower pressure needed to produce the same flow.

53
Q

What is the name to describe the rough muscular surface of the ventricle wall?

A

Trabeculae carneae

54
Q

What is the left atrial appendage and why is it clinically significant?

A

Additional volume outside of main chamber, blood can pool here, act more turbulent and clot.

55
Q

How can you diagnose aortic stenosis?

A

Ejection systolic murmur, as blood rushes out of aorta, hear the murmur

56
Q

How do you diagnose atrial regurgitation?

A

Hear murmur in early diastole as blood pools back into aorta

Murmur decrescendos in ventricular systole

57
Q

What can murmurs suggest?

A

Valve problems

58
Q

What is the mediastinum and what does it consist of?

A

Central compartment of the thoracic cavity surrounded by loose connective tissue.

Contains the heart and its vessels, oesophagus, trachea, the phrenic and cardiac nerves, the thoracic duct, the thymus and the lymph nodes of the central chest.

59
Q

What are the borders of the superior mediastinum?

A

Superior thoracic aperture to the thoracic plane at the angle of louis (T4).

60
Q

What are the borders of the inferior mediastinum?

A

Thoracic plane (T4) to diaphragm

61
Q

What three regions is the inferior mediastinum divided into?

A

Anterior - infront of the pericardium
Middle - pericardium and its contents
Posterior - behind the pericardium

62
Q

What is the superior mediastinum bounded by?

A

Superiorly by the thoracic inlet, the upper opening of the thorax

Inferiorly by the transverse thoracic plane (T4)

Laterally by the pleurae

Anteriorly by the manubrium of the sternum

Posteriorly by the first four thoracic vertebral bodies.

63
Q

What is the anterior mediastinum bounded by?

A

Laterally by the pleurae

Posteriorly by the pericardium

Anteriorly by the sternum, the left transversus thoracis and the fifth, sixth, and seventh left costal cartilages.

64
Q

What is the middle mediastinum bounded by?

A

The pericardial sac

65
Q

What is the posterior mediastinum bounded by?

A

Anteriorly by (from above downwards): bifurcation of trachea; pulmonary vessels; fibrous pericardium and posterior sloping surface of diaphragm

Inferiorly by the thoracic surface of the diaphragm (below);

Superiorly by the transverse thoracic plane;

Posteriorly by the bodies of the vertebral column from the lower border of the fifth to the twelfth thoracic vertebra (behind);

Laterally by the mediastinal pleura (on either side).

66
Q

The component of the primitive heart tube that forms the smooth walled parts of the atria…

A

Sinus venosus

67
Q

Which side is tricuspid and mitral on?

A

Mitral - left

Tricuspid - right

68
Q

What does the atrio-ventricular bundle (of His) peirce?

A

Pierces the fibrous skeleton which separates the atria from the ventricles

69
Q

What chamber forms most of the left radiographic margin of the heart?

A

Left ventricle

70
Q

A direct consequence of tricuspid valve incompetence i.e. a failure of the valve to close completely during ventricular contraction…

A

Raised right atrial pressure

71
Q

Anterior mediastinum contains

A

Thymus, internal thoracic vessels

72
Q

Middle mediastinum contains

A

Heart, pericardum, tracheal bifurcation, ascending aorta, SVC, cardiac plexus, left and right phrenic nerves

73
Q

Posterior mediastinum contains

A

Thoracic aorta, oesophagus, thoracic duct, Azygous veins, sympathetic trunks

74
Q

Superior mediastinum contains

A

Arch of aorta, SVC, vagus nerve, phrenic nerve, cardiac nerves, sympathetic trunk, trachea, oesophagus, thoracic duct.

75
Q

What is found at the thoracic plane?

A

RATPLANT

2nd rib 
aortic arch 
tracheal bifurcation
pulmonary trunk
ligamentum arteriosum
azygous vein 
nerves 
thoracic duct
76
Q

Vagus nerves enter the superior mediastinum via the

A

Carotid sheath

77
Q

When does the right vagus become the right recurrent laryngeal?

A

As it crosses the subclavian artery

78
Q

Right recurrent laryngeal loops beneath… and supplies…

A

Loops beneath the right subclavian artery and supplies the larynx

79
Q

When does the left vagus become the left recurrent laryngeal?

A

As it crosses the aorta

80
Q

Left recurrent laryngeal loops beneath… and supplies…

A

Loops beneath the ligamentum arteriosum and supplies the larynx

81
Q

Sympathetic roots of heart

A

T1-T5

82
Q

Phrenic roots

A

C3,4,5

83
Q

Costophrenic recess

A

Sharp angles between the thoracic wall and diaphragmatic pleurae

84
Q

Paralysis of half the diaphragm

A

Inspiration - paralysed hemidiaphragm rises due to push from abdominal viscera

Exhalation - paralysed hemidiaphragm descends due to positive pressure within the lungs

85
Q

Distention of the aortic arch vagus

A

Compression of left recurrent laryngeal as loops round the ligamentum arteriosum

Hoarse voice and gastroparesis

86
Q

What area is clamped during surgery

A

Transverse sinus

87
Q

Locations of heart sounds

A

Tricuspid - 4th IC space
Mitral - apex
Aortic - right 2nd IC space
Pulmonary - left 2nd IC space

88
Q

Three physiological shunts in foetal CV system

A

foramen ovale - RA to LA
ductus venosus - umbilical vein to the IVC
ductus arteriosis - pulmonary trunk to arch of aorta

89
Q

Changes at birth to CV system?

A

FO shuts forming fossa ovalis
Ductus arteriosis constricts (ligamentum arteriosum) when blood PO2 rises
Umbilical vein constricts (ligamenum teres) and ductus venosus forms the ligamentum venosum

Gross anatomy (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions