Mediastinum I

Question 1

what is within the inferior middle mediastinum?

Answer 1

heart
Pericardium

Question 2

what seperates the inferior and superior mediastinum?

Answer 2

a line between the sternal angle and T-4

Question 3

what is within the anterior inferior mediastinum?

Answer 3

Lymph nodes, vessels

Question 4

what is contained within the inferior anterior mediastinum?

Answer 4

Sternum -> pericardium
Fat
Sternopericardial ligaments
Lymphatics
- lymphatic vessels
- Parasternal lymph nodes
Internal thoracic vessels

In children- the inferior thymus

Question 5

what are the structures that the pericardium attaches to though connective tissue?

Answer 5

Vertebra
Sternum
Xiphoid
Diaphragm

Question 6

what is the superior pericardial ligaments?

Answer 6

sternopericardial ligaments

Question 7

what are the inferior pericardial ligaments?

Answer 7

xipho-pericardial

Question 8

what is the role of the sternopericardial ligaments?

Answer 8

helps retain the heat in its position in the thoracic cavity

Question 9

where does the thoracic lymphatic system originate?

Answer 9

Lymphatic vessles start from the anterior thoracic wall (the breast)

Question 10

what is the lymphatic flow in the thorax?

Answer 10

Lymphatic vessels from anterior thoracic wall drain into the parasternal lymph nodes

The parasternal lymph nodes drain into the bronchomediastinal trunks

These drain into the subclavian veins

Question 11

what are the parasternal lymph nodes associated with?

Answer 11

internal thoracic vessles

Question 12

where do the internal thoracic arterier originate?

Answer 12

from the left and right subclavian arteries

Question 13

where do the internal thoracic arteries branch?

Answer 13

to the anterior arteries and veins

Question 14

what do the internal thoracic arteries supply?

Answer 14

• intercostal muscles
• Diaphragm
• Pericardium
• Thymus

Question 15

where do the internal thoracic veins run?

Answer 15

Runs with the artery -> brachiocephalic veins

Question 16

what are the features of the base of the heart?

Answer 16

-Proximal
-Broad, towards the right shoulder
- Left (and right) atria

Question 17

what are the features of the apex of the heart?

Answer 17

-Distal
- Pointed
-Mid-claviculer line and 5th intercostal space
- left ventricle

Question 18

what vessel feeds into the right side of the heart?

Answer 18

The superior and inferior vena cava

Question 19

what vessel flows out of the right side of the heart?

Answer 19

Pulmonary trunk

Question 20

what feeds into the left side of the heart?

Answer 20

4x pulmonary veins

Question 21

what are the different sulci of the heart?

Answer 21

Coronary sulcus
Anterior and posterior interventricular sulci

Question 22

what are the features of the fetal heart that differ from the mature heart?

Answer 22

• Circulation bypasses the lungs
• Foramen ovale
• Ductus arteriosus
  (both close after birth (in the first breath))

Question 23

what is the formen ovale?

Answer 23

In fetal heart
- hole connecting right and left atria

Question 24

what is the ductus arteriosus?

Answer 24

In fetal heart
- artery connecting pulmonary artery and aorta

Question 25

what is the fossa ovaslis?

Answer 25

The closed over formen ovale - it is covered in connective tissue - Interatrial septum

Question 26

what is the ligamentum arteriosum?

Answer 26

The ductus arteriosus becomes the ligamentum arteriosum It connects the aortic arch to the pulmonary trunk Connective tissue within the superior mediastinum

Question 27

what are the right side primary cardiac blood vessels?

Answer 27

Coronary Posterior interventricular

Question 28

what are the left side primary cardiac blood vessels?

Answer 28

Coronary Circumflex Anterior interventricular Coronary sinus

Question 29

what is the function of the heart atria?

Answer 29

to collect blood -On the right side from the superior and inferior vena cavae - On the left side from the pulomnary veins

Question 30

what is the role of the atrioventricular valves?

Answer 30

-Close on ventricular contraction to prevent backflow

Question 31

what is the right atrioventricular valve?

Answer 31

Tricuspid

Question 32

what is the left atrioventricular valve?

Answer 32

Bicuspid (mitral)

Question 33

what moves blood from the atria to the ventricles?

Answer 33

Pectinate muscles

Question 34

what is the role of the ventricles?

Answer 34

Pumps blood out of the heart - on the right lungs to pulmonary trunk to arterier - on the left to the rest of the body to the ascending aorta

Question 35

what are the features of the muscular ventricle walls?

Answer 35

Left is thicker than the right (bigger area to reach) Trabeculae carnae Papillary muscles - AV valves - Chordae tendinae

Question 36

what are the semilunar valves?

Answer 36

Right- Pulmonary valves Left- aortic valve

Question 37

what are the layers of the heart wall?

Answer 37

- Endocardium - Myocardium - Epicardium - Pericardium

Question 38

what are the features of the endocardium?

Answer 38

Inner myocardial surface Lines chamers, valves Simple squamouse epithelium + areolar tissue Continuous with endothelium of the great vessels

Question 39

what are the features of the myocardium?

Answer 39

- Heart muscles - Striated - Arranged in spiral bundles - Have intercalated discs

Question 40

what are the features of the heart muscles?

Answer 40

-concentric layers - Blood vessels and nerves - Thicker on the left side of the heart

Question 41

what are the heart muscles arranged in spiral bundels?

Answer 41

LInks all parts of the heart together

Question 42

what is the function of intercalated discs?

Answer 42

Joins muscle fibres end to end -Contains gap junctions - Allows rapid spread of excitation

Question 43

what are the features of the epicardium?

Answer 43

- Outer surface - Visceral layer of serous pericardium Areolar tissue (closest to the myocardium) Mesothelium - closest to the pericardial cavity - secretes serous fluid

Question 44

what is the pericardium?

Answer 44

Sac of connective tissue covering the heart

Question 45

what is in the pericardial cavity?

Answer 45

Serous fluid - low friction environment

Question 46

what are the features of the parietal serous pericardium?

Answer 46

Mesothelium (inner) Areolar tissue (outer) Continuous with visceral serous layer at the root of the great vessels

Question 47

what are the features of the parietal fibrous pericardium?

Answer 47

Dense fibrous connective tissue Cone-shaped "bag" Base -> diaphragm Apex continuous with adventitia of great vessels (root) Sternopericardial ligaments Limits distention

Question 48

what is the blood supply to the heart and visceral pericardium?

Answer 48

coronary arteries and veins

Question 49

what is the blood supply to the parietal and fibrous pericardium?

Answer 49

internal thoracic arteries and veins

Question 50

what is the nerve supply to the heart and visceral pericardium?

Answer 50

cardiac plexus, vagus nerve, sympathetic trunk

Question 51

what is the nerve supply to the parietal and fibrous pericardium?

Answer 51

Phrenic nerve