Lab 7: Heart and Mediastinum

Question 1

Describe boundaries of mid mediastinum

Answer 1

Sup = sternal angle
Inf = diaphragm
Ant and post = fibrous pericardium

Question 2

Name roots of great vessels visible in mid mediastinum

Answer 2

Aorta
Pulmonary trunk, pulmonary arteries =x2 and pulmonary veins = x4
Ivc and svc

Question 3

What is ligamentum arteriosum

Answer 3

Ductus arteriosus closes = remnant
Shunt between pulmonary trunk and aorta - bypasses lungs

Question 4

Name neurovasculature outside pericardium

Answer 4

Phrenic
Pericardiophrenic vessels

Question 5

Describe phrenic

Answer 5

In front of hilum and vagus - posterior to hilum
Cardiac plexus

Question 6

Describe pericardiophrenic vessels

Answer 6

Arteries and veins
Run with phrenic nerves

Question 7

What else can we see in mid mediastinum

Answer 7

Coronary circulation
Heart and pericardial coverings
Primary bronchi = left and right

Question 8

Name the layers of the pericardium and their function generally

Answer 8

Serous membrane, pericardial cavity = potential space
Fibrous pericardium
Parietal serous pericardium
Visceral pericardium

Question 9

Describe fibrous pericardium

Answer 9

Attaches to diaphragm and sternum
Encompasses all, anchored to root of gre vessels and at diaphragm
Pericardial fat

Question 10

Describe parietal serous pericardium

Answer 10

Against fibrous

Question 11

Describe visceral serous pericardium

Answer 11

Against heart
Epicardial fat

Question 12

Describe coronary arteries

Answer 12

First branch aorta
Blood to heart

Question 13

Describe coronary sinus

Answer 13

Means you are posterior in av sulcus
Drains into right atrium along with svc and ivc
Opening close to ivc

Question 14

Name and describe branches of right coronary artery

Answer 14

Sinoatrial nodal branch = runs between svc and aorta towards posterior aspect, under - around auricle of right atrium
Right marginal artery = apex, towards side
Posterior interventricular artery = middle back, in some people = comes from left coronary

Question 15

Name and describe branches of left coronary artery

Answer 15

Anterior interventricular artery = big, down middle
Circumflex branch = around back and gives =
Left marginal artery = comes down sides

Question 16

Describe venous drainage of heart - mainly

Answer 16

Great cardiac vein = travels with anterior interventricular artery then with circumflex a
Middle cardiac vein = travels with posterior interventricular artery
Small cardiac veins = travels with right marginal artery

Question 17

Where do great, middle and small cardiac veins drain

Answer 17

Into coronary sinus

Question 18

Where do anterior cardiac veins drain

Answer 18

Right = drains into right atrium

Question 19

Describe psns and sns for heart

Answer 19

Sns = increase hr, sympathetic chain
Psns = decrease hr, vagus branches

Question 20

Describe filling of coronary arteries

Answer 20

Filled during diastole = ventricular relaxation
Aortic valve must be closed (semilunar)
Excess blood filled up valve

Question 21

Describe right atrium and ventricle

Answer 21

Pulmonary circulation
Atrium = collect deoxygenated from body = svc, ivc, and coronary sinus (all but svc has valves)
Ventricle = deoxygenated from atrium and pump to pulmonary trunk and arteries (left and right)

Question 22

Describe characteristics of right atrium

Answer 22

Svc and ivc openings into here
Opening for coronary sinus = near ivc
Fossa ovalis = circular indent, shunts = right to left atrium
Auricle
Pectinate muscle
Crista terminalis

Question 23

Describe walls of right atrium

Answer 23

Smooth posterior wall
Ant and lateral = pectinate muscle, expand without stress on wall

Question 24

What is crista terminalis of right atrium

Answer 24

Line, junction between pecitinate and smooth muscles

Question 25

Describe right ventricle

Answer 25

Right av valve = tricuspid Connects cusps to chordae tendinae and papillary muscles Trabeculae carnae= wall texture Pulmonary valve = lead to pulmonary trunk Septomarginal = aka moderator band

Question 26

Describe cups of right av valve - tricuspid

Answer 26

3 lobes like lung Ant, post and septal cusps

Question 27

What is fiction of papillary muscles

Answer 27

When shut during systole = Prevent backflow = holds cusps, prevent PROLAPSE

Question 28

Describe aortic and pulmonary valve

Answer 28

Both have 3 cusps Semi lunar for both

Question 29

Describe left atrium and ventricle

Answer 29

Systemic circulation

Question 30

Describe left atrium

Answer 30

Auricle Openings for pulmonary veins x4 Reverse imprint of fossa ovalis less pectinate muscle

Question 31

Describe left ventricle

Answer 31

Left av valve = bicuspid/mitral valve = only 2 cusps Chordae tendinae and papillary muscles = 2 sets Trabeculae carnae Aortic valve leading to ascending aorta Ventricle = way thicker = to whole body

Question 32

Describe borders of anterior mediastinum

Answer 32

Ant = sternum Post = anterior surface pericardial sac Sup= sternal angle Inf= diaphragm Lat= mediastinal surface of lungs

Question 33

Describe contents of anterior mediastinum

Answer 33

Thymus Gland = lymphoid, T cells, degeneration in adults Fat Ct

Question 34

Describe border of superior mediastinum

Answer 34

Ant = manubrium - sup vs inf = manubriosternal joint Post = vertebrae and thoracic wall Superior = rib 1/superior thoracic aperture Inferior = thoracic plane - plane between sternal angle and vertebrae t4/5 Lat= mediastinal surface of lungs

Question 35

Describe contents of superior mediastinum= arterial

Answer 35

Arterial = branches of arch of aorta: 1 brachiocephalic trunk (right subclavian and common carotid), 2 left common carotid, 3 left subclavian

Question 36

Describe difference between right and left vagus nerves

Answer 36

Right = under right subclavian artery, outside mediastinum Left =in superior mediastinum, under aortic arch

Question 37

Describe posterior mediastinum borders

Answer 37

Ant= post surface of pericardial sac Post = posterior thoracic wall Superior = thoracic plane, plane between sternal angle and vertebrae t4/5 Inferior = diaphragm Lat = mediastinal surface lungs

Question 38

Describe contents of posterior mediastinum = arterial

Answer 38

Arterial = thoracic -descending aorta (posterior intercostal arteries)

Question 39

Describe contents of superior mediastinum = venous

Answer 39

Venous = right and left brachiocephalic veins margining into svc, arch of azygous

Question 40

Describe contents of superior mediastinum = nerves

Answer 40

Nerves = right and left vagus and their recurrent laryngeal branches, right and left phrenic nerves, sympathetic chain, cardiac plexus, pulmonary plexus

Question 41

Describe contents of superior mediastinum = lymphatics and organs

Answer 41

Lymphatics = right lymphatic and thoracic ducts = drains into internal jugular + subclavian Organs = trachea - ant to - eso

Question 42

Describe contents of posterior mediastinum = venous

Answer 42

Venous = azygous (drains in sup, but located in post mediastinum) and hemi azygous system (post intercostal veins) = bypass svc and ivc, drains into base svc —> atrium, abdominal and thoracic wall

Question 43

Describe contents of posterior mediastinum = nervous

Answer 43

Nervous = left and right vagus transitioning to anterior and posterior a gal trunks After hilum of lungs, respectively, with associated plexuses, sympathetic Chain, splanchnic nerves = 3

Question 44

Describe contents of posterior mediastinum = lymphatics and organs

Answer 44

Lymphatics = thoracic duct - posterior Organs = esophagus