L26 - Mediastinum I

Question 1

where is the inferior anterior mediastinum?

Answer 1

anterior to the pericardium

Question 2

what is the inferior anterior pericardium filled with and why?

Answer 2

fat/adipose tissue for protection

Question 3

in children the inferior thymus is a lot larger, to where does it extend when you are younger?

Answer 3

4th costal cartilages

Question 4

what are the 4 types of sternopericardial ligaments?

Answer 4

• xiphoid
• diaphragm
• sternum
• vertebra

Question 5

what 2 types of sternopericardial ligament are found in the inferior anterior mediastinum?

Answer 5

sternum and xiphoid

Question 6

what aspect of the inferior anterior mediastinum does the sternopericardial ligament cross and where are it’s attachments?

Answer 6

superior, pericardium to sternum

Question 7

what aspect of the inferior anterior mediastinum does the xipho-pericardial ligament cross and where are it’s attachments?

Answer 7

inferior, pericardium to xiphoid process

Question 8

what is the function of the sternopericardial and xipho-pericardial ligaments?

Answer 8

restrict unwanted movement, helps retain heart in it’s position in the thoracic cavity

Question 9

what is the function of lymphatics?

Answer 9

to recycle fluid and maintain volume in the vascular system

Question 10

what does the lymphatic vessels form?

Answer 10

anterior wall - medial breast

Question 11

where does lymph drain into (3 steps) and at which location does toxin filtering occur?

Answer 11

lymph drains into parasternal lymph nodes (where filtering occurs) –> bronchomediastinal trunks –> subclavian veins to maintain volume of vasculature

Question 12

where is the heart?

Answer 12

inferior-middle mediastinum

Question 13

location of the apex

Answer 13

mid-clavicular line, 5th intercostal space

Question 14

where is the right coronary sulcus?

Answer 14

between right atrium and right ventricle

Question 15

where is the left coronary sulcus?

Answer 15

between left atrium and left ventricle

Question 16

where is the posterior interventricular sulcus?

Answer 16

between the left and right ventricles on the posterior surface of the heart

Question 17

where is the anterior interventricular sulcus?

Answer 17

between the left and right ventricles on the anterior surface of the heart

Question 18

what enters and exits the right side of the heart?

Answer 18

in - superior and inferior vena cavae
out - pulmonary trunk

Question 19

what enters and exits the left side of the heart?

Answer 19

in - 4x pulmonary veins
out - ascending aorta

Question 20

what hole connects the right and left atria in fetal hearts?

Answer 20

foramen ovale

Question 21

what artery connects pulmonary artery to aorta in fetal hearts?

Answer 21

ductus arteriosus

Question 22

what closes after the first breath after birth in fetal hearts?

Answer 22

foramen ovale and ductus arteriosus

Question 23

when foramen ovale closes, what is it covered by, what is it called and what does it act as?

Answer 23

covered by connective tissue, fossa ovalis, interatrial septum

Question 24

what does the ductus arteriosus become and what is it made of?

Answer 24

becomes ligamentum arteriosum, made of connective tissue

Question 25

what can happen to the ligamentum arteriosum if in an accident?

Answer 25

can tear and if it's bad enough it can tear part of the aorta which can be fatal

Question 26

what primary cardiac vessel is on the right side of the heart, where is it located and what is the associated sulcus?

Answer 26

coronary, found on posterior interventricular line, posterior interventricular sulcus

Question 27

what primary cardiac vessel is on the left side of the heart, what does it split into, what sulcus is associated?

Answer 27

left coronary, found on anterior heart, splits into circumflex and anterior interventricular, anterior interventricular sulcus

Question 28

what primary cardiac vessel do all other smaller branches drain into and where does it drain int next?

Answer 28

coronary sinus (vein), into right atrium

Question 29

what moves blood from atria to ventricles?

Answer 29

pectinate muscles

Question 30

what is the role of the atria? which atria collects from where

Answer 30

collects blood right - superior and inferior vena cavae left - pulmonary veins

Question 31

what is the role of the ventricles? which ventricle pushes blood to where?

Answer 31

pumps blood out of the heart right - to lungs --> pulmonary trunk --> arteries left - to rest of body --> ascending aorta

Question 32

which ventricle has a thicker muscle wall and why?

Answer 32

left has a thicker wall as it pumps blood to the whole rest of the body not just the lungs

Question 33

why does the pectinate muscle have trabeculae carnae?

Answer 33

these struts of muscle increase force while decreasing muscle mass

Question 34

what role do the papillary muscles have and what do they work with?

Answer 34

they attach from the ventricle wall to valves to keep the valves closed and prevent backflow, connect to the chordae tendineae which connect to the valve

Question 35

which valves are the right and left semilunar valves?

Answer 35

right - pulmonary valve left - aortic valve

Question 36

what are the 4 layers of the heart wall

Answer 36

endocardium myocardium epicardium pericardium

Question 37

what surface is the endocardium, what does it line and what epithelia is it (2)?

Answer 37

inner myocardial surface lines chambers and valves simple squamous and areolar tissue (on outisde)

Question 38

how is the myocardium arranged?

Answer 38

in spiral bundles to link all parts of the heart together?

Question 39

in what layer of the heart can you find intercalated discs and what roles do they have?

Answer 39

myocardium - joins muscle fibres - contains gap junctions - allows rapid spread of excitation

Question 40

what surface is the epicardium, what epithelia (2) and where are they?

Answer 40

outer surface = visceral layer of serous pericardium areolar tissue - closest to myocardium mesothelium - closest to pericardial cavity and secretes serous fluid

Question 41

what layer is the pericardium?

Answer 41

sac of CT covering the heart

Question 42

what is in the pericardial cavity and what function does it serve?

Answer 42

serous fluid to prevent friction

Question 43

what are the inner and outer layers of the parietal serous pericardium made from?

Answer 43

inner = mesothelium outer = areolar tissue

Question 44

what are the inner and outer layers of the parietal serous pericardium made from?

Answer 44

inner = mesothelium outer = areolar tissue

Question 45

what is the parietal fibrous pericardium made from

Answer 45

dense fibrous connective tissue

Question 46

important function of parietal fibrous pericardium

Answer 46

limits distension and prevents overfilling of the heart

Question 47

pericardiac blood supply heart and visceral pericardium

Answer 47

coronary arteries and veins

Question 48

pericardiac blood supply parietal and fibrous pericardium

Answer 48

internal thoracic arteries and veins

Question 49

pericardiac nerve supply heart and visceral pericardium

Answer 49

cardiac plexus, vagus nerve, sympathetic trunk

Question 50

pericardiac nerve supply parietal and fibrous pericardium

Answer 50

phrenic nerve