Posterior mediastinum and diaphragm

Question 1

What is the posterior mediastinum

Answer 1

the area behind the fibrous pericardium

Question 2

What structures are in the posterior mediastinum

Answer 2

descending thoracic arch, oesophagus, right and left ganglion sympathetic chain which has important nerves running off it, lymph nodes, running upwards is the thoracic ducts, vena azygous (right), hemizygous and accessory hemiazygos vein (left).

Question 3

What are the boundaries of the inferior mediatsinum

Answer 3

Superior - sternal angle
Inferior - diaphragm
Anterior - heart and pericardium
Posterior - T5-T12 vertebral bodies

Question 4

Where is the anterior mediastinum

Answer 4

T5-T9

Question 5

Where is the middle mediastinum

Answer 5

T5-T8

Question 6

Where is the posterior mediastinum

Answer 6

T5-T12

Question 7

What structures come of the sympathetic trunks (T5-T12 ganglia)

Answer 7

greater splachnic nerve, lesser splanchnic nerve, least splanchnic nerve – run anteriorly down the bodies of the vertebrae, hit the pre-aortic ganglia and plexuses.

Question 8

What are the contents of the posterior mediatsinum

Answer 8

Descending thoracic aorta, azygous veins, thoracic duct, Eosophagus, sympathetic trunk (DATES)

Question 9

Where is the thoracic duct located

Answer 9

ascending from cisterna kylie, moves superiorly through posterior mediastinum, crosses from right to left lateral at the superior margin of the posterior mediastinum, around the thoracic plane into the left venous angle

Question 10

How does the lymphatic system maintain homeostasis

Answer 10

by returning most of the fluid that has been diverted back into your blood

Question 11

What are the 4 main parts of the lymphatic system

Answer 11

lymph, lymph vessels, lymph nodes, lymph organs

Question 12

What is lymph

Answer 12

water solution (does not contain red blood cells), remains in closed circulatory loop because they are too large to be passed through capillary membranes

Question 13

What do lymphatic vessels help with

Answer 13

help reabsorb the fluid

Question 14

What is the function of lymph nodes

Answer 14

checkpoints that monitor and cleanse the lymph as it filters through.

Question 15

Examples of lymphoid organs

Answer 15

spleen, thymus adenoids, tonsils

Question 16

What are the thymus and spleen the site of

Answer 16

site for maturing lymphocytes

Question 17

What does most lymph start off as

Answer 17

blood plasma which gets forced out of your capillaries

Question 18

What are the capillary beds

Answer 18

where capillaries carry blood from your arterioles and arteries and feed blood into venules then veins

Question 19

What are capillary beds the site of

Answer 19

transfer of waste and nutrients as blood pressure force plasma out of arteriole end of capillaries and into the interstitial fluid between the cells of the tissue

Question 20

What pressure causes some of the fluid that has been lost to be absorbed at the venous end

Answer 20

osmotic pressure

Question 21

What are lymphatic capillaries made from

Answer 21

loosely overlapping endothelial cells that form little flap like valves that can only open in one direction

Question 22

What do the flap like valves in lymphatic vessels do

Answer 22

ensure lymph fluid will not leak back into the interstitial space

Question 23

What happens to the valves when pressure in interstitial fluid becomes greater than the pressure inside the lymphatic capillary

Answer 23

the flaps push open and take in fluid to remove the pressure

Question 24

What happens to the fluid that has been taken in by the lymphatic vessels

Answer 24

flows through successively larger lymphatic vessels to collecting vessels and then to larger trunks. Then into 1 of 2 large lymph ducts that feed back into the lowest pressure area of the circulatory system

Question 25

What does the right lymphatic duct drain

Answer 25

all the lymph collected from the right upper area of the torso, right arm , head and thorax into the internal jugular vein

Question 26

Where does the larger thoracic duct take the lymph

Answer 26

takes lymph from the rest of the body and dumps it into the subclavian vein

Question 27

What kind of muscle do lymphatic vessels have

Answer 27

skeletal muscle

Question 28

What helps lymph move along

Answer 28

pressure changes in the thorax during breathing and pulsations of adjacent arteries

Question 29

What muscle in the lymphatic vessel walls help lymph to move

Answer 29

smooth muscle

Question 30

What does recovering 3L of blood a day prevent

Answer 30

prevents drop in blood pressure and little/no oxygen delivery or waste pick up

Question 31

What does a blockage in lymphatic system result in

Answer 31

oedema or swelling that can constrain blood flow and lead to serious complications

Question 32

How does the lymphatic system have a role in the immune system

Answer 32

intestinal fluid that drains into lymph vessels contain bacteria that if not killed in the lymph system can enter your heart

Question 33

Which immune cells are housed in the lymphatic system

Answer 33

T cells, B cells, macrophages and reticular cells

Question 34

What regularly inspect lymph nodes

Answer 34

lymphocytes

Question 35

What can lymphocytes trigger the release of

Answer 35

macrophages and can activate the general immune system

Question 36

Where are lymphocytes found

Answer 36

the loose reticular connective tissue that makes up a large part of the nodes and most of your other lymphoid organs

Question 37

What are swollen lymph nodes a sign of

Answer 37

disease or infection

Question 38

Where is mucosa associated lymphoid tissue found

Answer 38

mucosa membrane around the body, outside of the lymphatic vessels (found in intestine etc..)

Question 39

What are Peyer's pathes

Answer 39

lymph tissue in small intestine which is a check point in GI tract.

Question 40

What do the azygous veins join

Answer 40

the superior vena cava

Question 41

Where do the azygous veins run

Answer 41

begins below the diaphragm and runs up along the right side of the vertebral column then arches over the right main bronchus

Question 42

Where do azygous veins receive blood from

Answer 42

the posterior and lateral parts of the chest wall

Question 43

On the right side what runs into the azygous veins

Answer 43

posterior intercostal veins

Question 44

Where do the posterior intercostal veins run into on the right side

Answer 44

the 2 hemi azygous veins which then empty into the azygous

Question 45

Describe the arrangement of the fibres of the diaphragm

Answer 45

fibres that converge from all around the circumference to insert on the central tendon of the diaphragm

Question 46

Where does the diaphragm arise from

Answer 46

arises from a line that goes right around the inside of the lower thoracic aperture that has one interruption

Question 47

Where is the line of the attachment of the diaphragm

Answer 47

goes from the back of the sternum (lower), along the inside of the costal arch and around to the tip of the 12th rib

Question 47

When does the diaphragm arises on each side of the fascia which overlies quadratus lumborum and psoas major muscles

Answer 47

between the 12th rib and the body of the second lumbar vertebra

Question 48

What 3 structures pass through the diaphragm

Answer 48

esophagus, inferior vena cava and descending aorta

Question 49

Where is the caval hiatus

Answer 49

T8

Question 50

What passes through the caval hiatus

Answer 50

inferior vena cava and terminal branches of the right phrenic nerve

Question 51

Where is the oesophageal hiatus

Answer 51

T10

Question 52

What passes through the oesophageal hiatus

Answer 52

oesopahgus, right and left vagus nerve, oesaphageal branches of left gastric artery/vein

Question 53

Where is the aortic haitus

Answer 53

T12

Question 54

What passes through the aortic hiatus

Answer 54

aorta, thoracic duct and azygous vein

Question 55

What is present on each of the openings of the diaphragm

Answer 55

a thickening called the crus (crura - plural)

Question 56

Where does the left crus arise

Answer 56

from the body of L2

Question 57

Where does the right crus arise

Answer 57

from the body of L3

Question 58

What do the 2 crura do

Answer 58

arch over the aortic opening forming the median arcuate ligament

Question 59

What surround the oesophageal hiatus

Answer 59

fibres of the 2 crura which cross over

Question 60

What happens to the diaphragm when it contracts

Answer 60

the whole sheet of muscle, together with the central tendon, moves downward, expanding the lungs and causing us to breathe in

Question 61

What happens to other structures when the diaphragm contracts

Answer 61

the structures below it (the contents of the upper part of the abdominal cavity) are pushed downward causing bulging of the abdominal wall

Question 62

How is inspiration produced at rest

Answer 62

by the downward pull of the diaphragm, with little or no movement of the ribs

Question 63

What is the return movement of the diaphragm produced in quiet expiration

Answer 63

movement is produced passively by elastic forces (elastic contraction of the lungs them selves