lec 12

Question 1

what and where is the mediastinum>

Answer 1

1. mediastinum is the space b/w the 2 pleural sacs
2. extends strenum -> vertebral col
3. contain all structures w/in thoracic cavity except the lungs and pleura

Question 2

what are the subdivision and what are there

Answer 2

1. superior mediastinum: superior thoracic aperture to sternal angle (inferior border of t4)
2. inferior mediastinum:
   from sternal angle to diaphragm

a. anterior mediastinum: anterior to heart and pericardium
b. middle mediastinum: pericardium and heart
c. posterior to pericardium and diaphragm

Question 3

superior mediastinum:

1. thymus
   a. involved in the development of what
   b. posterior to
   c. involutes when
   d. what is a disease of it

Answer 3

a. immune sys
b. manubrium
c. puberty
d. thymoma

Question 4

superior mediastinum:

2. great vessels
   a. brachiocephalic veins
   - > formed posterior to medial end of clavicle by union of what and what
   - > join to form the what where

Answer 4

• > IJV and subclavian vein

- > SVC near right 1st costal cartilage

Question 5

superior mediastinum:

3. great vessels
   a. SVC
   - > enters the RA where
   - > returns venous blood from everything superior to the diaphragm except what and what

Answer 5

• > middle mediastinum

- > lungs and heart

Question 6

superior mediastinum:

3. great vessels
   c. arch of aorta
   - > arches posterosuperior and to the left, anterior to what , & pass inferiorly adjacent to what
   - > gives off 3 branches:

Answer 6

• > trachae; vertebral column;

- > brachiocephalic trunk, left common carotid artery, left subclavian artery

Question 7

superior mediastinum:

3. great vessels
   d. pulmonary trunk
   - > branches into

Answer 7

-> r and l pulmonary arteries

Question 8

Nerves

a. vagus nerve (CN X)
- > right vagus: passes anterior to what,

• > breaks up into what posterior to the root of the right lungs
• > reforms then break up into
• > give branch to what and what

Answer 8

• > subclavin artery
• > pulmonary plexus
• > esophageal plexus
• > heart and lungs

Question 9

Nerves

a. vagus nerve (CN X)
- > left vagus: passes to the left of what

• > passes posterior to the root of what
• > gives branches to what, what, and what

Answer 9

• > arch of the aorta
• > root of the left lungs
• > lungs, esophagus, and heart

Question 10

Nerves

a. vagus nerve (CN X)
- > recurrent laryngeal nerves:
* right: hooks under the what to ascend to the neck
* left: hooks under the what and what to ascend into the neck b/w trachea and esophagus

Answer 10

• right subclavian artery

* ligamentum arteriosum; aortic arch

Question 11

Nerves

b. phrenic nerve
- > sole motor supply to who

• > sensory to who(4)
• > passes anterior to the root of the what, along the what to enter the diaphragm

Answer 11

• > diaphargm
• > pericardium, pleura(medistinal), pariental peritoneum, diaphargm
• > lung, pericardium

Question 12

trachea:

1. fibrocartilaginous tube anterior to what
2. ends by dividing into what at the level of the sternal angle
   - > the dividing pt. is called what

Answer 12

1. esophagous
2. the main primary bronchi
   - > carina

Question 13

esophagus

1. fibromuscular tube connecting the what to the stomach
2. b/w the what and what

Answer 13

1. pharynx

2. trachae and vertebral col

Question 14

Posterior mediastinum

a. thoracic (descending) aorta
- > descends along the left side of what
- > penetrates the diaphragm where along w/ the what and what

Answer 14

• > vertebral col

- > t12, thoracic duct, and azygos vein

Question 15

Posterior mediastinum

b. thoracic duct
- > passes upward from where through the aortic hiatus of the diaphragm

• > ascends through the posterior mediastinum b/w the what and the what
• > pass posterior to the esophagus to empty into the junction of what
• > receives all lymph from the left side of what(5) below the diaphragm
• > transport fat absorbed from the GI tract back to where

Answer 15

• > abdomen
• > aorta and azygous vein
• > left internal jugular and subclavian veins
• > head, neck, thorax, upper limb, and entire body
• > venous sys

Question 16

Posterior mediastinum

b. thoracic duct
- > azygous vein
1. interconnects the what and what
2. drains the what
3. ascends in the what to the right of the vertebral column, then arches over the root of the right lung to join the what
4. receives the hemiazygos vein which ascends on the left side of what and what

Answer 16

1. svc and ivc
2. posterior thoracic and abdominal wall
3. posterior mediastinum ; SVC
4. vertebral col; intercostal veins

Question 17

posterior mediastinum

c. esophagus
- > descends posterior to the what then through the esophageal hiatus of the diaphragm
- > constricted @ 3 regions

Answer 17

-> left atrium
-> @ the arch of the aorta, where it is crossed by the left mainstem bronchus,
@ the esophageal hiatus

Question 18

posterior mediastinum

d. sympathetic trunks
- > along the lateral sides of what
- > give rise to the what which pass through the diaphragm into the what

Answer 18

• > thoracic vertebrae

- > thoracic splanchnic nerves ; abdomen