Thorax

Question 1

what are the 3 general functions of the thoracic region

Answer 1

1. respiration
2. protection of vital organs
3. passage of structures

Question 2

what are the boundaries + components of the thorax

Answer 2

superior “trunk”
between neck and abdomen

consists of: wall, cavity, and floor

Question 3

superior thoracic aperture

Answer 3

manubrium
first rib
first thoracic vertebra

Question 4

inferior thoracic aperture

Answer 4

xiphoid process (sternum)
subcostal arch
rib 11/12
12th thoracic vertebra
diaphram

Question 5

thoracic cavity = wall of region. what does it consist of

Answer 5

anteriorly: sternum, costal cartilage, joints
laterally: ribs
posteriorly: spine (thoracic vertebrae, intervertebral discs)
intercostal space

Question 6

intercostal muscles and their fibre directions and function

Answer 6

external (superficial)
- fibre direction = anteriorly, inferiorly
contract to LIFT thoracic cage = inspiration
relaxation = expiration

internal + innermost (deep)
- both fibre directions = posteriorly, inferiorly
contract to LOWER thoracic cage - FORCED expiration

Question 7

name the structures in the intercostal space

Answer 7

intercostal arteries (ant + post)
intercostal veins (ant + post)
anastomose laterally
intercostal nerves - ventral ramus of spinal nerves (supply intercostal muscles, skin, and parietal pleural

Question 8

anterior joints of thoracic wall

Answer 8

sternum + ribs
= sternocostal (sternochondral), costochondral, interchondral

Question 9

posterior joints of thoracic wall

Answer 9

spine + ribs
= costovertebral, costotransverse

Question 10

sternocostal (sternochondral)

Answer 10

sternum to cartilage
synovial = movement
except between sternum and R1 (cartilaginous)

Question 11

costochondral

Answer 11

ribs to cartilage (R1-10)
cartilaginous - stability

Question 12

interchondral

Answer 12

R6-R9 costal cartilages
synovial = movement

Question 13

why are some anterior cage joints synovial

Answer 13

movement - for bbreathing

Question 14

vertebral column

Answer 14

interbody joints
cartilaginous = stability

Question 15

rib joints (3)

Answer 15

costovertebral
costotransverse
synovial = movement

Question 16

costovertebral joint

Answer 16

rib head + vertebral body
synovial

Question 17

costotransverse joint

Answer 17

rib tubercle + transverse process
- synovial = movement

Question 18

supporting ligaments for costovertebral joint

Answer 18

radiate + interarticular

Question 19

supporting ligaments for costotransverse joint

Answer 19

superior, lateral, anterior

Question 20

what makes the floor of the thorax/ fills the inferior thoracic aperture

Answer 20

diaphragm

sternal, costal (inferior ribs), lumbar attachments (specialised)

Question 21

diaphragm (shape,function, innervation, blood supply)

Answer 21

relaxed = dome-shaped
contracted = flat

primary muscle of respiration (increases vol of thorax for increased lung capacity during breathing)

innervation: phrenic nerve)

Blood supply: Internal thoracic artery

Question 22

internal thoracic artery

Answer 22

originates off subclavian arteries
its branches supply diaphragm (give rise to anterior intercostal arteries)

Question 23

phrenic nerve

Answer 23

innervates diaphragm
C3-5

behind subclavian vein, in front of lung root

runs as lateral as possible to run along lateral aspects of the great vessels of the heart (superior vena cava + pulmonary nerve)

supplies diaphragm, pericardium (parietal serous and fibrous) and pleura

Question 24

diaphragm apertures (holes) - 3 (with details)

Answer 24

aortic hiatus
- descending aorta
- thoracic duct
- azygous vein

(vena) caval foramen
- inferior vena cava
- right phrenic nerve

oesophageal hiatus
- oesophagu, vagus nerves
- arteries + veins, some lymphatic vessels

Question 25

structures associated with the thoracic wall (not part of it but integral to its function)

Answer 25

skin + superficial fascia (includes breast tissue) bones of shoulder girdle muscles (+ deep fascia) - pectoralis major, minor (inspiration) - serratus anterior (stabilizes scapula of chest wall) - abdominal muscles (muscles in M3)

Question 26

subdivisions of thoracic cavity

Answer 26

2 lateral pleural cavities 1 mediastinum

Question 27

the 2 lateral pleural cavities as a division

Answer 27

lungs - have their own pleural sac

Question 28

mediastinum as a division

Answer 28

centrally located separates the 2 pleural sacs has heart and pericardium

Question 29

pleural cavities (info)

Answer 29

each lung = own pleural sacs (thin, double layer, low friction) parietal = outside - thorax, mediastinum visceral = inside - lung surface - for lung expansion pleural cavity - pleural fluid (low friction)

Question 30

pleural cavity

Answer 30

potential space filled with serous fluid friction free movement of lungs without pain -ive intrapleural pressure which holds the parietal + visceral pleurae together movement of thoracic wall during inspiration = "stretch" of lungs