Thorax

Question 1

what is the shape of the thoracic cavity?

Answer 1

cone that is narrow superiorly and increasing inferiorly with a thin wall

Question 2

what is the thoracic cage supported by?

Answer 2

sternum + thoracic vertebrae

Question 3

what are the 3 divisions of the thoracic cavity?

Answer 3

1. mediastinum: houses thoracic viscera
2. right pulmonary cavity
3. left pulmonary cavity

Question 4

Fx’s of the thoracic wall

Answer 4

1. prtect organs
2. resist pressure from respiration
3. provide attachment + support for upper limbs, muscles, abdomen, neck

Question 5

the thoracic skeleton consists of?

Answer 5

1. 12 pairs of ribs + cartilages
2. 12 thoracic vertebrae
3. IV discs

Question 6

features of ribs

Answer 6

lightweight, resilient, inner bone marrow is spongy (hempoietic) and forms blood cells

Question 7

what are true ribs?

Answer 7

vertebrosternal, attach to sternum with own costal cartilages (ribs 1-7)

Question 8

what are false ribs?

Answer 8

vertebrochondral, cartilages connected to rib above (ribs 8-10)

Question 9

what are floating ribs?

Answer 9

vertebral, cartilage ends in abdominal musculature (ribs 10-12)

Question 10

What are the 4 typical ribs parts?

Answer 10

Head: 2 crests to attach to superior vertebrae and one for corresponding vertebrae
Neck: connect head with body
Tubercle: found at junction of body and neck
Body: thin, flat, protects nerves and vessels

Question 11

which ribs are the atypical ribs?

Answer 11

rib 1: broadest, shortest, facet on head for articulation with T1

rib 2: rough area on upper surface is tuberosity for serratus anterior

ribs 10-12: facet articulating with single vertebra

ribs 11-12: short with no neck or tubercle

Question 12

what is the fx of costal cartilage?

Answer 12

prolong ribs, give elasticity to thoracic wall

Question 13

what is the fx of intercostal spaces?

Answer 13

separate ribs + costal cartilages

Question 14

what are thoracic vertebrae?

Answer 14

bilateral costal facets with inferior + superior pairs that articulate with head of ribs

have demifacets (T2-T9)

Question 15

what do costal facets articulate with?

Answer 15

tubercle of rib

Question 16

what are spinous processes?

Answer 16

long slanting process that prevents sharp objects from entering vertebral canal to injure spinal cord

they overlap lower vertebra

Question 17

what limits movement btwn vertebra?

Answer 17

rib cage

Question 18

what does the sternum protect?

Answer 18

mediastinal viscera + heart

Question 19

what are the 3 parts of the sternum

Answer 19

1. menubrium
2. body
3. xiphoid process

Question 20

what happens to the sternum with age?

Answer 20

synchondroses: cartilaginous joints ossify in adulthood

Question 21

what are the characteristics of the menubrium?

Answer 21

Jugular notch: concave center which is easily palpated
Clavicular notch create sternoclavicular joints
Synchondrosis of 1st rib
Manubrialsternal angle: different angle connecting manubrium to sternum

Question 22

what are the characteristics of the body of sternum?

Answer 22

Costal notches creates joints for ribs

Transverse ridges: lines of fusion of sternums 4 original separate sternebrae

Question 23

what are the characteristics of the xiphoid process?

Answer 23

Cartilaginous in young, ossified in adults over 40

Question 24

what binds the superior aperture of thorax?

Answer 24

posterior: T1
lateral: 1st ribs + their costal cartilages
anterior: superior border of manubrium

Question 25

what binds the inferior aperture of thorax?

Answer 25

posterior: T12
posterolateral: 11-12th ribs
anterolateral: 7-10th ribs costal cartilage
anterior: xiphisternal joint

Question 26

what separates the inferior aperture from the abdomen?

Answer 26

the diaphragm