thorax

Question 1

thoracic cage

Answer 1

bony framework of the chest

Question 2

structure of the thoracic cage

Answer 2

thoracic vertebrae posteriorly (12), ribs laterally, sternum, and costal cartilages anteriorly

Question 3

function of the thoracic cage

Answer 3

a bony cage that protects the thoracic viscera, supports the shoulder girdle and upper limb, provides attachments for upper limb muscles
-houses the intercostal muscles that elevate and depress the thorax during respiration

Question 4

thorax key elemtns

Answer 4

-barrel shape
-somite development
-vasculature and innervation

Question 5

axial skeleton

Answer 5

forms the long axis of the body
supports the head, neck, and trunk, protects the brain, spinal cord and thoracic regions

Question 6

axial skeleton 3 main regions

Answer 6

skull
vertebral column
and thoracic cage

Question 7

what are the vertebral regions (5 regions)

Answer 7

-cervical: 7 vertebrae of the trunk
-thoracic: 12 vertebrae of thorax
-lumbar: 5 vertebrae of lower back
-sacrum: 5 fused vertebral segments; articulate with hip bones
-coccyx: 4 fused segments

Question 8

vertebrae
-vertebral body

Answer 8

hold weight

Question 9

vertebrae
-vertebral arch

Answer 9

(dorsal); muscle and ligament attachment

Question 10

vertebrae
-vertebral foramen

Answer 10

location of the spinal cord

Question 11

vertebrae
pedicle and lamina:

Answer 11

bony rami; connect processes to vertebral body

Question 12

vertebrae
spinus process and transverse process (2 transverse)

Answer 12

allow connections to other vertebra and muscles

Question 13

vertebrae
intervertebral foramen

Answer 13

where spinal nerve rami exit

Question 14

sternum

Answer 14

anteriorly located
-has 3 sections: manubrium, body, xiphoid processd

Question 15

sternum:
manubrium

Answer 15

superior section
-articulates with the medial ends of the clavicles and ribs 1 and 2

Question 16

sternum
body

Answer 16

middle portion
sides are notched at articulations for the costal cartilages of ribs 2-7

Question 17

sternum
xiphoid process

Answer 17

inferior end of sternum
plate of hyaline cartilage
fully ossifies around age 40

Question 18

three anatomical landmarks of sternum

Answer 18

-jugular notch: suprasternal notch, location of jugular veins
-sternal angle: lies anterior to arch of aorta, marks the start and end of aortic arch. anterior to corina (bifurcation of trachea). corresponds to IV disc between T4 and T5 vertebra, marks inferior boundary of superior mediastinum- gives volume
-xiphisternal joint: deep to this joint, heart lines on the diaphragm.

Question 19

how many ribs are present

Answer 19

24 total, 12 pairs on each side

Question 20

true ribs

Answer 20

superior 7 pairs; attach directly to the sternum by coastal cartilage

Question 21

floating ribs

Answer 21

inferior 5 pairs (8-12); attach to the sternum either indirectly or not at all

Question 22

floating ribs

Answer 22

ribs 11-12; have no anterior attachments, embedded in the muscles of the lateral body wall

Question 23

head of rib

Answer 23

articulates with the vertebral bodies by two facets

Question 24

tubercule

Answer 24

articulates with the transverse process of the thoracic vertebra of the same number

Question 25

shaft

Answer 25

bulk of the rib

Question 26

costal groove

Answer 26

located on the inferior border, houses the intercostal nerve and vessels

Question 27

synovial joints with ribs

Answer 27

there are two synovial joints at each rib articulation, gives ability to elevate and depress ribs

Question 28

intercostal space

Answer 28

separate ribs and are occupied by muscles, vessels, and nerves

Question 29

thoracic apertures

Answer 29

openings
thoracic inlet and thoracic outlet

Question 30

thoracic inlet

Answer 30

passage of trachea, esophagus vessels, and nerves. thoracic cavity communicates with the neck and upper limb.
-narrow, provides major blood supply to the head and limb (superior)

Question 31

boundaries of thoracic inlet

Answer 31

-posterior: T1 vertebra
-lateral: 1st ribs and costal cartilages
-anterior: superior border of manubrium

Question 32

thoracic outlet

Answer 32

more spacious than thoracic inlet; allows passage of IVC , esophagus and aorta, inferior and wider. diaphragm is located within

Question 33

boundaries of thoracic outlet

Answer 33

-posterior: T12 vertebra
-lateral: 11th and 12th ribs and cartilages, costal margin
-anterior: xiphersternal joint

Question 34

intercostal space

Answer 34

separate the ribs, remnants of somites.
-occupied by muscles blood vessels and nerves. they travel in the costal groove on the inferior surface of a rib, between the internal and innermost intercostal muscles

Question 35

innervation of thoracic body wall

Answer 35

ventral rami (intercostal nerves); innervate lateral ato anterior

Question 36

arterial supply of the thoracic body wall

Answer 36

carry oxygenated blood to the body, wrap around from the dorsal side to the anterioir side
1. anteriorly via the internal thoracic and anterior intercostal arteries off the subclavian arteries
2. subclavian artery
3. posterior intercostal and subcostal arteries via the thoracic aorta

Question 37

-inferior vena cava:

Answer 37

offset to the right side of the thorax, drains into the right side of the heart. on thh back wall

Question 38

right side venous drainage of thorax

Answer 38

-intercostal veins drain into the azygos vein which joins the superior vena cava

Question 39

left side venous drainage of the thorax

Answer 39

intercostal vein drain into the accessory hemiazygos and hemiazygos veins that drain into the azygous vein which drains into the SVC
-hemiazygos veins cross over vertebral body, underneath the aorta to reach azygous veins

Question 40

nerves of the thorax

Answer 40

12 pairs of thoracic spinal nerves
-anterior rami of T1-T11L form intercostal nerves on right and left sides
-anterior rami of T12 nerves: subcostal nerves
posterior rami of thoracic spinal nerves: supply the bones, joints, deep back muscles, and skin of the back and thoracic region

Question 41

diaphragm

Answer 41

the most important muscle of respiration
-flattens as it contracts, increases the volume of thoracic cavity
-runs in a transverse direction