vertebral column + thoracic cage muscles Flashcards
anatomical position
feet flat on floor, palms facing outwards, head looking straight Infront
superficial
toward/closer to body surface
deep
away from body surface/toward interior of body
medial
toward the midline
lateral
away from midline
proximal
toward an attached base
distal
away from an attached base
posterior
toward the back, behind
anterior
toward the front, in front of
superficial
toward/closer to body surface
deep
away from body surface/toward interior of body
superior
higher
inferior
lower
planes of section
-coronal/frontal
-sagittal (mid-sagittal)
-transverse/horizontal
coronal/frontal
anterior/posterior
-cuts into a front half and back half
sagittal (mid-sagittal)
right/left sides
transverse/horizontal plane
superior/inferior
-cut into upper and lower halves
what can the skeleton be divided into?
axial skeleton and appendicular skeleton
axial skeleton
-bones of the skull
-accessory bones
-vertebral column
-thoracic cage (ribs, sternum, thoracic vertebrae)
appendicular skeleton
-upper limbs and pectoral girdle
-lower limbs and pelvic girdle
how many bones are in the vertebral column
26
vertebrae
sacrum
coccyx
how many vertebrae
24 vertebrae
-7 cervical
-12 thoracic
-5 lumbar
function of vertebral column
-column of support
-protection of spinal cord, passage for nerves
-attachment site for muscles
foramen
hole
process
projection
what does the intervertebral foramen do?
allows for passage of nerves
facet
smooth, flat surface
what do intervertebral discs do? and parts of them
-they help to support with cushioning and movement
contain:
- nucleus pulposus(middle of it)
-annulus fibrosis(outside ring)
about features of cervical vertebrae
size-small
spinous process- bifid (split into 2 ends)
vertebral body- oval
-has transverse foramen
about features of thoracic vertebrae
size-medium
spinous process- downward sloping
vertebral body- heart shaped
-costal facets for ribs
about features of lumber vertebrae
size- large
spinous process- short, stumpy
vertebral body- kidney shaped
-no articular facets
what are the atypical vertebrae
C1 atlas and C2 axis
-C1: allows the “no” motion, has dens
-C2: has the projection
functions of the thoracic cage
-encloses and protects viscera of the thoracic cavity
-acts as an anchor for muscles (for upper limb, scapula)
parts of the thoracic cage
-sternum
-12 pairs of ribs
-thoracic spine (T1-T12)
parts of the sternum
-manubrium
(sternal angle)
-body
-xiphoid process
(articulation sites for ribs)
-clavicular notch (clavicle joins the manubrium here)
how many ribs are there
12 pairs of ribs
- true ribs (1-7): articulate directly with the sternum via costal cartilage
- false ribs 8-10: articulate indirectly via fused costal cartilage
- floating ribs 11 & 12: no anterior articulation
how do most ribs articulate with sternum
via costal cartilage
-gives elasticity of the thoracic cage
tubercle
bump/prominence
anatomy of a typical rib with a thoracic vertebrae
tubercle: articulates with transverse process of thoracic vertebrae
head: articulates with body of the thoracic vertebrae (via costal facet)
pectoralis major (OIAI)
origin- anterior surface of clavicle, anterior surface of sternum, external oblique aponeurosis, ribs costal cartilage
insertion- intertubercle of groove
action- adducts, flexes, medially rotates arm
innervation- medial & lateral pectoral
what are the 5 thoracic cage superficial muscles
- pectoralis major
- pectoralis minor
- subclavius
- serratus anterior
- serratus posterior
pectoralis minor
origin: ribs 3-5
intersection: coracoid process of scapula
action: pulls scapula down and anteriorly
innervation: medial pectoral n.
subclavius
origin: 1st rib
insertion: interior surface of clavicle
action: pulls down and stabilizes clavicle
innervation: C5-C6 subclavian
serratus anterior
origin: surface of ribs 1-8
insertion: medial border of scapula on the costal surface
action: protract scapula, elevate ribs
innervation: long thoracic n.
serratus posterior-superior
Origin: C7-T3 spinous processes
Insertion: superior borders of ribs 2-4
Action: elevates upper ribs
Innervation: T1-T4 ventral rami
serratus posterior- inferior
Origin: T11-L2 spinous processes
Insertion: inferior border of ribs 9-12
Action: depresses lower ribs
Innervation: T9-T12 anterior rami
which of the following muscles does NOT originate on the ribs?
A) pectoralis minor
B)subclavius
C)serratus anterior
D)serratus posterior superior
D)
what are the thoracic cage deep muscles
-external intercostals
-internal intercostals
-innermost intercostals
-transversus thoracis
-subcostales
external intercostals
Origin: inferior border of ribs
Insertion: superior border of the rib below
Action: elevate ribs (inspiration)
Innervation: intercostals nerves
internal intercostals
Origin: inferior borders of ribs
Insertion: superior border of the rib below
Action: lower ribs (expiration)
Innervation: intercostal nerves
how can you tell the difference between external and internal intercostals
function: External help with inspiration, internal help with expiration
muscles fibers: external run medially, internal run laterally
innermost intercostals
Origin: inferior border of ribs
Insertion: superior border of rib below
Action: lower ribs (expiration)
Innervation: intercostal nerves
transvers thoracis
Origin: pleural surface of ribs 2-6 (anteriorly)
Insertion: posterior surface of sternum, xiphoid process
Action: lowers ribs (expiration)
Innervation: intercostal nerves
subcostales
Origin: pleural surface of lower ribs (posteriorly)
Insertion: superior border of ribs below; lower ribs
Action: contracts, pulls ribs down (expiration)
Innervation: intercostals nerves
diaphragm
Origin: xiphoid process of sternum, L1-L4 vertebra, costal arch of ribs 7-12
Insertion: central tendon of diaphragm
Action: contracts and compresses abdomen (inspiration); relaxes (expiration) make room for more air
Innervation: phrenic n.
C3, 4, 5, keeps the diaphragm alive
what are the muscles in expiration
- internal intercostals
- innermost intercostals
- transversus thoracis
- subcostales
- diaphragm
primary muscles of inspiration
-external intercostals
-diaphragm
accessory muscles of inspiration
-scalenes
-sternocleidomastoid
primary muscles of expiration
-diaphragm
-internal intercostals
accessory muscles of expiration
-innermost intercostals
-anterior abdominal wall muscles
blood supply- anterior (right side)
right side:
1. arch of aorta
2.branchiocephalic artery
3. R. subclavian artery
4. R. internal thoracic artery
5. anterior intercostal arteries
blood supply- anterior (left side)
left:
1. arch of aorta
2. L. subclavian artery
3. L. internal thoracic artery
4. anterior intercostal arteries
what does the right side of blood supply (anterior) have not NOT the left
brachiocephalic artery
blood supply - posterior
- arch of aorta
- descending thoracic aorta
- posterior intercostal arteries
venous drainage
- hemiazygos vein
- accessory hemiazygos vein
- azygos vein
- superior vena cava
