Chapter 4 Flashcards
axial skeleton
skull and facial muscles
skull:calvaria
formed by 5 curved flat bones
protect the brain and the brain stem
may get fractured
temporal bone is most fragile
skull: facial bones
formed by 5 irregular bones
give it individuality
provide protection for eyes and air passages
allow chewing and entry of food
facial muscles
allow us to:
change expression
display emotions
form words
we close eyes to
close mouth to
keep them moist and prevent discomfort
chew
axial skeleton-thoric region
vertebral column
ribs and sternum
neck and back muscles
abdominal muscles
vertebral column
33 vertebrae
function: attachment for back muscles, protects the spinal cord and nerves, absorbs shock through invertebral discs
top down vertebraes
7 cervical (neck) 12 thoraic (chest) 5 lumbar (lower back) 1 sacrum = 5 fused vertebrae (mid butt) 1 coccyx = 3 or 4 fused vertebrae (tail bone)
ribs and sternum
12 pairs of ribs, some have extra cervical rib
made up of bone and costal cartilage
curved and slightly twisted
functions: give strength to cheast cage and allow it to expand
protect chest area
ribs top down
1-7 true ribs (attach to vertebrae and sternum)
8-10 false ribs (attach to sternum indirectly through 7th rib)
11 and 12 floating ribs (attach to vertabral column)
sternum
=midline breastbone 3 parts: manubrium sternal body xiphoid process provides direct attachments to clavicles and 1-7 rib pairs
neck and back muscles
head sits on C1
articulates with C2
permit a wide range of movement and allow you to hold up your head
neck and back muscles: anterior
the most important pair: sternocleidomastoids
allow to: flex head towards chest
neck and back muscles: posterior
large muscle mass = erector spinae muscle group: lliocostalis longissimus spinalis maintain erect position anti-gavity muscles stop working during loss of consciousness, body falls face forward
abdominal muscles
plywood-like muscular wall
trilaminar
3 layers positioned on top of each other
for low back support and rehabilitation
layers of abdominal muscles
external oblique
interal oblique : both lateral bending and rotation
rectus abdominis and transverese abdominins: flextion and extention
appendicular skeleton
pectoral gridle sacpulohumeral region upper limb pelvic gridle lower limb
pectoral gridle
suspends the supper limb away from the chest wall
enables a great range of movement
clavicle
collar bone
only bone directly connecting upper and axial skeleton
scapula
shoulder blade
has many muscle attachements to axial skeleton
muscles anterior
pectorlis major: clavicular head & sternal head
pectorlis minor: coracoid process of the scapula, stabilizes scapula
seratus anterior: steadies and holds scapula forward against chest wall,
butterfly stroke
subcapularis: adducts and medially rotates upper limb
muscles posterior
trapezius: upper fibers: shrugging sholders middle (tranverse fibers: retract the scapula lower fibers: depress the scapula
sternoclavicular joint
only joint connecting pectroal gridle (clavicle) and axial skeleton (sternum)
acromioclavicular joint
connects clavicle lateral end and scapula acromion process (shoulder seperations in hockey)
