Skeletal system Flashcards
Axial Skeleton
skull
sternum
ribs
vertebral column
main function
provide protection
skull
sits on top of the vertebral column and is divided into the cranium and the face, protect very important organs
sinuses
small cavities
sutures
immobile joints
groups skull
cranium & face
bones of the facial skeleton
14 bones: the orbits of the eyes, the nasal & oral cavities, the sinuses
vertebral column
help maintain balance, absorb shock, support head, enclose & protect spinal cord
4 curves
cervical & lumbar are anteriorly convex
thoracic & sacral/coccygeal are anteriorly concave
vertebra structure
cervical vertebra smallest
thoracic less mobile because the ribs
lumbar biggest & strongest
sacral transmit weight to pelvis & legs
sternum
flat bone starts bottom of the throat and ends halfway down the chsest
ribs
curved bones, articulate with sternum
total ribs
1-7 true ribs
8-10 false ribs
11-12 floating ribs
thoracic cage
sternum + ribs + thoracic vertebrae
intercostal muscles
located in-between the ribs
appendicular skeleton
shoulder girdle
upper limbs
pelvic girdle
lower limbs
main function
mostly involved in movement
shoulder girdles
clavicles & scapula
clavicles
articulate with sternum anteriorly
scapula
flat triangular bone
posterior to the ribcage
articulate with clavicle & humerus
upper limbs
humerus
radius & ulna
wrist
hand
humerus
articulates with forearm bones
radius & ulna
articulate with elbow joint
at wrist articulate with carpal bones
ulna
larger of the two forearm
carpal bones
short bones
arranged closely together in two rows of four
carpal bones
articulate with metacarpals & proximal phalanges
hand bones
8 bones wrist
5 bones palm (metacarpals)
14 bones fingers (phalanges)
pelvic girdles
connects bones of the lower limbs to axial skeleton
right & left hip bones
hip
large, flattened & irregular shaped
3 bones
ilium, ischium & pubis
lower limbs
thigh, leg & foot
femur
bone of the thigh, longest & heaviest
articulates
pelvis in a hollow area called the acetabulum from the hip joint
the larger tibia
smaller fibula
patella (kneecap)
small, triangular bone
located front of the knee
supports cuádriceps tendon
foot bones
tarsal bones (ankle)
phalanges bones (toes)
metatarsal bones (foot)
foot has:
5 metatarsals
5 proximal phalanges
5 distal phalanges
4 middle phalanges
skeleton functions
protection of vital organs
support & maintains posture
provides attachment points for muscles
storage & release minerals
blood cell production
storage of energy
types of joints
fibrous (immovable)
cartilage (semi moveable)
synovial (freely moveable)
bone types
long bones
short bones
flat bones
irregular bones
sesamoid bones
long bones
long cylindrical shaft & enlarged area at each end of bone
length alway greater than width
most important for movement
examples of long bones
femur, metatarsals & clavicle
short bones
small & cube shaped
articulate with more than one bone
examples of short bones
carpals of hand & tarsals of feet
flat bones
curved surface either thick or thin
provide protection & muscle attachment
examples of flat bones
sternum, scapula, ribs & pelvis
irregular bones
specialized shapes & functions
examples of irregular bones
vertebrae, sacrum & coccyx
sesamoid bones
short bone which embedded ni tendons where large amounts of pressure develop
examples of sesamoid bones
pisiform (2) - carpal bones
patella (2) - kneecap
connective tissue
cartilage (end of bones)
ligaments (connects bone - bone)
tendons (connects bone - muscle)
joints
a joint occurs where two or more bones articulate
main function of joints
increase mobility of the body & limbs
joint movement & stability
the more movement a joint has, less stability it has & greater risk of injury
factors that affect
shape of joint
area of contact
flexibility of ligaments
influence of other soft tissue
types of soft tissue
tendons, muscle, joint capsules etc
fixed / immovable
very stable
allow no observable movement
bones are often joined by strong fibers called sutures
cartilaginous / semi-moveable
- allows slight movement: slight compression of cartilage
- the end bones are covered with white pads of fibrocartilage
- act as shock absorbers
synovial / freely moveable
- most common
- allow wide range of movement
- subdivided according to movement possibilities
features of a synovial joint
articular cartilage
synovial membrane
synovial fluid
bursae
meniscus
ligaments
articular capsule
examples of synovial joints
tarsal bones, carpal bones, elbow joint, radioulnar joint, shoulder joint…