4.2: Anatomy of the Skeleton- Appendicular Skeleton Flashcards
Outcome 1: Identify anatomical structures of the skeletal system, including bones and ligaments and describe their function
appendicular skeleton
consists of the bones within:
- pectoral girdle
- pelvic girdle
- upper limbs
- lower limbs
pectoral girdle
- also known as the shoulder girdle
- specialized for flexibility and increased range of motion
- composed of two clavicles and two scapulae
- each clavicle (collarbone) connects with the sternum anteriorly and the scapula posteriorly
scapula
(shoulder blade)
- freely movable
- held in place only by muscles and ligaments
- attachment of the scapula allows it to follow the many movements of the arm
posterior side of the scapula
- supraspinatus fossa
- infraspinatus fossa
- scapular spine
acromion process
- projects from the scapular spine
- can be seen from both the posterior and anterior views
- connects to the clavicle anteriorly
neck of the scapula
on the lateral side contains the glenoid cavity
glenoid cavity
- where the head of the humerus articulates with the scapula
- very shallow
- much smaller than the head of the humerus
anterior side of the scapula
contains the subscapular fossa
coracoid process
- projects anteriorly from the scapula
- allowing for muscular attachment
- insertion: Pectoralis minor
- origin: Biceps brachii, short head
- origin: Coracobrachialis
humerus
- single long bone in the upper arm
- comprised of the head, neck, shaft, capitulum, and trochlea
- has a smoothly rounded head that fits into a socket of the scapula at the glenoid cavity
- needs to be held to the shallow glenoid cavity by the rotator cuff muscles and other ligaments
Dislocation
- typically occurs at a joint
- bone is removed from its socket
- (shoulder) head of the humerus is removed from the glenoid cavity in any direction
capitulum
articulates with a small portion of the radius
trochlea
articulates with the ulna
medial epicondyle
(of the humerus)
can be palpated on the medial side of the arm at the elbow
lateral epicondyle
(of the humerus)
can be palpated on the lateral side of the arm at the elbow
olecranon process of the ulna
is the prominent bone that can be palpated in the elbow posteriorly
ulna and radius
distal end of the humerus meets the two bones of the lower arm at the elbow
wrist
- has eight carpal bones
- look like small pebbles
- increase flexibility of the hand
carpal bones
promixal row from lateral to medial
- scaphoid
- lunate
- triquetral
- pisiform
carpal bones
distal row from lateral to medial
- trapezium
- trapezoid
- capitate
- hamate
metacarpal bones
five fan out to form a framework for the palm
phalanges
- Beyond the metacarpals
- the bones of the fingers and the thumb
- long, slender, and lightweight
- thumb, or first digit, is composed of two phalanges
- all other digits have three
pelvic girdle
- consists of two heavy coxal bones
- specialized for strength
coxal bones
- also called ossa coxae or innominate bones
- anchored to the sacrum posteriorly via a network of ligaments
- form a hollow cavity
- symmetrical and formed by the fusion of three bones: the ilium, ischium, and pubis
ilium
most superior of the sections and can be palpated on the lateral sides of the hips
ischium
- located posteriorly
- also known as the “sits” bones as these are the bony landmarks that can be felt when sitting upright in a chair
pubis
- forms the center anteriorly
- connected by the pubic symphysis
ASIS
anterior superior iliac spine
- located on the anterior portion of the ilium
AIIS
anterior inferior iliac spine
- located on the anterior portion of the ilium
differences in the male and female pelvic girdles
- pubic arch is wider in females than in males
- pubic brim, also known as the pelvic outlet is shaped more like a circle in males and an oval in females
- accommodate childbearing.
femur
largest, longest single bone in the body
hip joint
head of the femur articulates with the pelvic girdle at the acetabulum
patella
- sits anteriorly to the femur, formed within the quadriceps femoris tendon
tibia
(medial) lower leg bone
- has a ridge that can be easily palpated anteriorly
- larger of the two bones in the lower leg
- have a prominence that contributes to the ankle, the medial malleolus of the tibia on the medial side of the ankle
fibula
(lateral) lower leg bone
- smaller of the two bones in the lower leg
- have a prominence that contributes to the ankle, the lateral malleolus of the fibula on the lateral side of the ankle
What are the tarsal bones?
seven bones that make up the ankle:
- medial cuneiform
- intermediate cuneiform
- lateral cuneiform
- navicular
- cuboid
- talus
- calcaneus
metatarsal
Five bones span the distance between the ankle and toes
- longitudinal arches from the heel to the toes
- transverse arch across the foot
- provide a stable, springy base for the body
Flat feet
a condition that is likely to occur if the tissues binding the metatarsals together become weakened
hallux
- great toe
- first metatarsal only has a distal and proximal phalanx
phalange
- bones of the toes
- first metatarsal only has a distal and proximal phalanx
- metatarsals 2-5 all have a distal, middle, and proximal phalanx