Appendicular Skeleton

Question 1

what makes up the appendicular skeleton

Answer 1

upper and lower limbs, pectoral girdle and pelvic girdle

Question 2

what does the pectoral girdle do

Answer 2

attaches the upper limbs to the trunk

Question 3

what does the pelvic girdle do

Answer 3

attaches the lower limbs to the trunk

Question 4

pectoral girdle features

Answer 4

pectoral girdles do not encircle the body completely (scapulae do not join each other or the axial skeleton), is very light and upper limbs are mobile as only clavicle articulates with the axial skeleton and socket of the shoulder joint is shallow, which is good for flexibility but bad for stability

Question 5

define shoulder dislocation

Answer 5

head of humerus dislocates forward and downward because the structures reinforcing this joint are the weakest anteriorly/inferiorly, happens most often when falling on outstretched upper limb

Question 6

define shoulder separation

Answer 6

dislocation of the acromioclavicular joint, happens most when falling on an outstretched hand or on side of shoulder

Question 7

features of clavicles

Answer 7

extend horizontally across the superior thorax, sternal end, acromial end, ligaments attached to the clavicle stabilize its position

Question 8

functions of clavicles

Answer 8

provide attachment for muscles, hold scapulae and arms laterally, transmit compression forces from the upper limbs to the axial skeleton

Question 9

what part of the scapula does the clavicle attach to

Answer 9

manubrium

Question 10

why is it actually good that the clavicle fractures outwards (instead of inwards)

Answer 10

lungs and heart are deep to the clavicle so inwards fracture risks puncturing them, therefore the S shape of the clavicle is due to evolution

Question 11

what is the glenoid cavity

Answer 11

where the upper limb articulates to create the shoulder joint, shallow

Question 12

how many bones in each upper limb

Answer 12

30

Question 13

what bone is found in the arm

Answer 13

humerus

Question 14

humerus features

Answer 14

only bone of the arm, longest and strongest bone of upper limb, articulates with scapula at the shoulder, articulates with radius and ulna at the elbow

Question 15

what bones are found in the forearm

Answer 15

radius and ulna

Question 16

where do the proximal and distal ends of the forearm articulate

Answer 16

proximal end (ulna) articulates with the humerus, distal end (radius) articulates with carpals

Question 17

how do the radius and the ulna articulate with each other

Answer 17

via proximal and distal radioulnar joints and interosseous membrane

Question 18

what are the anatomical positions of the radius and ulna

Answer 18

radius is lateral, ulna is medial

Question 19

features of ulna

Answer 19

main bone responsible for forming elbow joint, hinge joint allows forearm to bend on arm, plays little to no role in hand movement

Question 20

features of radius

Answer 20

thin proximally and wide distally, contributes heavily to wrist joint, distal radius articulates with carpal bones and when the radius moves, the hand moves with it

Question 21

features of the carpus (hand)

Answer 21

forms the true wrist (the proximal region of the hand), composed of 8 marble-sized bones

Question 22

how are carpal bones arranged

Answer 22

in two irregular rows, scaphoid and lunate, which articulate with the radius

Question 23

features of metacarpus

Answer 23

5 metacarpals radiate distally from the wrist and form the palm, numbered 1 to 5 (beginning with pollex [thumb]), articulate proximally with distal row of carpals, articulate distally with proximal phalanges

Question 24

features of phalanges

Answer 24

numbered 1 to 5, starting with pollex, and except for the thumb, each finger has 3 phalanges (proximal, middle and distal)

Question 25

features pelvic girdle

Answer 25

attaches lower limbs to spine, supports visceral organs, attaches to axial skeleton by strong ligaments, consists of paired hip bones (coxal bones) and hip bones unite anteriorly and articulate posteriorly with sacrum to make bony pelvis

Question 26

what are the 3 components of the coxal bone

Answer 26

ilium, pubis and ischium

Question 27

what is the acetabulum and what is it good/bad for

Answer 27

deep socket on lateral pelvic surface that holds head of the femur, good for stability and bad for flexibility

Question 28

features of ilium

Answer 28

large flaring bone, forms superior region of coxal bone, site of attachment for many muscles

Question 29

features of ischium

Answer 29

forms posteroinferior region of coxal bone, has ischial tuberosities (strongest part of hip bone, rough protrusions AKA "sit" bones)

Question 30

features of pubis

Answer 30

forms anterior region of the coxal, contains pubic symphysis (the two pubic bones are joined by fibrocartilage at the midline)

Question 31

what are the bones in the lower limbs and their designations

Answer 31

femur within thigh, tibia & fibula within leg, tarsal bones within foot, metatarsals within foot and phalages within toes

Question 32

features of femur

Answer 32

single bone of thigh, longest and strongest bone in body, ball-shaped head articulate with acetabulum

Question 33

features of patella

Answer 33

sesamoid bone (a small bone found embedded in quadriceps tendon), protects knee and improves leverage of thigh muscles across the knee

Question 34

features of tibia

Answer 34

more massive medial bone of the leg, receives weight of body from femur, forms knee joint proximally and ankle joint distally

Question 35

features of fibula

Answer 35

stick-like lateral bone of leg, forms ankle joint distally

Question 36

what connects the tibia and fibula

Answer 36

interosseus membrane

Question 37

what is the foot composed of

Answer 37

tarsus, metatarsus and phalanges

Question 38

foot functions

Answer 38

supports body weight, acts as lever to propel body forward when walking, segmentation makes foot pliable and adapted to uneven ground

Question 39

features of tarsus

Answer 39

makes up posterior half of foot, contains 7 tarsal bones, body weight primarily beared by talus and calcaneus (heel)

Question 40

features of metatarsals

Answer 40

5 small long bones numbered 1 to 5, beginning with hallux (great toe), 1st metatarsal supports body weight

Question 41

features of phalanges

Answer 41

14 smaller and less nimble bones vs fingers, each toe has 3 phalanges (proximal, middle and distal, except great toe)

Question 42

what is a bunion

Answer 42

medial turning of 1st metatarsal and proximal phalange of big toe