Musculoskeletal System: Limbs

Question 1

what does the appendicular skeleton consist of?

Answer 1

limbs and girdles

Question 2

what two types of girdle are there?

Answer 2

pelvis girdle (pubis, ischium, ilium) and pectoral girdle (clavical and scapula)

Question 3

what is the collarbone called?

Answer 3

clavicle

Question 4

what is the shoulder blade called?

Answer 4

scapula

Question 5

what is the name of the bone in the top part of an arm?

Answer 5

humerus

Question 6

what are the names of the two bones in a forearm?

Answer 6

radious and ulna

Question 7

what are the bones in a hand called?

Answer 7

carpus, metacarpals, phalanges

Question 8

what is the bone in a thigh called?

Answer 8

femur

Question 9

what are the bones in the lower leg called?

Answer 9

tibia and fibula

Question 10

what is the knee bone called?

Answer 10

patella

Question 11

what is the heel bone called?

Answer 11

calcaneum

Question 12

what are the bones in a foot called?

Answer 12

tarsus, metatarsals, phalanges

Question 13

what is a synovial joint?

Answer 13

those in which the articulating bones are separated by a fluid-containing joint cavity

Question 14

are synovial joints mobile or immobile?

Answer 14

mobile

Question 15

where are synovial joints found?

Answer 15

most joints of the limbs are synovial.

Question 16

what is a fibrous joint?

Answer 16

the bones are joined by fibrous tissue and no joint cavity is present

Question 17

how mobile are fibrous joints?

Answer 17

some are slightly mobile but most are immobile

Question 18

where are fibrous joints found?

Answer 18

skull, between bones (i.e. ligament), teeth sockets

Question 19

what is a cartilaginous joint?

Answer 19

where the articulating bones are united by cartilidge

Question 20

how mobile are cartilage joints?

Answer 20

immobile

Question 21

where are cartilaginous joints found?

Answer 21

between sternum and ribs, pelvic symphysis

Question 22

where do you find a ball and socket joint?

Answer 22

shoulder and hip (girdles)

Question 23

what movement do you find at ball and socket joints?

Answer 23

circumduction

Question 24

how mobile are ball and socket joints?

Answer 24

most mobile joint

Question 25

where do you find a hinge joint?

Answer 25

at mid-point of limbs (knee, elbow) and between metacarpals/metatarsals and phalanges

Question 26

what movement to you find at a hinge joint?

Answer 26

flexion-extension

Question 27

how mobile are hinge joints?

Answer 27

more limited mobility than ball and socket

Question 28

where would you find a sliding joint?

Answer 28

between carpals and some tarsals

Question 29

how mobile are sliding joints?

Answer 29

limited movement

Question 30

what is flexion?

Answer 30

bending movement that decrease angle of joint and brings articulating bones closer together. e.g. bending head forward on chest, bending the knee, moving arms forward and back.

Question 31

what is extension?

Answer 31

reverse of flexion. increases the angle of joint and brings articulating bones further away from each other. e.g. straightening flexed neck or knee.

Question 32

what is abduction?

Answer 32

a movement of a limb AWAY from the midline of the body, along the frontal plane. e.g. raising arm or thigh laterally, spreading toes or finger apart.

Question 33

what is adduction?

Answer 33

opposite of abduction so moving a limb TOWARDS the midline.

Question 34

what is circumduction?

Answer 34

moving a limb so that is describes a cone in a space. e.g. moving arm in circle.

Question 35

what are supination and pronation?

Answer 35

refers to movement of radius around the ulna. supination, the movement is lateral rotation (e.g. turning the foot inwards) and in pronation, the movement is medial rotation (e.g. turning the foot outwards)

Question 36

in the embryo, what do limbs arise from?

Answer 36

limb buds from the lateral plate mesoderm (bone, connective tissue) and paraxial mesoderm i.e. somites (muscle)

Question 37

what did the earliest vertebrates lack?

Answer 37

paired appendages - they only had median (dorsal and ventral midline) fins to stop them rolling over

Question 38

what do paired fins help a swimming animal do?

Answer 38

stabilise its swimming and change direction

Question 39

what fish has limb-like fins?

Answer 39

angler fish

Question 40

what two types of fin are there?

Answer 40

delicate ray-fins and fleshy lobe-fins

Question 41

what type of fins have a strong internal skeleton?

Answer 41

fleshy lobe-fins

Question 42

what factors can influence the differentiation of limbs?

Answer 42

limb development switched on/off, elongation of one or more segments, increase in anteroposterioir axis and so increase in no of digits of proximodistal axis so increase in no of phalanges per digit, later changes e.g. failure to separate phalanges.