Topic 2: Introduction to Myology and Arthrology

Question 1

define the term joint

Answer 1

A joint is a union between two or more parts of the skeleton (bone and bone, bone cartilage etc)

Question 2

fibrous joint

Answer 2

Fibrous tissue (dense irregular connective tissue) uniting the bones
Amount of movement possible depends on the lengths of the fibres
Sub-types:
- Suture: immovable (skull)
- Syndesmosis: slightly moveable (radioulnar joint)
- Gomphosis: immovable (teeth)

Question 3

cartilaginous joints

Answer 3

Cartilage uniting bones
Amount of movement possible depends on type of cartilage
Sub-types:
- Primary cartilaginous (synchondrosis): immoveable (epiphyseal plate)
- Secondary (symphysis): slightly moveable (intervertebral discs, pubic symphysis)

Question 4

synovial joints

Answer 4

Joint cavity in between the bones, containing synovial fluid
All are freely moveable

Question 5

hinge joints

Answer 5

Uniaxial
Flexion and extension
Elbow

Question 6

pivot

Answer 6

Uniaxial
Rotational
atlantoaxial joint

Question 7

ellipsoid/condyloid joint

Answer 7

Biaxial
flexion, extension, adduction, abduction, and circumduction.
Wrist (radiocarpal) joint

Question 8

saddle

Answer 8

Biaxial
Flexion, extension, abduction, adduction and circumduction
1st carpometacarpal joint

Question 9

ball and socket

Answer 9

Multiaxial
Flexion, extension, abduction, adduction, circumduction, medial (internal) and lateral (external) rotation.

Question 10

plane joint

Answer 10

Multiaxial
Gliding movements
Intertarsal joints

Question 11

structure and function of ligaments

Answer 11

bands of fibrous tissue that occurs at joints
Acts as mechanical constraints (prevent unwanted movement, limits allowed movements)
sensory - proprioception

Question 12

structure and function of articular discs

Answer 12

Pads of fibrocartilage that are situated between the articular surfaces of some synovial joints
Functions:
- Act as shock absorbers
- increase stability
- Assist with lubrication
- Permit different movements to occur simultaneously at the same time

Question 13

structure and function of bursae

Answer 13

Synovial fluid-filled sacs are many synovial joints
Function: to reduce friction
- Located between layers of muscles and between muscles/tendons and bones

Question 14

medial vs lateral rotation

Answer 14

medial = towards midline
lateral = away from midline

Question 15

inversion vs eversion

Answer 15

inversion = turning sole of foot inwards
eversion = turning sole of the foot outwards

Question 16

parts of a skeletal muscle

Answer 16

muscle belly: contractile portion
attachment sites: tendons attaching the muscle to the bone

Question 17

parallel skeletal muscle

Answer 17

fascicles arrange parallel to the long axis of the muscle

Question 18

strap skeletal muscle

Answer 18

Narrow and strap-like
e.g. Sartorius

Question 19

fusiform skeletal muscle

Answer 19

Spindle-shaped
e.g. Biceps brachii

Question 20

flat (quadrilateral) skeletal muscle

Answer 20

Short and flat
e.g. Quadratus femoris

Question 21

oblique

Answer 21

Fascicles arranged obliquely to the tendon that runs the entire length of the muscle

Question 22

unipennate

Answer 22

Fascicles attach to one side of the tendon (extensor digitorum)

Question 23

bipennate

Answer 23

fascicles attach to both sides of the tendon (rectus femoris)

Question 24

multipennate

Answer 24

multiple bipennate arrangements attaching to one common tendon (deltoid)

Question 25

circular

Answer 25

fascicles arranged concentrically around an opening

Question 26

structure and function of tendon sheaths

Answer 26

thin layer of connective tissue function: aid in smooth movement of tendon tissue and prevent deviation during muscle contraction

Question 27

isometric muscle contraction

Answer 27

Tension developed, but no change in muscle length No change in length = no movement produced Example: holding a dumbbell still/holding a plank

Question 28

isotonic muscle contraction

Answer 28

Tension developed with change in muscle length Change in length = movement produced eccentric: muscle lengthens e.g. lowering dumbbell concentric: muscle shorten e.g. lifting dumbbell

Question 29

agonist muscle

Answer 29

muscle producing desired movement

Question 30

fixator (stabiliser)

Answer 30

muscle which stabilises a body segment so that the agonist can produce the desired movement e.g. back muscles when lifting

Question 31

antagonist

Answer 31

muscle which must relax to allow desired movement to occur

Question 32

synergis

Answer 32

muscle which contracts to cancel out unwanted action of the agonist e.g. forearm pronator during elbow flexion