Lecture 7 - Joints

Question 1

What are the three types of joint?

Which ones allow movement and which allow little to no movement?

Answer 1

Cartilaginous - held by cartilage e.g pubic symphysis

Fibrous - joined by fibrous connective tissue rich in collagen fibres e.g skull at coronal suture

Synovial - held by connective tissue within a capsule and often by ligaments

Cartilaginous and fibrous - little/no movement
Synovial - movement

Question 2

What are synovial joints surrounded by? Why?

Answer 2

Articular capsule, it reduces friction and shock

Question 3

Describe the structure of synovial joints

Answer 3

Between bone and bone, each end is surrounded by cartilage and synovial membrane, and in between this is synovial fluid for lubrication. There is also a fibrous joint capsule going from outer bone to outer bone below or above the ligament (crucial ligs on inside to stop rotation/slipping of bone). There is also tendon joining muscle to bone.

Question 4

Why is warming up in exercise important?

Answer 4

It encourages production and secretion of synovial fluid, meaning there is less stress and more phagocytotic cells to remove debris and microbes

Question 5

What are ligaments and tendons made of?

What is the stage from collagen molecules to tendons?

• of ligs/tens make * *

Answer 5

Collagen

Collagen molecules; fibrils; fibres; fasicle; tendon/ligament

Fibroblasts; collagen molecules

Question 6

What are the differences between ligaments and tendons?

Answer 6

Ligaments - fibroblasts dispersed, collagen less organised, elastic and strong

Tendons - fibroblasts in parallel rows, collagen well organised, non elastic and tough

Question 7

What is cartilage made of?

What is the matrix made of?

Answer 7

Collagen, elastic fibres and proteoglycan (heavily glycosylated proteins)
Matrix produced by chondroblasts that become chondrocytes, no blood vessels

Question 8

What are the three main types of cartilage?

Answer 8

Hyaline cartilage
Fibrocartilage
Elastic cartilage

Question 9

Hyaline cartilage is the most * and is in **

** is an example

Answer 9

Abundant; many locations

Articular cartilage

Question 10

What are the properties of fibrocartilage?

Answer 10

Strongest type, is in invertebral discs, tendon/cartilage interface and many more

Question 11

What is elastic cartilage not associated with?
Where can it be found?
What is the main property?

Answer 11

Bone
Eustachian tube
Flexible

Question 12

What is the difference between micro and macroscopic tendon failure?

What is the non surgical treatment?

Answer 12

Micro - several or single fibres
Macro - whole tendon

RICE

Question 13

How do you repair damaged ligaments?

Answer 13

Surgically - auto or allograft replacement (often from patella or hamstring tendon)
Can be synthetic and screwed into place

Question 14

What mechanical adaptations to tendons happen during strength/endurance training?

Answer 14

Remodelling via increased collagen turnover - anabolism dominates and the crosslinks increase

Also tendon fibroblasts sense/respond to stretch, and alter expression of extracellular matrix

Question 15

How does exercise affect ligaments, cartilage and synovial fluid?

Answer 15

Ligaments - increase strength and flexibility
Cartilage - increases thickness for protection and lower injury risk
Synovial fluid - increases production for lube/cushioning/shock absorption

Question 16

What are the 6 synovial joint classifications? Give an example for each and how they move

Answer 16

Ball and socket - shoulder
Pivot - radius, rotation
Hinge - elbow, unidirectional
Planar - intercarpal, gliding
Condyloid - hands, movement in different planes
Saddle - thumb, two direct movements/opposable

Question 17

Complex movements:
Gliding has no **
Rotation is around *
Angular is considered relative to * position (midline is * of body, * is outside)
OR anatomical * (* is horizontal, * is horizontal in relation to * and * is vertical birds eye)

Answer 17

Angle change
Axis
Anatomical; medial; lateral
Plane; transverse; coronal; sagittal

Question 18

What does angular movement include? (6)

Answer 18

Flexion - decrease in angle between articulating bones
Extension - increase in angle, often to restore anatomical position
Hyperextension - beyond anatomical position
Abduction - bone movement away from midline
Adduction- bone movement toward midline
Circumduction - movement of distal part of bone in a circle

Question 19

Motion and movement is often dependant on * and * movement, where * indicates / and * indicates movement around a * *

Answer 19

Linear; angular
Linear; speed/direction
Angular; fixed point

Question 20

What is the push/pull effect governed by?

Answer 20

Size and direction of the force

Question 21

How do muscles provide force and movement?

Give an example of the classes and the type of muscle representing it

Answer 21

Using lever systems

1st class - resistance downwards (head weight) and effort downwards, pivot in centre e.g neck

2nd class - pivot on end, resistance downward in middle and effort upward on other end e.g toe is pivot and heel is resistance (body weight)

3rd class - pivot at end, effort going upwards within the resistance, resistance going down e.g bicep curl

Question 22

3rd class levers are the **, have * resistance and need * effort to move

They have no * advantage but * muscle contraction produces * distance movement

Answer 22

Most common; lower; more

Mechanical; small; larger