Download 17 Locomotion in humans

17 Locomotion in humans
Class Practice
17.1 Why do animals need a skeleton?
17.2 The human skeleton
1. F
2. T
3. F
4. F
1. The functions of skeleton in vertebrates are for support and movement, for
3.
4.
protection, production of blood cells and storage of minerals (calcium).
A bone is made up of living tissues.
Cartilage also contains mineral salts.
17.3 General plan and functions of the human skeleton
A.
B.
1.
2.
C
A
D
C
B
A
F
E
D
B
A
C
Axial skeleton
Appendicular skeleton
rib
skull
femur
pectoral girdle
sternum
knee cap
17.4 Joints
1. F
2. T
3. F
4. T
5. F
1. A joint is a place where two or more bones meet.
3. The ligaments hold two bones at a joint so as to prevent dislocation.
5. Hinge joints allow movement in one plane only while ball-and-socket
joints allow movement in three planes and in all directions.
17.5 Muscles
1. F
3.
2. T
3. F
4. F
5. F
There are three main types of muscles in human bodies. Skeletal muscle is
one of them.
When muscles relax, energy is not required.
4.
5.
When a skeletal muscle contracts, it becomes thicker and shorter.
Lactic acid is formed when a muscle remains contracted for a long period.
1.
17.6 Locomotion in humans
A.
1. F
2. F
3. T
4. F
1. Each muscle is attached to the skeleton at both ends by tendons.
2.
B.
When a muscle relaxes, it cannot push a bone. Therefore another
muscle is required to pull the bone back to its original position.
4. An extensor straightens a limb when it contracts.
(a) A is biceps (or flexor) and B is triceps (or extensor).
(b) B contracts and A relaxes.
Exam Practice
A.
Multiple Choice Questions
1. B
2. C
3. D
4. C
5. D
6.
7.
8.
C
A
D
9. C
10. C
B.
Structured questions
1. (a) ball-and-socket joint
(b) at the shoulder and the hip
(c)
Name
Function
A
synovial fluid
acts as a lubricant to reduce friction
B
cartilage
absorbs shock
C
synovial membrane
secretes synovial fluid
D
ligament
connects bones to bones
(d) The metal joint do not have ligaments, synovial fluid or cartilage.
Red blood cells are not produced by the metal joint.
2. (a) X – ball-and-socket joint; Y – hinge joint
(b) Joint X allows movement in three planes / all directions.
Joint Y allows movement in one plane only.
(c) synovial fluid and articular cartilage
(d) C is ligament which connects bones to bones.
D is tendon which attaches muscles to bones.
(e) (i) They work in pairs but export opposing actions. When one
muscle contracts, the other relaxes.
(ii)
(f)
(g)
B is the flexor because it bends a limb by its contraction.
I
3.
Component of the arm
(a)
model
(i)
screw A
(ii) screw B
Structure in human arm
shoulder joint
elbow joint
(iii) balloon X
biceps
(iv) balloon Y
triceps
(v) string
tendon
(b) The human shoulder allows the upper arm to move in three planes
but in the model it only allows the wooden board to move in one
plane.
C.
STS Connections
(a) Cartilage discs join the vertebrae together and allow a limited degree of
bending.
(b) If the feet are close together, the worker may lose balance easily.
(c) A and D. They are extensors.
(d) Keep the arms and elbows close to the body when lifting. / Do not twist
the body.
Bend the knees when lowering the load; do not stoop. (any one) (Or other
reasonable answers)