1. Chapter 2
Locomotion and Support

2. 2.1 SUPPORT AND
LOCOMOTION IN HUMANS
AND ANIMALS

3. 2.1 Support and Locomotion in
Humans and Animals
 Importance of support and locomotion
◦ Search for food
◦ Provide protection by escaping from
enemies or avoiding danger
◦ Search for more conducive living
environment
◦ Find mates for reproduction
◦ Avoid overcrowding which enables the
offspring to move to another place

4. 2.1 Support and Locomotion in
Humans and Animals (cont’d)
 Human skeletal system
◦ Consist of two main part; axial skeleton and
appendicular skeleton
Human Parts
skeleton
Axial 1. Skull Cranium, bones of the face, jaw
skeleton 2. Vertebral Cervical vertebrae, thoracic
column (the vertebrae, lumbar vertebrae,
backbone) sacrum, coccyx
3. Ribcage Sternum and ribs
Appendicular 1. Pectoral girdle Scapula and clavicle
skeleton 2. Arm (forelimbs) Humerus, ulna, radius, carpals,
metacarpals, phalanges
3. Pelvic girdle Ischium, pubis, ischium
4. Leg (hind limbs) Femur, tibia, fibula, tarsals,
metatarsals. phalanges

5. 2.1 Support and Locomotion in
Humans and Animals (cont’d)
 Skull
◦ Cranium – enclose and
protect the brain
◦ Facial bones and jaw
 Protect the eyes and ears
 Upper jaw is fixed
◦ Skull is joined to the
vertebral column at the
base of cranium

6. 2.1 Support and Locomotion in
Humans and Animals (cont’d)
 Rib
◦ Twelve pairs of ribs
 Articulate with thoracic cavity
dorsally, and sternum
ventrally
◦ Sternum is the front part

7. 2.1 Support and Locomotion in
Humans and Animals (cont’d)
 Vertebral column
◦ Consists of 33 vertebrae, joined but
separated by discs of cartilage
◦ Five types of vertebrae
1. Cervical vertebrae (7)
2. Thoracic vertebrae (12)
3. Lumbar vertebrae (5)
4. Sacral vertebrae (5)
5. Coccyx

8. 2.1 Support and Locomotion in
Humans and Animals (cont’d)
Neural arch
Forms neural
canal
Neural spine
Muscle
attachment
Centrum
Gives support
Neural canal
Protects spinal
cord

9. 2.1 Support and Locomotion in
Humans and Animals (cont’d)

10. 2.1 Support and Locomotion in
Humans and Animals (cont’d)
 Support head and
neck
 Sentrum is short
and thick
 Large and thick
sentrum

11. 2.1 Support and Locomotion in
Humans and Animals (cont’d)
 Appendicular skeleton
◦ Consists of
1. Pectoral girdles and forelimbs (arms)
2. Pelvic girdle and hind limbs (legs)

12. 2.1 Support and Locomotion in
Humans and Animals (cont’d)
 Arms

13. 2.1 Support and Locomotion in
Humans and Animals (cont’d)
 Legs Pelvic
girdle

14. 2.1 Support and Locomotion in
Humans and Animals (cont’d)
 Joints
◦ Place where two bones
meet
◦ Bones are held together
by ligaments
◦ Sinovial joints – joints
that contains a cavity
filled with fluid
◦ End of bones are
covered with cartilage.

15. 2.1 Support and Locomotion in
Humans and Animals (cont’d)
 Joints
◦ Various types of joints
1. Hinge joint
 Allow movement in one plane
2. Ball-and-socket joint
 Allow movement in all directions

16. 2.1 Support and Locomotion in
Humans and Animals (cont’d)
 Movement in a limb
◦ Skeletal muscles are attached to bones by
tendons.
◦ Movements of cause by antagonistic
movement of muscles:
 One muscles is contracted, another is relaxed

17. 2.1 Support and Locomotion in
Humans and Animals (cont’d)
 Structure of a muscle
◦ Muscle fibre – single, long cylindrical cell that
contains many nuclei
◦ Myofibrils – smaller units that made up muscle
fiber
◦ Interaction of actin and myosin will cause muscle
contraction

18. 2.1 Support and Locomotion in
Humans and Animals (cont’d)
 Locomotion of earthworm
◦ Earthworms have a hydrostatic skeleton (the
force of contraction is applied to a coelum(fluid
filled chamber).
◦ Coelom is surrounded by two antagonistic
muscle
 circular muscles – surround the chamber
 longitudinal muscles – extend from one end to the
other.
◦ Thinner and longer: When circular muscle
contract and the longitudinal muscle relax. (and
vice verca)
◦ The muscles contract rhythmically to
produce peristaltic waves which begins at the
front and move towards the end of the body.

19. 2.1 Support and Locomotion in
Humans and Animals (cont’d)

20. 2.1 Support and Locomotion in
Humans and Animals (cont’d)
 Locomotion of grasshopper
◦ The flexor and extensor (antagonistic) muscles
are attached to the internal surface of the
exoskeleton.
◦ Flexor muscles bend a joint.
◦ Extensor muscles straighten it.
◦ The rear legs of a grasshopper are long and
muscular and is adapted for hopping.
◦ Sitting position: When the flexor muscle
contracts, the lower leg is pulled towards
the body. The hind leg is folded in a Z shape and
ready for a jump.
◦ Jump: When the extensor muscle contracts, the

21. 2.1 Support and Locomotion in
Humans and Animals (cont’d)
 Locomotion of grasshopper

22. 2.1 Support and Locomotion in
Humans and Animals (cont’d)
 Locomotion of grasshopper
◦ The flexor and extensor (antagonistic) muscles
are attached to the internal surface of the
exoskeleton.
◦ Flexor muscles bend a joint.
◦ Extensor muscles straighten it.
◦ The rear legs of a grasshopper are long and
muscular and is adapted for hopping.
◦ Sitting position: When the flexor muscle
contracts, the lower leg is pulled towards
the body. The hind leg is folded in a Z shape and
ready for a jump.
◦ Jump: When the extensor muscle contracts, the

23. 2.1 Support and Locomotion in
Humans and Animals (cont’d)
 Locomotion of fish
◦ Fish has streamlined body shape
◦ Scales that overlap one another, with free
ends pointing backwards to reduce friction
◦ Fish have W-shaped muscles called
myotome

24. 2.1 Support and Locomotion in
Humans and Animals (cont’d)
 Locomotion of
fish
◦ Fish move forward
from the
contraction and
relaxation
(antagonistic) of
myotome on either
side of the body

25. 2.1 Support and Locomotion in
Humans and Animals (cont’d)
 Locomotion of fish
◦ Function of fins in fish – balance the body
◦ Pectoral fins – for steering
◦ Pelvic fins – for balance, to prevent diving
and rolling

26. 2.1 Support and Locomotion in
Humans and Animals (cont’d)
 Locomotion of bird
◦ Bird can fly either by flapping their wings or
gliding

27. 2.1 Support and Locomotion in
Humans and Animals (cont’d)
 Locomotion of bird
◦ When wings move down
 Pectoralis major contracts
 Wings are pulled down
◦ When wings move up
 Pectoralis minor contracts

28. 2.1 Support and Locomotion in
Humans and Animals (cont’d)
 Locomotion of
bird
◦ During gliding,
wings are spread
– act as aerofoil
◦ Bernoulli principle
– provide upward
thrust

29. 2.3 SUPPORT SYSTEM IN
PLANTS

30. 2.3 Support Systems in Plants
 Support in plants is necessary to:
◦ Stay upright
◦ Obtain sufficient sunlight
◦ Bear the weight the plant
◦ Provide strength to withstand wind
ressistance

31. 2.3 Support Systems in Plants
(cont’d)
Plants
Aquatic Terrestrial
Submerged Floating Herbaceous Woody

32. 2.3 Support Systems in Plants
(cont’d)
 Submerged plants
◦ Hydrilla sp.
◦ Have thin, narrow and
flexible leaves – provide
little ressistance
◦ Air sacs inside the
leaves and stems - keep
the plant floating close
to the surface to obtain
maximum sunlight.

33. 2.3 Support Systems in Plants
(cont’d)
 Floating plants
◦ Lotus plant
◦ Have broad leaves that are firm but flexible
enough to resist tearing by wave action.
◦ Aerenchyma tissues (spongy tissues with
large air spaces between the cells) in the
stems and leaves provide buoyancy so that
the plants can float on the surface of the
water

34. 2.3 Support Systems in Plants
(cont’d)
 Herbaceous plant
◦ Support provided by the turgidity of the
parenchyma and collenchyma cells.
◦ Turgor pressure of the fluid content in
the central vacuole pushes the cell
membrane and the cell contents
against the cell wall, creating support
for the stem, root and leaves.
◦ The thickening of the cell walls with
cellulose and pectin in collenchyma
cells provide additional mechanical
strength

35. 2.3 Support Systems in Plants
(cont’d)
 Woody plants
◦ Support provided through tissue
modification
◦ Xylem tissues
 Strenghtened by lignin
 Lignin – tough, not elastic and nor
permeable to water
◦ Parenchyma tissues
 Store starch, sugars and water
 It become turgid – give support

36. 2.3 Support Systems in Plants
(cont’d)
 Woody plants
◦ Collenchyma tissues
 Thickened with cellulose and pectin
◦ Sclerechyma tissues
 Thickened with lignin