1. Locomotion and Support
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 skeleton
Parts
Axial skeleton
Skull
Vertebral column (the backbone)
Ribcage
Cranium, bones of the face, jaw
Cervical vertebrae, thoracic vertebrae, lumbar vertebrae, sacrum, coccyx
Sternum and ribs
Appendicular skeleton
Pectoral girdle
Arm (forelimbs)
Pelvic girdle
Leg (hind limbs)
Scapula and clavicle
Humerus, ulna, radius, carpals, metacarpals, phalanges
Ischium, pubis, ischium
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
Cervical vertebrae (7)
Thoracic vertebrae (12)
Lumbar vertebrae (5)
Sacral vertebrae (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
Pectoral girdles and forelimbs (arms)
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
Hinge joint
Allow movement in one plane
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.
Earthworm has chaetae (bristles) which anchor parts of the body to the ground so that other parts can be pulled towards it.

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 leg jerks backwards, propelling the grasshopper forward and upward into the air.

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 leg jerks backwards, propelling the grasshopper forward and upward into the air.

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)
Aquatic
Submerged
Floating
Terrestrial
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