Support and Movement in Humans and Animals

Question 1

Three types of skeletons

Answer 1

• Exoskeletons
• Endoskeletons
• Hydrostatic skeletons

Question 2

Necessity of skeletal systems in humans and animals

Answer 2

• Support soft body tissues and maintains body’s shape
• Muscle attachment
• Stores minerals, especially calcium and phosphorus
• Movement
• Protects the internal organs from injury

Question 3

Hydrostatic skeleton

Answer 3

Consists of fluids within body cavities. The fluid exerts pressure on the walls of the body surrounded by muscles. Soft-bodied organisms such as earthworms maintains a rigid body for muscular action.

Question 4

Human skeletal system consists of two main parts, which are

Answer 4

• axial skeleton

- appendicular skeleton

Question 5

Axial skeleton consists of the

Answer 5

• skull
• vertebral column
• ribs and sternum (breastbone)

Question 6

Human vertebral column consists of

Answer 6

• cervical vertebrae
• thoracic vertebrae
• lumbar vertebrae
• sacrum
• caudal

Question 7

Characteristics between vertebrae except the atlas vertebra

Answer 7

• Spinous process
• Transverse process
• Centrum (except atlas vertebra)
• Neural canals

Question 8

Cervical vertebrae

Answer 8

• Short spinous process
• Wide and short transverse process
• Small centrum
• Pair of transverse foramina

Question 9

Thoracic vertebrae

Answer 9

• Long spinous process
• Long transverse process
• Medium-sized centrum
• Does not have a transverse foramen

Question 10

Lumbar vertebrae

Answer 10

• Short spinous process
• Short transverse process
• Large centrum
• Does not have a transverse foramen

Question 11

What is a joint?

Answer 11

Meeting place of two or more bones or between cartilage and bones. Most joints allow bones to move in relation to one another.

Question 12

Three types of joints

Answer 12

• Immovable joints (sutures on cranium of skull)
• Slightly movable joints (cartilage discs between the first rib and sternum)
• Freely movable joints (hinge joints and ball-and-socket joints)

Question 13

Ball-and-socket joint

Answer 13

• Allows rotational movement in all directions
• It allows the swinging of arms and legs in circular motion
• Eg :
  a) Shoulder joint between the humerus and pectoral girdle
  b) Hip joint between femur and pelvic girdle

Question 14

Hinge joint

Answer 14

• Allows movement of bones in one plane
• The knee joint allows the lower leg to swing back and forth like a hinge on a door
• Hinge joints are also found in the elbows, phalanges of the fingers and toes

Question 15

Synovial membrane

Answer 15

secretes synovial fluid into the synovial cavity

Question 16

Capsule

Answer 16

fibrous tissue that encloses the joint and gives protection to the joint

Question 17

Synovial fluid

Answer 17

acts as a lubricant that reduces friction between the ends of the bones

Question 18

Cartilage

Answer 18

Acts as a cushion to the joints, it absorbs friction between the ends of bones. The cartilage also protects bones from wearing away.

Question 19

Ligaments

Answer 19

• At the joints, bones are held together by ligaments
• Consists of a bundle of strong, elastic and tough connective tissues
• Provide support and strength to the joints and allow the bones to bend at the joints
• Elastic –> allow bones to move on the joints and prevent joints from dislocation during movement

Question 20

Tendons

Answer 20

• Consists of tough, inflexible and unbendable fibres
• Join skeletal muscles to the bones
• When muscles contracts, the pulling force is transferred to the bones through the tendons to produce movement

Question 21

Skeletal muscles

Answer 21

• Cannot push and stretch but can only contract and pull
• To move bones, muscles work in pairs and act in opposing movements
• Opposing pair of muscles are known as antagonistic muscles
• If one of the muscles contract, the other muscles relaxes and vice versa
• Eg : biceps and triceps
• Muscles that straighten limbs during contraction are known as extensor. Eg : triceps
• Muscles that bends limbs during contraction are known as flexor. Eg : flexor