Human Body Movements and Joints

Body Movements

• Movements occur in the body, such as blinking and breathing.
• Body parts move while remaining in place (like writing) or move from one place to another (like walking).
• Animals move in various ways, including walking, running, flying, jumping, creeping, crawling, slithering, and swimming.

Human Body and Its Movements

• The body is capable of many movements.
• The arm can rotate at the shoulder in a circular motion.
• The leg can rotate at the hip.
• The arm can bend at the elbow, and the leg at the knee.

Joints

• Joints are where two parts of the body seem to be joined together, such as the elbow, shoulder, and neck.
• Bones are hard structures.
• Bones cannot be bent.
• We can bend or move our body only at points where bones meet.

Types of Joints

• Different joints allow different movements.

Ball and Socket Joints

• These joints allow movements in all directions.
• The rounded end of one bone fits into the cavity (hollow space) of another bone.

Pivotal Joints

• Pivotal joints allow bending the head forward and backward, and turning the head to the right or left.
• In a pivotal joint, a cylindrical bone rotates in a ring.
• The joint where the neck joins the head is a pivotal joint.

Hinge Joints

• Hinge joints allow movement back and forth.
• The elbow has this type of joint.

Fixed Joints

• Fixed joints do not allow movement.
• Bones in the head are joined together by this type of joint
• The joint between the upper jaw and the rest of the head is a fixed joint.

Skeleton

• The skeleton is a framework that gives shape to our body.

• X-ray images help to see the shapes of the bones and identify injuries.

• The bones in the body form a framework called the skeleton.

Rib Cage

• The ribs are bent and join the chest bone and the backbone to form a box called the rib cage.

Backbone

• The backbone is made of many small bones.

Skull

• The skull is made of many bones joined together.
• The skull encloses and protects the brain.

Cartilage

• Cartilage is found in the ear and in the joints of the body.
• Muscles move bones.

Muscles

• A muscle bulges due to contraction, becoming shorter and thicker during movement.
• Muscles work in pairs to move a bone.
• When one muscle contracts, the bone is pulled in that direction and the other muscle relaxes, and vice versa.
• Muscle can only pull and cannot push.

Gait Of Animals

• The movement of animals

Earthworm

• The earthworm's body is made up of many rings joined end to end.
• Earthworms has muscles to extend and shorten the body
• It extends the front part of the body, fixes it to the ground with bristles, shortens the body, and pulls the rear end forward.

Snail

• The shell of a snail is its outer skeleton but it is not made of bones.
• The shell has to be dragged along and is a single unit.
• The foot of the snail is made of strong muscles moves the snail in a wavy motion.

Cockroach

• Cockroaches walk, climb, and fly.
• The three pairs of legs help in walking.
• Thier body is covered with a hard outer skeleton.
• Muscles near the legs move the legs for walking.
• Breast muscles move the wings when the cockroach flies.

Birds

• Birds fly because their bodies are well suited for flying.
• Their bones are hollow and light.
• The bones of the hind limbs are typical of walking and perching.
• The forelimbs are modified as wings.

Fish

• Fish have a streamlined body shape, which helps them move in water.
• Muscles make the front part of the body curve to one side and the tail part swings to the opposite side.
• The fins help keep the balance of the body and in changing direction.

Snakes

• Snakes have a long backbone and many thin muscles that interconnect.
• The body curves into loops, and each loop gives it a forward push.