Movements Online Test 8th Science Lesson 13 Questions in English

Explanation

Movement is generally defined “as the act of changing the place or position by one or more parts of the body”.

Explanation

Movement helps to perform necessary functions such as pumping of blood to different parts of the body in an organism.

Explanation

Movement can be both voluntary and involuntary. For example walking is a voluntary movement while breathing is an involuntary movement.

Explanation

The movement of an organism from one place to another is known as locomotion. Locomotion helps an organism to find food, avoid harsh weather conditions, escape from their predator etc.

Explanation

Walking, running and swimming are few examples for different types of locomotion. In this process, there is the action of appendages such as limbs, wings, flagella and cilia.

Explanation

In most of the aquatic animals such as fish, whales, and shark, the locomotion results from a series of wave-like muscle contractions.

Explanation

Explanation

Movement is one of the significant features of living beings. This is the basic mechanism used in majority of the vertebrates including human. Animals exhibit a wide range of movements.

Explanation

The body of earthworm is made up of many rings joined end to end. It has muscles which help to extend and shorten the body. Under its body it has large number of bristles called setae which are connected with muscles. These bristles help to get grip on the ground.

Explanation

Earthworm makes it move forward by small distances. Repeating such muscle contraction and relaxation the earthworm can move through soil. A slimy substance secreted by its body helps this movement.

Explanation

A cockroach has three pairs of jointed legs, which help it to walk, run and climb. It also has two pairs of wings for flying.

Explanation

Large and strong muscles help in the movement of legs. The body is covered by chitin, a light protective material. Chitin is shed regularly so that the body can grow

Explanation

Birds can walk on the ground and fly as well. Some birds can also swim in the water. A bird has streamlined body. Its bones are light and strong. They are hollow and have air spaces between them. The hind limbs of birds are modified as claws which help them to walk and to perch. The breast bones are modified to hold massive flight muscles which help in moving wings up and down.

Explanation

Birds have special flight muscles and the forelimbs are modified as wings. The wings and tail have long feathers which help in flying.

Explanation

Birds show two types of flight: gliding and flapping.

Explanation

Gliding: During gliding the bird has its wings and tail spread out. In this movement the bird uses air currents for going up and down.

Explanation

Flapping: This is an active flight. The bird beats the air by flapping its wings. They use flight feathers for this purpose.

Explanation

The body of snake consists of a large number of vertebrae. The adjoining vertebrae ribs and skin are inter-connected with slender body muscles.

Explanation

When the snake moves, it makes many loops on its sides. The forward push of the loops against the surface makes the snake move forward. Movement of snake is called slithering movement. Many snakes can swim in water also.

Explanation

Since snakes do not have legs they use their muscles and their scales to move.

Explanation

Fish swims with the help of fins. They have two paired fins and an unpaired fin.

Explanation

The body of a fish is streamlined to reduce friction while moving in water. They have strong muscles which help in swimming.

Explanation

When a fish swims its front part curves to one side and the tail part stays in the opposite direction. In the next move, the front part curves to the opposite side and the tail part also changes its position to another side. The caudal or tail fin helps in changing direction.

Explanation

Fish have streamlined body structure which helps them to move smoothly with the flow of water. Muscles and fins on the body and the tail help to keep the balance.

Explanation

Humans can move some parts of their body in different directions; however some body parts can be moved only in one direction. Our body is made up of a frame work of bones called skeleton helps in the movement of the body.

Explanation

Some of the movements in body parts of human are: Movement of eyelids, Movement of the heart muscles, Movement of teeth and jaw, Movement of arms and legs, Movements of head, Movements of neck.

Explanation

Movement of some organs happens because of the combined action of bones and muscles. In such cases, movement is possible along a point where two or more bones meet.

Explanation

 A Cheetah can run 76 kilometer per hour.

 A Hippopotamus can run faster than a man.

 Cockroach is the fastest animal on 6 legs covering a meter per second.

 The fastest mammal, the Dolphin can swim up to 35 miles per hours

Explanation

Amoeboid movement: It is brought about by pseudopodia which are appendages which move with movement of protoplasm within a cell.

Explanation

Ciliary movement: This movement is brought about by appendages called as cilia which are the hair-like extensions of the epithelium. Both these kinds of movements are seen with cells of the lymphatic system.

Explanation

Muscular movement: It is a more complex movement which is brought about by the musculoskeletal system. This type of movement is seen in the higher vertebrates.

Explanation

The point at which two separate bones meet is called a joint. Depending on the type of movement they allow, joints can be of three types: fixed, slightly moveable and moveable joints.

Explanation

Fixed or Immoveable joints: In this type of joint no movement is possible between the two bones. The structures between the bones of the skull box are examples of immoveable joints.

Explanation

Slightly moveable joints: Here, only very little (partial) movement occurs between the two bones. The joint between a rib and the breast bone or between the vertebrae is the example for slightly movable joint.

Explanation

Freely movable joints: In this type, varying degree of movements is possible between the two bones forming the joint. There are six major types of movable joints.

Explanation

Types of movable joints.

Explanation

A synovial joint is a joint which makes connection between two bones consisting of a cartilage lined cavity filled with fluid which is known as a diarthrosis joint.

Explanation

Inflammation of joints is a condition that usually results either due to friction of articulating cartilage or due to lack of synovial fluid in the joint. During this condition, the person feels acute pain in joints particularly while moving joints. This disease is referred to as arthritis. Arthritis is however also caused due to the deposition of uric acid crystals in the joints.

Explanation

Explanation

The skeleton system provides the hard structure or framework to the human body which supports and protects the body. It is composed of connective tissues like bones, cartilage, tendons and ligaments. If the skeleton is without joints, no movement would take place and the significance of human body will be no more than a stone.

Explanation

On the basis of presence in the body, skeleton is of two types.

Explanation

Exoskeleton: It is the skeleton that is found on the exterior layer of the body and it basically originates from embryonic ectoderm or mesoderm. Like scales in the fishes, outer hard layer of the tortoise and feathers of the birds it is dead and it protects and preserves the inner organs.

Explanation

Endoskeleton: It is the skeleton that is found inside the human body and it originates from the mesoderm. These are found in almost all vertebrates and form the main body structure.

Explanation

Functions of skeleton: The skeletal system serves five important functions in the human body. It provides structure and shape to the body. It supports and surrounds the internal organs of the body. Calcium and phosphorus, the two minerals that the body needs for important regulatory functions, are stored inside the bones. Red blood cells are produced in the bone marrow. The bones of the skeletal system act as levers for muscular action. Muscular movement would not be possible without tendons (fibrous cords of tissue that attach muscle to bone) and ligaments (fibrous cords of tissue that attach bone to bone).

Explanation

Calcium and phosphorus, the two minerals that the body needs for important regulatory functions, are stored inside the bones.

Explanation

The femur or thighbone is the longest and strongest bone of the human skeleton. The stapes in the middle ear is the smallest and lightest bone of the human skeleton.

Explanation

Human skeleton consists of bone, cartilages and ligaments. Bones comprise the hard framework of the body. Cartilages are the supporting and connecting structures. For example, the cartilage supports the projecting external ears and the tip of the nose. Ligaments bind the bones together.

Explanation

There are different types of bones in human skeletal system. They are:
Long bones: Found in arms and legs.
Short bones: Found in wrist ankle, vertebral column.
Flat bones: Found in skull, ribs, shoulder and hips.

Explanation

Irregular bones: Found in spine and vertebral column, mandible, palatine, inferior nasal concha, and hyoid.

Explanation

The skeletal system is composed of bones and the related structures that aid body movement. It is divided into two major parts: the axial skeleton and the appendicular skeleton.

Explanation

The axial skeleton consists of the bones along the axis, or central line of the human body. The axial skeleton consists of the skull, facial bones, sternum, ribs, and vertebral column.

Explanation

Skull is a hard structure made up of small bones. It is formed by 22 bones out of which 8 bones are fixed together to form the cranium and 14 bones fuse to form the face.

Explanation

The only bone which has movable joint is the lower jaw. This movable joint is supported by muscles and ligaments. Skull placed on the top of the backbone can be moved up, down and side wards.

Explanation

Vertebral column: Vertebral column running at the back of the body is also called as spine or the backbone. It is in the trunk region to offer support to the upper part of the body. Vertebral column is made up of individual bones called as vertebrae.

Explanation

Total vertebral column consists of 7 cervical vertebrae, 12 lumbar vertebrae, 5 fused sacral and 3 fused coccygeal vertebrae.

Explanation

Vertebral column runs from the base of the skull to the hip bone forming a tube. Spinal cord passes through this hollow tube. Vertebrae are joined by gliding points which allow the body to be bent back, front or side wards.

Explanation

The functions of vertebral column are given below.
• It protects the spinal cord.
• It supports the head.
• It serves as an attachment for the ribs.
• It provides support and place of attachment for the pectoral and pelvic girdle.
• It provides movement for the human skeleton.
• It helps in walking and standing erect with correct posture.

Explanation

Sternum or Rib cage: Rib cage occupies the chest region. It is a cone-shaped structure made up of 12 pairs of ribs. Ribs are attached to vertebrae at the back which curve around to form a cage.

Explanation

10 pairs of ribs are attached to the breast bone at the front. 2 pairs of lower ribs are free at front. These are called as free-floating ribs.

Explanation

Rib cage is set up in such a way that it can contract and expand during the process of breathing. Rib cage protects the underlying lungs, heart and some part of liver.

Explanation

Humans and giraffes have the same number of bones in the necks, but the vertebrae in a giraffe’s neck are much, much larger.

Explanation

Specifically, the appendicular skeleton comprises the shoulder girdle; the arm, wrist, and hand bones; the pelvic girdle; and the leg, ankle, and foot bones.

Explanation

Shoulder bone is formed by collar bone at the front and the shoulder blade at the back. The collar bone is supported by breast bone at one end and the shoulder blade at the other end. The shoulder bone encloses a socket like cavity into which fixes the ball of the upper arm. This forms a ball and socket joint. This girdle is also called as pectoral girdle.

Explanation

Pelvic bone is also called as pelvic girdle. It is made up of strong bones to balance entire weight of the body. Pelvic girdle is formed by five fused vertebrae at the back and form a cavity in the center while reaching the front part. The thigh bones are attached to either side of the girdle with a ball and socket joint.

Explanation

Arm bone is the upper limb made up of humerus, radius, ulna, carpals, metacarpals and phalanges. All these bones are joined by hinge joints which allow the limb to move only in one direction.

Explanation

Humerus makes up the upper arm. Fore-arm is made up of radius and ulna. Wrist is made up of carpals. Palm is made up of metacarpals. Fingers are made up of phalanges.

Explanation

Leg bone is the lower limb made up of femur, tibia, fibula, tarsals, metatarsals and phalanges. All these bones are joined by hinge joints which allow the limb to move only in one direction.

Explanation

Knee is covered by a cap like structure called as patella or a knee cap. Femur makes up the thigh bone. Leg is made up of tibia and fibula. Ankle is made up of tarsals. Foot is made up of metatarsals. Toes are made up of phalanges.

Explanation

The muscles in the body provide the means of all movements. They cover the skeletal framework and also give shape to the body. Muscles help to maintain body posture while sitting, standing or walking.

Explanation

Most muscles are long bundles of contractile tissue. Each muscle usually has two ends – a fixed end where the muscle originates and a movable end which pulls some other part. This moveable end is drawn out to form a tough structure the tendon which is attached to the bone.

Explanation

When stimulated by a nerve the muscle contracts to become shorter and thicker and thus it pulls the bone at the moveable end. Muscles can only contact and relax, they cannot lengthen.

Explanation

There are muscles in the root of your hair that give you goose bumps. It takes 17 muscles to smile and 42 muscles to frown. The hardest working muscle is in eye.

Explanation

Muscles often work in pairs which work against each other. These are called antagonistic pairs. The muscles in the upper arm control the bending and straightening of the arm. The two muscles, the biceps and triceps are working against each other. When the biceps contracts the lower arm is raised and the arm bends. In this position the triceps muscle is relaxed. To straighten the arm the reverse happens. The triceps contracts straightening the arm while the biceps relaxes. Antagonistic muscles can be found all over the body.

Explanation

In the iris of the eye there are two sets of muscle. There are radial muscles which radiate from the pupil like spokes of a bicycle and there are circular muscles. The radial muscles make the pupil of the eye wider, while the circular muscles make the pupil smaller.

Explanation

Muscles found in higher vertebrates are of three types: Striated or skeletal muscles or voluntary muscles. Unstriated or smooth muscles or involuntary muscles and Cardiac muscles

Explanation

Explanation

Coordination of Muscles: Most actions in our body like standing, walking, running, playing tennis require combined action of several muscles. To a great extent the muscles have to be coordinated for a particular kind of movement.

Explanation

Muscles move body parts by contracting and then relaxing. Muscles can pull bones but they can’t push them back to the original position. So they work in pairs of flexors and extensors.

Explanation

The flexor contracts to bend a limb at a joint. Then, when the movement is completed, the flexor relaxes and the extensor contracts to extend or straighten the limb at the same joint. For example, the biceps muscle in the front of the upper arm is a flexor, and the triceps, at the back of the upper arm, is an extensor. When you bend your elbow the biceps contracts then the biceps relaxes and the triceps contracts to straighten the elbow.