Overview
This chapter introduces how animals — including humans — and some plants achieve movement. It explains the human skeleton and its role in support and protection, different types of joints that allow movement, and how muscles work (often in pairs) to pull bones and produce actions. The chapter contrasts endoskeletons and exoskeletons in animals, describes basic types of muscles (voluntary and involuntary), and shows simple examples of movement in animals and plants. Understanding body movements is important for appreciating how the body functions, for developing healthy habits to protect bones and muscles, and for noticing adaptations that help organisms move in their environments. By studying this chapter, students will learn key vocabulary, identify major bones and joints, explain how muscles and bones interact, and apply this knowledge to everyday care and safety.
Learning Objectives
- Define bone, cartilage, ligament, tendon, joint and bone marrow in one or two sentences each
- Describe the structure of a long bone (periosteum, compact bone, spongy bone, marrow) and label a given diagram
- Explain the functions of the human skeleton: support, protection, movement and blood cell formation
- Identify and classify types of joints as fixed, partly movable and movable, giving one example of each
- Distinguish between hinge, ball‑and‑socket and pivot joints and state an example and function for each
- Explain how muscles produce movement by contraction and by working in antagonistic pairs with examples
- Differentiate between voluntary and involuntary muscles with suitable examples
- Illustrate a skeletal muscle attached to bone via tendons with a neat labeled diagram
Topics in this chapter
8 topics · tap a topic title to jump straight to it.
Introduction
What is movement? Movement is a characteristic of all living organisms. It helps animals and plants find food, escape danger, reproduce and respond to their environment. In animals movement may mean whole-body locomotion (walking, swimming, flying) or local movements (waving a hand, opening the mouth). In plants movement is usually slow and is shown as growth or bending towards stimuli (like light or water).
Why do organisms move? Movement serves many purposes: obtaining food, finding shelter, escaping predators, mating, and responding to change in surroundings. Plants move to optimise light, water or to disperse seeds.
Support and movement structures
Most animals have a framework that supports the body and helps movement. Types of skeletons:
- Endoskeleton: internal bony skeleton (humans, vertebrates) — gives shape and support.
- Exoskeleton: external hard covering (insects, crabs) — protects and supports the body from outside.
- Hydrostatic skeleton: fluid-filled cavity providing support (earthworms, jellyfish).
Human skeleton and joints
The human skeleton has many bones joined together. Bones protect internal organs, give shape, and help movement. Where bones meet are joints. Types of joints include:
- Fixed (immovable): bones fused together (e.g., skull) — no movement.
- Slightly movable: small amount of movement (e.g., vertebrae of spine).
- Freely movable: large movement possible — several kinds such as hinge (elbow, knee), ball-and-socket (shoulder, hip), pivot (neck), and gliding joints (wrist).
Muscles and how they work
Muscles are soft tissues that contract (shorten) and relax to produce movement. There are three types: skeletal (attached to bones, usually voluntary), cardiac (heart, involuntary), and smooth (walls of internal organs, involuntary). Most skeletal muscles work in pairs across a joint: when one muscle contracts, the opposite muscle relaxes (for example, biceps contracts and triceps relaxes to bend the elbow).
Simple mechanical idea
Bones act like levers and joints act like pivots. Muscles apply force to bones to create movement. This simple lever action helps us lift and move objects efficiently.
Care of bones and muscles
Healthy diet (calcium, vitamin D, protein), regular exercise, correct posture and avoiding injuries keep bones and muscles strong and working properly.
- Walking and running (human locomotion) — skeletal muscles contract to move leg bones at hip, knee and ankle joints.
- Bending the elbow — biceps and triceps work as a pair (biceps contracts to bend, triceps contracts to straighten).
- Heart beating — cardiac muscle contracts rhythmically (involuntary movement).
- Earthworm movement — uses hydrostatic skeleton and circular/longitudinal muscles to move by waves of contraction.
- Fish swimming — muscles on either side of the body contract alternately to push against water.
- Phototropism in plants — shoots bend toward light because cells on the darker side grow faster.
- Speed = Distance / Time (useful to compare rates of movement; e.g., walking speed = 5 km / 1 h = 5 km/h).
- Mechanical advantage (lever idea) ≈ Effort arm length / Load arm length (simple way to compare how a lever amplifies force).
- Torque (basic rotational effect) = Force × Perpendicular distance from pivot (explains how muscle force at different distances from a joint changes turning effect).
Support and Movement Systems
What is the Support and Movement System? The support and movement system (locomotor system) is made of the skeleton and muscles working together to support the body, protect organs and produce movement. Bones form a framework that gives shape and strength; joints connect bones and allow movement; muscles attach to bones and pull them to make parts of the body move.
Main parts and their roles
- Skeleton: A rigid frame of bones. Human skeleton is an endoskeleton (inside the body). Functions: support the body, protect internal organs (e.g., skull protects brain, ribs protect heart and lungs), help in movement, store minerals and make blood cells (in bone marrow).
- Bones: Different shapes: long (femur), short (wrist bones), flat (skull, ribs), irregular (vertebrae). Bones are living tissues containing marrow and covered by a hard outer layer.
- Joints: Places where two or more bones meet. Types:
- Fixed joints: No movement (skull bones).
- Hinge joints: Movement in one plane like a door (elbow, knee).
- Ball-and-socket joints: Movement in many directions (shoulder, hip).
- Pivot joints: Rotation around one axis (neck allowing head to turn).
- Gliding joints: Bones slide over each other (wrist, ankle).
- Cartilage and ligaments: Cartilage is a smooth, flexible tissue at joint surfaces that reduces friction. Ligaments are tough bands that connect bones at joints and provide stability.
- Muscles: Contractile tissues that pull on bones to create movement. Types:
- Skeletal (striated) muscles: Usually attached to bones by tendons; under voluntary control (e.g., biceps).
- Smooth muscles: In organs, involuntary (e.g., stomach walls).
- Cardiac muscle: Heart muscle, involuntary and rhythmic.
- Tendons: Tough tissues that attach muscle to bone.
How movement happens
- Muscles can only pull — they contract (shorten) and relax (lengthen) but do not push.
- Most movable joints use antagonistic muscle pairs. Example: biceps and triceps at the upper arm. When biceps contract, the elbow bends; when triceps contract, the elbow straightens.
- Bones and muscles often act as levers. A lever has three parts: load (weight moved), effort (force applied by muscle), and fulcrum (joint). The arrangement determines the speed and force of movement.
Care of bones and muscles
- Eat a balanced diet with calcium and vitamin D for strong bones.
- Regular exercise and weight-bearing activities strengthen bones and muscles.
- Good posture and protective gear prevent injuries.
Summary: Support and movement come from a coordinated system of bones, joints, ligaments, cartilage and muscles. Bones give shape and protection, joints allow motion, and muscles supply the force to move bones often using lever action.
- Bending the elbow: biceps contract and pull the forearm up while triceps relax (antagonistic pair).
- Kicking a ball: thigh muscles (quadriceps) extend the knee using the femur and tibia as lever parts.
- Turning the head: pivot joint between the first two neck vertebrae allows rotation (saying 'no').
- Raising the arm overhead: shoulder (ball-and-socket) joint gives a wide range of motion.
- Walking: coordinated contraction and relaxation of leg muscles and movement at hip, knee and ankle joints.
- Chewing food: jaw (hinge joint) moved by contracting jaw muscles (masseter).
- Speed = Distance / Time (useful to express how fast a body part or object moves).
- Work = Force × Distance (when a muscle applies force to move a bone through a distance).
- Torque (moment) = Force × Perpendicular distance from pivot (explains how muscles produce turning effect at joints).
- Lever equilibrium: Effort × Effort_arm = Load × Load_arm (use to relate muscle force and distances on a bone lever).
- Mechanical advantage (MA) = Effort_arm / Load_arm (MA > 1 means less effort needed to move a load).
Human Skeleton
What is the human skeleton?
The human skeleton is the internal framework of bones that gives the body its shape, supports and protects organs, allows movement with the help of muscles, and stores minerals. Bones are living tissues that grow, repair, and contain bone marrow where blood cells are produced.
Main parts
- Axial skeleton: Skull, vertebral column (spine), ribs and sternum. These bones protect the brain, spinal cord and chest organs and form the central axis of the body.
- Appendicular skeleton: Shoulder girdle, pelvic girdle, and the bones of the arms and legs. These bones enable movement and manipulation of the environment.
Types of bones
- Long bones: e.g., femur, humerus — provide leverage for movement.
- Short bones: e.g., carpals and tarsals — provide stability and some movement.
- Flat bones: e.g., skull, ribs — protect organs and provide broad surfaces for muscle attachment.
- Irregular bones: e.g., vertebrae — specialised shapes for protection and support.
Joints and movement
Bones meet at joints. Joints allow different kinds of movement depending on structure and are held together by ligaments. Cartilage cushions joints and prevents friction. Main joint types:
- Immovable: e.g., skull sutures.
- Slightly movable: e.g., vertebrae (intervertebral discs).
- Freely movable (synovial): e.g., hinge (elbow, knee), ball-and-socket (shoulder, hip), pivot (neck).
Functions of the skeleton
- Support: Keeps body upright and holds organs and soft tissues.
- Protection: Skull protects brain; rib cage protects heart and lungs; vertebrae protect spinal cord.
- Movement: Bones and joints form levers moved by muscles.
- Blood cell production: Bone marrow produces red and white blood cells and platelets.
- Mineral storage: Bones store calcium and phosphorus that help metabolic processes.
Interesting facts (useful for Class 6)
- A newborn has about 270–300 bones; many fuse during growth to give an average adult total of 206 bones.
- Longest bone: femur (thigh bone). Smallest bone: stapes in ear.
- There are 12 pairs of ribs and 24 vertebrae in the main parts of the spine (cervical, thoracic, lumbar), plus sacrum and coccyx bones formed by fused vertebrae.
Care of the skeleton
To keep bones healthy: a balanced diet rich in calcium and vitamin D, regular exercise (especially weight-bearing), good posture, and avoiding injuries.
- Skull protecting the brain — wearing a helmet while cycling prevents head injury.
- Rib cage protecting heart and lungs — feeling safer during a punch in the chest is due to ribs.
- Using the elbow as a hinge joint when lifting a glass — muscles pull the forearm upward.
- Walking and running — femur, tibia, fibula and foot bones form strong levers and joints to support body weight and motion.
- Chewing food — movement of jaw (a movable joint) helps break down food.
- Torque (moment) = Force × Perpendicular distance (from pivot) ; T = F × d (units: N·m). Example: if a muscle applies 10 N at 0.04 m from a joint, T = 10 × 0.04 = 0.4 N·m.
- Mechanical advantage of a lever = Length of effort arm / Length of load arm. Example: effort arm 40 cm, load arm 10 cm → MA = 40/10 = 4 (you need 1/4 of the load force ignoring friction).
Joints
What is a joint?
A joint is a place where two or more bones meet. Joints allow the bones of the skeleton to move in different ways so that the body can perform activities like walking, running, writing and eating.
Why are joints important?
Joints provide movement and flexibility, give shape to the body, and help absorb shocks. Without joints our bones would be fused and movement would be impossible.
Types of joints
- Immovable (fixed) joints: Bones are tightly joined and cannot move. Example: sutures of the skull.
- Slightly movable (cartilaginous) joints: Bones can move a little. Example: joints between vertebrae and the pubic symphysis.
- Freely movable (synovial) joints: Allow a wide range of movements. Examples include the elbow, knee, shoulder and hip. These are the most common and most flexible joints.
Structure of a synovial joint
- Articular cartilage: Smooth tissue covering bone ends to reduce friction.
- Joint (synovial) capsule: A fibrous envelope that encloses the joint.
- Synovial membrane: Inner lining of the capsule that makes synovial fluid.
- Synovial fluid: Lubricant that nourishes cartilage and reduces friction.
- Ligaments: Tough bands of connective tissue that join bone to bone and provide stability.
- Tendons: Connect muscles to bones and transmit the pull of muscles that move the joint.
Common kinds of synovial joints and movements they allow
- Hinge joint: Movement in one plane — flexion and extension (example: elbow, knee).
- Ball-and-socket joint: Movement in many directions — flexion, extension, abduction, adduction, rotation (example: shoulder, hip).
- Pivot joint: Rotation around a central axis (example: joint between first two cervical vertebrae allowing head rotation).
- Gliding (plane) joint: Sliding movements between flat surfaces (example: wrist and ankle bones).
- Saddle and condyloid joints: Allow movement in two planes (examples: thumb saddle joint, wrist condyloid joint).
Movements at joints (simple terms)
Examples of movements include flexion (bending), extension (straightening), abduction (moving away from midline), adduction (toward midline), rotation (twisting) and circumduction (circular movement).
Keeping joints healthy
Regular exercise, a balanced diet with calcium and vitamin D, good posture, and avoiding excessive strain help keep joints healthy. Warm-up before exercise and use protective gear during sports to reduce injury risk.
- Skull sutures — immovable joints that protect the brain.
- Vertebrae — slightly movable joints that allow bending of the back.
- Elbow — a hinge joint allowing flexion and extension (e.g., lifting a cup).
- Knee — a hinge joint used when walking, running and jumping.
- Shoulder — a ball-and-socket joint allowing multi-directional arm movement (e.g., throwing).
- Hip — a ball-and-socket joint that supports body weight and leg movement.
- Torque (moment of force): τ = F × d (units: newton-meter, N·m). Explanation: Force F applied at a perpendicular distance d from the joint (fulcrum) creates rotation; explains how muscle force turns bones.
- Mechanical advantage of a lever: MA = effort arm / load arm (no units). Explanation: Bones act as levers and joints act as fulcrums; a longer effort arm means less force is needed to move a load.
- Work done in rotational movement (basic): W = τ × θ (τ in N·m, θ in radians). Explanation: Rotational analogue of work — torque times angular displacement.
- Angular speed (simple): ω = θ / t (θ in radians, t in seconds). Explanation: Useful to describe how fast a joint rotates during a movement.
Muscles
What are muscles?
Muscles are soft tissues in the body that can contract (shorten) and produce movement. They pull on bones and other structures to bring about motion. Muscles need energy (from food/ATP) and oxygen to work.
Types of muscles
- Skeletal (voluntary) muscles: Attached to bones by tendons. We control them consciously (e.g., biceps, quadriceps). They are striated (striped) in appearance.
- Cardiac muscle: Found only in the heart. It contracts rhythmically and continuously without conscious control.
- Smooth (involuntary) muscles: Found in walls of internal organs (intestine, blood vessels). They work automatically (e.g., peristalsis in the gut).
How skeletal muscles work
Muscles can only pull (contract); they cannot push. To move a bone in two directions, muscles work in pairs called antagonistic pairs. When one muscle of the pair contracts, the other relaxes. Example: biceps and triceps at the upper arm – biceps contract to bend the elbow, triceps contract to straighten it.
Muscles and levers in the body
Bones act as levers and joints act as fulcrums. Muscles apply effort to move loads (body parts or external objects). This lever arrangement helps the body lift, push and move efficiently.
Energy and fatigue
Muscles get energy by breaking down food to produce ATP. Continuous or strenuous use without rest leads to fatigue—reduced ability to contract—so rest and good nutrition are important.
Care of muscles
Regular exercise, balanced diet (protein, carbohydrates), warm-up before strenuous activity, proper rest and hydration keep muscles healthy.
- Bending the arm: biceps and triceps work as an antagonistic pair.
- Walking and running: many leg muscles (quadriceps, hamstrings, calf muscles) contract and relax in sequence.
- Heart pumping blood: cardiac muscle contracts rhythmically without conscious effort.
- Swallowing and digestion: smooth muscles in the oesophagus and intestines push food along (peristalsis).
- Breathing: diaphragm (a muscle) contracts to allow inhalation and relaxes for exhalation.
- Facial expressions: many small muscles move skin to smile, frown, blink.
- Work = Force × Distance (W = F × d). When a muscle produces a force F to move a bone through distance d, it does work. Units: joule (J).
- Power = Work / Time (P = W / t). Power measures how quickly muscles do work. Units: watt (W).
- Lever balance (moment): Effort × Effort arm = Load × Load arm (E × e = L × l). Used to describe how muscle force (effort) around a joint lifts a load.
- Mechanical advantage = Load / Effort. Shows how much a lever (bone-joint system) amplifies muscle force.
Movement in Various Animals
What is movement? Movement is a change in the position of an animal or part of its body. Animals move to obtain food, find shelter, escape predators and reproduce.
Main systems that allow movement
- Skeleton — gives shape and support; types: endoskeleton (inside, e.g., humans, fish, birds), exoskeleton (external, e.g., insects, crabs) and hydrostatic skeleton (fluid-filled body providing shape, e.g., earthworm).
- Muscles — contract to pull bones or body parts. Muscles usually work in antagonistic pairs (e.g., biceps and triceps).
How different animals move
- Unicellular animals — amoeba forms pseudopodia (false feet) by flowing cytoplasm; paramecium uses tiny hair-like cilia; Euglena uses a flagellum.
- Hydra — can bend, contract its body and perform somersault-like movement using its base and tentacles.
- Earthworm — uses peristaltic waves: alternate contraction of circular and longitudinal muscles plus tiny bristles (setae) to grip the soil.
- Insects (e.g., cockroach) — have an exoskeleton and jointed legs moved by muscles attached internally; can run quickly due to coordinated leg movement.
- Fish — swim by lateral undulation of the body and tail fin; fins provide steering and stability.
- Birds — fly using wings shaped as airfoils; wing flapping (powered by strong breast muscles) gives lift and thrust; hollow bones reduce weight.
- Snakes — move by different types of locomotion (lateral undulation, concertina, rectilinear) using muscles and scales for grip—no limbs required.
- Humans — endoskeleton (bones) with joints (hinge, ball-and-socket etc.) and muscles that contract to produce varied movements (walking, running, grasping).
Important ideas to remember
- Movement mechanisms vary with body design: small/simple organisms use cilia, flagella or cytoplasmic flow; larger animals rely on skeletons and muscles.
- Exoskeletons protect but must be shed (molting) to grow; endoskeletons grow with the animal.
- Muscles can only pull; an opposing muscle (antagonist) is needed to return a limb to its original position.
Classroom activity suggestion: Observe and draw an earthworm’s movement on wet soil (or watch a short video) and label the parts showing peristalsis and setae.
- Amoeba — moves and captures food by extending pseudopodia (false feet).
- Paramecium — swims using coordinated beating of cilia.
- Earthworm — moves by peristaltic waves of circular and longitudinal muscles and uses setae to hold ground.
- Cockroach — runs using six jointed legs attached to an exoskeleton; muscles inside the exoskeleton pull the leg segments.
- Fish (e.g., carp) — swims by side-to-side body and tail movement; fins steer and stabilize.
- Bird (e.g., sparrow) — flies using wing flapping; wings shaped for lift and thrust; hollow bones reduce weight.
- Speed = Distance / Time (useful to compare how fast animals move; typical units: m/s)
- Average speed = Total distance traveled / Total time taken
- Unit conversion: 1 km/h = 0.27778 m/s (useful when comparing speeds given in different units)
Keeping Bones and Muscles Healthy
Overview
Bones form the rigid framework of the body, protect internal organs and, together with joints and muscles, enable movement. Muscles contract to pull bones, producing movement. Healthy bones and muscles are essential for growth, posture, movement and protection.
How bones and muscles work together
- Bones act as levers; joints act as fulcrums; muscles provide the effort (pull) via tendons.
- When a muscle contracts, it pulls on the tendon attached to a bone, causing the bone to move about a joint.
Keeping bones healthy
- Nutrition: Eat a balanced diet with sources of calcium (milk, yogurt, cheese, leafy greens), phosphorus, protein and vitamin D (eggs, fortified foods, and sunlight helps the body make vitamin D).
- Physical activity: Weight-bearing activities (walking, running, jumping) and play help bones become stronger by stimulating bone formation.
- Good posture and ergonomics: Sit and stand correctly; avoid heavy backpacks carried on one shoulder.
- Safety: Use protective gear during sports to prevent fractures; learn and follow safe ways to lift heavy objects.
Keeping muscles healthy
- Regular exercise: Aerobic activities (running, cycling), strength activities (climbing, carrying light loads, body-weight exercises) and flexibility exercises (stretching) keep muscles strong and flexible.
- Protein and hydration: Adequate protein supports muscle repair and growth; drink water before, during and after exercise.
- Warm-up and cool-down: Reduce risk of strains by warming up before exercise and stretching afterwards.
- Rest and recovery: Muscles need rest between intense activities for repair and growth.
Common problems and simple care
- Sprains/strains: Rest, ice, compression and elevation (RICE) and see a doctor if severe.
- Fractures: Immobilize the limb and seek medical care immediately.
- Poor posture and back pain: Strengthen core muscles, maintain healthy weight and use ergonomically correct furniture.
School-level connections (levers and movement)
Bones and joints form different types of levers in the body: the arrangement of fulcrum, load and effort determines the lever type and mechanical advantage. Examples: seesaw-type actions (first-class levers), calf raising (second-class lever), and elbow lifting (third-class lever).
- Child running and jumping during play: weight-bearing activity that strengthens bones and develops muscle power.
- Lifting a school bag correctly with both shoulders and bending the knees: protects the spine and engages leg muscles to reduce back strain.
- Standing on tiptoe (calf raise): a second-class lever action where calf muscles lift the body—strengthens calf muscles and the bones of the foot and ankle.
- Using the elbow to lift a book with the forearm: a third-class lever—biceps provide effort close to the fulcrum (elbow) to lift the load at the hand.
- Spending short time in sunlight daily (with safe exposure): helps the skin make vitamin D, aiding calcium absorption for stronger bones.
- Torque (moment) = Force × Perpendicular distance from fulcrum (M = F × d). Useful to understand how muscle force and distance from joint produce turning effect.
- Mechanical Advantage (MA) of a lever = Length of effort arm / Length of load arm. If MA > 1 the lever multiplies force; if MA < 1 it increases speed of movement.
- Body Mass Index (BMI) = Mass (kg) / [Height (m)]². A simple index to check whether weight is appropriate for height (used with age-appropriate reference charts).
Practical Activities and Observations
What this topic covers
Practical Activities and Observations in the "Body Movements" chapter help students see how bones, joints and muscles produce different kinds of movement. These activities are simple, safe experiments and observations that show types of joints, how muscles work (often in pairs), and how the range of movement varies for different joints.
Typical practical activities (steps and what to observe)
- Observe elbow bending: Sit with arm relaxed. Bend and straighten the elbow several times. Use a protractor or mark angle on a paper fixed to the arm to note the change in angle. Observation: The elbow works like a hinge joint; angle decreases when bending and increases when straightening.
- Demonstrate muscles working in pairs: Place a rubber band or a strip of elastic across a model 'arm' (cardboard) representing the biceps and triceps. Pull one side to show contraction while the other side loosens. Observation: Muscles pull but cannot push; one muscle contracts while the opposite relaxes.
- Identify joint types on your body: Use a mirror and point to the knee, elbow, shoulder, neck and wrist. Try simple movements (bend, rotate, swing) and classify the joint (hinge, ball-and-socket, pivot, gliding). Observation: Knee and elbow = hinge; shoulder and hip = ball-and-socket; neck = pivot; wrist = gliding-type movement.
- Compare range of motion: Measure how far you can raise your arm forward, sideways and rotate the shoulder. Record angles using a protractor fixed on a sheet attached to the torso. Observation: Ball-and-socket joints have larger range of motion than hinge joints.
- Feel muscle contraction: Place fingers on your biceps. Hold a small weight and lift the forearm; feel the muscle bulge when it contracts and relax when lowered. Observation: The muscle becomes thicker on contraction and shorter in length.
Recording observations
Record initial and final angles, number of repetitions, subjective notes (pain-free/full range/limited range), and simple sketches showing joint position. Always note student name, date and safety precautions (no forced movements, stop if pain).
Conclusion points to draw
- Different joints allow different types of movement.
- Muscles work in pairs: while one contracts, the other relaxes.
- Bones provide support; joints allow movement.
- Practical observations help link structure (joint type) to function (range and direction of movement).
- Opening and closing a door — shows hinge-type movement similar to the elbow and knee.
- Turning the head from side to side — demonstrates a pivot joint (atlas and axis vertebrae).
- Swinging the arm in a circular motion — shows ball-and-socket joint behavior (shoulder).
- Walking and running — combined action of hinge (knee), ball-and-socket (hip) and muscles working in pairs.
- Using a rubber band model to show how one muscle contracts while the opposite relaxes (biceps and triceps demonstration).
- Angle change = final angle − initial angle (use degrees, °) — useful when measuring joint bending.
- Average speed = total distance moved / total time taken — can be used when timing a limb movement over distance.
- Percent change in range = (change in angle / original angle) × 100% — to compare improvement or restriction.
- Work (simple reference) = Force × Distance — not required in Class 6 but helpful if measuring effort to lift a weight.
Key Concepts
- Skeleton
- The internal framework of bones that gives shape, supports the body, protects internal organs and helps in movement.
- Bones
- Hard, living connective tissues that make up the skeleton; they store minerals and contain bone marrow.
- Bone marrow
- Soft spongy tissue inside some bones where blood cells are produced.
- Cartilage
- Flexible, rubbery connective tissue that cushions joints and shapes some body parts.
- Joint
- A point where two or more bones meet; joints may allow movement or be fixed.
- Fixed joint
- A joint where bones are fused and do not permit movement.
- Movable joint
- A joint that allows bones to move relative to each other, often cushioned by cartilage and supported by ligaments.
- Ball and socket joint
- A type of movable joint where a rounded bone head fits into a cup-like socket permitting movement in many directions.
- Hinge joint
- A joint that allows movement mainly in one plane (like opening and closing a door).
- Pivot joint
- A joint where one bone rotates around another, allowing rotational movement.
- Gliding joint
- A joint where flat or slightly curved bone surfaces slide over each other allowing small movements.
- Ligament
- Tough, flexible connective tissue that connects bone to bone at joints and stabilizes them.
- Tendon
- Flexible but strong fibrous tissue that connects muscle to bone and transmits the force of contraction.
- Synovial fluid
- A lubricating liquid found in movable (synovial) joints that reduces friction between joint surfaces.
- Vertebral column
- A column of small bones called vertebrae that forms the backbone, protects the spinal cord and supports the body.
- Rib cage
- The arrangement of ribs and the sternum that surrounds and protects the heart and lungs.
- Skull
- The bony structure forming the head that protects the brain and supports the face.
- Muscle
- Soft body tissue made of fibers that contract to produce movement or maintain posture.
- Skeletal muscle (voluntary)
- Muscles attached to bones that are under conscious control and produce body movements; they appear striated.
- Involuntary muscles (smooth and cardiac)
- Muscles not under conscious control: smooth muscles in internal organs perform movements like digestion, and cardiac muscle pumps the heart.
End-of-Chapter Trial Paper & Test Questions
Topic-wise questions to test your understanding of every concept in this chapter.
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Which type of joint allows movement in only one plane (like opening and closing a door)? / कौन-सा जोड़ केवल एक तल में गति की अनुमति देता है (जैसे दरवाजा खोलना-बंद करना)? (a) Ball-and-socket joint / गेंद-और-सॉकेट जोड़ (b) Pivot joint / धुरी जोड़ (c) Hinge joint / कब्जेदार जोड़ (d) Fixed joint / अचल जोड़
Show answer
(c) Hinge joint — examples are elbow and knee. It allows flexion and extension in one plane only, just like a door hinge. Ball-and-socket joints allow movement in many directions. / कब्जेदार जोड़ — उदाहरण कोहनी और घुटना। यह केवल एक तल में फ्लेक्शन और एक्सटेंशन की अनुमति देता है, जैसे दरवाजे का कब्जा।
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The tough, flexible tissue that connects muscle to bone is called: / मांसपेशी को हड्डी से जोड़ने वाले कठोर, लचीले ऊतक को क्या कहते हैं: (a) Ligament / लिगामेंट (b) Cartilage / उपास्थि (c) Tendon / कण्डरा (d) Marrow / मज्जा
Show answer
(c) Tendon — tendons connect muscles to bones and transmit the pulling force of muscle contraction to move bones. Ligaments connect bone to bone and stabilize joints. / कण्डरा — कण्डरा मांसपेशियों को हड्डियों से जोड़ती है और मांसपेशी संकुचन की खींचने वाली शक्ति को हड्डियों को हिलाने के लिए संचारित करती है।
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Which part of the human skeleton protects the brain? / मानव कंकाल का कौन-सा भाग मस्तिष्क की रक्षा करता है? (a) Rib cage / पसली पिंजर (b) Vertebral column / कशेरुक दंड (c) Skull / खोपड़ी (d) Sternum / उरोस्थि
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(c) Skull — the skull is made of fused flat bones that form a protective box around the brain. The rib cage protects the heart and lungs; the vertebral column protects the spinal cord. / खोपड़ी — खोपड़ी जुड़ी हुई चपटी हड्डियों से बनी होती है जो मस्तिष्क के चारों ओर एक सुरक्षात्मक बक्सा बनाती है।
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Muscles can only _______ (shorten), they cannot push. This is why they work in _______ pairs. / मांसपेशियाँ केवल _______ (छोटी हो सकती हैं) सकती हैं, वे धकेल नहीं सकतीं। इसीलिए वे _______ जोड़ों में काम करती हैं।
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contract / संकुचित हो; antagonistic / विरोधी — When biceps contract (elbow bends), triceps relax. When triceps contract (elbow straightens), biceps relax. This pair of opposing muscles ensures two-directional movement. / जब द्विशिर (बाइसेप्स) संकुचित होती है (कोहनी मुड़ती है), त्रिशिर (ट्राइसेप्स) शिथिल होती है। विपरीत मांसपेशियों की यह जोड़ी दोनों दिशाओं में गति सुनिश्चित करती है।
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The _______ joint at the shoulder allows the arm to move in many directions including rotation. / कंधे का _______ जोड़ हाथ को घुमाव सहित कई दिशाओं में हिलाने देता है।
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ball-and-socket / गेंद-और-सॉकेट — The rounded head of the humerus (upper arm bone) fits into the cup-like socket of the shoulder girdle, allowing movement in many directions. Hip is another example. / ह्यूमरस (ऊपरी बाहु की हड्डी) का गोल सिरा कंधे की करधनी के कप जैसे सॉकेट में फिट होता है जिससे कई दिशाओं में गति होती है।
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True or False: Cardiac muscle is a voluntary muscle that we can consciously control. / सत्य या असत्य: हृदय पेशी एक ऐच्छिक पेशी है जिसे हम सचेत रूप से नियंत्रित कर सकते हैं।
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False / असत्य — Cardiac muscle (heart muscle) is INVOLUNTARY — it works automatically, beating rhythmically without conscious effort. Skeletal muscles are voluntary (under conscious control). / हृदय पेशी अनैच्छिक है — यह स्वचालित रूप से काम करती है, बिना सचेत प्रयास के नियमित रूप से धड़कती रहती है। कंकाल पेशियाँ ऐच्छिक होती हैं।
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Name the two main divisions of the human skeleton and give one example of a bone from each. / मानव कंकाल के दो मुख्य विभागों के नाम बताइए और प्रत्येक से एक हड्डी का उदाहरण दीजिए।
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(1) Axial skeleton / अक्षीय कंकाल: protects central organs — example: skull / खोपड़ी (protects brain). (2) Appendicular skeleton / उपांगीय कंकाल: enables movement — example: femur / फीमर (thigh bone / जाँघ की हड्डी). Together they form the complete human skeleton of ~206 bones in adults. / मिलकर वे वयस्कों में ~206 हड्डियों का पूरा मानव कंकाल बनाते हैं।
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An earthworm moves by: / एक केंचुआ किस प्रकार गति करता है: (a) Using wings to fly / पंखों से उड़कर (b) Peristaltic waves of muscle contraction using circular and longitudinal muscles / वृत्ताकार और अनुदैर्ध्य पेशियों से क्रमाकुंचन (पेरिस्टाल्टिक) तरंगें (c) Rolling along the ground / जमीन पर लुढ़ककर (d) Using a hard exoskeleton and jointed legs / कठोर बाह्य कंकाल और जुड़े पैरों से
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(b) Earthworms have a hydrostatic skeleton and move by alternating contraction of circular muscles (body becomes thin and long) and longitudinal muscles (body becomes short and fat), plus setae (bristles) grip the soil. / केंचुए में द्रवस्थैतिक कंकाल होता है। वृत्ताकार पेशियाँ (शरीर पतला-लंबा) और अनुदैर्ध्य पेशियाँ (शरीर छोटा-मोटा) बारी-बारी सिकुड़ती हैं। शूक (सेटी) मिट्टी को पकड़ते हैं।
Related Laws & Principles
Explore allFoundational laws & principles behind this chapter. Each one opens a full page — what it says, why it matters, five practice questions and the mistakes to avoid.