BiologyNCERT Class 11

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Locomotion and Movement Notes

Study Notes

5 Topics15 Formulas15 PYQs43 Key Points

Chapter Overview Types of Movement Muscle Structure & Contraction Skeletal System Joints Musculoskeletal Disorders

Chapter at a Glance

Topics5

Key Points43

Formulas15

Diagrams18

NEET PYQs15

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Topics

Chapter Overview

Overview

Locomotion and Movement explains how animals and humans change body position, move body parts and perform coordinated actions using muscles, bones and joints. Movement may be amoeboid, ciliary or muscular, while locomotion is movement of the whole organism from one place to another. In humans, skeletal muscles contract by the sliding filament mechanism using actin, myosin, calcium ions and ATP. The skeletal system provides support, protection, mineral storage and attachment sites for muscles. Joints connect bones and allow different degrees of movement, especially synovial joints. The chapter also covers important disorders such as myasthenia gravis, muscular dystrophy, tetany, arthritis, osteoporosis and gout, which are frequently tested in NEET.

Key Points6

1Locomotion is always movement, but every movement is not locomotion.
2Muscles, bones and joints work as a lever system in human locomotion.
3The functional contractile unit of striated muscle is the sarcomere.
4Thin filaments are mainly actin; thick filaments are mainly myosin.
5Axial skeleton forms the central axis; appendicular skeleton includes limbs and girdles.
6Most NEET questions ask direct NCERT facts: bone numbers, joint examples, sarcomere bands and disorders.

Memory Tricks2

Movement Types

Remember A-C-M: Amoeboid, Ciliary, Muscular. A cell can crawl, cilia can beat and muscles can contract.

Skeleton Split

Think 80 in the Axis and 126 attached: axial skeleton is the central axis, appendicular skeleton is attached as limbs and girdles.

Examples2

Daily Life Example

Walking requires skeletal muscles to contract, bones to act as levers and synovial joints such as hip, knee and ankle to permit motion.

Cellular Example

Leucocytes show amoeboid movement to squeeze through capillary walls and reach infection sites.

Reference Tables2

Chapter Mind Map Summary

Unit	Core Idea	NEET Focus
Types of Movement	Amoeboid, ciliary and muscular movement	Examples and locomotion vs movement
Muscle Structure	Muscle fibre, myofibril, sarcomere, actin and myosin	Bands, zones and sliding filament theory
Skeletal System	206 bones divided into axial and appendicular skeleton	Bone counts and functions
Joints	Bone connections classified by structure and movement	Synovial joint examples
Disorders	Muscle, joint and bone diseases	Cause and symptom matching

Fast NCERT Numbers

Structure	Number
Total adult bones	206
Axial skeleton	80
Appendicular skeleton	126
Skull bones	22
Vertebrae in adult vertebral column	26
Pairs of ribs	12

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Common Mistakes2

Movement vs Locomotion

Do not write that all movement is locomotion. Blinking, heartbeat and peristalsis are movements but not locomotion of the whole organism.

Sliding Filament Misconception

During contraction, actin and myosin filaments slide past each other; the filaments themselves do not become shorter.

Formula Cards2

Human Bone Count

Adult human skeleton has 206 bones divided into axial and appendicular skeleton.

Variables

Axial bones=

Bones of skull, vertebral column, sternum and ribs

Appendicular bones=

Bones of limbs, pectoral girdle and pelvic girdle

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Diagrams3

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Types of Movement

Overview

Movement is a basic property of living organisms and can occur at cellular, organ or whole-body level. NCERT classifies animal movement mainly into amoeboid, ciliary and muscular movement. Amoeboid movement occurs through temporary cytoplasmic projections called pseudopodia and is seen in Amoeba, macrophages and leucocytes. Ciliary movement occurs through coordinated beating of cilia, such as movement of mucus in the trachea and movement of ovum through the female reproductive tract. Muscular movement depends on contraction of muscle fibres and includes walking, running, breathing, heartbeat and peristalsis. Locomotion is a special type of movement in which the entire organism changes place.

Key Points6

1Movement may occur without locomotion, but locomotion always involves movement.
2Amoeboid movement is important in immune defence and phagocytosis.
3Ciliary movement is highly coordinated and usually moves fluid or particles over epithelial surfaces.
4Muscular movement is the dominant movement type in higher animals.
5Muscles generally work in antagonistic pairs because they pull but do not push.
6NCERT examples are frequently asked directly in NEET.

Memory Tricks2

ACM Order

ACM = Amoeba Crawls, Cilia Move, Muscles contract. This recalls Amoeboid, Ciliary and Muscular movement.

Cilia Examples

Remember T-O: Trachea and Oviduct. Cilia clean the trachea and help ovum travel in the oviduct.

Examples3

Amoeboid Example

A macrophage surrounds bacteria by extending pseudopodia and then engulfs them by phagocytosis.

Ciliary Example

Ciliated epithelium in the trachea moves mucus loaded with dust and microbes toward the pharynx.

Muscular Example

Peristalsis in the alimentary canal is caused by coordinated contraction and relaxation of smooth muscles.

Reference Tables3

Types of Movement

Type	Main Structure Used	Mechanism	Examples
Amoeboid movement	Pseudopodia	Cytoplasmic streaming and extension of temporary projections	Amoeba, leucocytes, macrophages
Ciliary movement	Cilia	Coordinated beating of hair-like projections	Tracheal mucus movement, ovum movement in oviduct
Muscular movement	Muscle fibres	Contraction and relaxation of muscles	Walking, running, heartbeat, peristalsis, breathing

Locomotion vs Movement

Feature	Movement	Locomotion
Meaning	Change in position of body part or whole body	Movement of whole organism from one place to another
Scope	Broader term	Narrower term
Energy requirement	May be low or high	Usually significant
Examples	Blinking, heartbeat, bending arm	Walking, swimming, flying
Relationship	Includes locomotion	A type of movement

NCERT Highlights

Statement	Why It Matters
Leucocytes in blood show amoeboid movement	Common direct NEET example
Ciliary movement helps remove mucus from trachea	Links movement with respiratory defence
Movement of ovum in female reproductive tract is ciliary	Frequently confused with muscular movement
Limbs, jaws, tongue and eyelids show muscular movement	Examples of muscle-based movement

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Common Mistakes3

Ovum Transport

Students often mark ovum movement in oviduct as muscular only. NCERT specifically highlights ciliary movement in the female reproductive tract.

Leucocyte Movement

Do not associate leucocyte movement with cilia or flagella. Leucocytes move by amoeboid movement.

Locomotion Definition

Do not call heartbeat locomotion. It is muscular movement but not locomotion.

Formula Cards2

Logical Relation

Locomotion is a subset of movement because it involves displacement of the whole organism.

Variables

Locomotion=

Whole-body displacement from one place to another

Movement=

Change in position of body or body part

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Diagrams4

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Muscle Structure & Contraction

10m

Overview

Muscles are specialized tissues that convert chemical energy of ATP into mechanical work. NCERT describes three muscle types: skeletal, smooth and cardiac. Skeletal muscles are striated, voluntary and attached to bones; smooth muscles are non-striated and involuntary; cardiac muscles are striated, involuntary and branched. A skeletal muscle is made of muscle fibres containing myofibrils. Each myofibril has repeating sarcomeres, the functional units of contraction. Sarcomeres contain thin actin filaments and thick myosin filaments arranged into I bands, A bands, H zones and Z lines. According to sliding filament theory, actin slides over myosin using ATP and calcium-regulated cross-bridge cycling, causing sarcomere shortening and muscle contraction.

Key Points8

1Muscle fibre is surrounded by sarcolemma and contains sarcoplasm, mitochondria and sarcoplasmic reticulum.
2Myofibrils show alternating dark A bands and light I bands, producing striations.
3Actin filaments are attached to Z lines; myosin filaments occupy the central region of sarcomere.
4Troponin-tropomyosin complex regulates actin-myosin interaction.
5ATP is needed for myosin head cocking, power stroke cycle and detachment of myosin from actin.
6Motor neuron stimulation releases acetylcholine at the neuromuscular junction.
7Calcium ions are released from sarcoplasmic reticulum during excitation-contraction coupling.
8Rigor-like stiffness can occur when ATP is unavailable because myosin cannot detach from actin.

Memory Tricks3

Muscle Types

S-S-C: Skeletal is Striated and under Self-control; Smooth is Silent and involuntary; Cardiac is Contracting automatically.

Band Changes

A is Always same; I and H Hide during contraction. This recalls A band unchanged, I band and H zone shorten.

Sarcomere Boundary

Z to Z is the Zone of contraction: a sarcomere extends from one Z line to the next.

Examples3

Biceps and Triceps

During elbow flexion, biceps contract and triceps relax. During extension, triceps contract and biceps relax.

Muscle Fatigue

After repeated sprinting, leg muscles may feel heavy because intense activity can exceed aerobic ATP supply.

Cardiac Muscle

The heart beats rhythmically without conscious control because cardiac muscle is involuntary and autorhythmic.

Reference Tables3

Types of Muscles

Feature	Skeletal Muscle	Smooth Muscle	Cardiac Muscle
Control	Voluntary	Involuntary	Involuntary
Striations	Present	Absent	Present
Cell shape	Long cylindrical fibres	Spindle-shaped cells	Branched fibres
Nuclei	Many nuclei	Single nucleus	Usually one or two nuclei
Location	Attached to bones	Visceral organs, blood vessels	Heart wall
Special feature	Fast powerful contraction	Slow sustained contraction	Intercalated discs and rhythmicity

Sarcomere Bands and Changes During Contraction

Part	Composition	Change During Contraction
A band	Full length of myosin with overlapping actin	Remains constant
I band	Only actin	Shortens
H zone	Only myosin	Shortens or may disappear
Z line	Sarcomere boundary	Moves closer
M line	Middle of sarcomere	Remains central

Sliding Filament Sequence

Step	Event
1	Motor neuron releases acetylcholine at neuromuscular junction
2	Action potential spreads over sarcolemma and T-tubules
3	Sarcoplasmic reticulum releases Ca2+
4	Ca2+ binds troponin and shifts tropomyosin
5	Myosin heads bind actin to form cross-bridges
6	Power stroke pulls actin toward centre
7	ATP binds myosin, causing detachment
8	Ca2+ reuptake leads to relaxation

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Common Mistakes4

A Band Confusion

A band does not shorten during contraction. Only the overlap between actin and myosin increases.

Calcium Role

Calcium does not directly provide energy. It regulates exposure of actin-binding sites; ATP provides energy.

Muscle Fibre Nuclei

Skeletal muscle fibres are multinucleate, while smooth muscle cells are generally uninucleate.

Filament Shortening

Actin and myosin filaments slide; they do not individually shrink.

Formula Cards3

ATP Hydrolysis

The energy released energizes the myosin head for cross-bridge cycling.

Variables

ATP=

Energy-rich molecule used by muscle

ADP=

Lower-energy molecule formed after hydrolysis

Pi=

Inorganic phosphate released during ATP breakdown

Sarcomere Length

Contraction shortens the sarcomere by bringing Z lines closer.

Variables

Z line=

Boundary line of a sarcomere where actin filaments are anchored

Sarcomere=

Functional contractile unit of striated muscle

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Diagrams6

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Skeletal System

Overview

The skeletal system forms the structural framework of the human body and works with muscles to produce locomotion. Adult humans have 206 bones divided into axial and appendicular skeletons. The axial skeleton has 80 bones and includes the skull, vertebral column, sternum and ribs. It mainly protects the brain, spinal cord and thoracic organs. The appendicular skeleton has 126 bones and includes limb bones along with pectoral and pelvic girdles. Bones provide support, protection, leverage for movement, mineral storage and sites for blood cell formation in marrow. NEET frequently asks direct NCERT facts such as bone numbers, vertebral regions, rib types, limb bones and girdle composition.

Key Points8

1Bones and cartilage are specialized connective tissues.
2The skull protects the brain and supports structures of the face.
3The vertebral column is formed from 26 bones in adults due to fusion of sacral and coccygeal vertebrae.
4There are 12 pairs of ribs: true, false and floating ribs.
5The pectoral girdle attaches upper limbs; the pelvic girdle attaches lower limbs.
6The femur is the longest and strongest bone of the body.
7Bone marrow is important in haemopoiesis, especially red marrow.
8The skeleton acts as a system of levers for muscular movement.

Memory Tricks3

Axial vs Appendicular

Axis has 80; Appendages add 126. Axial is central, appendicular is attached.

Vertebral Formula

Breakfast at 7, lunch at 12, dinner at 5: cervical 7, thoracic 12, lumbar 5.

Rib Types

True 7, False 3, Floating 2 pairs. Remember 7-3-2 for rib categories.

Examples3

Protection Example

The skull protects the brain just as a helmet protects the head during a fall.

Lever Example

When the biceps contract, the forearm bones act as levers around the elbow joint.

Mineral Storage Example

Bones store calcium, which can be mobilized when blood calcium level falls.

Reference Tables4

Axial and Appendicular Skeleton

Feature	Axial Skeleton	Appendicular Skeleton
Number of bones	80	126
Main parts	Skull, vertebral column, sternum, ribs	Limbs, pectoral girdle, pelvic girdle
Main function	Protection and body axis support	Locomotion and limb movement
Examples	Cranium, vertebrae, ribs	Humerus, femur, scapula, hip bone

Important Bone Counts

Region	Bones
Skull	22 bones
Cranial bones	8 bones
Facial bones	14 bones
Auditory ossicles	6 bones
Hyoid bone	1 bone
Vertebral column	26 bones in adult
Rib cage	12 pairs of ribs plus sternum

Limb Bones

Region	Bones
Upper arm	Humerus
Forearm	Radius and ulna
Wrist	Carpals
Palm	Metacarpals
Fingers	Phalanges
Thigh	Femur
Knee cap	Patella
Leg	Tibia and fibula
Ankle	Tarsals
Sole	Metatarsals
Toes	Phalanges

Functions of Skeleton

Function	Explanation
Support	Maintains body shape and posture
Protection	Skull protects brain; vertebral column protects spinal cord; rib cage protects heart and lungs
Movement	Bones act as levers for muscles
Mineral storage	Stores calcium and phosphorus
Haemopoiesis	Bone marrow forms blood cells

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Common Mistakes3

Skull Count

Do not mix skull bones with auditory ossicles and hyoid. Skull is commonly counted as 22 bones: 8 cranial and 14 facial.

Adult Vertebrae

The adult vertebral column has 26 bones, not 33, because sacral and coccygeal vertebrae fuse.

Rib Classification

11th and 12th ribs are floating ribs, not false ribs in the strict NCERT classification.

Formula Cards3

Total Skeleton Count

NCERT division of adult human bones.

Variables

206=

Total bones in adult human skeleton

80=

Number of axial bones

126=

Number of appendicular bones

Vertebral Column Count

Adult vertebral column count after fusion of sacral and coccygeal bones.

Variables

Cervical=

Neck vertebrae

Thoracic=

Chest region vertebrae

Lumbar=

Lower back vertebrae

Sacrum and coccyx=

Fused vertebral bones in adult

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Joints

Overview

Joints are points of contact between bones or between bone and cartilage. They provide stability and determine the range of movement in the skeleton. Structurally, joints are classified into fibrous, cartilaginous and synovial joints. Fibrous joints, such as skull sutures, are immovable. Cartilaginous joints, such as joints between vertebrae, allow limited movement. Synovial joints are freely movable and have a synovial cavity, synovial fluid, articular cartilage, capsule and ligaments. NCERT emphasizes synovial joint types: ball-and-socket, hinge, pivot, gliding, saddle and condyloid joints. Joint movements include flexion, extension, abduction, adduction, rotation and circumduction, which together make locomotion efficient and controlled.

Key Points7

1Structural classification is based on tissue connecting bones and presence or absence of cavity.
2Functional mobility increases from fibrous to cartilaginous to synovial joints.
3Articular cartilage prevents bone ends from rubbing directly against each other.
4Ligaments connect bone to bone and stabilize joints.
5Tendons connect muscle to bone and transmit force.
6Ball-and-socket joints are multiaxial; hinge joints are mainly uniaxial.
7NEET often asks examples of each synovial joint type.

Memory Tricks3

Joint Mobility

Fi-Ca-Sy = Fixed, Can move little, Super movable: Fibrous, Cartilaginous, Synovial.

Synovial Types

Big Hinged Pivots Glide Smoothly Carefully: Ball-and-socket, Hinge, Pivot, Gliding, Saddle, Condyloid.

Abduction vs Adduction

Abduction takes a limb Away; Adduction Adds it back to the body midline.

Examples3

Shoulder Joint

The shoulder is a ball-and-socket joint, allowing rotation, circumduction, abduction and adduction.

Elbow Joint

The elbow is a hinge joint, allowing bending and straightening like a door hinge.

Neck Rotation

The atlas-axis pivot joint allows the head to rotate side to side.

Reference Tables3

Structural Classification of Joints

Joint Type	Connecting Material	Movement	Example
Fibrous joint	Fibrous connective tissue	Immovable	Sutures between skull bones
Cartilaginous joint	Cartilage	Slightly movable	Between adjacent vertebrae
Synovial joint	Joint cavity with synovial fluid	Freely movable	Knee, shoulder, hip, elbow

Types of Synovial Joints

Type	Movement	Examples
Ball-and-socket	Movement in many directions including rotation	Shoulder, hip
Hinge	Back-and-forth movement in one plane	Elbow, knee
Pivot	Rotational movement around an axis	Atlas-axis joint
Gliding	Sliding movement	Between carpals
Saddle	Movement in two planes	Carpometacarpal joint of thumb
Condyloid	Oval surface permits angular movement	Wrist, metacarpophalangeal joints

Joint Movements

Movement	Meaning	Example
Flexion	Decrease in angle between bones	Bending elbow
Extension	Increase in angle between bones	Straightening elbow
Abduction	Movement away from body midline	Raising arm sideways
Adduction	Movement toward body midline	Bringing arm back
Rotation	Movement around an axis	Turning head
Circumduction	Circular cone-like movement	Swinging arm in a circle

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Common Mistakes4

Tendon vs Ligament

Ligament connects bone to bone. Tendon connects muscle to bone.

Knee Joint Type

The knee is primarily a hinge joint, not a ball-and-socket joint.

Pivot Joint Example

Atlas-axis joint is a pivot joint. Do not confuse it with hinge joint.

Synovial Fluid Function

Synovial fluid is not the same as cartilage; it lubricates the cavity and reduces friction.

Formula Cards2

Joint Mobility Order

This order shows increasing range of movement among structural joint types.

Variables

Fibrous=

Joints connected by dense fibrous tissue; usually immovable

Cartilaginous=

Joints connected by cartilage; slightly movable

Synovial=

Joints with cavity and synovial fluid; freely movable

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Musculoskeletal Disorders

Overview

Musculoskeletal disorders affect muscles, bones, joints or neuromuscular transmission and are important NCERT-based NEET topics. Myasthenia gravis is an autoimmune disorder of the neuromuscular junction causing weakness and fatigue of skeletal muscles. Muscular dystrophy refers to inherited progressive degeneration of skeletal muscles. Tetany is rapid muscle spasm due to low calcium ion levels in body fluids. Arthritis is inflammation of joints causing pain, swelling and restricted movement. Osteoporosis is age-related reduction in bone mass, more common in elderly females due to decreased estrogen. Gout is inflammation caused by deposition of uric acid crystals in joints. NEET commonly asks cause, tissue affected and symptoms.

Key Points8

1Myasthenia gravis affects neuromuscular transmission, not the structure of bones.
2Muscular dystrophy is inherited and progressively worsens skeletal muscle function.
3Calcium is essential for muscle contraction regulation; low levels cause tetany.
4Arthritis primarily affects joints and may reduce mobility.
5Osteoporosis weakens bones by reducing bone mass.
6Gout is associated with uric acid crystal accumulation, often in joints.
7Symptoms such as weakness, spasms, joint pain or fractures help identify the disorder.
8NEET questions often use one-line clinical descriptions.

Memory Tricks3

Disorder Keywords

Myasthenia = My muscles are weak; Dystrophy = Degeneration; Tetany = Twitching from low calcium; Gout = uric acid in joints.

Osteoporosis

Osteo means bone, porosis means porous: porous bones break easily.

Arthritis

Arthro means joint, -itis means inflammation: arthritis is joint inflammation.

Examples4

Myasthenia Gravis Example

A patient whose eyelids droop and muscles become weaker with repeated use may be showing neuromuscular weakness.

Osteoporosis Example

An elderly person may fracture a hip after a minor fall because reduced bone mass makes bones fragile.

Gout Example

Sudden painful swelling in a joint due to uric acid crystal deposition is typical of gout.

Tetany Example

Low calcium can cause painful involuntary spasms of hand or facial muscles.

Reference Tables3

Disease Comparison Table

Disorder	Main Cause or Nature	Mainly Affected Part	Key Feature
Myasthenia gravis	Autoimmune disorder	Neuromuscular junction and skeletal muscles	Weakness and fatigue of skeletal muscles
Muscular dystrophy	Inherited disorder	Skeletal muscles	Progressive muscle degeneration
Tetany	Low calcium ion level	Muscles and nerves	Rapid muscle spasms
Arthritis	Joint inflammation	Joints	Pain, swelling and restricted movement
Osteoporosis	Age-related bone mass loss	Bones	Fragile bones and fractures
Gout	Uric acid crystal deposition	Joints	Painful inflammatory joint attacks

Clinical Summary Chart

Clue in Question	Likely Disorder
Autoimmune skeletal muscle weakness	Myasthenia gravis
Inherited progressive muscle degeneration	Muscular dystrophy
Low calcium with spasms	Tetany
Inflamed painful joints	Arthritis
Elderly female with fragile bones	Osteoporosis
Uric acid crystals in joint	Gout

Disorder Category

Category	Disorders
Muscle or neuromuscular	Myasthenia gravis, muscular dystrophy, tetany
Joint	Arthritis, gout
Bone	Osteoporosis

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Common Mistakes4

Myasthenia vs Muscular Dystrophy

Myasthenia gravis is autoimmune and affects neuromuscular transmission; muscular dystrophy is inherited progressive muscle degeneration.

Tetany Cause

Tetany is linked to low calcium ion concentration, not high calcium.

Gout vs Arthritis

Gout is a type of inflammatory joint condition due to uric acid crystals; general arthritis simply means joint inflammation.

Osteoporosis Tissue

Osteoporosis affects bone mass, not muscle mass.

Formula Cards3

Tetany Trigger

Reduced calcium ion level may cause rapid muscle spasms.

Variables

Ca2+=

Calcium ions required for normal muscle and nerve function

Tetany=

Rapid involuntary muscle spasms

Gout Cause Chain

Gout occurs when uric acid crystals accumulate in joints and provoke inflammation.

Variables

Uric acid=

Nitrogenous waste product from purine metabolism

Urate crystals=

Deposits that irritate joint tissues

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Formula Sheet

Human Bone Count

Adult human skeleton has 206 bones divided into axial and appendicular skeleton.

Variables

Axial bones=

Bones of skull, vertebral column, sternum and ribs

Appendicular bones=

Bones of limbs, pectoral girdle and pelvic girdle

ATP Use in Muscle Contraction

Energy from ATP hydrolysis powers myosin head movement and cross-bridge cycling.

Variables

ATP=

Adenosine triphosphate, immediate energy source

ADP=

Adenosine diphosphate formed after ATP hydrolysis

Pi=

Inorganic phosphate released during hydrolysis

Logical Relation

Locomotion is a subset of movement because it involves displacement of the whole organism.

Variables

Locomotion=

Whole-body displacement from one place to another

Movement=

Change in position of body or body part

Muscle Pair Action

At many joints, one muscle contracts while the opposite muscle relaxes to produce controlled movement.

Variables

Agonist=

Muscle mainly responsible for the movement

Antagonist=

Muscle producing opposite action when contracted

ATP Hydrolysis

The energy released energizes the myosin head for cross-bridge cycling.

Variables

ATP=

Energy-rich molecule used by muscle

ADP=

Lower-energy molecule formed after hydrolysis

Pi=

Inorganic phosphate released during ATP breakdown

Sarcomere Length

Contraction shortens the sarcomere by bringing Z lines closer.

Variables

Z line=

Boundary line of a sarcomere where actin filaments are anchored

Sarcomere=

Functional contractile unit of striated muscle

Contraction Result

A band remains constant because thick filament length does not change.

Variables

I band=

Light band containing only thin actin filaments

H zone=

Central region of A band containing only thick myosin filaments

A band=

Dark band corresponding to full length of myosin filaments

Total Skeleton Count

NCERT division of adult human bones.

Variables

206=

Total bones in adult human skeleton

80=

Number of axial bones

126=

Number of appendicular bones

Vertebral Column Count

Adult vertebral column count after fusion of sacral and coccygeal bones.

Variables

Cervical=

Neck vertebrae

Thoracic=

Chest region vertebrae

Lumbar=

Lower back vertebrae

Sacrum and coccyx=

Fused vertebral bones in adult

Rib Count

Ribs form the rib cage with the sternum and thoracic vertebrae.

Variables

True ribs=

First 7 pairs directly attached to sternum

False ribs=

8th to 10th pairs indirectly attached to sternum

Floating ribs=

11th and 12th pairs not attached anteriorly to sternum

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Movement is change in position of body parts; locomotion is movement of the whole organism from one place to another.

Main movement types are amoeboid, ciliary and muscular.

Skeletal muscle fibre contains myofibrils made of repeating sarcomeres.

Sarcomere contraction occurs by sliding of actin over myosin; filament length does not shorten.

Human skeleton has 206 bones: 80 axial and 126 appendicular.

Synovial joints are freely movable and include ball-and-socket, hinge, pivot, gliding, saddle and condyloid joints.

Calcium ions and ATP are essential for muscle contraction.

NCERT disorders: myasthenia gravis, muscular dystrophy, tetany, arthritis, osteoporosis and gout.

Locomotion is always movement, but every movement is not locomotion.

Muscles, bones and joints work as a lever system in human locomotion.

Amoeboid movement uses pseudopodia and cytoplasmic streaming.

Ciliary movement uses rhythmic beating of cilia.

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NEET PYQs — Locomotion and Movement

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NEET 2026Set 11MediumQ1

Match List I with List II related to muscular/skeletal system: Choose the correct answer from the options given below:

NEET 2026Set 11MediumQ2

Which of the following statements are correct with reference to human endoskeleton? A. Human skull is monocondylic. B. The joint between any two adjoining vertebrae is a cartilaginous joint. C. In human beings, the number of cervical vertebrae is seven. D. All ribs except the last 2 pairs are bicephalic. E. The occipital bone of skull is articulated with atlas vertebra. Choose the correct answer from the options given below:

NEET 2026Set 11MediumQ3

Choose the correct statements regarding muscle contraction: A. A motor neuron carries a signal sent by the Central Nervous System (CNS) to the sarcolemma of the muscle fibre. B. The neural signal generates an action potential which causes the release of Ca⁺⁺ into sarcoplasm. C. Increase in Ca⁺⁺ inactivates the actin for breaking cross bridges. D. Actin binds to the myosin head to form a cross bridge. E. Shortening of sarcomere takes place, by pulling actin filaments towards the centre of 'A' band. Choose the correct answer from the options given below :