LOCOMOTION AND MOVEMENT · Comparison Tables

1. Movement vs Locomotion; Types of Movement

Term / type	Definition or mechanism	Examples
Movement	Change in position of whole body or body part	Limbs, jaws, eyelids, tongue, cilia and tentacles
Locomotion	Voluntary movement resulting in change of place	Walking, running, climbing, flying and swimming
Amoeboid movement	Pseudopodia formed by protoplasmic streaming; microfilaments participate	Macrophages and leucocytes
Ciliary movement	Coordinated ciliary beating in internal tubular organs	Dust removal in trachea; passage of ova
Muscular movement	Muscle contraction moves body parts	Limbs, jaws and tongue

2. Skeletal vs Visceral vs Cardiac Muscle

Feature	Skeletal muscle	Visceral muscle	Cardiac muscle
Location	Attached to skeletal components	Walls of hollow visceral organs	Heart
Appearance	Striated	Smooth / non-striated	Striated and branching
Control	Voluntary	Involuntary	Involuntary; not directly controlled by nervous system
Main role	Locomotion and posture	Food movement through gut and gamete movement in genital tract	Heart contraction

3. Sarcomere Regions and Filaments

Structure	Composition / position	Significance
I band	Light isotropic band with thin actin; Z line bisects it	Shortens during contraction
A band	Dark anisotropic band with thick myosin; M line holds thick filaments centrally	Length remains constant during contraction
H zone	Central part of thick filament not overlapped by thin filament at rest	Reduces with contraction
Sarcomere	Region between successive Z lines	Functional unit of contraction
Myofilaments	Actin is thin and myosin is thick	Alternating arrangement creates striations

4. Actin vs Myosin

Feature	Actin	Myosin
Filament type	Thin	Thick
Basic organisation	Two helically wound F-actins, each polymerised from G-actin monomers	Polymerised from meromyosin monomers
Associated parts	Tropomyosin and regular troponin complex; resting troponin masks myosin-binding sites	Heavy meromyosin: head + short arm; light meromyosin: tail
Key functional feature	Ca²⁺-troponin interaction exposes active sites	Globular head is ATPase with ATP- and actin-binding sites; forms cross arm

5. Resting vs Contracting Sarcomere

Feature	Resting	Contracting
Ca²⁺	Stored in sarcoplasmic reticulum; troponin masks actin sites	Released into sarcoplasm and binds troponin, exposing actin sites
Cross bridge	Myosin not attached to masked actin site	ATP-powered myosin head binds actin; repeated bridge cycles slide filaments
Z lines / sarcomere	Normal separation	Z lines move inwards; sarcomere shortens
I band and H zone	Relatively wider	Reduced
A band	Normal length	Unchanged length

Relaxation Ca²⁺ is pumped back into sarcoplasmic cisternae, actin sites are masked again and cross bridges break when fresh ATP binds myosin.

6. Red vs White Muscle Fibres

Feature	Red fibres	White fibres
Myoglobin / colour	High myoglobin; reddish	Very little myoglobin; pale or white
Mitochondria	Numerous	Few
Energy metabolism	Aerobic; uses large oxygen store for ATP production	Predominantly anaerobic
Sarcoplasmic reticulum	Not the defining abundant feature	High amount

7. Axial vs Appendicular Skeleton; Girdles

Feature	Axial skeleton	Appendicular skeleton
Composition	80 bones: skull, vertebral column, sternum and ribs	Limb bones and pectoral/pelvic girdles
Important counts	Skull: 22; vertebral column: 26; ribs: 12 pairs	Each limb: 30 bones; hand/foot phalanges: 14 each
Major function	Main body axis, protection and support	Attachment and movement of limbs
Girdle detail	Not applicable	Pectoral half = clavicle + scapula; pelvic coxal = fused ilium, ischium and pubis.

Ribs 1st-7th pairs are true; 8th-10th are false / vertebrochondral; 11th and 12th are floating. Femur is the longest bone; patella covers knee ventrally.

8. Fibrous vs Cartilaginous vs Synovial Joints

Joint	Movement	Examples
Fibrous	None	Dense connective-tissue sutures between cranial bones
Cartilaginous	Limited	Between adjacent vertebrae
Synovial	Considerable; fluid-filled synovial cavity between articulating surfaces	Ball-and-socket shoulder, hinge knee, pivot atlas-axis, gliding carpals, saddle thumb joint

Disorders Myasthenia gravis: autoimmune neuromuscular-junction disorder. Muscular dystrophy: progressive genetic skeletal-muscle degeneration. Tetany: low Ca²⁺ spasms. Arthritis: joint inflammation. Osteoporosis: low bone mass. Gout: uric-acid crystals in joints.