Questions: Locomotion and Movement

Q1. Name the four types of movement shown by the cells of the human body, with one example of each.

Answer (English): Amoeboid movement is shown by macrophages and leucocytes, ciliary movement by the ciliated epithelium, flagellar movement by the sperm, and muscular movement by the limbs and the body. The first three are movements of cells or of the cell surface, while muscular movement moves the whole organism.

Hinglish: Amoeboid movement macrophages aur leucocytes mein, ciliary movement ciliated epithelium mein, flagellar movement sperm mein aur muscular movement limbs aur body mein hota hai.

Q2. Distinguish between skeletal, smooth and cardiac muscle.

Answer (English): Skeletal muscle is striated, voluntary and attached to bones, and it tires after use. Smooth muscle is non-striated, involuntary and found in the walls of internal organs such as the gut and the blood vessels. Cardiac muscle is striated but involuntary and forms the wall of the heart, where it contracts rhythmically without rest.

Hinglish: Skeletal muscle striated aur voluntary hai, smooth muscle non-striated aur involuntary hai, aur cardiac muscle striated hone ke baawajood involuntary hai aur heart ki wall banati hai.

Q3. What is a sarcomere and what are its parts?

Answer (English): A sarcomere is the part of a myofibril between two successive Z lines, and it is the functional unit of contraction. It contains the I band on either side, the A band in the middle with the H zone and the M line, and the Z line at each end. The thin actin filaments and the thick myosin filaments overlap in the A band, and the amount of overlap changes when the muscle contracts.

Hinglish: Sarcomere do Z lines ke beech ka hissa hai aur contraction ka functional unit hai. Isme I band, A band, H zone, M line aur Z line hote hain, aur A band mein actin aur myosin filaments overlap karte hain.

Q4. Explain the role of calcium ions in muscle contraction.

Answer (English): Calcium is stored in the sarcoplasmic reticulum and is released into the sarcoplasm when the muscle is stimulated. The calcium binds to a subunit of troponin, and that binding moves tropomyosin away from the active sites on the actin. The myosin heads can then bind actin and form cross bridges, which starts the contraction. When the calcium is pumped back into the sarcoplasmic reticulum, the sites are covered again and the muscle relaxes.

Hinglish: Calcium sarcoplasmic reticulum se release hota hai, troponin se bind karta hai, tropomyosin ko hata deta hai aur actin ke active sites khol deta hai, jisse myosin cross bridge banakar contraction shuru karta hai; calcium wapas pump hone par muscle relax hota hai.

Q5. What is the sliding filament theory?

Answer (English): The sliding filament theory explains contraction as the sliding of the thin actin filaments over the thick myosin filaments. The myosin heads bind actin, form cross bridges and tilt, pulling the actin filaments towards the centre of the sarcomere. ATP breaks each cross bridge and re-cocks the head for the next cycle. The filaments do not shorten, but the I band and H zone become smaller and the sarcomere shortens.

Hinglish: Sliding filament theory kehta hai ki actin filaments myosin filaments par slide karte hain. Myosin heads cross bridge banakar actin ko kheenchte hain, ATP bridge todta hai aur head dobara ready hota hai; filaments chhote nahi hote, lekin I band aur H zone chhote hote hain aur sarcomere short ho jata hai.

Q6. How many bones are there in the human skeleton and how are they divided?

Answer (English): The human skeleton has 206 bones. It is divided into the axial skeleton with 80 bones, which includes the skull, vertebral column, sternum and ribs, and the appendicular skeleton with 126 bones, which includes the girdles and the limbs. The axial skeleton lies along the central axis of the body and the appendicular skeleton hangs the limbs from it.

Hinglish: Human skeleton mein 206 bones hain: axial skeleton mein 80 (skull, vertebral column, sternum, ribs) aur appendicular skeleton mein 126 (girdles aur limbs).

Q7. Describe the human skull and the vertebral column.

Answer (English): The skull has 22 bones, made of 8 cranial bones and 14 facial bones, and the cranial bones are joined by sutures to form a case around the brain. The hyoid is a single U shaped bone in the neck. The vertebral column has 7 cervical, 12 thoracic and 5 lumbar vertebrae, a fused sacrum and a fused coccyx, giving 26 units in the adult. Intervertebral discs of cartilage separate the vertebrae, and the column has cervical, thoracic, lumbar and sacral curves that give it strength.

Hinglish: Skull mein 22 bones hain (8 cranial + 14 facial) aur hyoid neck ka U shaped bone hai. Vertebral column mein 7 cervical, 12 thoracic, 5 lumbar, fused sacrum aur fused coccyx hote hain, intervertebral discs unke beech hote hain aur column ke chaar curves use strength dete hain.

Q8. Explain the structure of the rib cage.

Answer (English): The rib cage has 12 pairs of ribs. Each rib is attached at the back to a thoracic vertebra. The first seven pairs are the true ribs because they attach directly to the sternum. Pairs 8, 9 and 10 are the false ribs because they join the cartilage of the rib above. Pairs 11 and 12 are the floating ribs because their front ends are free. The sternum lies on the ventral side and forms the front wall of the cage, which protects the heart and lungs and helps in breathing.

Hinglish: Rib cage mein 12 pairs ribs hain: pehli 7 true ribs sternum se seedha judti hain, 8-10 false ribs upar wali rib ke cartilage se judti hain, aur 11-12 floating ribs ke aage ke sire free hote hain; sternum ventral side par hota hai.

Q9. Differentiate between the pectoral and pelvic girdles.

Answer (English): The pectoral girdle has a clavicle and a scapula on each side, its glenoid cavity receives the head of the humerus, and its clavicle articulates with the sternum. The pelvic girdle has two coxal bones, each formed by the fused ilium, ischium and pubis, its acetabulum receives the head of the femur, and the two halves meet at the pubic symphysis and join the sacrum behind. The pelvic girdle is heavier and stronger because it carries the weight of the body, while the pectoral girdle is lighter and allows more movement.

Hinglish: Pectoral girdle mein clavicle aur scapula hote hain aur glenoid cavity humerus ko leti hai; pelvic girdle mein do coxal bones hote hain (ilium, ischium, pubis) aur acetabulum femur ko leta hai. Pelvic girdle bhaari aur mazboot hota hai kyunki body ka weight uthata hai.

Q10. Name the joint present at six different places in the body.

Answer (English): The joint between the atlas and the axis is a pivot joint. The joint between the carpal and the metacarpal of the thumb is a saddle joint. The joints between the phalanges are hinge joints. The joint between the femur and the acetabulum is a ball and socket joint. The joints between the cranial bones are fibrous joints or sutures. The joint between the two pubic bones is a cartilaginous joint.

Hinglish: Atlas-axis par pivot joint, thumb ke carpal-metacarpal par saddle joint, phalanges ke beech hinge joint, femur-acetabulum par ball and socket joint, cranial bones ke beech fibrous joint (suture), aur pubic bones ke beech cartilaginous joint hota hai.

Quiz pointer. A five question chapter quiz follows this page. Attempt it without looking back and read the explanation for every question you miss, because the quiz retests the muscle types, the sliding filament steps and the skeleton numbers.