Physiology - Muscle

Question 1

Sliding Filament Theory

Answer 1

Explains how the muscle contracts - Muscle allow movement: bones, tendon and ligaments which work together
FILAMENTS SLIDE IN & OUT - MUSCLE CONTRACTION

Question 2

Troponin

Answer 2

Complex of 3 protein attached to tropomyosin
MUSCE PROTEIN - ATTACHED TO ACTIN AND TROPOMYOSIN - CALCIUM PRESENT - PULLS TROPOMYOSIN TO UNCOVER BINDING SITES FOR MYOSIN

Question 3

Tropomysin

Answer 3

Actin binding protein regulating muscle contraction

PROTEIN - WIND ALONG THE ACTIN (THIN FILAMENTS) - COVERS THE MYOSIN-BINDING SITES IN ABSENCE OF CALCIUM

Question 4

Cross bridge

Answer 4

THICK FILAMENT - EXTENDS TOWARDS THIN FILAMENTS IN OVER LAP REGION

Question 5

Myofibrils

Answer 5

STRUCTURE: CYLINDRICAL ORGANELLE
- RUN IN LENGTH OF MUSCLE FIBRE - CONTAINS ACTIN AND MYOSIN FILAMENTS
- HOOK ANY MOLECULE - ITS HEAD IS FLEXIBLE AND WALKS ALONG THE ACTIN FILAMENTS - CONTAINS ENZYMES INSIDE
MYOFIBRILS BREAK DOWN ATP TO ADP AND Pi which binds the actin filaments

Question 6

Sarcromere

Answer 6

• FUNCTIONAL UNIT OF MYOFIBRILS (it is divided into I, A, H)
• COMPOSED OF ACTIN AND MYOSIN
• Basic contractile unit for both striated and cardiac muscle
• Made up complex mesh of thick filaments, thin filaments and giant protein titin

Question 7

Actin

Answer 7

Thin contractile protein filament - contains active or binding sites

Question 8

Myosin

Answer 8

• Thick contractile protein filament
• Responsible for muscle contraction & cell motility
• Myosin’s head lies on the filament surface - brings about contraction by cycle interaction with actin subunits in thin filaments.

Question 9

Transverse tubules

Answer 9

Extension of cell membrane penetrating centre of cardiac muscles and skeletal muscle cells.

Question 10

Acetylcholine

Answer 10

Aka ATP

Neurotransmitter which is used at the neuromuscular junction