⚪ Physiology - Dr. Magdy Sabry

🌿 Topics: CVS, Blood, Special senses, Endocrine, GIT, Respiratory and ANS.

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⚪ MCQs on PHYSIO

Important notes on physiology (written)


Enumerate :

- Function of Tropomyosin ?
In the resting state, the tropomyosin molecules cover the active sites of the actin strands, preventing attraction between the actin and myosin filaments .

- Function of T-tubular ?
conduct the action potential from the surface of the muscle to the
muscle fibrils inside.

- Factors affecting neuromuscular transmission:
1. Calcium: facilitates but Mg inhibits neuromuscular transmission.
2. Hypoxia: decrease neuromuscular transmission.
3. Hypoglycaemia: decrease neuromuscular transmission.
4. Drugs:
Anti-choline estrases : facilitate neuromuscular transmission.
Curare: bind with Ach receptors blocking them → inhibit transmission.
Succinyl-choline: initial stimulation of neuromuscular transmission then blocking by producing sustained state of depolarization.
Botulinum toxin: inhibit Ach release inhibit transmission.

- Properties of neuromuscular transmission ?
1) Unidirectional: from the nerve to the muscle not the reverse.
2) Delay: of about 0.5 msec. which is the time needed for the release of acetylcholine until the generation of action potential.
3) Easily fatigued: when depletion of the transmitter takes place.
4) Blocked by curare.
5) Mg prevents the release of the transmitter at the MEP→ decrease the neuromuscular transmission.

Complete :
- Muscle contraction occurs by ...... sliding myosin over actin

- The structural unit of the muscle is the............
Muscle cell (fibrer)

- True or false , muscle contraction occurs by sliding myosin over actin
False
Actin over myosin

- Ca-calmodulin complex is a second messanger

- True or false Unidirectional is from muscle to nerve
False➡️from nerve to muscle

- In neuromuscular transmission delay is happened by 0.5msec

- The Easily fatigue is the neuromuscular junction

Enumerate :

- Function of Tropomyosin ?
In the resting state, the tropomyosin molecules cover the active sites of the actin strands, preventing attraction between the actin and myosin filaments .

- Function of T-tubular ?
conduct the action potential from the surface of the muscle to the
muscle fibrils inside.

- Factors affecting neuromuscular transmission:
1. Calcium: facilitates but Mg inhibits neuromuscular transmission.
2. Hypoxia: decrease neuromuscular transmission.
3. Hypoglycaemia: decrease neuromuscular transmission.
4. Drugs:
Anti-choline estrases : facilitate neuromuscular transmission.
Curare: bind with Ach receptors blocking them → inhibit transmission.
Succinyl-choline: initial stimulation of neuromuscular transmission then blocking by producing sustained state of depolarization.
Botulinum toxin: inhibit Ach release inhibit transmission.

- Properties of neuromuscular transmission ?
1) Unidirectional: from the nerve to the muscle not the reverse.
2) Delay: of about 0.5 msec. which is the time needed for the release of acetylcholine until the generation of action potential.
3) Easily fatigued: when depletion of the transmitter takes place.
4) Blocked by curare.
5) Mg prevents the release of the transmitter at the MEP→ decrease the neuromuscular transmission.

Complete :
- Muscle contraction occurs by ...... sliding myosin over actin

- The structural unit of the muscle is the............
Muscle cell (fibrer)

- True or false , muscle contraction occurs by sliding myosin over actin
False
Actin over myosin

- Ca-calmodulin complex is a second messanger

- True or false Unidirectional is from muscle to nerve
False➡️from nerve to muscle

- In neuromuscular transmission delay is happened by 0.5msec

- The Easily fatigue is the neuromuscular junction

⚫ Biochemistry Book - Dr. Said Oraby

🌿 Topics: All BioChem topics.

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⚫ MCQs in Biochemistry

🌿 Topics: All BioChem topics.

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⚫ Some Medicine Exams for Biochemistry - KFS University

⚠️ NOTE: If your topics don't match with these exams, don't answer any question, Please.

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