Physiology and Pharmacology of Skeletal Muscle and Anaemia

These flashcards cover essential vocabulary and concepts related to the physiology of skeletal muscle, pharmacology of neuromuscular junctions, and the general principles of anaemia, including specific types and treatments.

Skeletal Muscle Functions

Movement of the body; maintenance of posture; heat production.

Difference Between Skeletal and Smooth Muscle

Skeletal muscle is striated and contains sarcomeres; smooth muscle is non-striated.

Troponin Role in Muscle Contraction

Troponin binds calcium, moving tropomyosin and exposing myosin-binding sites on actin.

Calcium's Role in Muscle Contraction

Calcium released from the sarcoplasmic reticulum binds troponin, facilitating actin-myosin cross-bridge formation.

Motor Unit

A single motor neuron and all the muscle fibers it innervates.

Skeletal Muscle Fatigue

Caused by ATP depletion and accumulation of metabolic by-products.

Acetylcholine at Neuromuscular Junction

Binds nicotinic receptors, causing depolarization and muscle contraction.

Non-Depolarising Neuromuscular Blockers

Competitive antagonists at nicotinic receptors, preventing acetylcholine binding.

Depolarising Neuromuscular Blockers

Cause paralysis through persistent receptor activation that prevents repolarization.

Anticholinesterases

Reverse non-depolarising block by increasing acetylcholine levels to outcompete the blocker.

Botulinum Toxin Action

Inhibits acetylcholine release by blocking SNARE proteins.

Myasthenia Gravis Pathophysiology

Autoantibodies destroy nicotinic acetylcholine receptors, reducing neuromuscular transmission.

Biologic Medicine

A medicine produced from living cells, usually large protein molecules.

Biologics and Oral Administration

Cannot be administered orally due to degradation by gastric acid and digestive enzymes.

Autoimmune Diseases Treated with Biologics

Rheumatoid arthritis; inflammatory bowel disease.

TNF-α Inhibitors Action

Bind TNF-α and block inflammatory signaling pathways.

Brand Name Prescription for Biologics

Biosimilars are not identical due to manufacturing variability.

Pre-Treatment Screening for Biologics

Tuberculosis screening; hepatitis B/C screening.

Counselling Points for Subcutaneous Biologics

Correct injection technique; proper refrigerated storage.

Risk of Biologic Therapy

Increased risk of infection.

Anaemia

A reduction in hemoglobin concentration or red blood cell mass.

Mean Corpuscular Volume (MCV) Significance

Classifies anaemia based on red blood cell size.

Microcytic vs Macrocytic Anaemia

Microcytic: low MCV; macrocytic: high MCV.

Common Symptoms of Anaemia

Fatigue; shortness of breath.

Cause of Iron Deficiency Anaemia

Chronic blood loss, e.g., gastrointestinal bleeding.

Iron Deficiency and Microcytic Anaemia

Reduced hemoglobin synthesis leads to smaller red blood cells.

Mechanism of Renal Anaemia

Reduced erythropoietin production results in decreased red blood cell formation.

Cause of Megaloblastic Anaemia

Impaired DNA synthesis due to vitamin B12 or folate deficiency.

Neurological Complication of Vitamin B12 Deficiency

Peripheral neuropathy.

Pathophysiology of Sickle Cell Anaemia

Abnormal haemoglobin polymerises, causing red blood cells to sickle and haemolyse.

Cause of Aplastic Anaemia

Bone marrow failure due to drugs, radiation, or autoimmune damage.

Polycythaemia and Thrombosis Risk

Increased blood viscosity reduces flow and promotes clot formation.