Study TipsMay 18, 20268 min read
MDCAT Coordination & Control 2026 — Nervous + Chemical Coordination
Premeth Team
Meth Experts
Coordination & Control is two PMDC syllabus chapters (Nervous + Chemical Coordination) that together contribute ~7 of 81 Biology MCQs. Focus on the action potential, synaptic transmission, reflex arc structure, and the 8 major endocrine glands.
- Estimated MCQs — 6–8 of 81 Biology MCQs (combined)
- Highest-yield neuro topics — action potential, synapse, reflex arc, CNS vs PNS
- Highest-yield hormone topics — insulin/glucagon, thyroxine, cortisol, ADH, oxytocin
- Major endocrine glands — Pituitary, Thyroid, Parathyroid, Pancreas, Adrenal, Ovary, Testis, Pineal
Source: PMDC MDCAT 2026 syllabus; UHS Biology Coordination question analysis 2008–2024.
Nervous Coordination
- Neuron anatomy — dendrites, cell body (soma), axon, axon terminals, myelin sheath, Nodes of Ranvier.
- Action potential — resting potential −70 mV; threshold −55 mV; depolarisation via Na+ influx; repolarisation via K+ efflux.
- Saltatory conduction — action potential “jumps” between Nodes of Ranvier in myelinated axons (faster).
- Synapse — Ca2+ influx triggers neurotransmitter release; binds postsynaptic receptors.
- Reflex arc — receptor → sensory neuron → interneuron (in CNS) → motor neuron → effector. Bypasses brain for speed.
- CNS — Brain + Spinal Cord. PNS — somatic (voluntary) + autonomic (sympathetic + parasympathetic).
Chemical Coordination — Major Hormones
| Gland | Hormone | Function |
|---|---|---|
| Anterior pituitary | GH, TSH, ACTH, FSH, LH, prolactin | Master regulation |
| Posterior pituitary | ADH, oxytocin | Water balance, labour |
| Thyroid | Thyroxine (T4), T3, calcitonin | Metabolism, Ca2+ lowering |
| Parathyroid | PTH | Ca2+ raising |
| Pancreas (Islets) | Insulin (β), Glucagon (α) | Lowers / raises blood glucose |
| Adrenal medulla | Adrenaline, noradrenaline | Fight-or-flight |
| Adrenal cortex | Cortisol, aldosterone | Stress; Na+/water retention |
| Ovary | Oestrogen, progesterone | Reproductive cycle |
| Testis | Testosterone | Male secondary characteristics |
| Pineal | Melatonin | Sleep-wake cycle |
Trap Concepts
- “Hormone secreted but stored elsewhere” — ADH and oxytocin are produced in the hypothalamus, stored in posterior pituitary.
- “Saltatory” vs “continuous” conduction — saltatory only in myelinated axons.
- Calcitonin LOWERS blood Ca2+; PTH RAISES it — opposite effects.
- Reflex arc passes through spinal cord — brain is not involved for speed reasons.
FAQ
Q: Is the action potential the most-tested neuro topic?
Yes — 2–3 MCQs per paper. Memorise the voltage values and the Na/K direction.
Q: Are tropic vs non-tropic hormones tested?
Yes — tropic hormones (TSH, ACTH, FSH, LH) act on other glands. Memorise their targets.
Q: Which is more weighted — nervous or chemical?
Roughly equal split (~3 MCQs each). Drill both.
Pair with our high-yield Biology guide, drill chapter MCQs, and track your accuracy.
Related Tags
#MDCAT#Biology#Nervous System#Hormones#Coordination
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