Control and Communication
Follow nervous and hormonal communication, including reflex arcs and negative control of blood glucose.
How to study National 5 Biology
Move between biological structures, processes, experimental evidence, data and justified explanations while using current official materials for exact paper and assignment conditions.
Core concepts
Concept 1
The central nervous system contains the brain and spinal cord; sensory, inter and motor neurons transmit electrical impulses.
Exam cue: Trace a reflex from receptor through sensory, inter and motor neurons to an effector.
Concept 2
Chemicals carry messages across synapses, and reflex arcs produce rapid automatic responses.
Exam cue: Distinguish electrical transmission along neurons from chemical transmission at synapses.
Concept 3
Endocrine glands release hormones into blood; only target cells with complementary receptors respond.
Exam cue: Use pancreas, liver, insulin, glucagon and glycogen in blood-glucose explanations.
Concept 4
Insulin and glucagon coordinate the liver’s conversion between glucose and glycogen to regulate blood glucose.
Risk pitfalls and guardrails
Calling every nerve part of the central nervous system.
Guardrail: Check the biological level, direction, location, units and whether the evidence supports the strength of the claim.
Saying a hormone affects every cell it reaches.
Guardrail: Check the biological level, direction, location, units and whether the evidence supports the strength of the claim.
Reversing the roles of insulin and glucagon.
Guardrail: Check the biological level, direction, location, units and whether the evidence supports the strength of the claim.
Memory anchors
Central nervous system
Brain and spinal cord.
Neuron order in a reflex
Sensory → inter → motor.
Synapse
A junction where chemicals transfer a message between neurons.
Hormone
A chemical messenger released by an endocrine gland into the bloodstream.
Insulin
Promotes removal of glucose from blood and conversion to glycogen.
Glucagon
Promotes conversion of glycogen to glucose, raising blood glucose.
Checkpoint rule
Do the check-up only after you can summarize each concept in one sentence and identify one dangerous pitfall from memory.
Knowledge Check (after reading)
Short check-up to confirm understanding of this module.
Check-up Questions
Which structures form the central nervous system?
Which neuron carries impulses from a receptor toward the CNS?
Answer all questions to submit.
Next step personalized recommendations
Continue learning
Move forward only after this module is stable.
What is Pass Harbor?
Completely free exam prep for 247 UK exams.
- Practice questions
- Flashcards
- Study guides
- Mock exams
- No registration
- No paywall
- Start instantly
“No more expensive exam prep. Quality study tools should be accessible to everyone.”