Control and Coordination – Key Vocabulary

Vocabulary flashcards covering major terms related to nervous control, plant and animal hormones, brain structure, reflexes, tropisms, and endocrine regulation described in the lecture notes.

Control and Coordination

Integrated processes that enable organisms to detect changes in the environment and produce appropriate responses.

Nervous Tissue

Specialised tissue composed of neurons that conducts information via electrical impulses.

Neuron

A nerve cell; structural and functional unit of the nervous system.

Dendrite

Branch-like part of a neuron that receives information from receptors or other neurons.

Cell Body (Soma)

Central part of a neuron containing the nucleus; processes incoming impulses.

Axon

Long fibre of a neuron that carries electrical impulses away from the cell body.

Synapse

Junction between two neurons where electrical impulses are converted to chemical signals.

Receptor

Specialised nerve-cell ending that detects stimuli such as light, sound, taste, or heat.

Neuromuscular Junction

Synapse between a motor neuron and a muscle fibre, triggering muscle contraction.

Reflex Action

Rapid, automatic response to a stimulus that does not involve conscious thought.

Reflex Arc

Neural pathway linking a receptor to an effector for producing a reflex action.

Spinal Cord

Bundle of nerves enclosed in the vertebral column; conducts impulses and houses reflex arcs.

Central Nervous System (CNS)

Comprises the brain and spinal cord; main coordinating centre of the body.

Peripheral Nervous System

Cranial and spinal nerves that connect the CNS to the rest of the body.

Fore-brain

Anterior part of the brain responsible for thinking, memory, and sensory interpretation.

Mid-brain

Brain region that relays information and controls some involuntary actions.

Hind-brain

Brain region containing cerebellum, pons, and medulla; regulates balance and vital functions.

Cerebellum

Part of the hind-brain that maintains posture, equilibrium, and precision of voluntary actions.

Medulla Oblongata

Lower part of the hind-brain that controls involuntary functions such as heartbeat and breathing.

Hypothalamus

Brain region that regulates pituitary activity and many homeostatic functions.

Cranial Nerves

Nerves arising from the brain that connect it to sense organs and facial muscles.

Spinal Nerves

Nerves arising from the spinal cord that connect it to the trunk and limbs.

Voluntary Muscles

Skeletal muscles under conscious control, enabling actions like walking.

Involuntary Muscles

Muscles not under conscious control, e.g., cardiac and smooth muscles.

Cerebrospinal Fluid

Protective fluid that cushions the brain inside the skull.

Vertebral Column

Bony structure (backbone) that encases and protects the spinal cord.

Tropism

Directional growth movement of a plant part in response to a stimulus.

Phototropism

Growth of plant parts toward or away from light.

Geotropism

Growth response of plant parts to gravity; roots show positive, shoots negative geotropism.

Hydrotropism

Directional growth of roots toward moisture.

Chemotropism

Growth movement in response to chemicals, e.g., pollen tube growing toward ovule.

Mimosa pudica (Sensitive Plant)

Plant whose leaves fold rapidly when touched; example of rapid plant movement.

Auxin

Plant hormone that promotes cell elongation and phototropic responses.

Gibberellins

Plant hormones that stimulate stem elongation, seed germination, and flowering.

Cytokinins

Plant hormones that promote cell division, especially in fruits and seeds.

Abscisic Acid

Plant hormone that inhibits growth and induces leaf wilting and dormancy.

Endocrine Gland

Ductless gland that secretes hormones directly into the bloodstream.

Hormone

Chemical messenger produced in one part of an organism and transported to target tissues.

Pituitary Gland

‘Master’ endocrine gland that secretes growth hormone and regulates other glands.

Growth Hormone

Pituitary hormone that stimulates overall body growth; deficiency causes dwarfism.

Thyroid Gland

Endocrine gland in the neck producing thyroxin to regulate metabolism.

Thyroxin

Iodine-containing hormone that controls metabolism of carbohydrates, proteins, and fats.

Goitre

Swelling of the neck due to iodine deficiency and enlarged thyroid gland.

Pancreas

Mixed gland that secretes insulin to regulate blood sugar levels.

Insulin

Pancreatic hormone that lowers blood glucose; deficiency leads to diabetes mellitus.

Adrenal Glands

Endocrine glands atop the kidneys that secrete adrenaline and other hormones.

Adrenaline

Fight-or-flight hormone that increases heart rate, breathing, and blood flow to muscles.

Testes

Male endocrine glands producing testosterone.

Testosterone

Male sex hormone responsible for secondary sexual characteristics and sperm production.

Ovaries

Female endocrine glands producing oestrogen and progesterone.

Oestrogen

Female sex hormone that regulates menstrual cycle and development of female sex organs.

Feedback Mechanism

Regulatory system in which the outcome of a process controls its own activity, e.g., insulin secretion.