Control and Coordination – Vocabulary Flashcards

A comprehensive set of vocabulary flashcards covering key terms and definitions from the lecture on control and coordination in animals and plants, including nervous system components, reflexes, tropisms, and major plant and animal hormones.

Neuron

A specialized nerve cell that conducts electrical impulses throughout the body.

Dendrite

Branched extensions of a neuron that receive information from receptors or other neurons.

Axon

The long fiber of a neuron that carries electrical impulses away from the cell body.

Synapse

The microscopic gap between two neurons across which chemical signals pass.

Receptor

A sensory nerve ending that detects stimuli such as light, sound, touch, taste, or smell.

Electrical Impulse

Rapid, transient electrical signal that travels along a nerve fiber.

Reflex Action

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

Reflex Arc

The neural pathway that mediates a reflex action, typically involving a sensory neuron, interneuron, and motor neuron.

Spinal Cord

A bundle of nerves protected by the vertebral column that transmits signals between the brain and body and houses many reflex arcs.

Central Nervous System (CNS)

The brain and spinal cord, responsible for integrating and processing information.

Peripheral Nervous System (PNS)

All nerves outside the CNS, including cranial and spinal nerves that connect the CNS to the body.

Fore-brain

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

Mid-brain

The central region of the brain that relays information and controls some involuntary actions.

Hind-brain

The rear part of the brain containing the cerebellum and medulla, regulating balance and vital functions.

Cerebellum

A hind-brain structure that coordinates voluntary movements, posture, and balance.

Medulla (Medulla Oblongata)

Part of the hind-brain that controls involuntary activities such as heartbeat, breathing, and vomiting.

Cerebrum

The largest part of the fore-brain, responsible for voluntary actions, intelligence, and memory.

Vertebral Column

The bony structure (backbone) that protects the spinal cord.

Neuromuscular Junction

The synapse where a motor neuron communicates with a muscle fiber to trigger contraction.

Voluntary Action

A movement consciously controlled by the brain, such as writing or speaking.

Involuntary Action

A movement not under conscious control, like heartbeat or digestion.

Tropism

Directional growth movement in plants in response to an environmental stimulus.

Phototropism

Growth movement of a plant toward or away from light.

Geotropism (Gravitropism)

Growth of plant parts in response to gravity; roots grow downward, shoots upward.

Hydrotropism

Directional growth of plant roots toward moisture.

Chemotropism

Growth movement of a plant or part toward or away from a chemical stimulus, e.g., pollen tube toward ovule.

Auxin

A plant hormone that promotes cell elongation and is involved in phototropism.

Gibberellin

A plant hormone that stimulates stem elongation, seed germination, and flowering.

Cytokinin

A plant hormone that promotes cell division, found abundantly in areas of rapid growth like fruits and seeds.

Abscisic Acid

A plant hormone that inhibits growth and induces wilting and dormancy.

Hormone

A chemical messenger produced in one part of an organism and transported to another to regulate activities.

Endocrine Gland

A ductless gland that secretes hormones directly into the bloodstream.

Adrenaline (Epinephrine)

A hormone from adrenal glands that prepares the body for ‘fight-or-flight’ by increasing heart rate and blood flow to muscles.

Thyroxin

A hormone from the thyroid gland that regulates metabolism of carbohydrates, proteins, and fats.

Insulin

A hormone from the pancreas that lowers blood sugar by facilitating glucose uptake by cells.

Growth Hormone (GH)

A pituitary hormone that stimulates overall growth and development; deficiency causes dwarfism.

Testosterone

The primary male sex hormone from testes, responsible for secondary sexual characteristics.

Oestrogen

The primary female sex hormone from ovaries, governing development of female reproductive organs and menstrual cycle.

Feedback Mechanism

A regulatory system in which the level of a hormone influences its further secretion, maintaining balance.

Pituitary Gland

The ‘master’ endocrine gland at the brain’s base that secretes multiple hormones controlling other glands.

Thyroid Gland

A butterfly-shaped gland in the neck producing thyroxin to regulate metabolism.

Adrenal Gland

A pair of glands above the kidneys that secrete adrenaline and other hormones for stress response.

Pancreas (Endocrine Part)

An organ that secretes insulin and glucagon to control blood glucose levels.

Tendril

A slender, touch-sensitive plant organ that coils around support structures through uneven growth.