Control and Coordination (Science) - Chapter 6

Vocabulary flashcards covering key terms from notes on nervous system, reflex actions, brain regions, protection, hormones, plant responses, and related concepts.

Nervous system

A network of nerves and supporting tissues that coordinates body activities by transmitting electrical impulses through neurons.

Neuron

A nerve cell; the basic unit of the nervous system, with a dendrite, cell body, and axon that transmits impulses and communicates at synapses.

Receptors

Sensory detectors in sense organs (e.g., gustatory for taste, olfactory for smell) that detect stimuli.

Synapse

The gap between two neurons where neurotransmitters cross to pass an impulse.

Central nervous system (CNS)

Brain and spinal cord; the main coordinating center of the body.

Peripheral nervous system (PNS)

Nerves outside the CNS (cranial and spinal nerves) that connect the CNS to the rest of the body.

Reflex arc

The neural pathway for a reflex action, usually processed in the spinal cord for a rapid, automatic response.

Fore-brain

The thinking part of the brain that receives sensory information and integrates it.

Mid-brain

A brain region involved in coordinating various inputs and outputs; part of the central brain.

Hind-brain

The brain region that controls involuntary actions; includes the medulla and cerebellum.

Medulla

A hind-brain region that regulates involuntary functions such as heartbeat and breathing.

Cerebellum

A hind-brain region responsible for precision of voluntary movements, balance, and posture.

Brain protection

The brain is protected by a bony skull and cushioned by cerebrospinal fluid inside a protective box.

Vertebral column

The backbone that protects the spinal cord.

Hormone

A chemical signal produced by endocrine glands that travels in blood to regulate processes in target organs.

Endocrine system

Glands and hormones that coordinate body activities through chemical signals.

Auxin

A plant hormone produced at the shoot tip; diffuses to the shaded side to promote cell elongation and bend toward light.

Gibberellins

Plant hormones that promote stem growth and development.

Cytokinins

Plant hormones that promote cell division, especially in rapidly growing tissues like fruits and seeds.

Abscisic acid

Plant hormone that inhibits growth and can cause wilting; helps stop growth.

Adrenaline (epinephrine)

Hormone released by the adrenal glands into the blood; increases heart rate, redirects blood, and raises breathing rate for fight-or-flight readiness.

Hypothalamus

Brain region that releases releasing factors to stimulate the pituitary and regulate hormones.

Pituitary gland

Master gland that secretes growth hormone and other hormones; regulated by hypothalamus.

Thyroxin (thyroxine)

Thyroid hormone that regulates metabolism; requires iodine for synthesis.

Iodine deficiency/goitre

Low iodine can cause goitre and impaired thyroxin production; iodised salt helps prevent it.

Growth hormone

Pituitary hormone that promotes growth in bones and other organs.

Testosterone

Male sex hormone produced by testes; influences puberty and secondary sex characteristics.

Estrogen (oestradiol)

Female sex hormone produced by ovaries; regulates reproductive development and cycles.

Insulin

Pancreatic hormone that lowers blood glucose; deficiency causes diabetes and is treated with injections.

Feedback mechanism

Regulation of hormone action by feedback; e.g., rising blood sugar increases insulin release, which then lowers sugar levels.

Phototropism

Directional growth of plant shoots toward light.

Geotropism (gravitropism)

Directional growth of plants in response to gravity; shoots grow upward and roots downward.

Hydrotropism

Growth response toward water.

Chemotropism

Growth response toward chemical stimuli (e.g., pollen tubes toward ovules).

Mimosa pudica (sensitive plant)

Plant that rapidly folds its leaves in response to touch; movement is not growth-based.

Tendril

Plant appendage that coils around supports to help climbing plants.

Nervous impulse

Electrical signal that travels along a neuron and triggers neurotransmitter release at a synapse.

Neuromuscular junction

Synapse between a neuron and a muscle cell where nerve impulses trigger muscle contraction.