Control and Coordination

Comprehensive vocabulary flashcards covering the nervous system, reflex actions, brain anatomy, plant movements, plant hormones, and the endocrine system from Chapter 6: Control and Coordination.

Gustatory receptors

Specialised receptors located in sense organs, such as the tongue, that detect taste.

Olfactory receptors

Specialised receptors located in sense organs, such as the nose, that detect smell.

Neuron

A nerve cell forming an organised network specialised for conducting information via electrical impulses from one part of the body to another.

Dendritic tip

The tip of a nerve cell where environmental information is acquired, setting off a chemical reaction that creates an electrical impulse.

Axon

The elongated fibre of a neuron along which an electrical impulse travels from the cell body to its terminal end.

Synapse

The microscopic gap between two neurons where electrical impulses release chemicals that cross over to initiate an electrical impulse in the next neuron.

Neuromuscular junction

The synapse between a motor neuron and a muscle cell that allows the delivery of nervous impulses to muscle fibres.

Reflex arc

A rapid connection formed in the spinal cord between an input sensory nerve and an output motor nerve that produces an action without prior conscious thinking.

Central nervous system (CNS)

The primary coordinating centre of the body, constituted by the brain and spinal cord, which receives and integrates information from all parts of the body.

Peripheral nervous system (PNS)

The communication network between the central nervous system and other body parts, consisting of cranial nerves from the brain and spinal nerves from the spinal cord.

Fore-brain

The main thinking part of the brain containing regions specialised for hearing, smell, and sight, association areas for interpreting sensory inputs, and a centre associated with hunger.

Medulla

A part of the hind-brain that controls involuntary actions such as blood pressure, salivation, and vomiting.

Cerebellum

A part of the hind-brain responsible for maintaining posture and equilibrium of the body, as well as the precision of voluntary actions.

Cranium

The bony skull box that encloses the brain and contains a fluid-filled balloon for shock absorption.

Vertebral column

The bumpy, hard bony backbone situated along the middle of the back that protects the spinal cord.

Chhui-mui

The 'sensitive' or 'touch-me-not' plant of the Mimosa family whose leaves fold up and droop in an immediate growth-independent response to touch.

Tendrils

Touch-sensitive threadlike organs on climbing plants (such as pea plants) that circle and cling to supports because the side away from contact grows faster than the side touching the object.

Phototropism

Directional growth movement of plant parts in response to light, wherein shoots show positive phototropism by bending towards light and roots show negative phototropism by bending away.

Geotropism

Directional growth of plant parts in response to gravity, where roots grow downwards towards the earth and shoots grow upwards away from it.

Chemotropism

Directional plant growth movement in response to chemical stimuli, such as the growth of pollen tubes towards ovules.

Auxin

A plant hormone synthesised at the shoot tip that diffuses to the shaded side, stimulating cells to grow longer and causing the shoot to bend towards light.

Gibberellins

Plant hormones that promote growth, specifically aiding in the growth of the stem.

Cytokinins

Plant hormones that promote cell division, present in high concentrations in rapidly dividing tissues such as fruits and seeds.

Abscisic acid

A plant hormone that inhibits growth, leading to physiological effects such as the wilting of leaves.

Adrenaline

An emergency hormone secreted directly into the blood by the adrenal glands that prepares animals to fight or run by speeding up heartbeat, increasing breathing rate, and diverting blood to skeletal muscles.

Endocrine system

A bodily communication network consisting of ductless glands that secrete hormones directly into the bloodstream for chemical control and coordination.

Thyroxin

A hormone produced by the thyroid gland requiring iodine that regulates carbohydrate, protein, and fat metabolism for optimal body growth.

Goitre

A disorder characterised by a swollen neck caused by iodine deficiency in the diet, which prevents adequate synthesis of thyroxin.

Growth hormone

A hormone secreted by the pituitary gland that regulates overall growth and body development; childhood deficiency results in dwarfism.

Testosterone

A male sex hormone secreted by the testes responsible for physiological changes associated with puberty in boys around $10\text{--}12$ years of age.

Oestrogen

A female sex hormone secreted by the ovaries that directs the development of female sex organs and regulates the menstrual cycle.

Insulin

A hormone produced by the pancreas that regulates blood sugar levels; deficient production causes blood sugar to rise, leading to diabetes.

Feedback mechanism

A regulatory mechanism that adjusts the timing and amount of hormone secreted, such as pancreatic cells increasing insulin secretion when blood glucose levels rise.

Hypothalamus

A brain structure that regulates endocrine secretion by producing releasing factors, such as growth hormone releasing factor which stimulates the pituitary gland.