Control and Coordination in Humans and Plants

These flashcards cover the key concepts of human and plant coordination, including the central and peripheral nervous systems, reflex arcs, brain functions, plant tropisms, and endocrine hormones.

Reflex action

A sudden action in response to something in the environment that occurs without thinking about it or feeling in control of the reaction.

Reflex arc

The connection between an input nerve and an output nerve, typically formed in the spinal cord, that allows for a quick response to a detected signal.

Central Nervous System (CNS)

The coordinating centre of the body consisting of the brain and the spinal cord which receive and integrate information from all body parts.

Peripheral Nervous System (PNS)

The system facilitating communication between the CNS and other parts of the body, consisting of cranial nerves arising from the brain and spinal nerves from the spinal cord.

Fore-brain

The main thinking part of the brain which receives sensory impulses from receptors and contains specialised areas for hearing, smell, and sight.

Medulla

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

Cerebellum

A part of the hind-brain responsible for the precision of voluntary actions and maintaining the posture and balance of the body.

Cranium

A bony box inside which the brain sits for protection; it contains a fluid-filled balloon for shock absorption.

Tropic movements

Directional movements in plants that can be either towards or away from an environmental stimulus such as light or gravity.

Phototropism

A directional growth movement where shoots respond by bending towards light while roots respond by bending away from it.

Geotropism

The upward and downward growth of shoots and roots in response to the pull of earth or gravity.

Chemotropism

Directional growth movements in response to chemicals, such as the growth of pollen tubes towards ovules.

Adrenaline

A hormone secreted by the adrenal glands directly into the blood to prepare the body for 'fighting or running away' by increasing heart and breathing rates.

Thyroxin

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

Growth hormone

A hormone secreted by the pituitary gland that regulates the growth and development of the body.

Dwarfism

A condition resulting from a deficiency of growth hormone during childhood.

Insulin

A hormone produced by the pancreas that helps in regulating blood sugar levels.

Feedback mechanism

A regulatory system that controls the timing and amount of hormone released, such as the secretion of insulin by the pancreas when blood sugar levels rise.