Coordination and Response

Flashcards covering the human nervous system, sense organs, hormones, homeostasis, and tropic responses.

Neurones

Specialized cells that make up the human nervous system and transmit electrical impulses.

Axon

A long thread of cytoplasm in a nerve cell that transmits electrical impulses.

Stimuli

Changes in an organism's environment.

Receptor

Specialized cells which sense stimuli.

Effector

Respond to the stimuli.

Nerve Impulse

Electrical signal/information passes along a neurone.

CNS (Central Nervous System)

Brain and Spinal Cord

PNS (Peripheral Nervous System)

Nerves and receptors outside of the spinal cord and brain.

Reflex arc

Pathway along nerve impulse passes the sensory neurone, relay neurone and motor neurone

Reflex action/Involuntary Action

Automatic and rapid action of the body.

Synapse/Synaptic cleft

Gap between two neurons, ensure impulses travel in one direction only

Involuntary action

Unconscious action, not under conscious control.

Sense organs

Group of receptor cells responding to specific stimuli: light, sound, touch, temperature and chemicals.

Skin

Touch (pressure, pain, hot/cold temperatures).

Tongue

Taste (chemicals).

Nose

Smell (chemicals).

Eyes

Sight (Light).

Ears

Hearing (Sound).

RODS

Small part of the retina showing rods and a cone, sensitive to dim light - respond to black and white

CONES

Small part of the retina showing rods and a cone, sensitive to bright light - respond to red, green, and blue light.

Pupil reflex

Pupil action when response to bright light and dim light.

Accomodation

Adjustment of the lens size to focus light to get a clear image on the retina

Hormone

Chemical substance produced by a gland, carried by the blood, which alters the activity of one or more specific target organs.

Adrenaline

Prepares body for vigorous action.

Insulin

Reduces the concentration of glucose in the blood.

Testosterone

Causes the development of male secondary sexual characteristics.

Oestrogen

Causes the development of female secondary sexual characteristics, and helps in the control of the menstrual cycle.

Tropisms/Tropic response

Growth response by a plant towards the stimulus(surrounding changes) (light/gravity)

Phototropism

Growth response towards/away from the light

Gravitropism

Growth response towards/away from the gravity

Auxin

Hormone (chemicals) in plants naturally produced in the shoot tip, stimulates cells elongation