Human Responces End of Topic Test

Neuron (Nerve Cell)

The basic structural and functional unit of the nervous system. Specialised to transmit electrical impulses

Electrical Impulse

A quick temporary change in the electrical charge along a neuron's membrane that carries information

Central Nervous System (CNS)

Consists of the brain and spinal cord. It processes information and coordinates responses

Peripheral Nervous System (PNS)

Consists of all the nerves outside the CNS. It connects the CNS to the limbs and organs

Sensory Neuron

Transmits impulses from a receptor to the CNS

Relay Neuron (Interneuron)

Found entirely within the CNS and connects sensory and motor neurons

Motor Neuron

Transmits impulses from the CNS to an effector (muscle or gland)

Effector

A muscle or gland that carries out the response

Receptor

A specialised structure that detects a specific stimulus such as light sound or pressure

Reflex Arc

The pathway of a nerve impulse from a receptor to an effector during a reflex action

Reflex Action

A rapid involuntary automatic response to a stimulus

Five Senses

Sight detects light

hearing detects sound waves

touch detects pressure and temperature

taste detects chemicals in solution

smell detects chemicals in the air

Synapse

A specialised junction or gap between two neurons

Synaptic Gap (Synaptic Cleft)

The tiny space separating two neurons

Neurotransmitter

A chemical released into the synaptic gap that transmits the impulse to the next neuron

Vesicle

Small membrane-bound sacs that store neurotransmitter molecules

Receptor Protein

Proteins on the postsynaptic neuron that bind with specific neurotransmitters

Unidirectional Flow

Impulses can only travel in one direction across a synapse

Homeostasis

The maintenance of a constant internal environment in the body

Negative Feedback

A control system that reverses a change to restore balance

Hormone

A chemical produced by an endocrine gland and carried by the blood to target organs

Nervous Control

Uses electrical impulses

fast action and short-lasting effects

Hormonal Control

Uses chemical hormones in the blood

slow action and long-lasting effects

Set Point

The ideal or target value for a physiological variable

Thermoregulation

The process of maintaining a constant body temperature (37°C)

Hypothalamus

The brain region that monitors and controls body temperature

Vasodilation

Blood vessels near the skin widen to increase blood flow and heat loss

Sweating

Water is released onto the skin and evaporation removes heat from the body

Vasoconstriction

Blood vessels near the skin narrow to reduce heat loss

Shivering

Rapid involuntary muscle contractions that generate heat

Pancreas

The gland that releases insulin and glucagon to control blood glucose

Insulin

A hormone that lowers blood glucose by helping cells take in glucose and storing excess glucose as glycogen in the liver

Glucagon

A hormone that raises blood glucose by stimulating the liver to break down glycogen into glucose

Adrenaline (Epinephrine)

The fight or flight hormone that increases heart rate breathing rate pupil size and blood glucose

Type 1 Diabetes

A disease where the pancreas produces little or no insulin

Type 2 Diabetes

A disease where the body does not effectively use the insulin it produces (insulin resistance)