Science Definitions Flashcards
Nervous System
A communication network that controls & coordinates the functioning of the body.
Central Nervous System
Brain & Spinal Cord.
Peripheral Nervous System
All the neurons that function outside the central nervous system. Divided into two parts - somatic & autonomic.
Cerebrum
Responsible for higher-order thinking, highly folded.
Lobe
Region of the cerebrum.
Cerebellum
Controls movement, balance & co-ordination.
Brain stem
Contains medulla which controls involuntary actions such as breathing, heart rate & digestion.
Neuron
Specialised cell that carries electrical impulses around the nervous system.
Dendrite
Receives a message and sends it to the cell body.
Cell body
Contains nucleus that transmits the stimuli.
Axon
Carries the message away from the cell body to the synapse.
Myelin sheath
Fatty covering that insulates and speeds up electrical impulses.
Axon terminals
Found at the end of the neuron, release chemicals to assist the message travelling to the next neuron.
Sensory neuron
Receive information from receptors and send a message to the CNS.
Motor neuron
Carry messages from the CNS to a muscle cell.
Interneuron
Link sensory & motor neurons.
Reflex
An involuntary movement in response to a stimulus.
Stimulus.
Any information that the body receives that causes the body to respond.
Receptor
Detects a stimuli or change in the normal functioning of the body.
Sense organs
Organs in the body that detect changes
E.g. eye, ear.
Endoctrine System
A collection of glands that make and release hormones.
Thyroid gland
Found in the neck, controls the rate food is turned into energy, regulates temperature.
Thyroxine
Hormone released from thyroid, controls metabolic processes (breakdown/buildup of molecules).
Pituitary Gland
Found in brain, master gland that secretes hormones that can tell other endocrine glands to secrete their hormones.
ADH
Hormone released by the pituitary, regulates water reabsorption in the kidney.
Pancreas
Endocrine glands that secretes hormones which control blood sugar levels.
Insulin
Hormone that decreases blood sugar levels.
