science lwk

Nervous System, body’s fast control network that sends electrical signals to coordinate all body actions

nervous system

CNS, Central Nervous System made of brain and spinal cord that processes information and makes decisions

PNS, Peripheral Nervous System made of all nerves outside the CNS that carries messages to and from the CNS

Neuron, nerve cell that is the basic unit of the nervous system and carries electrical impulses

Dendrites, branch-like parts of a neuron that receive signals from other neurons

Axon, long tail of a neuron that carries signals away from the cell body

Myelin Sheath, fatty coating around the axon that speeds up nerve impulses

Synapse, small gap between two neurons where signals cross using chemical neurotransmitters

Cerebrum, largest part of the brain that controls thinking memory movement and senses

Cerebellum, part of the brain under the cerebrum that controls balance coordination and smooth movement

Brain Stem, connects the brain to the spinal cord and controls automatic functions like breathing and heart rate

Reflex, fast automatic response that happens without thinking and protects the body from harm

Stimulus–Response, the sequence of how the body reacts to changes stimulus to receptor to control centre to effector to response

Endocrine System, slow chemical control system that uses hormones in the blood to regulate body functions

Hormone, chemical messenger made by glands that travels in the blood to affect specific target organs

Pituitary Gland, known as the master gland located in the brain that controls other glands and makes growth hormone

Thyroid Gland, gland in the neck that controls metabolism and how the body uses energy

Pancreas, organ behind the stomach that controls blood sugar levels and makes insulin

Adrenal Gland, glands on top of the kidneys that release adrenaline to trigger the fight or flight response

Homeostasis, the ability to keep a stable internal balance like temperature blood sugar and water levels even when the outside changes

Negative Feedback, the main way the body maintains homeostasis by detecting a change and then reversing it back to normal

Fight or Flight, response where the nervous and endocrine systems work together using adrenaline to prepare the body for danger

Pathogen, any disease-causing germ such as bacteria virus or fungus

White Blood Cell, special immune cell that fights pathogens and makes antibodies

Antibody, protein made by white blood cells that marks pathogens so they can be destroyed

3 Lines of Defence, the body’s protection system first line is physical barriers like skin and tears second line is general attacks like fever and inflammation third line is specific defence using antibodies

Vaccine, contains a weak or dead pathogen that teaches the body to make antibodies without getting sick and creates immunity