Chapter 9: Body systems and responses | Oxford Insight Science Stage 5 (Years 9 & 10)

hydrotropism

the growth or turning of plant roots towards or away from moisture

phototropism

the process where a plant's cells in the dark expand to bend the plant towards a light source; the growth or turning of a plant towards or away from light

deciduous

a type of plant that loses its leaves during the cooler months, to conserve energy when there is less sunlight; annual shedding of leaves

endotherm

an animal that regulates its own body temperature

ectotherm

an animal that is unable to regulate its own body temperature

migrate

the movement of an animal from one region to another, typically in response to changing seasons

hibernation

an extended period of inactivity, typically in response to colder conditions

receptor

a structure that detects a stimulus or change in the normal functioning of the body

stimulus

any information that the body receives that causes the body to respond

brain

the primary organ of the central nervous system consisting of soft nervous tissue and contained in the skull of vertebrates

central nervous system

the brain and spinal cord

spinal cord

the cylindrical bundle of nerve fibres and associated tissue which is enclosed in the vertebrae

peripheral nervous system

all the neurons (nerve cells) that function outside the brain and spinal cord

somatic nervous system

the part of the nervous system that controls the muscles that are attached to the skeletal system

autonomic nervous system

the part of the nervous system that controls involuntary actions such as heartbeat, breathing and digestion

synaptic terminal

a bulb at the end of the axon of a neuron which stores and releases neurotransmitter molecules to stimulate the following neuron

myelin sheath

a fatty layer that covers the axon of a nerve cell

dendrite

the part of a neuron (nerve cell) that receives the message and sends it to the cell body

sensory neuron

a nerve cell that carries a message from a receptor to the central nervous system

motor neuron

a nerve cell that carries a message from the central nervous system to a muscle cell

interneuron

a nerve cell that links sensory and motor neurons; also known as a connector neuron

reflex

an involuntary movement in response to a stimulus

endocrine system

a collection of glands that make and release hormones

hormone

a chemical messenger that travels through blood vessels to target cells

target cell

a cell that has a receptor that matches a specific hormone

feedback mechanism

a feedback loop where the system responds to a particular stimulus; can be positive or negative

negative feedback mechanism

a regulatory loop in which the stimulus causes a response that acts in the opposite direction to whatever is being regulated

fight, flight or freeze

a stress response that helps an organism to react toperceived threats

homeostasis

the process by which the body detects and responds to stimuli to ensure a stable internal state is maintained

germ theory

the current accepted theory that explains that pathogens cause infectious diseases

pathogen

an infectious-disease-causing agent

inoculation

the introduction of a pathogen, usually weakened, into a host

antibiotics

a medicine used in the treatment of bacterial infections

immune system

a system of organs and structures that protect an organism against disease

phagocyte

an immune system cell that surrounds, absorbs and destroys pathogens

B cell

an immune system cell that produces antibodies in response to pathogens

antibody

a specific molecule produced by B cells that binds to a pathogen

T cell

an immune system cell that recognises and kills pathogens

immune

able to fight an infection as a result of prior exposure

vaccination

an injection of an inactive or artificial pathogen that results in the individual becoming immune to the disease

epidemic

a widespread outbreak of an infectious disease that is typically isolated to a specific region

pandemic

a widespread outbreak of an infectious disease that is spread across multiple global regions