body system Flashcards
(24 cards)
Homeostasis
he maintenance of a relatively constant internal physiological environment of the body or part of the body (e.g. blood glucose level, pH, body temperature) in varying external conditions
Neurotransmitter
chemical released from the axon terminals into the synapse between your nerve cells (neurons) during a nerve impulse
receptor
special cells that detect energy and convert it to electrical energy that is sent to the brain
Myelin
a fatty, white substance that encases the axons (connecting branches) of the neurons in the nervous system
Neuron
nerve cell
motor neuron
the nerve cell that causes an organ, such as a muscle or gland, to respond to a stimulus
inter neuron
a nerve cell that carries nervous impulses through the central nervous system. They provide the link between sensory neurons and motor neurons.
sensory neuron
a nerve cell in the sense organs. It detects change in the environment and sends a message to the central nervous system
Negative feedback
a response that reduces the original stimulus
cerebellum
the part of the brain that controls balance and muscle action
cerebrum
he largest part of the brain (about 90 per cent of total brain volume), responsible for higher order thinking, controlling speech, conscious thought and voluntary actions. It is made up of the frontal, temporal, parietal and occipital lobes.
brain stem
the part of the brain connected to the spinal cord, responsible for breathing, heartbeat and digestion. Sometimes called the medulla.
central nervous system
the part of the nervous system composed of the brain and spinal cord
peripheral nervous system
made up of sensory and motor neurons. It connects the central nervous system to the rest of the body, and detects and responds to change.
digestive system
a complex series of organs and glands that processes food in order to supply your body with the nutrients it needs to function effectively
respiratory system
the body system involving the lungs and associated structures, which take in air and supply the blood with oxygen to deliver to the body’s cells so they can carry out their essential functions; it also performs gas exchange to remove the waste gas carbon dioxide
circulatory system
the body system that circulates oxygen in blood to all the cells of the body. The circulatory system consists of the heart, blood vessels and blood.
cellular respiration
the chemical reaction involving oxygen that moves the energy in glucose into the compound ATP. The body is able to use the energy contained in ATP.
mechanoreceptor
special cells within the skin, inner ear and skeletal muscles that are sensitive to touch, pressure and motion, enabling you to balance, hear and sense pressure and movement
chemoreceptor
special cells within a sense organ (especially the nose and tastebuds) that are sensitive to particular chemicals, giving you the sensations of smell and taste
thermoreceptor
special cells located in your skin, part of your brain and body core that are sensitive to temperature
photoreceptor
a receptor cell located in your eye that is stimulated by light, converting it to electrical energy that is sent to the brain, giving you the sensation of light
independent variable
a variable that is deliberately changed during an experiment
dependent variable
a variable that is expected to change when the independent variable is changed. The dependent variable is observed or measured during the experiment.
