Chapter 2: Control and Coordination Flashcards
the maintenance by an organism of a constant internal environment (for example, blood glucose level, pH, body temperature)
Homeostasis
a system in which a change (stimulus) is detected by receptors leading to a response, which acts to alter and return the variance to normal
Stimulus-response model
occurs when the response is in an opposite direction to the stimulus
Negative feedback
a homeostatic mechanism that enhances the original stimulus
Positive feedback
it is composed of the central nervous system (CNS), which contains your brain and spinal cord and the peripheral nervous system (PNS), which contains the nerves (neurons) that connect to the rest of the body.
Nervous system
the part of the nervous system containing nerves that connect to the central nervous system
PNS
the part of the nervous system composed of the brain and spinal cord
CNS
another name for nerve cell, a specialised cell for transmitting a nerve impulse
Neuron
a nerve cell in the sensory organs that conducts a nerve impulse from receptors to the central nervous system
Sensory neuron
a nerve cell that conducts a nerve impulse from the central nervous system to the effector such as a muscle or gland so that it may respond to a stimulus
Motor neuron
a neuron which transmits impulses between other neurons
Interneuron
signalling molecules released from the axon terminals into the synapse.
Neurotransmitter
it controls and regulate functions such as metabolism, growth, development and sexual reproduction.
Hormones
part of a neuron that contains the nucleus
Cell body
structure that relays information towards the cell body of a neuron
Dendrite
long structure within a neuron through which the nervous impulse travels from the dendrite and the cell body
Axon
a fatty, white substance that encases the axons of neurons
Myelin
the gap between adjoining neurons where neurotransmitters travel
Synapse
a quick response to a stimulus that does not involve the brain (for example, knee jerk)
Reflex arc
a specialised structure that detects stimuli (such as light, sound, touch, taste and smell) in your environment
Sense organ
A change you are detecting
Stimuli
special cells within a sense organ that are sensitive to particular chemicals
Chemoreceptor
special cells located in your skin, part of your brain and body core that are sensitive to temperature
Thermoreceptor
special cells within the skin, inner ear and skeletal muscles that are sensitive to touch, pressure and motion
Mechanoreceptor
a special cell located in your eye that is detected by light
Photoreceptor
the control of body temperature
Thermoregulation
he part of the brain connected to the spinal cord, responsible for breathing, heartbeat and digestion
Brainstem
the largest part of the brain responsible for higher order thinking, controlling speech, conscious thought and voluntary actions
cerebrum
the part of the brain that controls balance and muscle action
cerebellum
the lowest part of the brain and the lowest portion of the brainstem.
medulla
the body system composed of different glands that secrete signalling molecules (hormones) that travel in the blood for internal communication and regulation and to maintain homeostasis
Endocrine system
organs that produce hormones, which are released into the bloodstream
Endocrine glands
a simple sugar which is an important energy source in living organisms and is a component of many carbohydrates
Glucose
a large gland in the body that produces and secretes the hormone insulin
Pancreas
hormone that reduces blood glucose levels
Insulin
organs that respond to a stimuli to initiate a response
Effector
Consists of 2 hemispheres. Outer surface of cerebrum
cerebral cortex
A voluntary action is a response to a stimulus. It is consciously controlled or co-ordinated by the brain and involves many neurons. Like eating and writing
Voluntary action
An involuntary action is a response to stimulus. It is not consciously controlled by the brain and only require minimum number of neurons. Like blinking of the eyes, jerking of the knee.
Involuntary action
