Glossary

• Stimulus = detectable change in the environment of an organism that results in some functional activity
• Response = behaviour that is manifested as a result of a stimulus
• Receptors = cell or group of cells that receive information from stimuli
• Effector = bodily tissue/structure/organ that becomes active in response to stimulation
• Coordinator = cell/organ that decides how to respond to a stimuli
• Taxis = directed movement towards or away from a stimulus
• Kinesis = random movement of organisms due to a stimulus
• Tropism = the turning part of an organism in a particular direction due to a stimulus
• Plant growth factor = any group of proteins that stimulate the growth of specific tissues
• IAA = plant hormone that regulates various aspects of plant growth and development
• Positive phototropism = plant responding to light
• Gravitropism = coordinated process of differential growth by a plant in response to gravity
• Central nervous system = body's processing centre made of the brain and spinal cord
• Peripheral nervous system = network of nerves that carries messages to and from the CNS
• Sensory neurones = nerve cells that are activated by sensory input from the environment
• Motor neurones = nerve cells that regulate voluntary and involuntary movements by transmitting signals
• Voluntary nervous system = component of the peripheral nervous system associated with the movements of skeletal muscles
• Autonomic nervous system = component of the peripheral nervous system that regulates involuntary physiologic processes
• Reflex = an involuntary and instantaneous movement in response to a stimuli
• Reflex arc = nerve pathway followed by a reflex action
• Synapse = junction between two neurones that allow a signal to pass between them
• Pacinian corpuscle = sensory receptors for vibration and deep pressure located in the skin
• Generator potential = electrical signals generated in sensory receptors in response to stimulation
• Tendons = soft, fibrous tissues that connect muscle to bone
• Depolarised = a change within a cell during which the cell undergoes a shift in electric charge distribution
• Transducers = translate physical/chemical stimuli into electrical/chemical signals
• Rod cells = type of photoreceptor cell in the retina that function at low light levels
• Cone cells = type of photoreceptor in the retina that gives us colour vision
• Visual acuity = ability of the eye to distinguish details at a given distance
• Sympathetic nervous system = network of nerves that helps the body activate its "fight or flight" response
• Parasympathetic nervous system = network of nerves that relaxes the body after periods of stress or danger
• Antagonistic = an interaction between organisms so that one organism benefits at the other's expense
• Sinoatrial node = generates an electrical signal that causes the upper heart chambers to contract
• Atrioventricular node = electrically connects the atria and ventricles to coordinate their beating
• Purkyne tissue = tissue located in the inner ventricular walls of the heart
• Bundle of His = conducts electrical impulses that regulate the heartbeat from the right atrium to the left and right ventricles