Chapter 6 - Body coordination Flashcards
Peripheral Nervous System
Made of nerves that carry messages to the CNS from receptors and from the CNS to effectors
Nervous System
Sends information as electrochemical impulses around the body at 100m/s. Divided into two parts: CNS and PNS
Stimulus
Any deviation from the normal state. A change in environmental factors
Receptor
Specialised cells designed to detect a specific stimulus
Effector
The part of the body that causes a change in response to the stimulus
Response
Caused by effector and is usually a return to the normal state
Sapictive receptors
Taste
Mechanoreceptors
Touch
Photoreceptors
Light
Thermoreceptors
Temperature
Chemoreceptors
Food, chemicals
Autistic receptors
Sound
Olfactory receptors
Smell
Neuron
Part of the nervous system, carries electrical messages called nerve impulses from one part of your body to another
Cell body
Contains the nucleus, which is the control centre of the cell
Dendrite
Fibres that receive messages from other neurons
Axon
Fibres that send messages to other neurons
Myelin sheath
Fatty coating of ‘insulation’. It insulates the neurons from each other and increases speed of nerve impulse
Reflex arc
Stimulus response pathway designed to work quickly and automatically. Bypasses brain and uses spinal chord as control centre
Reflex arc events (diagram)
Stimulus > Receptor > CC (spinal chord) > Effector > Response
Motor neurons
Carry messages from CNS to effectors (from control centre to effectors)
Sensory neurons
Carry messages from cells in the sense organs to the brain and spinal chord. Attached to a receptor (from receptors to control centre)
Interneurons
Connect motor and sensory neurons together
Central Nervous System
Consists of brain and spinal chord. Received information from all around the body and the sends messages on how the body should respond
Transmit message across synapse
Messages sent along neurons are electrical. When the message reaches an axon, a neurotransmitter, which is a chemical, is released into the synapse. The NTM sends the message from the axon to the dendrite as electrochemical in nature. The dendrite then sends it off as an electrical signal
Slow response
Slow responses in multicellular organisms are produced by hormones through the endocrine system. Signals in the body tell the glands to produce hormones to send to target cells. These reactions are slower than the nervous system. Some take weeks to change. Eg: thyroxine produced by the thyroid which controls metabolism rates
Homeostasis
Maintenance of constant internal environment, despite changing external environment
Brain with nervous and endocrine systems
Brain links endocrine and nervous system because the brain contains the PG – which controls endocrine system. Brain is the control centre for the CNS. Brain contains hypothalamus –links both systems together
Oxygen transport
Allows oxygen into the body and into blood stream through aveoli and diffusion. Allows carbon dioxide out of body. Uses respiratory system
Digestion
Digestive system - breaks down food into glucose for cellular respiration
Excretion
Removal of waste (urea) through excretory system. Expulsion of metabolic waste
Metabolism
Chemical reactions and processes that allow Organism growth, reproduction, maintenance of structure and respond to their environments. Also breaks down organic matter –Breaks down glucose to release energy
