Nervous system Flashcards
What is the function of the Nervous system?
Generation and interpretation of nervous impulses - Swift regulation of body activity by using nerve impulses.
What are the TWO main divisions of the Nervous system?
Central & Peripheral
What is the main function of the Central NS?
Analysis & storage of sensory information,
Decision making.
What is the main function of the Peripheral NS?
Detection of changes/stimuli using receptors in the body.
What does the Central NS consist of?
The brain & spine.
What does the Peripheral NS consist of?
43 pairs of Cranial & Spinal nerves
What are the TWO sub-divisions of the Peripheral NS?
Somatic & Autonomic.
What are the TWO sub-divisions of the Autonomic NS?
Sympathetic & Para-sympathetic.
What is the difference between an afferent and efferent impulses?
Afferent impulses are sent UP to the CNS by the PNS, while Efferent impulses are sent DOWN to the effector.
What are the TWO types of Nervous tissue?
Neurons & Neuroglia.
What is a Tract?
A bundle of axons in the CNS.
What is a Nerve?
A bundle of axons in the PNS, aswell as connective tissue and blood vessels.
What are the FOUR types of Neuroglia?
Astrocytes,
Microglia,
Ependymal cells,
Oligodendrocytes.
What is the function of an Astrocyte?
Physical support, brace and anchor of neurons,
Helps form the BBB,
Maintains the chemical environment for the generation of nerve impulses.
What is the function of an Microglia?
Functions as a phagocyte in the CNS.
What is the function of Ependymal cells?
Assist with production of CSF.
Form an epithelial layer that lines ventricles in the brain & spinal cord.
What is the function of Oligodendrocytes?
Formation and maintenance of the Myelin sheath in the CNS.
What is the function of the Sympathetic NS?
Responds to emergencies & the need for energy expenditure.
What is the function of the Parasympathetic NS?
Restores & conserves body energy. Includes the 3 decreases.
What is Dual innervation?
Body organs which receive both sympathetic & parasympathetic impulses.
What is the function of a Mechanoreceptor?
Detection of stretch, pressure & touch.
What is the function of a Chemoreceptors?
Detects chemical concentrations in the body.
What is the function of a Thermoreceptor?
Detects temperature changes within the body.
What is the function of a Nociceptor?
Detection of tissue damage & trauma.
What is the function of Photoreceptors?
Detection of changes in light.
-Only found in the eye
What is the function of Osmoreceptors?
Detection of osmotic pressure.
What is the function of Proprioceptors?
Detection & sense of orientation of body parts.
What is the definition of Sensation?
A conscious awareness of incoming sensory information.
What is the definition of Adaptation?
A decrease of perception, even if the stimulus remains constant.
What are the THREE neurons involved in pain pathways?
1st order neuron,
2nd order neuron,
3rd order neuron.
What is the function of a 1st order neuron?
Carry signals from peripheral NS to the Spinal cord.
What is the function of a 2nd order neuron?
Carry signals from the spinal cord to the thalamus.
What is the function of a 3rd order neuron?
Carry signals from the Thalamus to the primary somatosensory area.
What is the main difference between the Parasympathetic & Sympathetic NS?
The fibres of each division originate at different sites in the body.
-Sympathetic are thoracolumbar.
-Parasympathetic are Craniosacral.
