The Nervous System Flashcards
Efferent
Conducted outwards, away from the CNS to the muscles.
Sensory Input
Same as Afferent. Conducted towards the brain or CNS. Eyes.
Motor Output
Same as Efferent. Conducted away from the brain or CNS. Muscle.
CNS
Comprises of the Brain and the Spinal Cord. It is the processing centre and control centre of the Nervous System.
PNS (Peripheral Nervous System)
Is the part of the nervous system outside the brain. It consists of Nerves that extend from the brain and spinal cord.
Somatic Nervous System
Made of somatic motor nerve fibres that conduct impulses from the CNS to the skeletal muscles. Is known as the VOLUNTARY nervous system as it lets us consciously control our skeletal muscles.
Autonomic Nervous System
Consists of visceral motor fibres that regulate the activity of smooth muscles and glands. It is know and the INVOLUNTARY nervous system.
Sympathetic Division
Mobilises body systems during activity.
Parasympathetic Divisions
Conserves Energy and promotes house keeping functions of the body during rest.
Afferent
Conducted inwards or towards something. I.e. Nerves to CNS
Resting Membrane Potential
The voltage (charge) difference across the cell membrane when the cell is at rest.
Na+_______
K+_______
Na+ is Sodium
K+ is Potassium
Absolute Refractory Period
The period immediately after an action potential. Caused by the voltage gated channels of Na+ being inactive.
It ensures each AP is a separate event.
Relative Refractory Periodically
The period immediately after the Absolute Refractory Period. The Inactivated Na+ voltage channels are transitioning from an inactive state to a resting state.
Saltatory Action Potential
Fast conduction along a Myelinated Axon. APs are generated only in the myelin sheath gaps (Nodes of Ranvier) and appear to jump rapidly from gap to gap.
