Nervous system Flashcards
Nervous System
Central and Peripheral NS
Central NS
Brain and spinal cord
Peripheral NS
Controls somatic and autonomic NS
Autonomic
Self-regulatory and involuntary control over internal muscles, organs and glands. Parasympathetic and Sympathetic
Somatic
Control of voluntary muscle movements, contains sensory neurons, motor neurons and reflex arc.
What is the function of the nervous system?
To detect, interpret, and coordinate a response to stimuli (both external and internal)
Types of receptors
mechanoreceptors, chemoreceptors, photoreceptors, thermoreceptors, nociceptors
mechanoreceptors
Pressure, touch, vibration
chemoreceptors
Chemicals (taste and smell)
Photoreceptors
Light
thermoreceptors
Temperature changes
nociceptors
Pain
Sympathetic NS referred to as…
Fight/flight/freeze
Parasympathetic NS referred to as…
Rest and digest
Sympathetic NS - description and function
Activates bodily functions responsible for the flight/flight response
Sympathetic NS - physiological effects
Speed up heart rate
Delivers more blood to areas which need oxygen more and less to areas that need it less
dilated pupils
sweating
increased breathing rate
airways expand for more breathing
Parasympathetic NS - description and function
Maintains homeostasis, conserves energy
Parasympathetic NS - physiological effects
Decrease in heart rate
increase digestion
decrease blood flow to stress response organs
Reflex arc
Receptor senses stimulus
Sensor and inter neurons transmits signal up the PNS to the CNS
Integration centre decodes the signal
Motor neurons send directions back to the site of the stimulus
Effector cells respond by controlling or secreting
Soma
The main part of the neuron, all the normal cell function occur here. The nucleus is the Soma
Dendrite
Receive incoming messages from the previous neuron
Axon
The fibre that carries the message away from the Soma
Myelin Sheath
Insulates the neuron, ensuring the message stays within the neuron and travels quickly
Synapse
Thew microscopic gap between the neuron over which the neurotransmitter pass to stimulate the next neuron.
Axon Terminal
Releases neurotransmitter into the synapse
sensory neurons
They transmit sensory information from the sensory organs to the brain
interneurons
They connect the sensory neurons to the motor neurons
motor neurons
They transmit motor information from the brain to the effector (muscles, organs, and glands)
neurotransmitter
A chemical messenger that is released from one neuron and travels across the synapse to bind to the next neuron
action potential
the electrical impulse that is transported along a neuron
Role of MRI
To detect and identify abnormalities like tumours, cysts, brain trauma and areas of affected by a stroke
Role of fMRI
To see what brain areas are activated and connected during different activities
Role of EEG
EEGs help monitor alertness and brain activity in various states (like sleep), assess normal or abnormal patterns, and identify seizure disorders such as epilepsy.
