Nervous System Flashcards
Define neuron
excitable cells that generate and transmit electrical energy called action potentials
Define glial cell
Provide support, nourish and can insulate neurons.
Also important during development and can supply nutrients/
Axon
conducts action potential away from the cell body
axon terminal
synapse with target cell. Releases neurotransmitter.
Axon Hillock
Information collated which may lead to axon potentials initiation
In what ways to neurons most commonly vary?
Number of dendrites
- some neurons have bushy dendrites and collect information from many neurons
- neurons with fewer process fewer inputs
Axon length
- some neurons communicate over long distances via long axons
Central Nervous system
The brain and the spinal cord
What are the 2 branches of the peripheral nervous system?
- Autonomic and Sensory-somatic nervous system
What is the autonomic nervous system and what does it involve?
- Part of the peripheral nervous system that controls involuntary activity
- Consists of parasympathetic and sympathetic nervous system
What are the 2 types of glial cells?
- Oligodendrocytes (CNS)
- Schwann cells (PNS)
Function of glial cells
Insulate and increase the speed of communication between neurons
Afferent neurons
Carry sensory infor to the CNS.
- dendrites are found in the skin, muscles and organs
- terminals end in the spinal cord and connect to interneurons
Efferent neurons
Carry motor info from the CNS to muscles and organs
- dendrites are in the spinal cord
- terminals found in muscles and organs
What do interneurons do
Enable communication between afferent (sensory) & efferent (motor) neurons and the CNS
What does sensory receptor cells do?
Sensors or receptors that convert physical and chemical stimuli (such as light, pressure, sound etc.)
into action potentials.
Is neural communication chemical or electrical?
Communication is electrical within the neuron and chemical between neurons.
Define action potential
An action potential is a rapid change in charge difference across the nerve cell membrane.
Membrane Potential
Electrical potential or the charge difference, across the membrane.
Why is the resting potential negative?
In axons, at resting, there is
- a more positive charge outside
- more negative charge inside
- this creates a charge difference across membrane (ie. POLARISED)
Resting potential?
When the neuron is not active the membrane potential is at resting potential.
What are the 2 characteristics of an action potential?
All-or-none event
- An action potential either goes or it doesnt
Self-regenerating
- Because an action potential spreads to the adjacent membrane regions in the axon.
Neuromuscular junction
Site of chemical communication between a neuron and a muscle cell
Difference between introception and exteroception
Interoception: Sensitivity to stimuli originating inside the body - to maintain a stable environment
Exteroception: Sensitivity to stimuli originating outside the body
What terms are given to describe the convoluted nature of the cerebral cortex?
Gyri
- Ridges of the cortex
- hills
Sulci
- Valleys
Frontal lobe
Diverse functions best described as feeling and planning
Parietal Lobe
Touch and pressure via thalamus
Temporal Lobe
recognising, identifying and naming objects
Occipital Lobe
processes visual information
Association cortex
Integrate or associate higher order, complex, sensory information or memory.
Describe the function of the BROCA’S area and what happens when it’s damaged?
- frontal lobe
- movements required to produce speech
If damaged:
- loss of ability to produce language
- broken speech (motor aspect)
- patient is aware and can understand language
Describe the function of the WERNICKE’S area and what happens when it’s damaged?
- Parietal and temporal lobes
- Understand speech and use of correct words
If damaged:
- Inability to understand language
- can’t choose correct words to express thoughts
- patient is not aware
ie. the words are clear but does not make sense
What is sleep and its characteristics?
A period of reduced activity and decreased responsiveness
- reversible
- characterised by changes in brain wave activity
What is consciousness?
State of being aware of and responsiveness to one’s surroundings
