Nervous system Flashcards
Whats the role of nervous system?
- Monitor internal and external environment
- Process information
- Direction behaviour and body processes
What are three types of neurons?
- Sensory (sensory input)
- Motor (motor output)
- Interneuron (integration)
What are the componenets of a neuron?
- Cell body (Soma) – information process
- Dendrites (receives information)
- Axon hillock (information summed together collecting positive and negative neurotransmitters)
- Terminal branches (attached to presynaptic cell to send on action potential)
How are neuro glial cells physiologically demanding?
- Maintain local extracellular environment
- Support neuronal function
- Maintain local concentrations of neurotransmitters
- Supply nutrients
- Support and guide neuronal development
- Stabilise neuronal networks
- Improve communication speeds
- Provide immunological defence
Two conceptual divisons of the nervous system
anatomical
functional
State the anatomical divisions of the nervous system
**Central nervous system **
- Brain
- Spinal cord
**Peripheral nervous system **
- Cranial nerves
- Spinal nerves
- (ganglia to base activate sensory nerve endings eg. Dorsal root ganglion)
Whats the ganglia?
Peripheral nervous system
Defined as a collection of neuronal cell bodies
What are the functional divisions of the nervous system?
- Somatic nervous system – voluntary
- Autonomic nervous system – involuntary (heartbeat, sweating)
Som and Auto (sensory pathway) -> CNS -> som and auto (motor pathways) -> effectors
Whats the difference between afferent and efferent in nervous system?
Sensory PNS – afferent – conducting towards central nervous system
Motor PNS – efferent – conducting away from central nervous system
WHat are the functional divisions of the autonomic nervous system?
- Sympathetic – flight or fight
- Parasympathetic – rest and digest
Whats the pia mater?
Soft thin membrane covering the brain.
Whats the arachnois mater?
- spidery mother’
- Outer membrane making subarachnoid space where cerebrospinal fluid (relaxed in arachnoid villi valves so leaks into Venus blood vessels) can flow through which is nutritive and protective of brain tissue
- also containing arachnoid trabeculae forms pillars throughout space
State the three membrane layer of the brain
- pia mater (soft)
- Arachnois mater (spidery)
- dura mater (tough)
Whats the dura mater?
Tough mother – lots of collagen and connective tissue – very strong membrane which doesn’t stretch
- Two layer – periosteal (Bone layer) and meningeal
What are the two layers of the dura mater?
periosteal (Bone layer) and meningeal
Whats the meninges?
- Three layers of membranes protecting brain and spinal cord
- Pia, arachnoid and dura mater
What is cerebrospinal fluid?
- Produced in one of 4 ventricles of brain
- Choroid plexus – area that produces fluid – also in the tissues of the brain
- Leak out through arachnoid villi – one-way valves where it leaks into the Venus blood vessels
- Flow through subarachnoid space providing nutrients and protection to the brain tissue
Whats the choroid plexus?
– area that produces cerebrospinal fluid – also in the tissues of the brain
What are arachnoid villi?
one-way valves where cerebrospinal fluid leaks into the Venus blood vessels
What are the 4 roles of cerebrospinal fluid?
- Protective medium for brain floatation
- Protective cushioning – trauma
- Removal of metabolites
- Providing stable ionic environment (low conc. Of protein and slightly higher potassium and sodium conc.)
What are gyri of the brain?
ridge of the brain
surface level
Whats sulci of the brain
the grooces in the brain
in the crease is the culci
Whats a fissure?
A deep sulcus (groove in the brain)
State the lobes of the brain
- frontal
- temporal
- parietal
- occipital
