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
Whats the post-central gyrus?
Key component of receiving sensory information
State types of gyri and sulus in the brain
- Pre central gyrus
- Lateral sulcus
- Central sulcus
- Post-central gyrus
What are the two types of brain matter?
grey and white
Whats grey matter in the brain?
short, non-myelinated neurons and neuron cell bodies
- Neurons
- Glial cells
- Blood vessels
- No major long fibre tracts
Whats white matter in the brain?
Mostly myelinated axons primarily in fibre tracts
Dense coating of fatty myelin gives it colour
- Fibre tracts
- Information super highway as connects different areas of brain
- Also sensory and motor pathways through ascending and descending tracking to rest of nervous system
What does the frontal lobe do?
Planning, emotion, mood, behaviour, motor function and smell
What does the parietal lobe do?
Touch, pain, temperature and sensation
What does the temporal lobe do?
Hearing, language and memory
What does the occipital lobe do?
vision
What does the cerebellum do?
- Balance and coordination
- Influence posture and muscle tone
- Coordination of movement
- Motor learning
What does insula (gyri) do?
- Conscious awareness
- Gustation
- Cognitive emotional processing
- Audio-visual integration
- Interception (autonomic sensory monitoring and regulation)
- Homeostatic error detection
What does motor cortex somatic do?
- Motor control of skeletal muscle
- Motor planning – general
- (In pre-motor cortex getting motion ready then somatic does the action)
State three typres of cortex?
sensory
visual
auditory
What does the sensory cortex do?
- Input from skin
- Input from proprioceptors
- Spatial discrimination
What does the visual cortex do?
- Mapping visual input
- Visual recognition
What does the auditory cortex do?
- Associate pitch, loudness and location
- Auditory memory – sound recognition
What does brocas area do?
- Motor control of speech
- Speech planning (stutter)
- Motor planning (general)
- Language output area
What does wernickes area do?
- Language
- Reading or listening
- Recognition of words
- Association with meanings
- Context
Selecting the correct words to use
What id the language loop model?
To read outload
1. Visual cortex
2. Wernicke’s area
3. Broca’s area
4. Motor cortex somatic
5. Auditory cortex
What is somatotopy?
Body maps onto brain surface
Relationship between particular body regions correspond with motor areas of the brain
What is homunculi?
Distribution of nerve endings across the body is uneven. More in hands and lips than other areas
State the areas of brain stem
- Midbrain
- Pons
- Medulla
- Reticular formation – group of nuclei (controlling things like breathing, autonomic heart rate)
- Cerebellum – balance and coordination (lots of nerve cells so very tight folding)
What are the functions of brainstem?
- Contain ascending and descending nerve tracts
- Origin of cranial nerves
- Contain reticular formation
- Consists of medulla, pons and midbrain
What does the reticular formation do?
- Filtering
- Control of sleep and consciousness
- Modulation of pain
- Regulation of cardiovascular and respiratory systems
- Somatic motor control
- Gaze centres
