Lecture 1 - Nervous System Structure Flashcards
4 types of receptors:
Thermoreceptors,
Mechanoreceptors,
Photoreceptors,
Chemoreceptors
3 Functions of Nervous System
Monitors internal/external environments,
Integrates sensory information, Coordinates voluntary/involuntary responses
What are Neuroglia?
Neuroglia - support framework for nerve cells (neurons).
3 CNS Functions
Integrates sensory data,
Transmission of motor commands,
Coordinates higher function
Parts of CNS
Brain + Spinal Cord
Parts of PNS
Neural Tissue outside of CNS
2 Functions of PNS
Deliver sensory info to CNS,
Carry motor commands to periphery tissue
Main difference between CNS/PNS Functions
No integration of sensory data in PNS
Difference between Afferent/Efferent
Afferent = carries info from sensory receptors
Efferent = carries info to motor receptors
Divisions of PNS
Somatic/Autonomic Nervous Systems
Function of Somatic NS
Coordinates conscious activity
E.g. skeletal muscle contraction
Function of Autonomic NS
Coordinates unconscious activity
E.g. heart rate, blood pressure
Divisions of Autonomic NS
Parasympathetic/Sympathetic Divisions
Function of Parasympathetic Division
Rest and Digest
Function of Sympathetic Division
Fight and Flight and Freeze responses
4 types of neurons
Anaxonic,
Bipolar,
Unipolar,
Multipolar
Anaxonic Neurons (3 points)
Found in Brain/special sense organs,
Very small,
No anatomical difference between dendrites and axon
Bipolar Neurons (3 points)
1 dendrite and 1 axon with cell body between them
Rare,
Found in special sense organs
Unipolar Neurons (2 points)
1 continuous axon with cell body lying off to the side,
Most sensory neurons are unipolar
Multipolar Neurons (4 points)
Multiple dendrites and 1 axon
Common in CNS
Contains myelin sheath
Motor neurons are multipolar
Parts of neuron
Dendrite
Axon
Cell body
Dendrite branches (sensitive to stimuli)
Axon terminals
Direction of action potential?
Down the axon
3 Spinal Cord Function
Integrates info
Controls spinal reflexes
Controls automatic motor responses
Number of Spinal cord segments
31
Why is white matter myelinated?
Found in Afferent + Efferent Divisions, so needs to be quick transmission
Why is grey matter unmyelinated?
Found in inter neurons, so doesn’t need to be quick
Function of Dorsal Root Ganglia
Bundle of neurons relaying sensory info from Afferent pathway to CNS
Function of Ventral roots
Contain axons of motor neurons for info to be sent to efferent pathway
Routes for Afferent/Efferent pathways into spinal cord
Afferent = Dorsal route,
Efferent = Ventral route
Components of White Matter in spinal cord
Myelinated/Unmyelinated axons
Components of Grey Matter in spinal cord
Cell bodies
Neuroglia
2 sections of grey matter in spinal cord
Somatic + Visceral
Functions of Somatic/Visceral Grey Matter
Somatic = conscious info
Visceral = unconscious info
4 regions of spinal cord
Cervical
Thoracic
Lumbar
Sacral
Definition of dermatome
Specific region monitored by a pair of spinal nerves
Responsible for nerve pain not originating from point of injury
5 Stages of Reflex Arc
Stimulus detection at receptors
Activation of sensory neuron
Info processed in CNS
Activation of motor neuron
Response by peripheral effector
Inhibition within Withdrawal Reflex Arc
Flexors stimulated whilst extensors inhibited to make reflex arc more effective
Function of Golgi Tendon Organs (3 points)
Senses tension in muscle contraction
Has inhibitive afferent neuron
Decreases contraction when excessive force is applied for protection
6 regions of the brain
Cerebrum
Cerebellum
Diencephalon
Mesencephalon
Pons
Medulla oblongata
4 Lobes of Cerebral Cortex
Frontal
Temporal
Occipital
Parietal
Components/Function of Frontal Lobe
Pre central gyrus
Premotor Cortex
Prefrontal cortex
Voluntary motor activity
Components/Function of Temporal Lobe
Auditory association area
Auditory cortex
Olfactory cortex
Initial reception of auditory info
Components/Function of Occipital Lobe
Visual association area
Visual cortex
Initial reception of visual info
Components/Function of Parietal Lobe
Postcentral gyrus
Somatic sensory association area
Processing sensory info
Regions of Cerebellum (grey matter)
Cerebellar Cortex
Cerebellar Nuclei
Regions of Cerebellum (white matter)
Arbor vitae
Cerebellar peduncles
Transverse fibers
3 Cerebellar Peduncles + Function
Superior - links to midbrain/diencephalon/cerebrum
Middle - links to cerebellum/pons
Inferior - links to medulla oblongata/spinal cord
Regions of Diencephalon (5 points)
Thalamus
Epithalamus
Hypothalamus
Pituitary gland
Pineal gland
Function of midbrain
Processing of audio and visual info
Regions of midbrain (4 points)
Tectum
Walls + Floor
Nuclei
Cerebral Peduncles
Components/Functions of Tectum (2 points)
Superior colliculus - process info/initiate response for visual stimuli
Inferior colliculus - process info/ initiate response for auditory stimuli
Components/Functions of Walls/Floor (3 points)
Substantia nigra - regulation of basal nuclei
Red nucleus - subconscious control of upper limb position/background muscle tone
Reticular formation - automatic processing of involuntary responses
Regions of Pons (5 points)
Descending/Ascending Tracts
Transverse fibers
Apneutic/Pneumotaxic centres
Reticular formation
Cranial Nerves
Function of Pons
Links cerebellum to mesencephalon, Diencephalon, cerebrum and spinal cord
Physical protection in the brain (3 points)
Cranium bones
Cranial meninges
Cerebrospinal fluid
Biochemical Isolation in the brain (2 points)
Blood brain barrier
CNS isolation from circulatory system
Function of Cranial meninges
Protects the brain from cranial trauma
3 Layers of Cranial Meninges
Dura mater
Arachnoid mater
Pia mater
Functions of Cerebrospinal fluid
Cushion, support, transport of nutrients and chemicals/waste products
Cerebrospinal fluid properties
Surrounds all exposed surfaces of CNS
Interchanged with interstitial brain fluid
CSF same density and brain fluid
12 Cranial Nerves
I - Olfactory - Sensory
II - Optic - Sensory
III - Occulomotor - Motor
IV - Trochlear - Motor
V - Trigeminal - Both
VI - Abducens - Motor
VII - Facial - Both
VIII - Vestibulocochlear - Sensory
IX - Glossopharyngeal - Both
X - Vagus - Both
XI - Accessory - Motor
XII - Hypoglossal - Motor
Grooves in Spinal cord
Fissure > Sulcus
