Nervous System Flashcards
How many planes are there and what are they?
3 planes
Sagittal, Coronal/Frontal, Horizontal/Transverse
How many directions are there and what are they?
4 directions
Superior/Cranial, Posterior/Dorsal, Anterior/Ventral, Inferior/Caudal
How many neurons are involved in sensory pathway?
3 neurons
Starting from dorsal root ganglion in peripherary, then through 2nd neuron in spinal cord then to the brain
How many neurons are involved in motor pathway?
2 neurons
Starting from the brain out to peripherary
Involuntary motor control neuron pathway
Technically 3, even if it is motor
Multipolar neuron function?
Motor control
Bipolar neuron function?
4 special senses
Pseudo-unipolar neuron function?
general sensation (sensory)
CNS includes?
brain & spinal cord
PNS includes what kinds of nerves?
cranial nerves, spinal nerves, and peripheral nerves (ganglion)
Name the 4 CNS Neuroglia
Astroglia
Oligodendrocytes (myelination)
Microglia
Ependymal Cells
Name the 2 PNS Neuroglia
S&S
Schwann Cells (myelination)
Satellite Cells
Afferent (sensory) neurons
Convey impulses TOWARD the CNS from the peripherary
Interneurons
Form an integrating network between the sensory and motor neurons
Efferent (motor) neurons
Convey impulses FROM the CNS towards the peripherary
What structures make up the Brainstem?
Largest part of the brain!
Pons, Midbrain, Medulla oblongata, Diencephalon
What is the Diencephalon? What makes it up?
In the brainstem and made up of:
Thalamus: relaying of sensory & motor signals to the cerebral cortex (sleep, consciousness, alertness)
Hypothalamus: body temperature, hunger, thirst
What is the midbrain function?
In the brainstem
Function: vision, hearing, motor control
What is the pons function?
In the brainstem
Function: sleep, respiration, swallowing, hearing
What is the medulla oblongata function?
In the brainstem
Function: breathing, heart rate, blood pressurek.
What are the brain divisions?
Cerebrum (2 hemispheres), Cerebellum, and Brain Stem
What is gray matter?
Neuronal cell bodies are in the gray matter
What is white matter?
The myelinated axon projections of neurons form the white matter
What are the 5 lobes of the brain?
Frontal, temporal, parietal, occipital and Insula
What structures are located in the Cerebral Cortex?
Gyri, Sulci
Lobes: frontal, temporal, parietal, occipital and Insula
Frontal Cerebral Cortex Function
personality, reward, attention, skilled motor processing, short term memory
Temporal Cerebral Cortex Function
process sensory input into memories, language comprehension and emotion
Parietal Cerebral Cortex Function
integrates sensory info (sensation)
Occipital Cerebral Cortex Function
visual processing center
Insula Cerebral Cortex Function
consciousness, emotion, homeostasis
What is the spinal cord?
- A collection of neuronal cell bodies in the central gray matter surrounded by axonal projections in the white matter
- Extends from brainstem into the vertebral column
- 31 spinal nerves
Cranial nerves
12 nerves
Are attached to the brain or brainstem
May be sensory or motor or both
How many Spinal Nerves are there? Are they sensory only, or motor also?
31 Pairs
Are attached at the spinal cord
Mostly both sensory and motor
What are ganglia?
A collection of neuronal cells bodies located outside of the CNS
How many spinal nerves are in each section?
Cervical- 8
Thoracic- 12
Lumbar- 5
Sacral- 5
Coccygeal- 1
What is an anesthetic?
Drug that causes reversible loss of sensation
Blocks voltage-gated Na channels and APs
Sensory info fails to reach CNS
What is an analgesic?
Relieves pain without eliminating sensation
What is modality?
Characteristics used to describe a particular type of stimulus
Particular form of sensory perception
Particular mode in which something exists or is expressed
Receptor activation can be accelerated by what?
Agonists
Receptor activation can be terminated by what?
Antagonists
How does NT get terminated at the synapse?
- Enzymatic degradation of NT
- NT re-uptake by the pre-synaptic membrane
- Diffusion away from the synaptic cleft
What is a stroke?
Spinal Cord Injury
Sudden death of brain cells due to lack of oxygen (blockage of blood flow/artery rupture)
What is a spinal cord transection?
Complete tear of the spinal cord
What is a spinal cord disc herniation?
Tear in the outer fibrous ring of an intervertebral disc
What is the 3 neuron pathway to the Primary Sensory Cortex?
- Sensory Ganglion
- Spinal cord or brain stem nuclei, axon crosses midline
- Thalamus
Classes of axons
A Alpha (skeletal muscle)
Beta
Gamma
Delta (SHARP pain)
B (myelinated)
C (non-myelinated and DULL pain)
What is Cranial Nerve #5
Trigeminal Nerve (both motor and sensory)
sensation in face, biting and chewing
What kinds of receptors are modality specific?
Sensory receptors
Where is the primary somatosensory cortex located?
The post central gyrus (parietal lobe)
Sensory Innervation of the Head & Neck
V1 Ophthalmic: Trigeminal Nerve
V2 Maxillary
V3 Mandibular
**V1 V2 only sensory
** V3 both motor and sensory
What are the sensory pathways of the face?
Trigeminal nerve, nucleus and ganglion
Thalamus
Facial region of sensory cortex
What is the sensory homunculus?
A map of sensory space in SSS cortex
SSS-somatosensory
What regions of the SSS Cortex have the highest sensory receptor density?
The face and hands (cortical area)
What structures are included in the maxillary division of the trigeminal innervation?
Maxillary teeth and palate
What structures are included in the mandibular division of the trigeminal innervation?
Mandibular teeth, tongue and floor of the mouth
What is the Brodmann’s area? Where is it located?
Region of cerebral cortex defined by its cellular composition and organization of cells
What is Epilepsy? What are the 3 types?
A brain disorder involving repeated seizures
3 Types: focal, petit mal, and grand mal
Focal epilepsy
epileptic activity starts in just part of the person’s brain
Petit Mal epilepsy
very uncommon, begins suddenly & occurs w/o any warning signs
Grand Mal epilepsy
features a loss of consciousness and violent muscle contraction
William’s syndrome
A distinctive small facial appearance along with a low nasal bridge
Caused by a deletion of 26 genes
Fear/Phobias
Have increased insular activity
Classes of axons
A Alpha (skeletal muscle)
Beta
Gamma
Delta (SHARP pain)
B (myelinated)
C (non-myelinated and DULL pain)
