Neurocytology and Organization of the Nervous System Flashcards
What is the Nervous system?
Control voluntary and involuntary actions and
brief responses to stimuli
What is the Endocrine system?
Adjusts metabolic operations and Directs long-term changes.
What does the Central Nervous System consist of?
Brain and spinal cord
What does the Peripheral Nervous System consist of?
All neural tissue outside CNS
1. Sensory neurons
2. Motor neurons (somatic and
autonomic)
What are the two Functional divisions of nervous system?
Afferent and Efferent
What is Afferent?
Sensory information from receptors to CNS
What is Efferent?
Motor commands to muscles and glands
What does Efferent divided up into?
Somatic division and Autonomic division
What is Somatic division?
Voluntary control over skeletal muscle
What is Autonomic division?
Involuntary regulation of smooth and cardiac muscle, glands
What is an example of Functional divisions of nervous system?
You see (Sensory Receptors) –>Sensory input is Afferent –>Integration –> Motor Output (efferent) –> effector.
What is the Frontal Lobe in charge of?
Memory, Intelligence, Reasoning, Movement, Decision- Making, Mood, Personality.
What is parietal lobe in charge of?
Sensation, Language, reading, intelligence, reasoning, telling right from left.
What is the temporal lobe in charge of?
Memory, vision, speech, behavior, hearing, emotions.
What is the occipital lobe in charge of?
Vision
What is the cerebellum in charge of?
Balance, Coordination, Fine motor control.
What does the brainstem consist of?
left and right hemisphere cerebrum, cerebellum, diencephalon.
The brain stem serves as what?
On/Off switch to control cortical activity and consciousness.
Brain Stem and its associated cranial nerves do what?
control many stereotyped involuntary motor tasks.
What are the involuntary motor tasks that the brain stem and cranial nerves control?
Rhythmic breathing, heartbeat modulation, swallowing, sneezing, involuntary facial expressions.
What are the four major things that make up brain stem?
Diencephalon, midbrain, pons, and medulla.
How many cranial nerve pairs are there?
12
What is the composition of the olfactory nerve?
Sensory Only
What are the functions of the olfactory nerve?
Olfaction aka smell
What is the composition of the optic nerve?
Sensory Only
What are the functions of the optic nerve?
Vision
What is the composition of the oculomotor nerve?
Motor and Sensory
What are the functions of the Oculomotor nerve?
Serves muscles of the eye.
What is the composition of the trochlear nerve?
Motor and Sensory
What are the functions of the trochlear nerve?
Serves the superior oblique eye muscle.
What is the composition of the trigeminal nerve?
Motor and Sensory
What are the functions of the trigeminal nerve?
Sensory from face and mouth; motor to muscles of mastication (chewing)
What is the composition of the abducens?
Motor and Sensory
What are the functions of the abducens?
Serves the lateral rectus eye muscle.
What is the composition of the facial nerve?
Motor and Sensory
What are the functions of the facial nerve?
Serves the muscles of facial expression, lacrimal glands, and salivary glands.
What is the composition of the vestibulocochlear nerve?
Sensory Only
What are the functions of the vestibulocochlear nerve?
Equilibrium and hearing.
What is the composition of the glossopharyngeal?
Motor and Sensory
What are the functions of the glossopharyngeal?
Serves the pharynx (throat) for swallowing, posterior third of tongue, parotid salivary gland.
What is the composition of the vagus nerve?
Motor and Sensory
What are the functions of the vagus nerve?
Sensations from visceral internal organs, and parasympathetic motor regulation of visceral organs.
What is the composition of the accessory nerve?
Motor and Sensory
What are the functions of the accessory nerve?
Serves muscles that move head, neck, and shoulders.
What is the composition of the hypoglossal nerve?
Motor and Sensory
What are the functions of the hypoglossal nerve?
Serves Muscles of the tongue.
How many nerve pairs does the spinal cord have?
32
How many pairs of nerves does the cervical portion of the spinal cord have?
8 pairs
How many pairs of nerves does the thoracic portion have?
12 pairs
How many nerve pairs does the lumbar portion have?
5 pairs
How many nerve pairs does Sacrrum have?
5 pairs
How many nerve pairs does the coccyx have?
2 pairs
What is gray matter?
Where neuron cell bodies are clustered, so it is where all synapses are.
What is white matter?
Where trillions of axons are running between different part of CNS, in bundles of “tracts”
• Remember, tracts are in CNS, vs nerves in PNS
Why is white matter white?
White is from the myelin sheaths
What are the four lobes of the cerebral cortex?
Temporal, Occipital, Parietal, and Frontal lobe.
what are Dorsal half of “H”?
Cell bodies of interneurons
What are Ventral half of “H”?
Cell bodies of motor neurons
What are the two types of cells in the brain?
Neurons and supporting cells known as neuroglia
What type of neurons cells are in the PNS?
- Schwann cells
* Satellite cells
What type of neuron cells in the CNS?
- Astrocytes
- Oligodendrocytes
- Microglia
- Ependymal cells
Glial cells or neuroglia cells are known as what?
Nerve glue
What is the main defining characteristic of neurons?
have the property of electrical excitability - ability to produce
action potentials or impulses in response to stimuli
What are structural classification of neurons based on?
Based on number of processes found on cell body.
What is the most common cell type in the brain and spinal cord?
Multipolar
What is a multipolar neuron?
Several dendrites and one axon
What is a bipolar neuron?
One main dendrite and one axon.
Where are bipolar neurons found?
In retina, inner ear, & olfactory (interneuron)
What are unipolar neurons?
one process only, sensory only (touch, stretch)
Unipolar neurons develop from?
A bipolar neuron in the embryo.axon and dendrite fuse and then branch into 2 branches near the soma - both have the structure of axons (propagate APs) - the axon that projects toward the periphery = dendrites (Sensory neuron)
Where are the Purkinje cells?
In the cerebellum
Where are the Renshaw cells?
In the spinal cord
What do Sensory (afferent) neurons?
transport sensory information from skin, muscles,
joints, sense organs & viscera to CNS
What do Motor (efferent) neurons do?
send motor nerve impulses to muscles & glands
What do Interneurons (association) neurons do?
connect sensory to motor neurons.
90% of neurons in the CNS
What are the three main types of neurons?
Interneuron, Motor Neuron, and Sensory Neuron.
How many neurons are there?
100 billion
What is the magnification of glial cells to neurons?
10x more glial cells thant neuron
What is important to know about glial cells?
do NOT generate electrical impulses,
divide by mitosis, two types in PNS, Four types in the CNS
How do glial cells support neurons?
Provide physical support as well as nutrients.
Who covers neurons with myelin?
Glial cells
Cleans up debris, housewives are?
glial cells
What are Satellite cells?
surround neuron cell body (Structural func2on, protec2ve
cells, supply nutrients, receptors to interact with neurons)
What are Schwann cells?
Form myelin in PNS, maintain and protect neurons.
What makes up myelin?
lipoprotein
Myelin increases what?
speed of conduction, large axons
Main function for myelin?
insulation and prevent leakage
What are nodes of Ranvier?
Layers of spaces between cells.
What happens in MS patients?
patches of myelin are destroyed in the brain and spinal cord; Maligant Peripheral Nerve Sheath Tumors (MPNSTs)
What are the four CNS glial cells?
Astrocytes, microglia, ependymal cells, oligodendrocytes.
What are astrocytes?
Involved in metabolism & synapse formation
What do astrocytes look like?
Star shaped; the most numerous
What are microglia?
Phagocytes
What are ependymal cells?
Line the cavity of CNS and spinal cord; cilia
What are oligodendrocytes?
Produce myelin sheaths in CNS
Glial cells support neurons and do what?
maintain their environment