Nervous System Flashcards
What are the 4 ways the nervous system can be classified?
- CNS (central nervous system)
- PNS (peripheral nervous system)
- Somatic nervous system
- Autonomic nervous system
What organs can be found in the 4 nervous system classifications?
- CNS: brain and spinal cord
- PNS: cranial nerves and spinal nerves
- Somatic: Conscious control over organs
- Autonomic: Unconscious control over organs
At the cellular level, what are the 2 main type of cells in the nervous system? What are their function?
Neurons: Functional cells –> Dont divide
Neuroglial cells: Cells that support/helps the neurons
Describe the three anatomical structures of a neuron and the function of each part.
- Dendrites: Receives nerve impulses
- Cell body: Computes/process nerve impulse
- Axon: Sends out the nerve signal rapidly
Describe the direction of the nerve impulses.
Direction of nerve impulses is downward
Based on shape, what are the 3 types of neurons?
- multipolar
- bipolar
- unipolar
Describe the 3 neuron shapes
multipolar: has many dendrites and an axon
bipolar: has one dendrite and an axon
unipolar: has an axon, but no dendrites
What are the main 3 types of neurons and what is their shape?
- sensory (afferent): unipolar shape
- motor (efferent): multipolar
- interneuron/association
What does the sensory/afferent neuron do?
Delivers sensory info to the central nervous system
What does the motor/efferent neuron do?
Take motor commands outside of the central nervous system
What does the interneuron/association do?
Acts as the middle-man b/w the sensory and motor neuron
What makes up gray matter?
dendrites and cell body
What makes up white matter?
Myelinated axon
What are the anatomical terms used to describe white and grey matter in the PNS?
Ganglia (grey matter)
Nerves (white matter)
What are the anatomical terms used to describe white and grey matter in the CNS?
Brain
- Cortex and nuclei (gray)
- tracts (white matter)
Spinal Cord
- Horns (grey matter)
- fibers or tracts (white matter)
Which one is far worse if it gets damaged, white matter or grey matter?
White matter
Does nerve and neuron mean the same thing?
No
What does neuron refer to?
singular cell
What does nerve refer to?
bundle of myelinated axons
What are the 3 main types of tracts in the CNS?
- commissural tract
- association tract
- projection tract
What is commisural tract? provide an example
Connects right and left cerebrum
example: corpus callosum
What is the association tract? provide an example
Connects neighboring areas together on the same side
Example: accurate tract
What is the projection tract? provide an example
Connects to the PNS.
Example: pyramids
Where can the association tract only be found?
Only on the left side of brain
What are the 4 glial cells found in the CNS?
- Astrocytes
- Oligodendrocytes
- Microglia cells
- Ependymal cells
What are astrocytes?
Cells that act as a barrier and supports nutrition
What are oligodendrocytes?
Cells that wrap and insulate the axon; makes the myelin sheath
What are microglial cells?
White blood cells that help with neuron defense
What are ependymal cells?
Cells that help with fluid production
What are the 2 types of glial cells found in the PNS?
- Satellite cells
- Schwann cells
What are satellite cells?
Cells that protect the cell body and neurons
What are schwann cells?
Cells that also make the myelin sheath
What is the myelin sheath?
Protective layer over the axon
What makes the myelin sheath in CNS and PNS?
CNS: Oligodendrocytes
PNS: Schwann cells
Demyelination of oligodendrocytes leads to what?
Leads to multiple sclerosis
Damage to schwann cells leads to what?
Guillain barre syndrome
What are the two main structures of the Blood Brain Barrier (BBB)?
- continuous capillaries
- astrocytes (glial cells)
What kind of molecules (size and polarity) can cross the BBB? Provide an example
Small and nonpolar molecules can cross the BBB
example: Alcohol
What are the three layers of meninges?
- Dura Matter: Superficial layer
- Arachnoid Matter: b/w other 2 layers; has fine spider-web like
- Pia Matter: Intimate layer
Where is CSF produced in the central nervous system?
Fluid is made in the arteries
How many ventricles does the brain contain?
Has 4 ventricles
- In this, there are 2 lateral ventricles
What does the cerebral aqueduct do?
Connects the 3rd and 4th ventricle
Describe the CSF chemical composition (2)
- water
- electrolytes
What are the cells that make the CSF? (2)
- ependymal cells that lines the ventricles
- Choroid plexus in the ventricles
Where does the CSF circulate?
Circulates around the superior sagittal sinus
Where/how is the CSF drained and returned to the blood?
Via the arachnoid granulation
What’s hydrocephalus? What cause it?
- It’s the buildup of CSF.
- What causes it is that CSF is either produced too much or it cannot be reabsorbed properly
