Chapter 3: Anatomy of the Nervous System Flashcards
What does the CNS contain?
The skull and the spinal cord
What does the PNS contain?
Everything outside of the skull and spine
Where is the somatic NS? What does it do?
In the PNS. Interacts with the external environment.
Where is the autonomic NS? What does it do?
In the PNS. Regulates the body’s internal environment.
What are afferent nerves?
Nerves that carry signals towards the CNS.
What are efferent nerves?
Nerves that carry signals away from the CNS.
Where are the sympathetic nerves located?
Located in the thoracic and lumbar spine.
Where are the parasympathetic nerves located?
Located in the brain and sacral spine.
What does the fact that parasympathetic/sympathetic nerves are “two-stage” neural paths mean?
The neurons project from the CNS and only go part of the way to the target organs before they synapse on other neurons that finish the journey.W
What is the difference between the two stages of the parasympathetic and sympathetic neural paths and their respective second-stage neurons?
Parasympathetic: the transfer happens very close to the target (second-stage neurons are very short)
Sympathetic: the transfer happens far away from the target (second-stage neurons are relatively long)
What are the parasympathetic and sympathetic NS’s responsible for?
Parasympathetic: psychological relaxation/fight or flight(think: para-lyzed)
Sympathetic: psychological arousal/rest and digest
Where do most PNS nerves project from? What is the exception?
Most PNS nerves project from the spinal cord.
Exception: the 12 pairs of cranial nerves, which project from the brain
What are the 12 pairs of cranial nerves?
olfactory optic oculomotor trochlear trigeminal abducens facial vestibulocochlear glossopharyngeal vagus spinal accessory hypoglossal
How do the functions of cranial nerves give information and clues about possible diagnoses for patients?
Because the nerves are located in specific areas of the brain and have specific functions, disruptions of particular nerve functions can show location and extent of problems in the brain.
What 3 things are the brain and spinal cord protected by?
Bone and 3 meninges (protective membranes), cerebrospinal fluid
What are the 3 meninges?
Outer: dura mater
Middle: arachnoid membrane/subarachnoid space
Inner: pia mater
Where is cerebrospinal fluid likely produced?
The choroid plexuses
What is the blood-brain barrier?
A filtering mechanism of the capillaries that carry blood to the brain and spinal cord tissue, blocking the passage of certain substances.
Which cranial nerves are purely sensory?
Olfactory and Optic
Which cranial nerves are the longest?
Vagus
A tumor near the ____ ____ can produce hydrocephalus.
Cerebral aqueduct
What are the two types of cells in the nervous system?
Neurons and glial cells.
What is the neuron cell membrane composed of?
A lipid bilayer, embedded with protein molelcules
What is a multipolar neuron?
The most common neuron, with more than two processes extending from its cell body.
What is a unipolar neuron?
A neuron with one process extending from its cell body.
What is a bipolar neuron?
A neuron with two processes extending from its cell body.
What are interneurons? What is their function?
Neurons with a short axon or no axon at all. They integrate neural activity within a single brain structure, rather than conduct signals from one to another.
What are the two kinds of gross neural structures in the nervous system?
Those composed of cell bodies, those composed of axons.