Exam 2 Flashcards
(170 cards)
What two categories can the nervous system be divided into?
Structural and Functional
The STRUCTURAL organization of the nervous system is broken into the ______ and ______ NS, while the FUNCTIONAL organization is broken into the _____ and _____ NS.
Structural: Central and Peripheral
Functional: Sensory and Motor
The central NS includes the _____ and _____, while the peripheral NS includes the _______, _______, and ______.
- Brain and Spinal Cord
2. Cervical Nerves, Spinal Nerves, and Ganglia
The CNS and PNS perform three general
functions:
- Collecting information: Receptors detect
changes in the internal and external environment; pass the information on to the CNS - Processing and evaluating information: CNS determines the required response
- Responding to information: CNS initiates nerve impulses to effectors to react to changes in the body’s environment
The sensory NS is divided into the _____ and ______, while the motor NS is divided into the ____ and _____.
- Somatic Sensory and Visceral Sensory
2. Somatic Motor and Autonomic Motor
The sensory NS and motor NS are also called the ______ and _____ respectively.
- Afferent NS
2. Efferent NS
Describe the two distinct type of cells within the nervous system:
- Neurons (nerve cells): Electrically excitable cells that initiate, transmit, and receive nerve impulses
- Glial cells: Nonexcitable cells that support and protect the neurons
What is the basic structural unit of the NS?
The Neuron
What are 3 special characteristics of neurons?
– High metabolic rate
– Extreme longevity
– Nonmitotic
What are the 3 main structural regions of the neuron?
- Cell body
- Dendrites
- Axon
______ receive nerve impulses and carry them to the cell body
Dendrites
Neurons without an axon are called _____
Anaxonic
What is the axon hillock?
The region where the axon connects to the cell body
- Axon collaterals:
- Telodendria:
- Synaptic knobs:
- Side branches off the main axon
- Fine terminal extensions at the end of the axon and its collaterals
- Expanded regions at the tip of telodendria
What 3 ways are neurons classified STRUCTURALLY?
- Unipolar: Single, short process that branches like a T
- Bipolar: Two processes, one dendrite and one axon
- Multipolar: Many dendrites and a single axon; most common type of neuron
What 3 ways are neurons classified FUNCTIONALLY?
- Sensory (afferent): Transmit impulses from sensory receptors to the CNS
- Motor (efferent): Transmit impulses from CNS to muscles or glands
- Interneurons: Facilitate communication between sensory and motor neurons
Brain tumors are more likely to be derived
from ______ than neurons, because they are: (2)
- Glial cells
2. Mitotic and more numerous
What are the 4 types of glial cells found in the CNS?
- Astrocytes
- Ependymal cells
- Microglial cells
- Oligodendrocytes
The most common and least common types of glial cells are _____ and _____ respectively.
- Astrocytes
2. Microglia
What are the 6 functions of astrocytes?
- Helping form the blood-brain barrier (BBB)
- Regulating tissue fluid composition
- Helping regulate synaptic transmission
- Forming a structural network
- Replacing damaged neurons
- Assisting neuronal development
Astrocytes are ______ cells with ________. They are in contact with _______.
- Large
- Numerous Processes
- Neurons and Capillaries
Ependymal cells are _________ cells that line the ________ and the _____________.
- Ciliated cuboidal epithelial
- Ventricles of the brain
- Central canal of the spinal cord
Ependymal cells not only ________, but also ______.
- Produce the CSF
2. Form the choroid plexus
Microglia are _____ cells that _______________, specifically by ____________.
- Small
- Wander through the CNS and exhibit phagocytic activity
- Removing cellular debris from dead or dying cells