Chapter 3 Flashcards
Central Nervous System
Brain and Spinal Cord
Peripheral Nervous System
Outside of skull and spine, brings information into the CNS and carry signals out as well
Collections of axons
Nerve - collection of axons OUTSIDE the CNS
Tract - collection of axons INSIDE the CNS
Describe the flow of information
Afferent - information carried into region of interest *Arrive
Efferent - information carried away from region of interest *Exit
Neurons found as a cluster
Ganglion - cluster of neuron cell bodies OUTSIDE the CNS
Nucleus - cluster of cell bodies INSIDE the CNS
PNS subdivisions?
Somatic Nervous System & Autonomic Nervous System
Somatic Nervous System
Interacts with body’s external environment; body surface and muscles
Autonomic Nervous System
Interacts with body’s internal environment; internal organs
Sympathetic motor nerves
Project from neurons in lumbar and thoracic
- controls involuntary movement of internal organs, prepares body using fight or flight, causes arousal
Parasympathetic motor nerves
Project from neurons in cranial and sacral
- promotes vegetative, nonemergency responses; rest and restore
Structures that protect the CNS
Physical and Chemical protection
Physical: bones, membranes (meninges), cerebrospinal fluid
Chemical: blood brain barrier
Meninges
Three meninges:
Duramater - tough outer membrane Arachnoid membrane - weblike membrane Pia mater - adheres to CNS surface
Cerebral Spinal Fluid (CSF)
Two main functions:
- Acts as shock absorber
- Provides exchange medium between blood and brain
Blood Brain Barrier (functions and general properties)
Functions
- protects the brain from foreign substances
- protects the brain from hormones and neurotransmitters in rest of body
- maintains constant environment for brain
General Properties
- large molecules do not pass through BBB easily
- lipid soluble molecules rapidly cross through into the brain but do not penetrate
- molecules that are highly charged are slowed
Neurons
Specialized cells for the reception, conduction, and transmission of electrochemical signals
Consists of: soma, axon, axon terminals, and dendrites
Glia
Outnumber neurons 10:1
Serve to support the functions of neurons
- structural support, insulation, nourishment
Classes of Glia
Oligodendrocytes, Schwann, Astrocytes, Microglia
Structure of the Spine
Cervical, Thoracic, Lumbar, Sacral, and Coccyx (geal for the nerve)
Agonistic
When an externally administered drug binds to an activates a receptor mimicking effect of neurotransmitter
Antagonistic
Externally administered drug binds and inhibits a receptor, preventing effect of neurotransmitter
Acetylcholine
First neurotransmitter to be discovered
Plays a role in cortical activation, learning and memory, indirectly in reward and sleep
Dopamine
Plays a role in reward, motivation, certain types of memory
Norepinephrine
Plays a role in attention, sleep and wakefulness, feeding behaviour, emotions
Serotonin
Mood, aggression, sleep-wake cycles, dreaming, appetite
5 major categories of large molecule neurotransmitters
Miscellaneous peptides, brain-gut peptides, pituitary peptides, hypothalamic peptides, opioid peptides
