Basic functions of the nervous system
Sensory input - when information is gathered by sensory receptors about internal and external changes
Integration - processing and interpretation of sensory input
Motor output - activation of effector organs products a response
What is the central nervous system?
Brain and spinal cord
Integration and control center
What is the peripheral nervous system?
Spinal nerves to and from spinal cord
Cranial nerves to and from brain
What are the 2 cell types of the nervous tissue?
Neuroglia - small cells tang surround and wrap delicate neurons (most cells in the brain)
Neurons - excitable cells that transmit electrical signals
What are 2 types of neuroglia?
Astrocytes (CNS)
Oligodendrocytes (CNS)
Myelin sheaths in the CNS are formed by multiple processes of oligodendrocytes
Yes
What is white matter?
Regions of the brain and spinal cord with dense collections of myelinated fibers
What is gray matter?
Mostly neuron cell bodies and nonmyelinated fibers
What are the 3 types of neurons?
Multipolar
- 3 or more processes
- 1 axon, other dendrites
- most common, major in the CNS
Bipolar
- 2 processes
- 1 axon and 1 dendrite
- rare
Unipolar
- 1 short process
- divides T like (both branches considered axons)
- distal process
- proximal process
4 regions of the brain
Cerebral cortex
Diencephalon
Cerebellum
Brain stem
(Ventricles)
What are ventricles?
Spaces filled with cerebrospinal fluid
Protects brain against jolts/trauma
Chemical stability
Neutral buoyancy (weightless brain)
Functional areas of the cerebral cortex:
Motor areas - control voluntary movement
Sensory areas - conscious awareness of sensation
Association areas - integrate diverse information
What structures are in the diencephalon?
Thalamus - gateway to cerebral cortex, sorts and edits incoming stuff, mediates sensation
Hypothalamus - controls autonomic nervous system, blood pressure etc. Physic responses to emotion, perception of pleasure and fear. regulates body temp, hunger, water balance. Regulate sleep clock (suprachiasmatic nucleus)
Epithalamus - pineal gland describes melatonin to help sleep cycle
3 parts of brain stem:
Midbrain
Pons
Medulla oblongata - functions overlap with hypothalamus. Responsible for vomiting, hiccuping, swallowing, coughing, sneezing
Cardiovascular center
In medulla oblongata
- Cardiac center adjusts force and rate of heart contraction
- Vasomotor center adjusts blood vessel diameter for blood pressure regulation
Cerebellum:
Smooth coordinated movements
Thinking, language, emotion
What is the limbic system?
Hypothalamus
Hippocampus - memory
Olfactory bulb
- interacts with prefrontal lobe
- react emotionally to things we understand
What is affected in Alzheimer’s disease?
Hippocampus
Reticular activating system:
Send impulses to cerebral cortex to keep it conscious and alert
Severe injury results in coma
Reticular formation
Motor function
Helps control limb movements
What is a blood brain barrier?
A selective barrier that allows nutrients to move by facilitated diffusions
Allows fat soluble substances to pass (alcohol, nicotine, anesthetics)
True or false
A stroke is when there’s too much Ca2+ inside the cell and action potential goes up
True