ST #1 SCIENCE Flashcards
Gathers information from both inside and outside the body
Sensory Function
Processes the information in the brain and spine
Integration Function
Sends information to the muscles, glands, and organs so they can respond appropriately
Motor Function
The Nervous System is divided into Two Main Divisions:
_____________?
_____________?
-Central Nervous System (CNS)
-Peripheral Nervous System (PNS)
Controls Organs in times of stress.
Sympathetic Nervous System
Controls Organs when the body is resting.
Parasympathetic Nervous System
- Basic functional cell of nervous system
- Transmits impulses (up to 250 mph)
Neuron
Receive stimulus and carries it impulses toward the cell body
Dendrite
Nucleus & most of cytoplasm
Cell Body with Nucleus
Fiber which carries impulses away from cell body
Axon
Cells which produce myelin or fat layer in the Peripheral Nervous System
Schwann Cells
Dense lipid layer which insulates the axon and makes the axon look gray
Myelin sheath
Gaps or nodes in the myelin sheath
Node of Ranvier
Impulses travel from dendrite to cell body to axon.
NOTE
Three types of Neurons
*Sensory neurons – bring messages to CNS
*Motor neurons - carry messages from CNS
*Interneurons – between sensory & motor neurons in the
CNS
A ______ is a change in the environment with sufficient strength to initiate a response.
Stimulus
_______ is the ability of a neuron to respond to the stimulus and convert it into a nerve impulse.
Excitability
The stimulus is either strong enough to start and impulse or nothing happens
All of Nothing Rule
-small gap or space between the axon of one neuron and the dendrite of another
-the neurons do not actually tough at the synapse
Synapse
Chemicals in the junction which allow impulses to be started in the second neuron
Neurotransmitters
Receptor
reacts to a stimulus
Afferent pathway (sensory neuron)
conducts impulses to the CNS
. Interneuron
- consists of one or more synapses in the CNS (most are in the spine)
Efferent pathway (motor neuron)
conducts impulses from CNS to effector
Effector
Muscle fibers (as in the Hamstring muscle) or glands responds by contracting or secreting a
product.
Initiated and completed at the spinal cord level. Occur without the involvement of higher brain
centers.
Spinal reflexes
Central Nervous System
* Brain
-Brain stem – medulla, pons, midbrain
-Diencephalon – thalamus & hypothalamus
-Cerebellum
-Cerebrum
* Spine
-Spinal Cord
Note
Coordination of movement and
aspects of motor learning
Cerebellum
Conscious activity including
perception, emotion, thought, and planning
Cerebrum
– Brain’s switchboard
– filters and then relays information to various brain regions
Thalamus
Vital reflexes as heart beat and respiration
Medulla
Medulla, pons, and midbrain
(involuntary responses) and relays information from spine to upper brain
Brainstem
Involved in regulating activities
internal organs, monitoring information from the
autonomic nervous system, controlling the pituitary gland and its hormones, and regulating sleep and appetite
Hypothalamus
- Is the largest portion of the brain encompasses about two-thirds of the brain mass
- It consists of two hemispheres divided by a fissure – corpus callosum
- It includes the cerebral cortex, the medullary body, and basal ganglia
- The cerebral cortex is the layer of the brain often referred to as gray matter because it has cell bodies and synapses but no myelin
Cerebrum
Lobes of the Cerebrum
- Frontal – motor area involved in
movement and in planning &
coordinating behavior - Parietal – sensory processing, attention, and language
- Temporal – auditory perception, speech, and complex visual perceptions
- Occipital – visual center – plays a role in processing visual information
What Lobe? the motor area involved in movement and in planning & coordinating behavior
Frontal
What Lobe? Sensory processing, attention, and language
Parietal
Auditory perception, speech,
and complex visual perceptions
Temporal
- visual center
– plays a role in
processing visual information
Occipital
– located in the frontal lobe
– important in the production of speech
Broca’s area
.
A group of brain structures (aamygdala, hippocampus, septum, basal ganglia, and
others) that help regulate the expression of emotions and emotional memory
Limbic System
_____ _____ are rhythmic fluctuation of electric potential between parts of the brain as seen on an electroencephalogram (EEG).
Brain Waves
-
-
-
-Beta
-Alpha
-Theta
-Delta
- 12 pair
- Attached to undersurface of brain
Cranial nerves
- 31 pair
- Attached to spinal cord
Spinal nerves
- Relays information from skin, sense organs & skeletal
muscles to CNS - Brings responses back to skeletal muscles for voluntary
responses
Somatic Nervous System (voluntary)
- Regulates bodies involuntary responses
- Relays information to internal organs
- Two divisions
*Sympathetic nervous system – in times of stress
-Emergency response
-Fight or flight
*Parasympathetic nervous system – when body is at rest or with normal functions
-Normal everyday conditions
