COMD501 Lesson 2 (part 1) Powerpoint
Based off of Dr. Barnes powerpoint of lesson 2
What are the anatomical divisions of the nervous system called?
Central Nervous System & Peripheral Nervous System
What are the functional divisions of the nervous system called?
Autonomic vs. Somatic
What does the central nervous system consist of?
Brain & spinal cord
Where is the central nervous system housed?
Within the skull and vertebral column
What is the peripheral nervous system made of?
12 pairs of cranial nerves & 31 pairs of spinal nerves (can be sensory or motor)
____________feedback travels back to the brain
____________ feedback tells the muscles what to do
What are the 2 divisions of the nervous systems?
Functional (Autonomic vs. Somatic) & Anatomical (Central vs. Periphheral)
What do autonomic neurons do
? they are involuntary & govern life processes (heart, digestion, glands, sweating, dialation of pupils, etc)
What do somatic neurons do?
They control all voluntary movements
What does ANS stand for?
Autonomic Nervous System
What are the 2 subsystems of the ANS?
Sympathetic & Parasympathetic
What is the sympathetic system?
expends energy; increases blood pressure, heart rate, sweat, constricts blood vessels. Prepares you for "fight or flight"
What is the parasympathetic system?
conserves energy; opposite of sympathetic response, allows for sustained activity
The motor component of the somatic system may be subdivided into what 2 systems?
Pyramidal & extrapyramidal
What does the pyramidal system do?
Initiates voluntary motor acts (i.e. raising one's arm)
What does the extrapyramidal system do?
It is responsible for background tone and movement supporting primary motor acts (i.e. moving the arm further to the left or right, etc.)
What are the 3 functions of the nervous system?
To sense stimuli, analyze, & respond
What kind of Stimuli?
Hunger, thirst, proprioception, pain, touch, movement, hearing, vision. Any sensory stimuli
How is stimuli analyzed?
through experience, memory and cognition
What is the reponse governed?
With muscular or glandular action
What are the 4 major regions of the central nervous system?
Cerebrum, Diencephalon, Brainstem, Cerebellum
What is the Cerebrum?
What we think of as the brain - the 2 hemispheres of gray matter
What is the Diencephalon?
Beneath gray matter, controls autonomic and attentional responses. (involuntary actions)
What is the Brainstem?
Controls primitive & lifesaving functions. Regulates arousal, i.e.awake/sleep cycles. Also responsible for breathing, beating heart, etc.
What is the cerebellum?
Means little brain, is responsible for coordination & balance
How does the brain develop?
Begins the 4 week of life with 3 major sections
What are the 4 major sections of the brain as its developing?
The forebrain (prosencephalon), midbrain (mesencephalon) & hindbrain (rhombencephalon)
What does the forebrain/prosencephalon consist of?
The cortex & subcortical structures
What does the hindbrain/rhombencephalon consist of?
The pons, cerebellum,& medulla oblongata
The prosencephalon breaks down intowhat other 2 "cephalons"?
The Telencephalon (cerebral hemispheres) & the Diencephalon ( thalamus, hypothalamus, ventricles)
The rhombencephalon breaks down into what other 2 "cephalons"?
the Metencephalon ( pons, cerebellum) & Myelencephalon ( medulla oblongata)
Describe the cerebrum?
two hemispheres, divided by the longitudinal fissure connected by the corpus collosum
What function do the Basal ganglia serve?
They are involved in movement initiation and termination
The Diencephalon consists of what 3 parts?
The thalamus, hypothalum & ventricles
What does the thalamus do?
It is responsible for the relay/integration center for sensory information delivered to the hemispheres
What does the hypothalamus do?
It influences/controls ANS reaction, visceral activities (temperature, sleep, hunger, thirst, etc), emotions
What do the ventricles do?
It both creates and circulates the cerebrospinal fluid through the brain & around the skull (Provides the brain with cushion!)
What does the mesencephalon do?
It connects forebrain and hindbrain &has cerebral aqueduct which connects the fourth ventricle to the ventricles in the forebrain
What 2 parts does the Metencephalon consist of?
The cerebellum & pons
What is the cerebellum responsible for?
The coordination of limb movement, balance and posture; contains cortex (gray matter) & interior (white matter and gray nuclei)
What does the pons do?
Joins the two hemispheres of the cerebellum and joins the cerebellum to the cerebrum and the spinal cord
What 2 parts does the Myelencephalon consist of?
The medulla oblongata & the 4th ventricle
Where is the medulla oblongata located?
Where the spinal cord merges into the brain
What percentage of efferent fibers decussates to the other side of the brain?
70 - 95 percent
Describe the fourth ventricle
the CSF-filled central canal of the spinal cord
What do Cerebral spinal fluids do?
The CNS is wrapped in CSF, CNS bathed in and nourished by CSF, & Cushions neural tissues
What are the 4 CSF filled spaces in the brain?
The 2 lateral ventricles, the 3rd ventricle & 4th ventricle
How does circulation of the CSF work?
Circulates from ventricles around brain and spinal columns, Is finally absorbed by venous system, & Replenishes at ventricles every 7 hours
What are the meninges?
The 3 layers of protective connective tissues that surrounds the brain & spinal cord
What are the 3 types of meninges?
Dura mater, Arachnoid mater, & pia mater
What is dura mater?
The outermost layer
What is arachnoid mater?
Beneath the dura mater, its loose & web like with many blood vessels passing through it
What is the pia mater?
Fits into the grooves of the sulci of the brain, covers it in a shrink wrap type way
Why are there a lot of convolutions in the cerebrum?
Allows a greater surface area as brain growth outstrips skull growth
What is the gyrus/gyri?
The "mountains" of the brain
What is sulcus/sulci?
The "valley" of the brain
What is a fissure?
A very deep sulcus
What is the lateral sulcus?
It divides the frontal lobe from the temporal lobe
What is the central sulcus?
It divides the motor & sensory parts of the brain as well as the parietal lobe & the frontal lobe