divisions of the nervous system
DESCRIPTION
Divisions of the Nervous System. Unit 8: Human Body Systems Chapter 35-3. Brain Spinal Cord. Central Nervous System. Nervous System. Peripheral Nervous System. Nerve cells. Divisions of the Nervous System. 2 major divisions:. A. The Central Nervous System (CNS). - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/1.jpg)
Divisions of the Divisions of the Nervous SystemNervous System
Unit 8: Human Body SystemsChapter 35-3
![Page 2: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/2.jpg)
Divisions of the Nervous Divisions of the Nervous SystemSystem
• 2 major divisions:
Nervous System
Central Nervous System
Peripheral Nervous System
BrainSpinal Cord
Nerve cells
![Page 3: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/3.jpg)
A. The Central Nervous System (CNS)• Control center of the
body• Relays messages,
processes & analyzes information
• Made of two parts:– BrainBrain– Spinal cordSpinal cord
![Page 4: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/4.jpg)
• 1. The Brain1. The Brain– Impulses flow to and from the
brain– 100 billion neurons, mainly
interneurons
![Page 5: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/5.jpg)
•2. Spinal Cord– Main
communication link between brain and the rest of the body
– Processes information such as reflexes
![Page 6: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/6.jpg)
1. Protection of the CNS• Brain and spinal cord are protected by:• a) Bone – skull and vertebrae• b) Meninges – layers of connective
tissue that surround the organs• c) Cerebrospinal fluid – fluid found in
between meninges and organ– Acts as a shock absorber– Continually circulates around the brain
![Page 7: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/7.jpg)
• DISEASE: Meningitis– Inflammation of the meninges– Can be caused by an viral ,
bacterial or microorganism infection
– Causes headaches, neck stiffness, confusion, sensitivity to light and sound
– Can be life threatening • DISEASE: Hydrocephalus
(“water on the brain”)– Accumulation of CSF in the
brain– Exerts pressure on the brain
causing brain damage
![Page 8: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/8.jpg)
2. Regions of the Brain• Regions of the Brain
–Cerebral hemispheres (Left & Right)
–Diencephalon–Brain stem–Cerebellum
![Page 9: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/9.jpg)
a. Cerebral Hemispheres a. Cerebral Hemispheres (Cerebrum)(Cerebrum)
• Left and right hemispheres– Left brain – logic,
language, math– Right brain – creativity
• Connected by the corpus callosum (communication link between right and left)
![Page 10: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/10.jpg)
![Page 11: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/11.jpg)
• The surface is made of ridges (gyri) and grooves (sulci)
![Page 12: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/12.jpg)
Fissures Fissures (deep grooves) (deep grooves) divide the cerebrum divide the cerebrum into four lobesinto four lobes
1.1. Occipital LobeOccipital Lobe: visual integration
2.2. ParietalParietal: spatial knowledge, math
3.3. TemporalTemporal: memories, auditory, language
4.4. FrontalFrontal: emotion, future planning, judgment, muscle movements, language
![Page 13: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/13.jpg)
![Page 14: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/14.jpg)
• Limbic System – involved in emotion, motivation, arousal, memory, and learning– Amygdala – fear– Hippocampus –
memory formation
![Page 15: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/15.jpg)
b. Diencephalon• Relay and control center• Sits on top of brain stem• Two main parts:
– 1) Thalamus – relay between sensory areas and cerebrum– 2) Hypothalumus – regulates involuntary responses & hormone secretions of
the pituitary gland
![Page 16: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/16.jpg)
c. Brain Stem• Attaches brain to spinal
cord• Parts of the brain stem
– Midbrain – vision, hearing, motor control
– Pons – breathing, sleep– Medulla oblongata -
involuntary activities (breathing, heart rate, blood pressure)
![Page 17: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/17.jpg)
![Page 18: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/18.jpg)
d. Cerebellum• “Little brain”
inferior to and posterior to cerebral cortex
• Coordination, posture, motor learning
![Page 19: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/19.jpg)
3. Spinal Cord• Cylinder of nervous
tissue that begins at base of brain
• Protected by the vertebral column and meninges
![Page 20: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/20.jpg)
• Spinal nerves extend from the cord through each vertebrae
• Main communication link between brain and the body
![Page 21: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/21.jpg)
4. Traumatic Brain Injuries & Diseases• Concussion
– Slight or mild brain injury– Bleeding & tearing of nerve fibers
happened– Recovery likely with some memory loss
• Contusion– A more severe TBI– Nervous tissue destruction occurs– Nervous tissue does not regenerate
• Cerebral edema– Swelling from the inflammatory
response– May compress and kill brain tissue
![Page 22: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/22.jpg)
• Cerebrovascular Accident (CVA)Cerebrovascular Accident (CVA)– Commonly called a stroke– The result of a blocked or ruptured
blood vessel supplying a region of the brain
– Brain tissue supplied with oxygen from that blood source dies
– Loss of some functions or death may result
![Page 23: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/23.jpg)
![Page 24: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/24.jpg)
Alzheimer’s Disease• Progressive degenerative brain disease• Mostly seen in the elderly, but may
begin in middle age• Structural changes in the brain include
abnormal protein deposits and twisted fibers within neurons
• Victims experience memory loss, irritability, confusion and ultimately, hallucinations and death
![Page 25: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/25.jpg)
![Page 26: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/26.jpg)
Peripheral Nervous System Peripheral Nervous System (PNS)(PNS)
Sensory Division Motor Division
Somatic NS Autonomic NS
Sympathetic Parasympathetic
![Page 27: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/27.jpg)
B. Peripheral Nervous System B. Peripheral Nervous System (PNS)(PNS)
• Peripheral Nervous System Peripheral Nervous System is made up of all the nerves and ganglia (nerve cell bodies) that carry messages between the body and the CNS
• Receives info from the environment
• Transmits commands from CNS to organs and glands
• Contains mostly motor and Contains mostly motor and sensory neuronssensory neurons
![Page 28: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/28.jpg)
Divisions of the PNSDivisions of the PNS•Sensory
division –transmits impulses from sense organs to the central nervous system
•Motor division –transmits impulses from the central nervous system to the muscles or glands
–Divided into 2 divisions•Somatic•Autonomic
![Page 29: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/29.jpg)
Motor DivisionMotor Division•Somatic N.S.• Regulates activities
that are under conscious control
• Example: movement of muscles (wiggle toe)
• Involved in reflexes (quick, automatic response to stimulus)
•Autonomic N.S.
• Regulates activities that are automatic or involuntary
• Example: heart rate
• Consists of only motor nerves
• Divided into two divisions– Sympathetic
division– Parasympathetic
division
![Page 30: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/30.jpg)
Autonomic N.S. DivisionAutonomic N.S. Division•Sympathetic• “Fight-or-Flight”• Takes over to
increase activities• Remember as the
“E” division = exercise, excitement, emergency, and embarrassment
•Parasympathetic
• “Rest and Digest• Conserves energy• Maintains daily
necessary body functions
• Remember as the “D” division = digestion, defecation, and diuresis (urination)
![Page 31: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/31.jpg)
Peripheral Nervous Peripheral Nervous System & ReflexesSystem & Reflexes
•The peripheral nervous system is also involved in reflexes.
•A reflex is a quick and unconscious response to a stimulus
•The brain is not involved with reflexes.
![Page 32: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/32.jpg)
• The impulse travels up sensory neurons, to the spinal cord (interneuron), then immediately travels down motor neurons for a response.
• The pathway the impulse travels is called the reflex arc
![Page 33: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/33.jpg)
Reflex ArcReflex Arc
• Receptor (sense organ) sensory neuron spinal cord motor neuron effector (muscle)
![Page 34: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/34.jpg)
Internal CommunicationInternal Communication•Internal communication is critical to maintain homeostasis.
•Sensory neurons are constantly sending information to the brain about the internal environment.
•The brain responds by sending signals through the motor neurons to maintain homeostasis.
![Page 35: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/35.jpg)
![Page 36: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/36.jpg)
The Nervous SystemThe Nervous System
PNSPNSCNSCNS
Somatic NSSomatic NSVoluntary Movement
Autonomic NSAutonomic NSInvoluntary Movement
Sympathetic Sympathetic NSNS
fight or flight
ParasympatheParasympatheticticNSNS
rest & digest
BrainBrain Spinal Spinal CordCord
![Page 37: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/37.jpg)
Reflex Pathway• Sensory input >
– Sensory Neuron > •Spine (Interneuron) >
–Motor neuron »> Involuntary Reflex (response)
![Page 38: Divisions of the Nervous System](https://reader036.vdocuments.net/reader036/viewer/2022062520/56815e08550346895dcc6035/html5/thumbnails/38.jpg)
Conscious Response Pathway
• Sensory Input >– Sensory Neuron >
•Brain (Interneurons) >–Motor Neuron >
»Voluntary Movement (Response)