Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside...
-
Upload
ethel-alexander -
Category
Documents
-
view
222 -
download
0
Transcript of Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside...
![Page 1: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/1.jpg)
Nervous System
![Page 2: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/2.jpg)
![Page 3: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/3.jpg)
Functions of the Nervous System
• Sensory Input– Monitors changes
(stimuli) inside and outside the body
• Integration– Processes and interprets
sensory input to decide what should be done
• Motor Output– Supplies response by
activating muscles or glands
![Page 4: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/4.jpg)
Nervous System Divisions
• Central Nervous System (CNS)– Includes the Brain and Spinal Cord
• Peripheral Nervous System (PNS)– Includes Spinal nerves & Cranial nerves
![Page 5: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/5.jpg)
![Page 6: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/6.jpg)
![Page 7: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/7.jpg)
Further Breakdown of PNS
• Sensory (afferent) Division– Sends impulses to the CNS from sensory
receptors in body– Somatic sensory fibers: messages from skin,
muscles and joints– Visceral sensory fibers: messages from
internal organs
• Motor (efferent) Division– Carries impulses from CNS to effector organs
(muscles and glands) to cause a response
![Page 8: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/8.jpg)
SAMESensory = Afferent
(comes first, body brain)Motor = Efferent
(comes second, brain body)
![Page 9: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/9.jpg)
Further Breakdown of Motor Division
• Somatic System– Voluntary control of skeletal muscles
• Autonomic System– Involuntary body responses, such as smooth
& cardiac muscles, and glands
![Page 10: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/10.jpg)
![Page 11: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/11.jpg)
![Page 12: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/12.jpg)
Nervous Tissue
• Made up of two types of cells– Supporting Cells: these structures do not
directly transmit any signals, but they help the neurons to function properly; aka “glia”
– Neurons: actually pass signals
![Page 13: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/13.jpg)
Supporting Cells
• Neuroglia: supporting cells (glia) lumped together (term is commonly used to reference all types of supporting cells)
![Page 14: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/14.jpg)
Neuroglia Cells
Neuron Cell Body
![Page 15: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/15.jpg)
Types of Supporting Cells in CNS
• Astrocytes– Form barrier between capillaries and neurons– Help control chemical environment in brain– “To Make Mice Smarter, Add A Few
Astrocytes!”– Scroll to bottom of website to see how astrocytes communicate
• Microglia– Dispose of debris, such as dead brain cells
and bacteria (immune system)
![Page 16: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/16.jpg)
Each astrocyte has its own territory (they don't overlap), and each may interact with
several neurons and hundreds to thousands of
synapses to properly integrate information.
"End-feet" connect to blood vessels in the brain. By signaling blood vessels
to expand or narrow, astrocytes regulate local blood flow to provide oxygen and nutrients to neurons in
need.
Astrocytes can release gliotransmitters (like glutamate) by
exocytosis to send signals to neighboring neurons.
![Page 17: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/17.jpg)
Astrocytes
Neurons
![Page 18: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/18.jpg)
![Page 19: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/19.jpg)
![Page 20: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/20.jpg)
Types of Supporting Cells in CNS
• Ependymal– Lines cavity of brain & spinal cord– Circulate cerebrospinal fluid
• Oligodendrocytes– Wrap around nerve fibers, forming myelin
sheaths
![Page 21: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/21.jpg)
![Page 22: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/22.jpg)
![Page 23: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/23.jpg)
Types of Supporting Cells in PNS
• Schwann cells: form myelin sheaths in PNS
• Satellite Cells: protective, cushioning cells in PNS
![Page 24: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/24.jpg)
Neuroglia Cells
Neuron Cell Body
![Page 25: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/25.jpg)
Parts Of A Neuron
• Cell Body: metabolic center, contains rough ER (Nissl substance) and neurofibrils (maintain shape)
• Dendrites: convey incoming messages toward cell body
![Page 26: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/26.jpg)
Parts Of A Neuron
• Axons: conduct outgoing messages away from cell body (has only one originating at axon hillock)
• Axon Terminal: branching at end of axon which contain neurotransmitters
![Page 27: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/27.jpg)
![Page 28: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/28.jpg)
Parts Of A Neuron
• Synaptic Cleft (Synapse): gaps between neurons
• Myelin Sheath: protects and insulates nerve fibers (axon), increases rate of nerve impulses; made of proteins and lipids
![Page 29: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/29.jpg)
Parts Of A Neuron
• Schwann cells: cells forming myelin sheath in PNS– CNS =
oligodendrocytes
• Nodes of Ranvier: gaps between Schwann cells on axon
Did you know Einstein’s brain was STOLEN? Here the story here.
![Page 30: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/30.jpg)
FYI: Multiple Sclerosis
• Myelin sheaths around the fibers are destroyed, and converted into hardened sheaths called scleroses
• Person loses ability to control muscles
![Page 31: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/31.jpg)
Neuron Classification
• Functional– Sensory (afferent): carry impulses from
sensory receptors to CNS– Motor (efferent): carry impulses from CNS to
body– Association (interneurons): connect motor and
sensory neurons in neural pathways of CNS
![Page 32: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/32.jpg)
![Page 33: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/33.jpg)
Neuron Classification
• Structural– Multipolar: several
extensions from cell body (common for motor neuron)
– Bipolar: one axon and one dendrite from cell body (common for interneurons)
– Unipolar: single process from cell body, process divides (common for sensory neuron)
![Page 34: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/34.jpg)
Central Nervous System
![Page 35: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/35.jpg)
http://www.youtube.com/watch?v=snO68aJTOpM
![Page 36: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/36.jpg)
Central Nervous System
…also called the CEREBRUM
![Page 37: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/37.jpg)
![Page 38: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/38.jpg)
Brain Characteristics
• Gyri: elevated ridges of tissue (gyrus is singular)
• Sulci: shallow grooves separating gyri (sulcus is singular)
• Fissures: deep grooves separating large regions of brain
• Lobes: separations of hemispheres of brain
![Page 39: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/39.jpg)
Senses & Controls of Brain - Cerebrum
• White matter: collections of myelinated nerve fibers, usually found in deeper brain matter; carries the impulses (axons)
• Gray matter: collections of UNmyelinated nerve fibers and cell bodies; usually found in the outer areas; contains the neuron cell bodies
![Page 40: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/40.jpg)
![Page 41: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/41.jpg)
Cerebrum
• The cerebrum is divided into right and left hemispheres by the longitudinal fissure
• Controls consciousness
• Senses and motor control occurs here!
• Each hemisphere divided into 4 lobes
![Page 42: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/42.jpg)
Funny thing about the brain…
• The somatic sensory area (cortex)– Where your senses are picked up & processed– Upside down
• Signals from body parts toward the head are picked up at the base of the area, while signals from lower (inferior) body parts are picked up at the top of the area
– Crossed pathways• Left side of the sensory area receives impulses from
the right side of the body, and vice versa
![Page 43: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/43.jpg)
Funny thing about the brain…
• The primary motor area (cortex)– Responsible for sending out signals for
movement– Also upside down with crossed pathways
![Page 44: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/44.jpg)
![Page 45: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/45.jpg)
Senses & Controls of Brain - Cerebrum
• Occipital Lobe: contains visual sense
• Temporal Lobe: contains smell & auditory senses– Also includes the
hippocampus, which is responsible for long-term memory (including forming new memories about events) and spatial navigation
![Page 46: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/46.jpg)
![Page 47: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/47.jpg)
Frontal Lobe…• Broca’s area: ability to
speak (vocalize), usually more developed in left hemisphere
• Language comprehension area: word meanings
Broca’s Area
Senses & Controls of Brain - Cerebrum
Language Comprehension
![Page 48: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/48.jpg)
Senses & Controls of Brain - Cerebrum
• Speech Area (aka Wernicke’s Area)– located at the junction
of the temporal, parietal, and occipital lobes
– Allows one to context spoken words (use them correctly)
– Usually more developed in left hemisphere
Speech Area
![Page 49: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/49.jpg)
![Page 50: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/50.jpg)
Senses & Controls of Brain - Cerebrum
• The Corpus Callosum is a very large nerve fiber tract (bundle) that connects the cerebral hemispheres & allows them to communicate
![Page 51: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/51.jpg)
![Page 52: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/52.jpg)
Cerebellum
• Provides timing for skeletal muscle activity
• Controls balance and equilibrium
• Are you clumsy? Uncoordinated? Blame your cerebellum!
![Page 53: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/53.jpg)
![Page 54: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/54.jpg)
Sections of Diencephalon
• Thalamus– Relay station for
sensory impulses up to correct part of sensory cortex
– Like an e-mail server… sends the message to the right place!
![Page 55: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/55.jpg)
![Page 56: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/56.jpg)
Sections of Diencephalon• Hypothalamus
– Helps regulate body temp, water balance, and metabolism (homeostasis)
– Involved with emotions; contains thirst, appetite, sex, pain, fear, rage, affection, and pleasure centers
![Page 57: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/57.jpg)
Sections of Diencephalon– Regulates the
pituitary gland (attached)
– Mammillary body (smell recognition) and optic chiasma (optic nerves crossing) attached
ANATOMY HUMOR…
The hypothalamus is one of the most important parts of the brain,
involved in many kinds of motivation, among other functions.
The hypothalamus controls the “Four F’s”: fighting, fleeing, feeding,
and mating.
-Unknown psychology professor in neuropsychology course
![Page 58: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/58.jpg)
![Page 59: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/59.jpg)
![Page 60: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/60.jpg)
Sections of Diencephalon
• Epithalamus– Pineal body: assists in
biological clock (daily/seasonal/life cycles) by releasing melatonin
– Choroid plexus: forms cerebrospinal fluid (there is also another one in the brainstem)
![Page 61: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/61.jpg)
![Page 62: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/62.jpg)
Sections of Brainstem• Midbrain
– Conveys ascending and descending impulses
• Pons– Conveys ascending
and descending impulses
– Helps to regulate breathing
![Page 63: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/63.jpg)
Sections of Brainstem• Medulla Oblongata
– Conveys ascending and descending impulses
– Regulates autonomic activities such as heart rate, blood pressure, breathing, swallowing, vomiting, defecation, sneezing, coughing… the list goes on
• As soon as it passes out of the skull (through the foramen magnum), the brainstem is then known as the spinal cord
![Page 64: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/64.jpg)
![Page 65: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/65.jpg)
Meninges of the CNS
• Dura Mater: thick, outer-most
• Arachnoid: spiderweb-like• Pia Mater: innermost,
clings to brain
![Page 66: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/66.jpg)
![Page 67: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/67.jpg)
Cerebrospinal Fluid
• A watery broth that circulates and protects the brain & spinal cord from trauma
• Formed by choroid plexuses, circulated by ependymal cells
• A very weak salt solution with low amounts of protein (200 mL total; 135-150 mL around the brain)
• Any change in composition (levels of protein, presence of blood, glucose levels) may be a sign of meningitis, tumors, infection, or something else
• Tested through a spinal tap
![Page 68: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/68.jpg)
• Ventricles– Set of structures
(openings) containing CSF in the brain
– Drains into the central canal of the spinal cord
![Page 69: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/69.jpg)
![Page 70: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/70.jpg)
![Page 71: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/71.jpg)
Central Nervous System
• Brain• Spinal Cord
– Extends from medulla oblongata (at foramen magnum) to the T12 vertebrae (last thoracic vertebrae)
– Below T12 is the cauda equina (a collection of spinal nerves)
![Page 72: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/72.jpg)
![Page 73: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/73.jpg)
Spinal Cord – 3 Basic Parts
• Inner gray matter columns– Mostly cell bodies
• Outer white matter columns– Conduction tracts– Composes most
of spinal cord
• Central canal filled with CSF
![Page 74: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/74.jpg)
![Page 75: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/75.jpg)
Peripheral Nervous System
• Composed of Nerves: bundles of nerve fibers
• Neuron fibers surrounded by connective tissue (work similar to muscle fibers!)
• Two Types of Peripheral Nerves: Spinal & Cranial Nerves
![Page 76: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/76.jpg)
Nerves
• Endoneurium surrounds each fiber
• Groups of fibers are bound into fascicles by perineurium
• Fascicles are bound together by epineurium
![Page 77: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/77.jpg)
Spinal Nerves
• Spinal Nerves– 31 originating from
spinal cord– Named for segments
• Cervical – 8 (not 7)• Thoracic – 12• Lumbar – 5• Sacral – 5• Coccygeal – 1 (not
4)• Spinal nerves continue on
to form the rest of the nerves in your body!
![Page 78: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/78.jpg)
![Page 79: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/79.jpg)
Nerves
• Endoneurium surrounds each fiber
• Groups of fibers are bound into fascicles by perineurium
• Fascicles are bound together by epineurium
![Page 80: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/80.jpg)
Nerves
• Cranial Nerves– 12 originating from
brainstem• Olfactory – smell• Optic – vision• Oculomotor – eye lens
shape, pupil size (moving eyeball)
• Trochlear – follow moving objects with eye
![Page 81: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/81.jpg)
Nerves
• Trigeminal – skin senses from face, chewing muscles
• Abducens – roll eye laterally• Facial – facial expression muscles, lacrimal
(tear) and salivary (spit) glands, taste• Vestibulocochlear – sense of balance, hearing• Glossopharyngeal – swallowing and saliva
production
![Page 82: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/82.jpg)
Nerves
• Vagus – sense & motor of pharynx & larynx• Accessory – activate sternocleidomastoid and
trapezius muscles (turn neck, shrug shoulders)
• Hypoglossal – control tongue movements
![Page 83: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/83.jpg)
![Page 84: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/84.jpg)
Transmitting Impulses
• Nerve impulses have a domino effect
• Each neuron receives an impulse and must pass it on to the next neuron– Dendrites pick up the impulse– Shuttled through the axon– Transmitted to next neuron at axon terminal
![Page 85: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/85.jpg)
Sending The Signal
![Page 86: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/86.jpg)
Impulse through a neuron…• Polarized: the neuron at rest
– More sodium ions outside the cell, less potassium ions on the inside (in comparison to the # of Na ions on outside)
– Sodium/Potassium pumps keep it this way
– Because the abundance of sodium ions outside the cell is way higher than the abundance of potassium ions on the inside, we would say that there is a partially positive charge on the outside of the cell, and a partially negative charge on the inside of the cell
– This balance of charges is called the Resting Potential
![Page 87: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/87.jpg)
Through a neuron…
• Depolarization: A stimulus comes along, and Na+ moves into the membrane
– The stimulus (neurotransmitter) opens sodium channels, allowing Na+ to rush in
– The neuron continues to open channels all along membrane
![Page 88: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/88.jpg)
Through a neuron…
• Action Potential: The depolarization wave continues to move down the membrane– Once this process is started, it continues
to move all the way down the membrane
• Once you “pop”, you can’t stop!
![Page 89: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/89.jpg)
Through a neuron…
• Repolarization: K+ ions move outside, and Na+ ions stay inside the membrane
– Potassium channels on inside of membrane open to allow K+ to move out
![Page 90: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/90.jpg)
Through a neuron…
• Refractory period: Everything gets put back to normal… K+ returns to inside, Na+ returns to outside
– All thanks to Na+/K+ pump– Can’t respond to another stimulus during this
period
• The cell is then returned to the polarized state until another impulse comes along
• Remember: the process takes less time if it has a myelin sheath around the neuron processes!
![Page 91: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/91.jpg)
• http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter14/animation__the_nerve_impulse.html
![Page 92: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/92.jpg)
Between neurons…
• Remember that action potential that was created? Well, eventually, it reaches the end of the axon (axon terminals)
• When it does, it goes through steps to pass the signal on to the next neuron…
![Page 93: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/93.jpg)
Between neurons
• Calcium gates in axon terminals open, allowing Ca+2 in
• Due to Ca+2 entering the axon terminal, a specific neurotransmitter gets released
• Neurotransmitter diffuses across synapse
• Neurotransmitter binds with specific receptors on the next neuron
![Page 94: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/94.jpg)
Returning to normal
• The neurotransmitter can do one of two things…– If received by another neuron, it will open Na+
gates on the next neuron, beginning a new action potential on the new neuron
– If received by some body part, it will stimulate some sort of change (muscles, glands, etc.)
• After neurotransmitter does its job, the receptor releases it back into synapse, and finds its way back to the neuron so it can be re-released
![Page 95: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/95.jpg)
• http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter14/animation__chemical_synapse__quiz_2_.html
![Page 96: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/96.jpg)
• There are approximately 20 known neurotransmitters
![Page 97: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/97.jpg)
Types of neurotransmitters
• Acetylcholine (ACh) – voluntary movement of muscles
• Norepinephrine – wakefulness or arousal• Dopamine – motivation, pleasure, associated
with addiction and love• Serotonin – memory, emotions, temperature
regulation• Histamine – wakefulness• Endorphins – natural pain killer
** Many neurotransmitters also have hormonal effects.
![Page 98: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/98.jpg)
Nervous System Conditions
![Page 99: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/99.jpg)
Meningitis
• Inflammation of the meninges
• Can then spread to actual nervous tissue of CNS, and inflame the brain (encephalitis)
![Page 100: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/100.jpg)
Hydrocephalus
• CSF accumulates (most commonly) because of an obstruction
• “Water on the Brain”
![Page 101: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/101.jpg)
Myelitis
• Swelling of the spinal cord
• Disrupts CNS functions linking the brain and limbs
![Page 102: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/102.jpg)
Multiple Sclerosis
• Myelin sheaths around the fibers are destroyed, and converted into hardened sheaths called scleroses
• Person loses ability to control muscles
• Victims experience muscle weakness, abnormal muscle spasms, and difficulties in movement, coordination, & balance
![Page 103: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/103.jpg)
Cerebrovascular Accident
• Commonly called a stroke
• The result of a 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 104: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/104.jpg)
Alzheimer’s Disease
• Progressive degenerative brain disease
• Structural changes in the brain include abnormal protein deposits, twisted fibers within neurons, and atrophy of the brain
• Victims experience memory loss, irritability, confusion, and hallucinations
![Page 105: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/105.jpg)
Parkinson’s Disease
• Loss of dopamine-secreting cells
• Causes other transmission problems, which leads to symptoms
• Victims experience tremors, rigidity, and gait issues (posture and walking)
![Page 106: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/106.jpg)
Traumatic Brain Injury (TBI)
• Concussion– Slight or mild brain injury– Bleeding & tearing of nerve fibers happened– Recovery likely with possible memory loss
• Contusion– A more severe TBI– Nervous tissue destruction occurs– Nervous tissue does not regenerate
![Page 107: Nervous System. Functions of the Nervous System Sensory Input –Monitors changes (stimuli) inside and outside the body Integration –Processes and interprets.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e0e5503460f94af8706/html5/thumbnails/107.jpg)
Traumatic Brain Injury (TBI)
• TBI can often result in either temporary or permanent amnesia– Anterograde amnesia: new events are not
transferred to the permanent as long-term memory
– Retrograde amnesia: inability to recall memories of the past