Nervous SystemNervous System

By: Zach HardinBy: Zach Hardin

Nervous System Nervous System Definition Definition The Nervous System consist of The Nervous System consist of

the brain, spinal cord, sensory the brain, spinal cord, sensory organs, and all the nerves that organs, and all the nerves that connect the organs to the rest of connect the organs to the rest of the body. the body.

Functions of the Functions of the Nervous SystemNervous System Sensory: This function of the system Sensory: This function of the system

includes collecting information from includes collecting information from sensory receptors that monitor the sensory receptors that monitor the body’s internal and external condition. body’s internal and external condition.

Integration: This is the function of Integration: This is the function of processing many sensory signals that processing many sensory signals that come through the CNS at a given time. come through the CNS at a given time.

Motor: This function happens once the Motor: This function happens once the CNS evaluates the sensory information CNS evaluates the sensory information and has decided on its action and how and has decided on its action and how it will respond to the stimulus. it will respond to the stimulus.

Divisions of the Divisions of the Nervous SystemNervous System Central Nervous System- the brain and spinal Central Nervous System- the brain and spinal

cord come together to form the CNS. The CNS cord come together to form the CNS. The CNS acts as the control center for the body by acts as the control center for the body by providing its processing, memory, and providing its processing, memory, and regulation systems. The CNS monitor conscious regulation systems. The CNS monitor conscious and subconscious information. The CNS is also and subconscious information. The CNS is also responsible for language, creativity, responsible for language, creativity, expressions, emotions, and personality. expressions, emotions, and personality.

Peripheral Nervous System- this is all the parts Peripheral Nervous System- this is all the parts of the nervous system outside the spine and of the nervous system outside the spine and brain. These parts of the PNS include spinal brain. These parts of the PNS include spinal nerves, ganglia, and sensory receptors. nerves, ganglia, and sensory receptors.

Somatic Nervous System- the SNS is a Somatic Nervous System- the SNS is a division of the PNS that includes all of the division of the PNS that includes all of the voluntary efferent neurons. This is the only voluntary efferent neurons. This is the only consciously controlled part of the PNS. The consciously controlled part of the PNS. The SNS is also responsible for stimulating SNS is also responsible for stimulating skeletal muscles. skeletal muscles.

Autonomic Nervous System- the ANS is also Autonomic Nervous System- the ANS is also a division of the PNS that include all a division of the PNS that include all involuntary efferent neurons. The ANS involuntary efferent neurons. The ANS controls subconscious things such as controls subconscious things such as visceral muscle tissue, cardiac muscle visceral muscle tissue, cardiac muscle tissue, and glandular tissue.tissue, and glandular tissue.

The Nerve The Nerve

Definition: The Definition: The nerve is a bundle nerve is a bundle of axons in the of axons in the Peripheral Nervous Peripheral Nervous System that acts System that acts like a information like a information highway between highway between the brain, spinal the brain, spinal cord, and the rest cord, and the rest of the body. of the body.

Axons- extend Axons- extend from cell body and from cell body and send messages to send messages to other neuronsother neurons

Dendrites- extend Dendrites- extend from the cell body from the cell body and pick up and pick up signals from the signals from the environment environment

Types of NervesTypes of Nerves

Afferent Nerves- this is a Afferent Nerves- this is a nerve that carries nerve that carries information from the information from the sensory receptors to the sensory receptors to the Central Nervous System.Central Nervous System.

Efferent Nerves- this is a Efferent Nerves- this is a nerve that carries signals nerve that carries signals from the Central Nervous from the Central Nervous system to muscles and system to muscles and glands. glands.

Mixed Nerves- these Mixed Nerves- these contain both afferent and contain both afferent and efferent axons and act as a efferent axons and act as a two way street for signals.two way street for signals.

Cranial Nerves- these Cranial Nerves- these provide a direct connection provide a direct connection to the brain for special to the brain for special sense organs. There are 12 sense organs. There are 12 pair of cranial nerves. They pair of cranial nerves. They are identified by their are identified by their location and function. location and function.

Spinal Nerves- these are Spinal Nerves- these are mixed nerves that extend mixed nerves that extend from left to right. There are from left to right. There are 31 pair of spinal nerves. 31 pair of spinal nerves. These are split into groups: These are split into groups: 8 pair of cervical nerves, 8 pair of cervical nerves, 12 pair of thoracic nerves, 12 pair of thoracic nerves, 5 pair of lumbar nerves, 5 5 pair of lumbar nerves, 5 pair of sacral nerves, and 1 pair of sacral nerves, and 1 pair of coccygeal nerves. pair of coccygeal nerves.

The NeuronThe Neuron

Neurons are cells Neurons are cells that communicate that communicate with the body by with the body by transmitting transmitting electrical and electrical and chemical signals. chemical signals. A neuron is A neuron is composed of a cell composed of a cell body with all the body with all the organelles. organelles.

Types of NeuronsTypes of Neurons

Afferent Neuron- (sensory neuron) Afferent Neuron- (sensory neuron) transmits sensory signals to the Central transmits sensory signals to the Central Nervous System to the receptors in the Nervous System to the receptors in the body.body.

Efferent Neuron- (motor neuron) Efferent Neuron- (motor neuron) transmits signals to muscles and glands transmits signals to muscles and glands in the body.in the body.

Interneurons- combine the information Interneurons- combine the information received from the sensory neurons and received from the sensory neurons and sends the function to the motor neurons. sends the function to the motor neurons.

NeurogliaNeuroglia

This is also known as a This is also known as a glial cell and the glial cell and the “helper” to the nervous “helper” to the nervous system. system.

Each neuron in the body Each neuron in the body is covered by 6-60 is covered by 6-60 neuroglia cells. neuroglia cells.

The glial cells help the The glial cells help the neuron by protecting, neuron by protecting, feeding, and insulating. feeding, and insulating.

The glial cell is vital in The glial cell is vital in maintaining a functional maintaining a functional nervous system.nervous system.

The BrainThe Brain

The brain is a soft The brain is a soft wrinkled organ that wrinkled organ that weighs about three weighs about three pounds.pounds.

The brain is located The brain is located inside the cranium inside the cranium where the bones of the where the bones of the skull surround and skull surround and protect it. protect it.

The brain and the spinal The brain and the spinal cord come together to cord come together to form the Central form the Central Nervous System. Nervous System.

The Spinal CordThe Spinal Cord

The spinal cord is a The spinal cord is a long, thin bundle of long, thin bundle of neurons that carry neurons that carry information through the information through the vertebral cavity. vertebral cavity.

The spine starts at the The spine starts at the medulla oblongata and medulla oblongata and continues to the lumbar continues to the lumbar region of the spine. region of the spine.

Cauda Equina- this is a Cauda Equina- this is a bundle of nerves shaped bundle of nerves shaped like a horses tale like a horses tale located in the lumbar located in the lumbar region of the spine and region of the spine and continuing to the continuing to the coccyx.coccyx.

Cerebrospinal Fluid Cerebrospinal Fluid

The space The space surrounding the surrounding the organs of the Central organs of the Central Nervous System is Nervous System is filled with a clear filled with a clear liquid know as liquid know as Cerebrospinal Fluid. Cerebrospinal Fluid.

Choroid Plexuses- Choroid Plexuses- these help form these help form cerebrospinal fluid cerebrospinal fluid from blood plasma. from blood plasma.

Functions of Functions of Cerebrospinal Fluid.Cerebrospinal Fluid. Absorb shock between the brain and the skull Absorb shock between the brain and the skull

and between the spinal cord and vertebrae. and between the spinal cord and vertebrae. The brain and spinal cord float in the fluid The brain and spinal cord float in the fluid

which reduces their weight. The reduction of which reduces their weight. The reduction of weight allows the blood vessels of the brain weight allows the blood vessels of the brain to stay open and help the nervous tissue to stay open and help the nervous tissue from crushing under its own weight.from crushing under its own weight.

The cerebrospinal fluid helps maintain The cerebrospinal fluid helps maintain chemical homeostasis. It contains nutrients chemical homeostasis. It contains nutrients that support chemical balance of the nervous that support chemical balance of the nervous system. The cerebrospinal fluid also removes system. The cerebrospinal fluid also removes waste products from cellular metabolism. waste products from cellular metabolism.

Connection to other Connection to other Systems Systems The nervous system interacts with the The nervous system interacts with the

skeletal, cardiovascular, muscular, skeletal, cardiovascular, muscular, endocrine, lymphatic, respiratory, digestive, endocrine, lymphatic, respiratory, digestive, reproductive, urinary, and integumentary reproductive, urinary, and integumentary system.system.

Skeletal System- the bones of the skull Skeletal System- the bones of the skull protect the brain from injury. The vertebrae protect the brain from injury. The vertebrae protect the spinal cord. protect the spinal cord.

Cardiovascular System- cerebrospinal fluid Cardiovascular System- cerebrospinal fluid drains into the venous blood supply. The drains into the venous blood supply. The brain regulates heart rate and blood brain regulates heart rate and blood pressure.pressure.

Muscular System- receptors in the Muscular System- receptors in the muscles allow the brain to know the muscles allow the brain to know the position and movement of the body.position and movement of the body.

Endocrine System- hormones allow Endocrine System- hormones allow information to the brain for neural information to the brain for neural processing. Reproductive hormones processing. Reproductive hormones affect the development of the nervous affect the development of the nervous system. system.

Lymphatic System- the brain can Lymphatic System- the brain can stimulate the defense mechanisms to stimulate the defense mechanisms to fight infection.fight infection.

Respiratory System- the brain monitors Respiratory System- the brain monitors respiratory volume and blood gas levels. respiratory volume and blood gas levels. The brain regulates respiratory rate. The brain regulates respiratory rate.

Digestive System- the autonomic nervous Digestive System- the autonomic nervous system controls the tone of the digestive system controls the tone of the digestive tract. The brain controls drinking and eating tract. The brain controls drinking and eating behavior. The brain controls the muscles for behavior. The brain controls the muscles for eating. eating.

Reproductive System- reproductive Reproductive System- reproductive hormones affect the brains development. hormones affect the brains development.

Urinary System- the bladder sends sensory Urinary System- the bladder sends sensory information to the brain. The brain controls information to the brain. The brain controls urination. urination.

Integumentary System- receptors in the skin Integumentary System- receptors in the skin send sensory information to the brain. The send sensory information to the brain. The autonomic nervous system regulates autonomic nervous system regulates peripheral blood flow and sweat glands. peripheral blood flow and sweat glands. Nerves control muscles connected to hair Nerves control muscles connected to hair follicles. follicles.

Disease: Alzheimer’s Disease: Alzheimer’s

This is a progressive, degenerative This is a progressive, degenerative disease that occurs in the brain and disease that occurs in the brain and results loss of memory, thinking, results loss of memory, thinking, and behavior. This disease usually and behavior. This disease usually occurs in mid to old age people. occurs in mid to old age people. This disease is the cause of This disease is the cause of neurons breaking connection with neurons breaking connection with each other and eventually passing. each other and eventually passing.

Fun Facts about the Fun Facts about the Nervous SystemNervous System There are more nerve cells in the human brain There are more nerve cells in the human brain

that there are stars in the Milky Way.that there are stars in the Milky Way. If we were to line up all the neurons in our If we were to line up all the neurons in our

body, it would be around 600 miles long.body, it would be around 600 miles long. There are 100 billion neurons in your brain There are 100 billion neurons in your brain

alone.alone. There are around 13.5 million neurons in the There are around 13.5 million neurons in the

human spinal cord. human spinal cord. The total surface area of the human brain is The total surface area of the human brain is

about 25,000 square cm. about 25,000 square cm. On average, you use only 4% of the cells in On average, you use only 4% of the cells in

your brain at any one time. your brain at any one time.

CitationsCitations

www.infovisual.info. www.infovisual.info. 8/27/138/27/13 www.naturalhealthschool.com. www.naturalhealthschool.com. 8/26/138/26/13 www.thepsychologyforum.com. www.thepsychologyforum.com. 8/28/138/28/13 www2.wlu.edu. www2.wlu.edu. 8/28/138/28/13 www.allaboutthenervoussystem.weebly.comwww.allaboutthenervoussystem.weebly.com

8/27/138/27/13 www.123rf.comwww.123rf.com. 8/26/13 . 8/26/13 www.histologygyolm.stevegall.org. 8/27/13www.histologygyolm.stevegall.org. 8/27/13 www.theinnerbody.com. 8/25/12www.theinnerbody.com. 8/25/12 www.medicalcenter.osu.edu. 8/28/13www.medicalcenter.osu.edu. 8/28/13 www.facultywashington.edu. 8/28/13www.facultywashington.edu. 8/28/13