Introduction to Health ScienceIntroduction to Health Science

The Nervous System (Regulatory System)The Nervous System (Regulatory System)

The Basic Functions of the Nervous SystemThe Basic Functions of the Nervous System

• SensationSensation– The ability of the nerves to The ability of the nerves to

detect stimuli, such as detect stimuli, such as pressure, temperature pressure, temperature changes, taste, smell or light, changes, taste, smell or light, and send a message in the and send a message in the form of impulses to the brain form of impulses to the brain and spinal cord.and spinal cord.

IntegrationIntegration• The nervous system recieves and The nervous system recieves and

interprets sensory stimuli from the interprets sensory stimuli from the body and determines an body and determines an appropriate response to those appropriate response to those stimuli.stimuli.

MovementMovement• The ability of the brain to send The ability of the brain to send

impulses through motor nerves to impulses through motor nerves to muscles and glands to cause muscles and glands to cause movement or secretion of movement or secretion of hormones.hormones.

The Basic Structures of the Nervous The Basic Structures of the Nervous SystemSystem

The BrainThe Brain

•The brain is responsible for The brain is responsible for analyzing information, processing analyzing information, processing information and relaying messages information and relaying messages to the rest of the body. It is the to the rest of the body. It is the main control center of the body. main control center of the body. •Along with the spinal cord, it Along with the spinal cord, it forms the body’s Central Nervous forms the body’s Central Nervous System or CNS.System or CNS.•The brain is composed of three The brain is composed of three main parts:main parts:– CerebrumCerebrum– CerebellumCerebellum– Brain StemBrain Stem

Brain Structures and FunctionsBrain Structures and Functions

• CerebrumCerebrum– The cerebrum is the largest part of The cerebrum is the largest part of

the brain. It has two distinct halves the brain. It has two distinct halves called hemispheres. The cerebrum called hemispheres. The cerebrum has many folds and grooves to has many folds and grooves to increase the number of nerves found increase the number of nerves found in the brain.in the brain.

• The cerebrum is divided into four The cerebrum is divided into four lobeslobes..– Frontal LobeFrontal Lobe– Parietal LobeParietal Lobe– Temporal LobeTemporal Lobe– Occipital LobeOccipital Lobe

• Frontal Lobe Frontal Lobe – The frontal lobe controls skeletal The frontal lobe controls skeletal

muscle movement, interprets the muscle movement, interprets the sense of smell, is responsible for our sense of smell, is responsible for our personalities, and our ability to personalities, and our ability to learn, think, problem solve and learn, think, problem solve and concentrate.concentrate.

• Parietal LobeParietal Lobe– The parietal lobe interprets many of The parietal lobe interprets many of

our senses including taste, touch, our senses including taste, touch, temperature, and pain.temperature, and pain.

• Occipital LobeOccipital Lobe– The occipital lobe interprets The occipital lobe interprets

the sense of sight.the sense of sight.

• Temporal LobeTemporal Lobe– The temporal lobe interprets The temporal lobe interprets

the senses of balance and the senses of balance and hearing. It also contains hearing. It also contains structures (such as the structures (such as the hippocampus) which store hippocampus) which store memory.memory.

CerebellumCerebellum• The cerebellum is the second The cerebellum is the second

largest part of the brain. In fact, largest part of the brain. In fact, cerebellum means the “little cerebellum means the “little cerebrum.” It is located at the cerebrum.” It is located at the back of the head below the back of the head below the cerebrum.cerebrum.

• It functions to coordinate the It functions to coordinate the muscular movements and helps muscular movements and helps the muscles move gracefully and the muscles move gracefully and efficiently. It also helps with the efficiently. It also helps with the body’s ability to balance.body’s ability to balance.

BrainstemBrainstem• The brain stem is located below The brain stem is located below

the cerebellum and connects the the cerebellum and connects the spinal cord to the brain.spinal cord to the brain.

• The brain stem is composed of The brain stem is composed of two structures – the medulla two structures – the medulla oblongata and the pons.oblongata and the pons.– The medulla oblongata is continuous The medulla oblongata is continuous

with the spinal cord and helps to with the spinal cord and helps to regulate the heart beat, blood regulate the heart beat, blood pressure, pressure, breathing, swallowing, breathing, swallowing, hiccupping, and vomiting. It also hiccupping, and vomiting. It also relays nerve impulses between the relays nerve impulses between the brain and the spinal cord.brain and the spinal cord.

– The pons is a small bulge above the The pons is a small bulge above the medulla oblongata. It is important to medulla oblongata. It is important to help us regulate the rate and depth help us regulate the rate and depth of breathing.of breathing.

The Spinal CordThe Spinal Cord• Along with the brain, it is part of Along with the brain, it is part of

the Central Nervous System.the Central Nervous System.• It is the major communication It is the major communication

link between the brain and the link between the brain and the rest of the body.rest of the body.

• It can process many reflexes – It can process many reflexes – unconscious, automatic unconscious, automatic responses to stimuli.responses to stimuli.

• There are 31 pairs of spinal There are 31 pairs of spinal nerves which branch from the nerves which branch from the spinal cord to control such spinal cord to control such processes as breathing, arm processes as breathing, arm movement, and leg movement.movement, and leg movement.

Cerebrospinal FluidCerebrospinal Fluid• CSF is a clear, watery fluid which CSF is a clear, watery fluid which

bathes the brain and the spinal bathes the brain and the spinal cord to protect it by acting as a cord to protect it by acting as a shock absorber.shock absorber.

• CSF allows for the exchange of CSF allows for the exchange of nutrients and waste products nutrients and waste products between the blood and the between the blood and the nervous tissue.nervous tissue.

• CSF circulates between the two CSF circulates between the two layers of the meninges, through layers of the meninges, through the center of the spinal cord, and the center of the spinal cord, and through large openings in the through large openings in the brain (ventricles).brain (ventricles).

MeningesMeninges• A set of three layers of A set of three layers of

connective tissue that enclose connective tissue that enclose the brain and spinal cord. They the brain and spinal cord. They are located under the skull and are located under the skull and attach directly to the brain.attach directly to the brain.

• Meninges help to provide a small Meninges help to provide a small amount of protection to the brain amount of protection to the brain and spinal cord.and spinal cord.

• Cerebrospinal fluid circulates Cerebrospinal fluid circulates between two layer of the between two layer of the meninges.meninges.

NervesNerves

• Nerves (neurons) are the Nerves (neurons) are the basic units of structure and basic units of structure and function for the nervous function for the nervous system.system.

• Nerves are capable of sending Nerves are capable of sending electrical messages called electrical messages called impulses.impulses.

• There are two main types of There are two main types of nerves:nerves:– Sensory nervesSensory nerves– Motor nervesMotor nerves

Types of NervesTypes of Nerves

• Sensory nerves detect Sensory nerves detect changes and carry impulses changes and carry impulses to the brain and spinal cord to the brain and spinal cord from the sense organs.from the sense organs.

• Motor nerves detect changes Motor nerves detect changes and carry impulses away and carry impulses away from the brain and spinal from the brain and spinal cord to muscles. cord to muscles.

Nerve StructureNerve Structure• There are three basic parts of a There are three basic parts of a

neuron:neuron:– DendritesDendrites• Short, branchlike extensions which Short, branchlike extensions which

conduct electrical signals toward the cell conduct electrical signals toward the cell body.body.

– Cell BodyCell Body• Contains large nucleus and other cellular Contains large nucleus and other cellular

organelles.organelles.– AxonAxon• Extends from the cell body. Responsible Extends from the cell body. Responsible

for carrying nerve impulses to other for carrying nerve impulses to other neurons, muscles or glands.neurons, muscles or glands.

Describe Diseases Disorders of the Describe Diseases Disorders of the Nervous SystemNervous System

• MeningitisMeningitis– Meningitis is an infection that causes the Meningitis is an infection that causes the

inflammation of the brain and spinal cord inflammation of the brain and spinal cord coverings. Most common forms are coverings. Most common forms are bacterial or viral.bacterial or viral.

– Symptoms: fever, chills, headache, nausea, Symptoms: fever, chills, headache, nausea, vomiting, stiff neckvomiting, stiff neck

– Treatment: Antibiotics for bacterial Treatment: Antibiotics for bacterial meningitismeningitis

EpilepsyEpilepsy

• Epilepsy is a brain disorder Epilepsy is a brain disorder involving repeated seizures of involving repeated seizures of any kind. Seizures are episodes of any kind. Seizures are episodes of disturbed brain function that disturbed brain function that cause changes in attention or cause changes in attention or behavior. behavior.

• Symptoms:• Loss of consciousness• Staring spells• Violent convulsions.

• Treatment:• Varies depending on the

cause. • May be controlled by

medications.

ConcussionConcussion

• Post traumatic impairment Post traumatic impairment of neural function caused of neural function caused by a direct blow to the by a direct blow to the head resulting in bruising head resulting in bruising of the brain.of the brain.– Symptoms may include headache, Symptoms may include headache,

loss of consciousness, ringing of loss of consciousness, ringing of the ears, nausea, irritability, the ears, nausea, irritability, confusion, disorientation, dizziness, confusion, disorientation, dizziness, amnesia or difficulty concentrating.amnesia or difficulty concentrating.

– Treatment may include removal Treatment may include removal from play, rest avoiding re-injury, from play, rest avoiding re-injury, medications for pain, physical medications for pain, physical therapy and relaxation.therapy and relaxation.

StrokeStroke

• Stroke, also known as a CVA or Stroke, also known as a CVA or cerebrovascular accident, occurs cerebrovascular accident, occurs when there is an interruption of when there is an interruption of the blood supply to any part of the the blood supply to any part of the brain. brain. • Symptoms appear suddenly

and can include weakness or paralysis of an extremity, numbness, vision changes, slurred speech, difficulty swallowing and loss of memory

• It is important to get immediate care to reduce permanent complications. Physical therapy and/or occupational therapy may be needed.