Download Autonomic Nervous System

Nervous &
Sensory Systems
How does the nervous system
control your body?
 The nervous system directs the functions of all human
body systems.
 Every activity is controlled by some of the more than
100 billion nerve cells in the body.
 CNS (Brain & Spinal Cord) – acts as a control center
 PNS (Nerves) – carry messages to and from this center
Neurons (Nerve cells) – Basic
Element of the Nervous System
 Each nerve is a bundle of neurons
(sends electrical messages to the body’s
organs and muscles).
 Each neuron consists of 3 parts:
 The cell body – reach out to send or
receive impulses.
 Dendrites – conduct nerve impulses
toward the cell body.
 The axon – conducts nerve impulses
away from the cell body.
Nerve Impulses

What is the tissue called that covers the axon?

What is the space called where impulses jump
between neurons?
Nerve Impulses

What is the tissue called that covers the axon?


Myelin Sheath
What is the space called where impulses jump
between neurons?

Synapse
Two Basic Properties of
Neurons

Excitability – the ability to respond to a stimulus

Conductivity – the ability to transmit a signal
Three Types of Neurons

Efferent or Motor – convey information to the
muscles and glands from the CNS

Afferent or Sensory – carry information from
sensory receptors to the CNS

Interneurons – carry and process sensory
information
Electrical Impulses to Organs &
Muscles
Cells of the Body
Release Electrical Energy After
an External Stimuli or Stimulation from Internal
Chemical
Impulse
Passes Through Nerve Cell
Nerve
Received by Tissues & Organs (Receptors)
Transmitted to Other Receptors
Neuroglias

Connect, protect, and remove debris from the system

Do not transmit impulses

Along with capillaries, these cells form the Blood
Brain Barrier

Blood Brain Barrier – permits some chemical
substances to reach the brain’s neurons while
blocking most others
The Central Nervous System –
Center of Control

Composed of brain and spinal cord.

Receives and interprets all stimuli and sends nerve
impulses
•

Voluntary & Involuntary Movement
Brain has 4 major divisions:
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•
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Brainstem
Cerebellum
Cerebrum
Diencephalon
Cerebrum – 2 Hemispheres & 4 Lobes

Responsible for reasoning, thought, memory,
judgment, speech, sensation, sight, smell, hearing,
and voluntary body movement.


Includes the:
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Frontal Lobe - voluntary motor movement, expression, moral behavior
•
Parietal Lobe - interprets senses and taste
•
Temporal Lobe - memory, equilibrium, emotion, and hearing
•
Occipital Lobe - vision, some forms of expression
Contains Cerebral Cortex (outer portion) – area of
conscious decision making

Start Claymation
Divisions of the Brain
Central Nervous System

Brain Stem
•
Midbrain – concerned with visual reflexes
•
Pons – respiratory functions
•
Medulla Oblongata – contains centers that regulate heart and lung
functions, swallowing, vomiting, coughing, and sneezing

Cerebellum
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Coordinates Musculoskeletal Movement
Central Nervous System

Diencephalon
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Thalamus
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Hypothalamus
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Integrates with the ANS to control:
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HR
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BP
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Temp
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Water & Electrolyte Balance
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Digestion
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Behavioral Responses
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Grandular Activities
Cerebrospinal Fluid (CSF)

Between the area of the brain and the cranium

A water liquid that contains various compounds and
flows throughout the brain and around the spinal
cord

Cradles and cushions the brain

Ventricles in the brain also contain this fluid
Spinal Cord

Extends from the base of the brain to near the first
lumbar vertebra

Contained within the vertebral column in a space
called the vertebral canal

Protected by:

Vertebral Column

CSF

Spinal Meninges
Layers of the Meninges
The Meninges

Dura Mater – outer layer, covers the entire length of
the spinal cord and contains channels for blood to
enter brain tissue

Arachnoid Mater – middle layer, runs across the space
containing CSF

Pia Mater – innermost layer, thin membrane
containing blood vessels to nourish the spinal cord
Epidural Space - b/w
the dura mater & the
bones
The Peripheral Nerves

Twelve pairs of cranial nerves carry impulses to and
from the brain.

Thirty-one pairs of spinal nerves carry messages to
and from the spinal cord and the body.

Contains 2 subsystems:

Somatic Nervous System

Autonomic Nervous System (ANS)
The Peripheral Nerves

The somatic nervous system receives and processes
sensory input and excites the voluntary contraction of
skeletal muscles.

The autonomic nervous system carries impulses from
the central nervous system to glands, various
involuntary muscles, cardiac muscle, and various
membranes.
•
Divided into 2 Divisions
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Sympathetic
•
Parasympathetic
The Peripheral Nerves

The somatic nervous system receives and processes
sensory input and excites the voluntary contraction of
skeletal muscles.

The autonomic nervous system carries impulses from
the central nervous system to glands, various
involuntary muscles, cardiac muscle, and various
membranes.
•
Divided into 2 Divisions
•
Sympathetic
•
Parasympathetic
Autonomic Nervous System –
both divisions play opposite roles

Sympathetic Division– operates under stress (fight or
flight)

Parasympathetic Division– operates to keep the body
in homeostasis, under normal conditions
Autonomic Nervous System –
both divisions play opposite roles
What are the three parts of neurons?
Autonomic Nervous System –
both divisions play opposite roles
What are the three parts of neurons?

Cell Body

Dendrites

Axon
Sensory System or Special
Senses

The sensory system includes any organ or part that
perceives or receives stimuli from the outside world.
Sensory System

Sight—the Eye

Hearing and Equilibrium—the Ear

Touch, Pain, and Temperature—the Skin

Smell—the Nose

Taste—the Tongue and Oral Cavity
Major Parts of the Sensory
System

Sight - the Eye

Hearing – the Ears

Touch - the Skin

Smell - the Nose

Taste - the Mouth
Sight – The Eye
 Outer Layer
• The sclera – supports the eyeball and nourishes the
cornea
• Cornea – transparent layer where light is bent
(refracted) as it enters the eye
 Middle Layer
• Choroid – focuses the eye
 Interior Layer
• Retina – decodes light waves and sends the info to
the brain
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Rods – black and white
Cones - color
Optic Disk – where the retina connects to the nerve
Sight – The Eye
Chambers of the Eye

Anterior Chamber
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Posterior Chamber
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Lies between the cornea and iris
Nourishes the lens and cornea
Maintains constant pressure of the eyeball
Lies between the iris and the lens
Nourishes the lens and cornea
Maintains constant pressure of the eyeball
Vitreous Chamber – occupies about 80% of the space
in the eyeball
•
Nourishes parts of the eye and maintains structure to keep the
eye from collapsing
Chambers of the Eye

Eyelids

Eyebrows and Eyelashes

Lacrimal Glands
The Ear

Major divisions of the ear
•
The external ear, or pinna.
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The middle ear includes the eardrum, or tympanic
membrane.
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The inner ear, which contains three semicircular
canals and the cochlea.
The Ear
Smell – The Nose

Olfactory relates to the sense of smell.
•
The sense of smell is activated by receptors located at
the top of the nasal cavity.
•
The receptors are nerve cells covered with hairlike cilia
that send messages to the brain
Taste - the Tongue and Oral Cavity

Taste buds sense the taste of food.
•
Located on the surface of the tongue in small raised
structures called papillae.

Four main types of taste buds to match taste
sensations
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Sweet
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Sour
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Salty
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Bitter
Taste
The Sensory
Which part of the eye decodes light waves and sends
the information to the brain?
The Sensory
Which part of the eye decodes light waves and sends
the information to the brain?
The retina