Download The skin performs all of the following except

The skin performs all of the
following except
a. PRODUCTION OF CHEMICAL MESSENGERS
b.
c.
ELIMINATION OF WASTE PRODUCTS
CONTROL OF BODY TEMPERATURE
d.
PROTECTION
Students will know…
 Explain what an action potential is?
 K+ ions are entering the neuron
 Negatively charged proteins are leaving the neuron
 Na+ ions are entering the neuron
 The myelin coat has broken down and ions are
crossing freely
Students will know…
 Which is the correct path a nerve impulse will follow
in a reflex arc?
 Put these three terms in order
 Motor neuron, sensory neuron and interneuron
Nervous System
 Chapter 33.1
Structure of the Nervous System
 Neurons conduct electrical impulses
 allow cells, tissues, and organs
 detect and respond to stimuli
Neurons
 Specialized cells
 Help you gather information
Neuron
Neuron
 Dendrites – receive
signals and send them to
the cell body
Neuron
 Dendrites – receive
signals and send them to
the cell body
 Cell body – nucleus of
the neuron and other
organelles
Neuron
 Dendrites – receive
signals and send them to
the cell body
 Cell body – nucleus of
the neuron and other
organelles
 Axon – caries the nerve
impulse from cell body to
other neurons and
muscles
Reflex Arc
 Nerve pathway
 Basic structure of the
nervous system
 Sensory neuron to an
interneuron, and a motor
neuron
An Action Potential
 Nerve impulse
 A stimulus reaches threshold
 Channels in the plasma membrane open
 Potassium ions leave the cell
 Change in charge moves
Action Potential
Which of the following pairs lists the
fiber-like extensions that are
components of neurons?
a. AXONS AND MYELIN
b. SYNAPSES AND MYELIN
c. DENDRITES AND SYNAPSES
d. DENDRITES AND AXONS
Organization of Nervous System
 Chapter 33.2
Organization of the Nervous System
 Central nervous system
 Peripheral nervous system
The Central Nervous System
 CNS
 Spinal Cord
 Brain
 Relays messages
 Processes information
 Analyzes responses
The Brain
 Made up of 100 billion neurons
 Maintains homeostasis
 Control center
The Brain
 Made up of 100 billion neurons
 Maintains homeostasis
 Control center
 Homeostasis – maintains a constant condition
The Brain
The Brain
Cerebrum
 Largest part
 Divided into two hemispheres
 Thought process of memory, language, speech,
voluntary body movements and sensory perception
Cerebellum
 Controls balance, posture
and coordination
 Back of brain
Brain Stem
 Connects the brain to the spinal cord
 Made up of
 Medulla oblongata (signals between brain and spinal cord)
 Pons (signals between cerebrum and cerebellum)
Spinal Cord
 Nerve column from your brain to the lower back
 Protected by vertebrae
Spinal Cord
The Peripheral Nervous System
 Somatic Nervous System
 Autonomic Nervous System
Somatic Nervous System
 Relays information to and from skin and skeletal
muscles
 Voluntary
Autonomic Nervous System
 Relays information to internal organs
 Involuntary
Autonomic Nervous System
Sympathetic
Parasympathetic
 Pupil dilation
 Pupil constriction
 Heart rate increased
 Heart rate decrease
 Bronchial muscle
 Bronchial muscles
relaxed
 Small intestine muscle
contractions reduced
contracted
 Digestion increased
Unit 9
Chapter 33.3
Quiz
1. Draw and label a neuron
2. Describe a Reflex Arc
Pathway
3. Describe an Action
Potential
The Senses
 Chapter 33.3
The Senses
 Sensory receptors allow you to detect the world
around you
Taste and Smell
 Stimulated by chemicals
 Work together
Smell
 Sensory receptors high in the nose
 Respond to chemicals
 Signal the brain
Taste
 Taste buds
 Detect sweet, sour, salty
and bitter
 Nature
 August 2006
 Wrong!
Sight
 Light enters the eye
 Through the cornea
 Behind the iris is the lens
 To the retina (rods and cones)
 Signals sent to brain
 Brain interprets
Sight
Hearing and Balance
 Function of the ear
 Volume
 Highness and lowness
To Hear
 Sound waves
 Ear canal
 Eardrum to vibrate
 Through the malleus, incus, stapes
 Inner ear cochlea
 Sends signals to the brain
Ear
To Balance
 Cochlea
 Semicircular Canals
 At 900
 Fluid filled, lined hairs
 Head moves the fluid moves and sends signals to
brain
Ear
Touch
 Sensory receptors
 Respond to temperature pressure and pain
 Epidermis and dermis
 Tips of fingers have lots
 Not everywhere