section 35-2 the nervous system pg 897-900
How are neurons classified?
3 types according to the direction in which an impulse travels. SENSORY neurons carry impulses from the sense organs to the spinal cord and brain. MOTOR neurons carry impulses from the brain and spinal cord to muscles and glands. INTERNEURONS connect sensory and motor neurons and carry impulses between them.
How does a nerve impulse begin?
A nerve impulse begins when a neuron is stimulated by another neuron or by its environment.
Complete the concept map.
Attached on back
Label the following features in the drawing of a neuron: cell body,dendrites, and axon.
Attached on back
The central nervous system consists of the____ and the ___
Brain and spinal cord
Hypothalamus
Controls hunger, thirst, fatigue, anger, and body temperature
Cerebrum
Controls voluntary activities of the body
Cerebellum
Coordinates and balances the actions of the muscles
What is gray matter, and where is it found?
Densely packed nerve cell bodies and is found in the cerebral cortex of the cerebrum.
How does a nerve impulse follow the all-or-nothing principle?
Either a stimulus will produce an impulse, or it won't, depending on it's strength.
Is the following sentence true or false? Sensory neurons carry impulses from the brain and the spinal cord to muscles and glands.
False
Is the following sentence true or false? The left hemisphere of the cerebrum controls the body's left side.
False
What is the advantage of a reflex?
It allows your body to respond to danger immediately, without spending time thinking about a response.
Why is it important to have two systems that control the same organs?
One system speeds up the activities of the organs, and the other system slows down the activities of the organs.
Identify the four lobes of the brain.
Parietal lobe, Frontal lobe,Temporal lobe,Occipital lobe
Thalamus
Receives and relays messages from the sense organs
Brain stem
Regulates the flow of information between the brain and the rest of the body
What describes an action potential?
Reversal of charges due to the flow of positive ions into a neuron
What are three types of neurons?
Sensory neurons Motor neurons Interneurons
What is the function of the central nervous system?
The central nervous system relays messages, processes information, and analyzes information.
What is the function of the myelin sheath?
The myelin sheath increases the speed at which nerve impulses can travel.
What is the function of the nervous system?
The nervous system controls and coordinates functions throughout the body and responds to internal and external changes.
Describe what happens when an action potential arrives at an axon terminal
The sacs release neurotransmitters into the gap between the two cells. The neurotransmitters diffuse across the gap and attach to receptors on the membrane of the neighboring cell, causing positive ions to rush across the cell membrane and stimulate the second cell.
Is the following sentence true or false? The outer surface of the cerebrum is called the cerebral cortex.
True
Circle the letter of each activity that is controlled by the somatic nervous system.
Wiggling the toes, Lifting a finger, Pulling foot away from tack
What are neurotransmitters?
are chemicals that are used by a neuron to transmit an impulse across a synapse to another cell.
The brain and spinal cord are bathed and protected by
cerebrospinal fluid
The two hemispheres of the brain are connected by a band of tissue called the
corpus callosum
what is part of the peripheral nervous system
cranial nerves, spinal nerves, ganglia
The two regions of the brain stem are the
medulla oblongata And the pons
The electrical charge across the cell membrane of neuron in resting state is called its
resting potential
The minimum level of a stimulus that is required to activate a neuron is called the
threshold
Is the following sentence true or false? Three layers of connective tissue known as meninges protect the brain and spinal cord
true
