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Nervous Regulation
Functions of Regulation
 The ability of a cell to respond to its environment is called
_____________________________.
 Humans regulate the coordination of responses with both the
__________________________________________.
Mechanism of Nervous Regulation
 Nerve cells carry ______________ through an organism.
There are 2 types of structures that work with nerve cells.
 ______________________________________________
 __________– a specialized structure that responds to the commands of
the _______________________________
 __________________ - Anything that causes a receptor to start
impulses in a nerve pathway.
 There are 3 basic events in nervous regulation:
 __________________________________________
 Impulses are started in associated nerve pathways.
 _______________________ responds to the impulse
Structure of Neurons
 The neuron (nerve cell) is the basic structure in the nervous system.
 Consists of 3 main parts:
1. ___________ – contains the nucleus and organelles.
2. ______________ – short, highly branched fibers that
__________________________________________.
3. ______ – a long, thin fiber that extends from the cell body. Carry
impulses away from _______________ and sends them to
___________________________.
 ___________ cells – produce _____________which is a fatty white
substance that covers the axon
 Gaps in the _______________between schwann cells are called the
________________________________
Types of Neurons
 There are three types of neurons: __________________,
_______________________, & ___________________.
 Sensory neurons carry impulses from _______________
_____________________________________________.
 Motor neurons carry impulses from the ______________ ______ to
__________________. The junction between nerves and muscles is
called a ______________ junction.
 ____________________ relay impulses from one neuron to another in
the brain and spinal cord.
The Synapse
 The axon ends in a __________________ which contains special
chemicals called ________________________.
 The space between the __________________________ of two neurons
is called the _____________________.
 When a nerve impulse reaches the synapse the ________ ___________
are released into the ________________.
 The _____________________diffuses across the gap and starts the
__________________________of the next cell.
 The nerve impulse cannot cross the gap without the neurotransmitter.
 The ___________ the impulse the more neurotransmitter that is
released.
 _______________ break down the chemical to clear the gap for the
____________________.
The Nerve Impulse
 When a neuron is resting the outside of the membrane has a
_______________ and the inside a _____________ charge. This is
called ___________________________.
 Sodium-Potassium pump – Active transport mechanism __________
___________that allows the ___________________. It actively pumps
____________ out of the cell to create the ______________________
inside the membrane.
 When a neuron is stimulated (heat, light, touch, pain etc.) ________
______________cross the neuron’s membrane. During the resting
potential the ____________________ do not cross the membrane
because the protein channels are _________________.
 Notice in the diagram (b) that the green protein channels are not
allowing the Na and K ions to cross the cell membrane; the impulse has
not been generated and the neuron is at a ____________________.
 During the ___________________ the nerve is stimulated and Na+ ion
____________________________________________________, thus
activating the nerve impulse. This causes the K+ ion to _____________
of the neuron at the same time.
 ___________________ - a brief period where the nerve cannot be
_____________________________________.
Review of the nerve impulse:
http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter14/
animation__the_nerve_impulse.html
Ch. 15 - The Human Nervous System
 The human nervous system has 2 sub systems:
1. ____________________________ – Brain & spinal cord
2. ________________________ – A vast network of nerves that conduct
impulses between the body and the CNS.
The Central Nervous System
 Controls ______________________________________.
 The brain is the most active organ in the human body.
 There are 3 major parts of the brain:
1. ____________________
2. ____________________
3. ____________________
The Cerebrum
 ___________________ part of the human brain.
 The outermost layer is called the ___________________
 Beneath the _______ matter is the _______ matter which is made up of
__________________________________.
 Connects the __________ to the other parts of the nervous system and
makes up the __________________.
The Cerebrum
 The cerebrum, the ______________ of the human brain, is divided into
_________________________________ connected to each other by
the _______________________.
 The hemispheres are covered by a thin layer of ___________________
known as the _____________________, the most recently evolved
region of the vertebrate brain.
 The cortex in each hemisphere of the cerebrum is between 1 and 4 mm
thick. Folds divide the cortex into four lobes: _____________________
_________________________________________________________
 No region of the brain functions alone, although major functions of
various parts of the lobes have been determined.
 The occipital lobe (back of the head) receives and processes _________
___________________________.
 The temporal lobe receives ___________________________________
________________________________________________________.
 The parietal lobe is associated with the ____________________ and
processes information about __________________________________
______________________________________________________.
 The frontal lobe conducts three functions:
1. __________________________________________
2. __________________________________________
3. __________________________________________
The Cerebellum
 Found below the _______________________________.
 Controls all ________ and some _________ movements.
 The cerebellum receives impulses from the muscles and then sends
impulses to the cerebral cortex to correct and
____________________________________.
 Also responsible for _____________________________.
 This region of the brain is enlarged in _________ and controls muscle
action needed for ________________.
The Medulla
 Located beneath the ________________ and connected to the
____________________________.
 Made mainly of nerve fibres that connect the ______________ to the
______________________.
 Responsible for controlling ___________________ such as
___________________________________________.
The Spinal Cord
 Connects the nerves of the _________________ nervous system with
the brain.
 Controls certain reflexes which are _________________ responses
The Brain
 Some other parts of the brain:
 Thalamus – serves as a relay centre between various parts of the
brain and spinal cord.
 Hypothalamus – helps control body temperature, blood pressure,
sleep and emotions.
 The Pons (midbrain) – links the spinal cord, medulla, cerebellum
and the cerebrum.
The Peripheral Nervous System
 The PNS has 2 parts:
1. The ____________ Nervous System – made up of _____ and ________
neurons. Connects the CNS to the ______ muscles,
__________________________.
2. The _____________ Nervous System – Made up of only ______
neurons. Controls the internal organs of the body.
 The ANS has 2 divisions:
1. Parasympathetic Nervous System
2. Sympathetic Nervous System
 These 2 systems are antagonistic.
 The autonomic nervous system is made entirely of ________________.
 Impulses in this system start in motor neurons in the ______________
__________. The axons of these nerves ________________________
_________________________________________________________.
 The axon of the original neuron synapses with a second motor neuron
which carries the impulse to its final destination.
 Organs served by the ANS generally have nerve endings from both the
sympathetic and parasympathetic divisions.
 The organs are able determine which division the impulse is from
because the divisions use different _________________ in the organs.
 The sympathetic uses ______________________ while the
parasympathetic uses _________________________.
 You will not be required to know about reflexes or reflex arcs.
Sense Receptors – The Eye
Structure of the Eye:
1. ______________ – Tough outer layer (White of the eye). Provides
protection.
2. _______ – Transparent layer on the front of the eye.
_____________________________________________.
3. Choroid coat – Beneath the sclera. Contains the _______ ______ and
prevents light from reflecting within the eye.
4. Optic Nerve – Carries the image created by the ________
_________________________________.
5. Iris – The _________ part of the eye. Controls the
______________________ entering the eye by opening or closing the
pupil. The iris is controlled by the ______.
6. Lens – behind the iris. Focuses ___________________. Cilliary
muscles hold the lens in place and manipulate it’s size & shape to focus
the image.
7. Retina – the innermost layer of the eye. Contains 2 types of light
receptors:
1. Rods: Sensitive to ______________________.
2. Cones: Sensitive to ______________________. 3 types of
cones – each type is sensitive to either
______________________________________.
Sense Receptors: The Ear
Structure of the ear:
 There are 3 parts to the ear: Outer, middle and inner ear.
 The Outer Ear
1. _________________ – Acts as a funnel for sound waves.
2. ________________ – carries the sound to the middle ear. Have glands
that produce ____________________.
3. _______________________________ – Stretches across the inner end
of the auditory canal
The Inner Ear
1. ________________ – The organ of hearing. Composed of
_____________________________________ that are sensitive to
___________. The sound is then transmitted as impulses to the brain
via the ____________________.
2. Semi circular canals – responsible for _______________.