Date post: | 16-Dec-2015 |
Category: |
Documents |
Upload: | bertha-harmon |
View: | 222 times |
Download: | 2 times |
Chapter 9- Regulation
• Regulation:–The coordination and control of
the life activities.–The internal environment must
remain stable Homeostasis.
•Nervous and Endocrine systems
• Stimulus:– Any change in the internal or external
environment that causes a response.• Response:– Reaction to a stimulus.
• Receptors:– Structures that are specialized to receive certain
stimuli. Ex. Five senses.
• Impulse:–An electrochemical charge generated along
a neuron. The message!• Effectors:–Parts of the body that respond. Ex. Muscles
or glands.
Neurons
The Neuron:– Aka nerve cell- receives and transmits impulses.– Composed of:• Dendrites– Detect stimulus– Cell branches– Receives impulses
• Cyton– Cell body that contains the nucleus
• Axon– Branch of the cell that transmits impulses away from the
cyton.• Terminal branches– End of the axon– Secretes neurotransmitters (made by synaptic knobs)
• Synapse:– Gap (space) between neurons– Neurotransmitters:– Chemicals secreted into the
synapse by terminal branches.
– Helps impulses jump the synapse.
– Example acetylcholine, norepinephrine
Types of Neurons: Pathway is always sensory ->inter->motor
• Sensory neuron:– Carries impulse from receptors (5 senses) to brain and
spinal cord (CNS).
• Interneuron:– Neuron found between sensory and motor neurons.– Located in brain and spinal cord.
• Motor neurons:– Carries impulse away from brain and spinal cord (CNS) to
the effectors (muscles or glands).
The Brain:
• Composed of millions of neurons– 3 divisions
• cerebrum:• largest part of the brain• area where sensory impulses are interpreted• memory, thinking, and reasoning
• cerebellum:– Balance and motor coordination
• medulla:– connects spinal cord to the brain.– Controls involuntary activity: breathing, heart beat,
digestion
The Spinal Cord:• Thick nerve located within the vertebrae.• Protected by: vertebrae, meninges, cerebrospinal fluid.• Connects directly with the base of the brain.• Function: center for the reflex action– Reflexes: simple, involuntary, inborn patterns of behavior.– Reflex arc: pathway over which impulses travel.
• Stimulus receptorsensory neuroninterneuronmotor neuroneffectors (RSIME!!)
The peripheral nervous system (PNS)
• Nerves outside CNS • Carry impulses to other parts of the body.• Breaks into somatic and autonomic – Somatic – voluntary activities Ex: batting a ball– Autonomic – involuntary activities Ex: breathing
Malfunctions of the Nervous System
• Cerebral Palsy• May occur before/during /after birth.• Damage to the motor areas of the brain.• Difficulty in coordinating voluntary muscle
• Meningitis• Inflammation of the meninges. It can be viral or
bacterial.
• Stroke• Supply of blood to the brain is cut off. A clot or a
hemorrhage can form.• Brain damage and paralysis occurs.
• Polio• Viral disease of the CNS. Results in
paralysis.**Immunization- Salk and Sabin vaccine