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The Nervous System. Homeostasis. What is it? Homeostasis: the process of keeping internal conditions relatively constant. The Nervous System. What does it do? Controls functions in the body responds to internal and external stimuli. The Nervous System. What does it do?
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Homeostasis What is it? Homeostasis: the process of keeping internal conditions relatively constant.
The Nervous System What does it do? • Controls functions in the body • responds to internal and external stimuli.
The Nervous System What does it do? • maintains homeostasis Lumosity.com
The Nervous System What is it? Nervous system: • Complex network of specialized cells that transmit messages in the body Lumosity.com
The Nervous System Two halves • CNS = Central Nervous System • PNS = Peripheral Nervous System
The Nervous System Two halves • CNS = Central Nervous System • Brain • Spinal cord
The Nervous System Two halves • CNS = Central Nervous System • PNS = Peripheral Nervous System • Cranial nerves (nerves off brain) • Spinal Nerves (off the spinal cord)
The BRAIN www.webhealthguides.net
Parts of the Brain • Cerebrum • responsible for all voluntary activities
Parts of the Brain • Cerebrum • Two hemispheres • Left and Right hemispheres • Right hemisphere controls left side of body, left controls the right
Parts of the Brain • Cerebrum • Four lobes Parietal lobe Frontal lobe Occipital lobe Temporal lobe
Parts of the Brain • Cerebellum • means “little brain” • controls coordination • Let’s see how well your cerebellum works…..
Parts of the Brain • Brainstem • connects brain to spinal cord • Controls heart rate, breathing, and swallowing • Also vomiting, hiccupping, coughing and sneezing
Parts of the Brain • Parts of the Brainstem • Midbrain • Pons • Medulla oblongatta
Parts of the Brain • Thalamus and Hypothalamus
Parts of the Brain • Thalamus: receives messages from the sense organs • Hypothalamus: control center for hunger, thirst, fatigue, anger and body temp. • So, the hypothalamus maintains what?
The Nervous System • CNS = Central Nervous System • Brain • Spinal cord • PNS = Peripheral Nervous System • Cranial nerves (nerves off brain) • Spinal Nerves (off the spinal cord)
Spinal Cord • Main communication link between brain and rest of body • Protected by... • 31 pairs of nerves branch off • Reflex happens within the spinal cord the vertebral column
Reflex • When an impulse skips going to the brain and just comes right back out the spinal cord
Neurons: A nerve cell 2 3 4 8 Axon terminals 5 Node 6 1 Schwann’s cells 7
The Nerve Impulse Nerve Impulse: flow of electrical charges along the neuron Starts at the dendrite, travels to cell body or soma, down the axon and then the axon terminal. Then a neurotransmitter will carry the impulse across the synapse
The Neuron Electrical flow of the nerve impulse: Dendrites Soma Axon Axon Terminals
The next slide shows what it will look like when you put several neurons in a row (in other words a nerve)
Three types of neurons… • Sensory neuron • Sends impulse from sense organs toward brain • Motor neuron • Away from brain/spinal cord to muscles/organs • Interneuron • Connect sensory to motor neurons • Found only in the spinal cord
Synapse • Gap between one neuron and the next neuron • Where the impulse jumps to the next neuron
Neurotransmitter: Chemicals used to pass the impulse Let’s label the picture:
Axon terminal Neurotransmitter Axon Synapse Synapse Soma Transport protein Neurotransmitter
Neurotransmitters One common neurotransmitter is: ACETYLCHOLINE
Cranial nerves • Cranial nerves: nerves that branch directly off of the brain • Most of them are sensory • Others are motor
Olfactory: • Optic • Oculomotor • Troclear • Trigeminal • Abducens • Facial • Auditory (vestibulocochlear) • Glossopharyngeal • Vagus • Accessory • Hypoglossal
Olfactory: smell • Optic • Oculomotor • Troclear • Trigeminal • Abducens • Facial • Auditory (vestibulocochlear) • Glossopharyngeal • Vagus • Accessory • Hypoglossal
Cranial Nerves • Olfactory: smell • Optic: vision (forward and peripheral) • Oculomotor • Troclear • Trigeminal • Abducens • Facial • Auditory (vestibulocochlear) • Glossopharyngeal • Vagus • Accessory • Hypoglossal