chapter 7:6 the nervous system. key terms autonomic nervous system brain central nervous system...
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Chapter 7:6
The Nervous System
Key Terms
• Autonomic Nervous System• Brain• Central Nervous System• Cerebellum• Cerebrospinal Fluid• Cerebrum• Diencephalon• Hypothalamus• Medulla Oblongata• Meninges• Midbrain• Nerves
• Nervous System• Neuron• Parasympathetic• Peripheral Nervous System• Pons• Somatic Nervous System• Spinal Cord• Sympathetic• Thalamus• Ventricles
The Nervous System
• Neuron (nerve cell) – the basic structural unit of the nervous system
• Consists of:• Cell body (soma) – contains the nucleus• Dendrites – nerve fibers (carries impulses towards the
cell body)• Axon – single nerve fiber (carries impulses away from
the cell body)
The Nervous System (Axons)
• Many axons have a lipid covering called a myelin sheath• Increases the rate of impulse
transmission• Insulates and maintains the axon
• The axon of one neuron lies close to the dendrites of other neurons
• Synapses – the spaces between one neuron and the dendrites of another• Impulses “jump” the synapses to
reach the next dendrite• Neurotransmitters (a special chemical)
are located at the end of each axon
Draw and Label Your Own Neuron
To Label:
AxonCell Body (Soma)DendritesMyelin SheathTerminal Branches
Central Nervous System (brain and spinal cord)
• Main Structures of the brain:• Cerebrum – the largest and highest section of the
brain• Responsible for reasoning, thought, memory,
judgment, speech, sensation, sight, smell, hearing, and voluntary body movements
• Cerebellum – section below the back of the cerebrum• Responsible for muscle coordination, balance,
posture, and muscle tone
Central Nervous System(brain and spinal cord)
• Main Structures of the brain:• Diencephalon – section located between the
cerebrum and midbrain, contains the thalamus and hypothalamus• Thalamus – allows conscious recognition of pain
and temperature• Hypothalamus – regulates and controls the ANS,
temperature, appetite, water balance, sleep, and blood vessel dilation and constriction. Also involved in emotions.
Central Nervous System(brain and spinal cord)
• Main parts of the brain:• Midbrain – located below the cerebrum at the top of the
brainstem• Conducts impulses for certain eye and auditory reflexes
• Pons – located below the midbrain and in the brainstem• Responsible for certain reflex actions such as chewing,
tasting, and saliva production; also helps with respiration
• Medulla Oblongata – lowest part of the brainstem• Responsible for regulating heartbeat, respiration,
swallowing, coughing, and blood pressure
Draw and Label Your Own Brain
To Label:
CerebellumCerebrumFrontal LobeMedulla OblongataMidbrainOccipital LobeParietal LobePonsTemporal Lobe
Central Nervous System(brain and spinal cord)
• Spinal Cord• Continues down from the medulla oblongata and ends
at the first or second lumbar vertebrae• Meninges – cover and protect the brain and spinal
cord• Dura Mater – thick, tough, outer layer• Arachnoid Membrane – middle layer that is
delicate and weblike• Subarachnoid Space – contains cerebrospinal fluid• Pia Mater – innermost layer that is closely attached
to the brain and spinal cord – provides nourishment to the nerve tissue
Peripheral Nervous System
Consists of:
1. Somatic Nervous System: • 12 pairs of cranial nerves
• Some cranial nerves are responsible for special senses
• Other cranial nerves receive general sensations such as touch, pressure, pain, and temperature
• 31 pairs of spinal nerves• Carry messages to and from the spinal cord• Each nerve goes directly to a particular part of the body
Peripheral Nervous System
Consists of:
2. Autonomic Nervous System• Helps to maintain a balance in the involuntary
functions of the body• Allows the body to react in times of emergency
• 1. Sympathetic Nervous System• Fight or flight response (increasing heart rate,
respiration, and blood pressure, slow the digestive system
• 2. Parasympathetic Nervous System• After the emergency, it returns the body to
normal
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