Download Chapter 17 - Biology12-Lum

Chapter 17
The Brain
• CNS  Central Nervous System. Brain and
Spinal cord
– Interpretation, thought, autonomic nervous
system
• PNS  Peripheral Nervous System. Nerves in
the body
– Sensory receptors, Effectors
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Parts of the Brain
Medulla oblongata stem of brain
Cerebrum  the outer part of the brain
Thalamus  Underneath the Corpus Callosum
Cerebellum Behind the Medulla oblongata and
underneath the cerebrum.
Hypothalamus  Underneath the thalamus
Pituitary Gland  hangs below the hypothalamus
Corpus Callosum Between the thalamus and the
cerebrum
Meninges thin watery layer around the CNS
What do the parts of the Brain do?
• Medulla oblongata
– Does all the involuntary actions. Breathing, heartbeat,
sneezing, coughing and etc.
• Cerebrum
– Has two halves. Communication, higher thinking,
memory.
• Corpus Callosum
– Connects the two halves of the brain. Allows
communication between the halves of the brain.
• Thalamus
– Takes in sensory information and relays it other parts
of the brain. Also does memory and emotion
• Hypothalamus
– Center for autonomic nervous system.
– Helps maintain homeostasis, regulates thirst, hunger, water,
sleep, etc.
– Controls the pituitary gland
– Link between nervous system and endocrine system
• Pituitary Gland
– Releases hormones into the body.
– Major part of the endocrine system
• Cerebellum
– Maintains muscle tone. Posture, balance, ensures muscles
work in a coordinated manner.
• Meninges
– Covers the central nervous system. Protects the CNS
Voluntary and Involuntary
• Autonomic Nervous System
– No control over. Heartbeat, breathing, sneezing,
digestion, salivation.
• Somatic Nervous System
– Have control over. When though is put into
something. Picking up an object, speaking.
Parasympathetic vs. Sympathetic
• Parasympathetic Nervous System
– Digestion, Low Heart Rate, Slow Breathing, Small Pupils.
– State of rest
– Neurotransmitter used is acetylcholine
• Sympathetic Nervous System
– Fast Heart Rate, Fast Breathing, dilates bronchi, Pupils of
eyes are dilated.
– More oxygen for muscles. More light in to see better
– Neurotransmitter used is norepinephrine
– Initiated by the adrenal gland  releases hormone called
epinephrine. This hormone activates the Sympathetic
Nervous system. Comes from the adrenal medulla.