Download The Brain

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Today:
The Brain – The Centre of All Homeostasis
Homeostasis Summative Lab – Examining the
Brain in More Detail…
Reminders:
Catalase Lab due on FRIDAY! No exceptions!
Turnitin also.
YELLOW
BLACK
PURPLE
ORANGE
BLUE
GREEN
BLUE
RED
YELLOW
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What do you put in a toaster?
Did you say toast? The answer is bread, silly!
Say the word “silk” 5 times. Spell the word silk
Now tell me what cows drink
Did you say milk? Cows drink water, silly!
A red house is made of red bricks. A blue
house is made of blue bricks. A yellow house
is made of yellow bricks. What is a green
house made out of?
Glass!
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You are driving a bus and you make the
following stops. Do these calculations without
a calculator
You start with 50 bus passengers
You stop in Toronto and drop off 5 people
but pick up 10
You stop in Mississauga and drop off 7
people but pick up 11
You stop in Brampton and drop off 2 people
and pick up 5
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How old is the bus driver?
Did you read the question carefully...it said
YOU are driving a bus...
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The human nervous system is organized
into the central nervous system (CNS)
and the peripheral nervous system (PNS)
The CNS is comprised of the brain and
spinal cord
Together, the CNS is the main
processing centre for feedback. The
spinal cord and brain receive messages
(inputs) from the body, process the
information, and send a
response (recall lesson 1: feedback
mechanisms).
In doing so, the CNS helps the body
achieve homeostasis.
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The spinal cord extends from the base of the
brain through a canal inside the vertebrae of
the backbone
It carries impulses between the brain and the
peripheral nervous system (PNS) (nerves of
the body)
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The brain and spinal cord are
surrounded with, and protected
by, three layers of connective
tissue called the meninges
Meninges
◦ Membrane covering the brain
The brain is divided into 2
hemispheres (left and right). The
Corpus Callosum is a
◦ Bundle of nerves connecting two
hemispheres
The Pituitary Gland is an endocrine
gland (hormone secreting organ) in
the brain.
◦ 2 lobes
◦ Anterior: secretes FSH, LH, GH,
PRL, ACTH, and TSH
◦ Posterior: secretes ADH &
Oxytocin
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Medulla Oblongata (aka Medulla)
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Cerebellum
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Pons
◦ Connects brain to spinal cord. Coordinates
reflexes and maintains homeostasis (e.g.
heart rate, etc., especially involuntary
responses)
◦ “Little brain”. Coordinates posture, reflexes,
motor skills, especially voluntary responses
◦ AKA Brainstem: RELAYS information between
different areas of the brain
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The midbrain is in the ‘middle’ of the brain.
Notice that it is above the brainstem and
spinal cord. Those structures close to the
spinal cord function in reflexes (close to
nerves) and RELAYING or CONNECTING
peripheral nerves to the brain. Since the
midbrain is close to this area, it receives
information and...
Midbrain:
◦ Processes information from sensory neurons in eye,
ears, nose.
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The forebrain is at the forefront! Think
about structure and function again. If a
structure is at the forefront, what kinds
of functions would be associated with it?
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Thalamus
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Hypothalamus
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Cerebrum
◦ “Relay station”. Connects forebrain & hindbrain
and sensory system (besides smell)
◦ Regulates temperature, blood pressure, needs,
emotions, and coordinates the pituitary gland to
help release hormones
◦ Largest part of brain. Divided into right and left
hemispheres. Contain centres for intellect,
memory, language.
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“Left Brain” = logic, math, sequences
“Right Brain” = artistic, visual, intuitive
Right hemisphere controls left half of body &
vise versa. Hemispheres are separated by the
corpus callosum
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Outer portion = cerebral cortex
4 major lobes of the cerebrum
◦ Frontal lobe
 Conscious thought
 Motor cortex
◦ Parietal Lobe
 Sensory (temp, touch, pain, pressure from skin)
◦ Occipital Lobe
 vision
◦ Temporal Lobe
 Hearing and smelling