Section 9.3 Assignment The Central Nervous System

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Section 9.3 AssignmentThe Central Nervous System

• Biology 12
• S.Dosman

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Meninges

• Protective membranes that surround the brain and
  spinal cord.

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Cerebrospinal fluid

• Cushioning fluid that circulates between the
  innermost and middle membranes of the brain and
  spinal cord it provides a connection between
  neural and endocrine systems.
• It is contained within the ventricular system of
  the brain and it continuous with the spinal cord.

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Olfactory lobes

• Areas of the brain that process information about
  smell.
• Also known as the olfactory bulbs.

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Cerebrum

• Largest and most highly developed part of the
  human brain, which stores sensory information and
  initiates voluntary motor activities.

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Cerebral cortex

• Outer lining of the cerebral hemispheres.
• The cortex contains groves known as sulci and
  bumps called gyri.
• The folds and wrinkles increase the surface area
  of the cerebrum.

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Corpus callosum

• Nerve tract that joins the two cerebral
  hemispheres.

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Thalamus

• Area of brain that coordinates and interprets
  sensory information and directs it to the
  cerebrum.

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Cerebellum

• Part of the hindbrain that controls limb
  movements, balance, and muscle tone

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Pons

• Region of the brain that acts as a relay station
  by sending nerve messages between the cerebellum
  and the medulla.

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Medulla Oblongata

• Region of the hindbrain that joins the spinal
  cord to the cerebellum one of the most important
  sites of autonomic nerve control.
• http//www.youtube.com/watch?vUfC4u5GCy3I

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1. What are the three membranes that make up the
meninges of the brain and what is their function?

• The meninges of the brain are composed of three
  membranes known as the dura mater, arachnoid
  mater and the pia mater.
• Together they form the blood-brain barrier which
  determines what chemicals will reach the brain

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2. What is the function of the cerebrospinal
fluid and how can it be used to diagnose
infection?

• The function of the cerebrospinal fluid is to
  absorb shock and act as a transport medium that
  carries nutrients to the brain cells and also
  relaying wastes from the cells to the blood.
• Doctors can withdraw this fluid in a process
  known as a lumbar puncture or spinal tap and it
  can be tested for the presence of bacteria or
  viruses.

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3. Summarize the function, location, and
composition of the spinal cord. You may use
point form.

• The spinal cord is part of the central nervous
  system and its function is to carry sensory nerve
  messages from receptors to the brain and to relay
  motor nerve messages from the brain to muscles,
  organs and glands.
• It extends from the base of the brain and through
  an opening in the skull known as the foramen
  magnum. It continues down through the openings
  in the vertebrae and is effectively protected
  within the backbone.

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3. Summarize the function, location, and
composition of the spinal cord. You may use
point form.

• The spinal cord is composed of both white
  (myelinated) and grey (nonmyelinated) matter.
• The central grey matter (interneurons) is
  surrounded by the white matter (sensory and motor
  neurons).

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4. Identify the three distinct regions of the
brain. (Hint they all have the word brain in
them!)

• The brain has three distinct regions known as the
  forebrain, the midbrain and the hind brain.
• Forebrain consists of the cerebrum, thalamus and
  hypothalamus.
• Midbrain is the top portion of the brainstem and
  it connects forebrain to hindbrain.
• Hindbrain consists of the cerebellum, pons and
  medulla oblongata.

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5. What happens within the cerebrum of the human
brain?

• The cerebrum is the largest portion of the
  forebrain and it contains a right and left
  hemisphere.
• It is the major coordinating centre from which
  sensory information and coordinating motor
  actions originate.
• It also controls speech, reasoning, memory and
  personality.

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6. What is the difference between the left and
right side of the brain and how are they
connected?

• The cerebrum has a right and left hemisphere.
• The right hemisphere is associated with visual
  patterns or spatial awareness.
• The left hemisphere is linked to verbal skills.
• The hemispheres are connected by the corpus
  callosum which allows for communication between
  the left and right side.

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7. What are the four lobes of the brain?

• Each hemisphere of the cerebrum is further
  divided into four lobes the frontal lobe,
  temporal lobe, occipital lobe and the parietal
  lobe.
• Table 1 on page 429 identifies the four lobes and
  the functions associated with each lobe and we
  will explore them in further detail at a later
  point.

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8. Why are there more nerve tracts going to
certain areas of the body?

• Certain areas of the body such as the thumb and
  fingers are capable of and responsible for
  delicate or fine motor skills.
• Due to this fact they have more nerve tracts
  leading to them than areas such as the wrist
  which has limited movements.

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9. What occurs in the midbrain?

• The midbrain connects the forebrain and the
  hindbrain.
• It is composed of four spheres of grey matter and
  it acts as a relay center for some eye and ear
  reflexes.
• Portions of the midbrain are also involved in the
  control of body movement.
• Degeneration of neurons in the midbrain is linked
  to Parkinsons disease.

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10. What are the parts of the hindbrain?

• The hindbrain is composed of the cerebellum, pons
  and the medulla oblongata.
• The cerebellum controls limb movements, balance
  and muscle tone.
• The pons is a relay station that passes
  information between the two regions of the
  cerebellum and between the cerebellum and the
  medulla oblongata.

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11. What is the function of the medulla
oblongata?

• The medulla oblongata is the connection between
  the peripheral and the central nervous system.
• It controls involuntary muscle actions such as
  breathing movements, the diameter of blood
  vessels and heart rate.
• It also acts as the coordinating center for the
  autonomic nervous system.

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12. How do we know what parts of the brain are
responsible for different actions?

• Scientists gathered evidence about the regions of
  the brain and their associated actions from
  stroke patients.
• When a stroke occurs brain cells are denied
  oxygen and nutrients and the cells are damaged.
  Damage to cells on the right side of the motor
  cortex affect actions or cause paralysis on the
  left side of the body.

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13. Read the case study on Phineas Gage on page
432. Why do you think he experienced such
changes in behaviour following his accident?

• http//www.youtube.com/watch?vFrULrWRlGBA
• Destroyed connections in his brain controlling
  social behaviour.
• The iron bar destroyed areas of his frontal lobe,
  a portion of the brain associated with
  intellectual activities and personality.