1. Presentation title slide

2. UNIT B: Human Body Systems
Chapter 8: Human Organization
Chapter 9: Digestive System
Chapter 10: Circulatory System and Lymphatic System
Chapter 11: Respiratory System
Chapter 12: Nervous System:
Section 12.3
Chapter 13: Urinary System
Chapter 14: Reproductive System

3. Chapter 12: Nervous System
UNIT B
Chapter 12: Nervous System
Chapter 12: Nervous System
In this chapter, you will learn about the structure and function of the nervous system.
How might a researcher study the effects of frequent head trauma?
How might one determine which part of the brain has been affected by repeated blunt impacts?
Given the available information about CTE, what steps do you feel should be taken to prevent its occurrence (if any)?
Sport-Related Head Trauma and Brain Function. Neurosurgeon Dr. Robert Cantu has studied the brains of many deceased athletes, including hockey and football players. He has found that these players often suffered from chronic traumatic encephalopathy (CTE), a degenerative brain disease caused by repeated blunt impact to the head.
Chapter opener figure background:
Former NHL players Rick Rypien, Wade Belak, and Derek Boogaard had something in common; they were all “enforcers.” They were expected to
fight during hockey games.
There is another similarity among these men. They are all dead. Each died of causes that increasingly seem tied to their activities on the ice. Neurosurgeon Dr. Robert Cantu has studied the brains of many deceased athletes, including hockey and football players. He has found that these players often suffered from chronic traumatic encephalopathy (CTE), a degenerative brain disease caused by repeated blunt impact to the head. CTE seems to manifest itself in addiction, depression, and anxiety, conditions suffered by some or all of the deceased players.
Dr. David Goldbloom, senior medical adviser at Toronto’s Centre for Addiction and Mental Health, thinks it is important not to assume that the deaths of the players were all the result of the same thing. Each was an individual and each had his own mental health history. Rypien and Belak had battled depression, and Boogaard was still recovering from previous concussions. Goldbloom feels that attributing the deaths to CTE is an oversimplification, but he does think further study in this area is worth pursuing.
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4. 12.3 The Central Nervous System
UNIT B
Chapter 12: Nervous System
Section 12.3
12.3 The Central Nervous System
The central nervous system is composed of the spinal cord and the brain.
Brain: controls breathing, heart rate, body temperature, blood pressure, emotions, reasoning, memory, and creativity
Spinal cord: a means of communication between the brain and the peripheral nerves that leave the cord
central nervous system: where sensory information is received and motor control is initiated; includes the spinal cord and the brain
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5. UNIT B
Chapter 12: Nervous System
Section 12.3
The brain and spinal cord are wrapped in protective membranes called meninges
The spaces between meninges are filled with cerebrospinal fluid, which cushions and protects the CNS
This fluid is produced and stored in the brain’s ventricles (hollow cavities) and the spinal cord’s central canal
If the fluid accumulates in the brain and does not properly drain, the brain can push against the skull, causing brain damage
meninges: (sing., meninx) protective membranes wrapping around both the spinal cord and the brain
cerebrospinal fluid: a fluid in between the meninges of the spinal cord and brain, which cushions and protects the central nervous system
ventricles: hollow interconnecting cavities in the brain; produce and serve as a reservoir for cerebrospinal fluid
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6. UNIT B Chapter 12: Nervous System Section 12.3
Figure 12.7 Organization of the nervous system. The CNS is composed of the spinal cord and brain. The PNS is composed of the motor and sensory pathways.
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7. The Spinal Cord UNIT B Structure of the Spinal Cord
Chapter 12: Nervous System
Section 12.3
The Spinal Cord
Structure of the Spinal Cord
Individual vertebra protect the spinal cord
Spinal nerves project from the cord between the vertebrae in the vertebral column
Fluid-filled intervertebral disks cushion and separate the vertebrae
spinal cord: the nerve cord that is continuous with the base of the brain and housed within the vertebral column
Figure 12.8 Spinal cord. a. The spinal cord passes through the vertebral canal formed by the vertebrae.
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8. UNIT B Central canal: contains the cerebrospinal fluid
Chapter 12: Nervous System
Section 12.3
Central canal: contains the cerebrospinal fluid
Grey matter: centrally located, shaped like the letter H
Contains parts of sensory neurons, motor neurons, and interneurons
Dorsal root: contains sensory fibres entering grey matter
Ventral root: contains motor fibres exiting grey matter
Spinal nerves: part of PNS
Figure 12.8 Spinal cord. b. The spinal cord has a central canal filled with cerebrospinal fluid, grey matter in an H-shaped configuration, and white matter. The white matter contains tracts that take nerve impulses to and from the brain.
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9. UNIT B White matter: surrounds grey matter
Chapter 12: Nervous System
Section 12.3
White matter: surrounds grey matter
Contains ascending tracts taking information to the brain and descending tracts taking information from the brain
Tracts cross each other after entering and exiting CNS
Left side of brain: controls right side of body
Right side of brain: controls left side of body
Figure 12.8 Spinal cord c. Photomicrograph of a cross section of the spinal cord.
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10. Functions of the Spinal Cord
UNIT B
Chapter 12: Nervous System
Section 12.3
Functions of the Spinal Cord
The spinal cord sends sensory information to the brain, receives motor input from the brain, and carries out reflex actions.
Example: Sensation
When someone touches your hand, sensory receptors generate nerve impulses that pass through sensory fibres to the spinal cord and up ascending tracts to the brain
Example: Voluntary movement
When we move our limbs, motor impulses in the brain pass down descending tracts to the spinal cord and out to our muscles through motor fibres
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11. The Brain UNIT B The brain has four major parts:
Chapter 12: Nervous System
Section 12.3
The Brain
The brain has four major parts:
Cerebrum (two lateral ventricles)
Diencephalon (third ventricle)
Cerebellum (fourth ventricle)
Brain stem (fourth ventricle)
brain: located in the cranial cavity of the skull; contains four major parts: the cerebrum, the diencephalon, the cerebellum, and the brain stem
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12. UNIT B Chapter 12: Nervous System Section 12.3
Figure 12.9 The human brain. a. The cerebrum, seen here in longitudinal section, is the largest part of the brain in humans. The right cerebral hemisphere is shown here.
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13. UNIT B
Chapter 12: Nervous System
Section 12.3
The Cerebrum
The cerebrum is the largest part of the brain in humans
Communicates with and coordinates activities of other parts of the brain
cerebrum: largest portion of the brain; communicates with and coordinates the activities of the other parts of the brain
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14. Structure and Function of the Cerebrum
UNIT B
Chapter 12: Nervous System
Section 12.3
Structure and Function of the Cerebrum
The cerebrum has two halves (cerebral hemispheres) that communicate via the corpus callosum, a bridge of nerve tracts.
The cerebral cortex is a thin outer layer of grey matter that covers the cerebral hemispheres
Grooves called sulci divide the hemisphere into four lobes: frontal, parietal, occipital, temporal
cerebral hemispheres: the two lobes of the cerebrum
cerebral cortex: a thin, highly convoluted outer layer of grey matter that covers the cerebral hemispheres
Figure 12.9 The human brain. The cerebrum has left and right cerebral hemispheres, which are connected by the corpus callosum.
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15. UNIT B Chapter 12: Nervous System Section 12.3
Figure The lobes of a cerebral hemisphere. Each cerebral hemisphere is divided into four lobes: frontal, parietal, temporal, and occipital. The frontal lobe contains centres for reasoning and movement, the parietal lobe for somatic sensing and taste, the temporal lobe for hearing, and the occipital lobe for vision.
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16. UNIT B Frontal Lobe Primary motor area: involved in voluntary movement
Chapter 12: Nervous System
Section 12.3
Frontal Lobe
Primary motor area: involved in voluntary movement
Premotor area: involved in organizing motor functions
Prefrontal area: processing centre involved in reasoning and planning
Broca’s area: involved in speech musculature (lips, tongue, larynx)
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17. UNIT B
Chapter 12: Nervous System
Section 12.3
Parietal Lobe
Primary somatosensory area: involved in somatic sensing
Primary taste area: involved in taste
Somatosensory association area: processes and analyzes sensory information from skin and muscles
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18. UNIT B Temporal Lobe Primary auditory area: involved in hearing
Chapter 12: Nervous System
Section 12.3
Temporal Lobe
Primary auditory area: involved in hearing
Auditory association area: associates new audio information with previous audio information
Wernicke’s area: helps us understand written and spoken words
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19. UNIT B Occipital Lobe Primary visual area: involved in vision
Chapter 12: Nervous System
Section 12.3
Occipital Lobe
Primary visual area: involved in vision
Visual association area: associates new visual information with previous visual information (e.g., facial recognition)
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20. UNIT B Chapter 12: Nervous System Section 12.3
12.11 The primary motor and somatosensory areas. In these drawings, the size of the body part reflects the amount of cerebral cortex devoted to that body part. For example, the amount of primary motor cortex (a) and somatosensory cortex (b) devoted to the thumb, fingers, and hand is greater than that for the foot and toes.
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21. UNIT B Central White Matter
Chapter 12: Nervous System
Section 12.3
Central White Matter
Most of the cerebrum beneath the cerebral cortex is composed of white matter
Tracts within the cerebrum take information between different sensory, motor, and association areas
Basal Nuclei
Basal nuclei are masses of grey matter located deep within the white matter of the cerebrum
Integrate motor commands to ensure proper muscle groups are activated or inhibited
basal nuclei: masses of grey matter located deep within the white matter that integrate motor commands
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22. The Diencephalon UNIT B
Chapter 12: Nervous System
Section 12.3
The Diencephalon
The diencephalon is a region that encircles the third ventricle.
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23. Structure and Function of the Diencephalon
UNIT B
Chapter 12: Nervous System
Section 12.3
Structure and Function of the Diencephalon
Hypothalamus
Integrating centre that helps maintain homeostasis
Regulates hunger, sleep, thirst, body temperature, and water balance
Controls the pituitary gland and serves as a link between the nervous and endocrine systems
hypothalamus: an integrating centre that helps maintain homeostasis; regulates hunger, sleep, thirst, body temperature, and water balance; also controls the pituitary gland and thereby serves as a link between the nervous and endocrine systems
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24. Consists of grey matter that receives all sensory input except smell
UNIT B
Chapter 12: Nervous System
Section 12.3
Thalamus
Consists of grey matter that receives all sensory input except smell
Integrates visual, auditory, taste, and somatosensory information and sends it to the appropriate area in the cerebrum
Involved in higher mental functions (memory, emotions)
Pineal gland
Secretes the hormone melatonin, which is involved in maintaining a normal sleep-wake cycle
thalamus: two masses of grey matter that receive all sensory input except for smell
pineal gland: a gland in the third ventricle of the brain that produces melatonin
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25. UNIT B
Chapter 12: Nervous System
Section 12.3
The Cerebellum
The cerebellum is located under the occipital lobe of the cerebrum.
cerebellum: a portion of the brain that coordinates skeletal muscles to produce smooth, graceful motions
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26. Structure and Function of the Cerebellum
UNIT B
Chapter 12: Nervous System
Section 12.3
Structure and Function of the Cerebellum
Has two portions that are primarily composed of white matter (a thin layer of grey matter overlays the white matter)
Involved in maintaining posture and balance
Receives sensory input from the joints, muscles, and other sensory pathways about the position of body parts
Receives motor output from the cerebral cortex about where body parts should be located
Involved in producing smooth, coordinated voluntary movements (e.g., playing piano, hitting a baseball)
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27. UNIT B
Chapter 12: Nervous System
Section 12.3
The Brain Stem
The brain stem contains the midbrain, the pons, and the medulla oblongata.
brain stem: a portion of the brain that contains the midbrain, the pons, and the medulla oblongata
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28. Structure and Function of the Brain Stem
UNIT B
Chapter 12: Nervous System
Section 12.3
Structure and Function of the Brain Stem
Midbrain
A relay station for tracts passing between the cerebrum and spinal cord or cerebellum
Has reflex centres for visual, auditory, and tactile responses
Pons
Contains bundles of axons travelling between the cerebellum and the rest of the CNS
Functions with medulla oblongata to regulate breathing rate
midbrain: part of the brain stem that acts as a relay station for tracts passing between the cerebrum and the spinal cord or cerebellum; also has reflex centres for visual, auditory, and tactile responses
pons: part of the brain stem that contains bundles of axons travelling between the cerebellum and the rest of the central nervous system; functions with the medulla oblongata to regulate the breathing rate
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29. Regulates heartbeat, breathing, and blood pressure
UNIT B
Chapter 12: Nervous System
Section 12.3
Medulla oblongata
Regulates heartbeat, breathing, and blood pressure
Contains reflex centres for vomiting, coughing, sneezing, hiccupping, and swallowing
Reticular activating system (RAS)
Relay centre that is involved in alertness
Also involved in filtering out unnecessary sensory stimuli (e.g., studying while the TV is on)
medulla oblongata: part of the brain stem that regulates vital functions like heartbeat, breathing, and blood pressure; also contains reflex centres for vomiting, coughing, sneezing, hiccuping, and swallowing
reticular activating system (RAS): the area of the brain that contains the reticular formation; acts as a relay for information to and from the peripheral nervous system and higher processing centres of the brain
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30. Check Your Progress UNIT B Summarize the functions of the spinal cord.
Chapter 12: Nervous System
Section 12.3
Check Your Progress
Summarize the functions of the spinal cord.
Identify the four major parts of the brain and describe the general functions of each.
Describe the types of symptoms you would expect to see in a person who has sustained damage to the cerebellum, medulla oblongata, or RAS.
ANSWERS
1. The spinal cord provides a way for the brain to communicate with the peripheral nerves. This communication involves incoming sensory information and outgoing motor information.
2. Cerebrum: Receives sensory information, integrates it, and commands voluntary motor responses. It receives information from other parts of the brain and is involved in high-level analytical functions such as speaking and interpreting language, thinking critically, and formulating appropriate behaviours
Diencephalon: Hypothalamus: serves as a link between the nervous and endocrine system, maintaining homeostasis. It regulates hunger, sleep, thirst, body temperature, and water balance.
Thalamus: receives sensory inputs (visual, auditory, taste, and somatosensory information) except for smell. It is also involved in the arousal of the cerebrum. It participates in higher mental functions, such as memory and emotions.
Pineal gland: secretes the hormone melatonin, involved in the sleep-wake cycle
Cerebellum: Processes information about body position and maintains posture and balance
Ensures muscles work together to produce smooth, coordinated voluntary movements
Brain stem: Acts as a relay between the cerebrum and spinal cord or cerebellum
Regulates breathing through the pons
Regulates vital functions through the medulla oblongata
Receives and sends signals between the higher brain centres and the spinal cord
3. Damage to the cerebellum: Poor balance and uncoordinated voluntary muscle movements
Damage to the medulla oblongata: Erratic heartbeat, breathing and blood pressure
Uncoordinated reflexes for vomiting, coughing, sneezing, hiccupping and swallowing
Damage to the RAS: Inability to be alert to sensory stimuli, possibly become comatose
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31. UNIT B
Chapter 12: Nervous System
Section 12.3
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32. UNIT B
Chapter 12: Nervous System
Section 12.3
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