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UNIT B: Human Body Systems Chapter 8: Human Organization Chapter 9: Digestive System Chapter 10: Circulatory System and Lymphatic System Chapter 11: Respiratory.

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Presentation on theme: "UNIT B: Human Body Systems Chapter 8: Human Organization Chapter 9: Digestive System Chapter 10: Circulatory System and Lymphatic System Chapter 11: Respiratory."— Presentation transcript:

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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 In this chapter, you will learn about the structure and function of the nervous system. UNIT B Chapter 12: Nervous System TO PREVIOUS SLIDE 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.

4 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 UNIT B TO PREVIOUS SLIDE Section 12.3 Chapter 12: Nervous System

5 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 o This fluid is produced and stored in the brain’s ventricles (hollow cavities) and the spinal cord’s central canal o If the fluid accumulates in the brain and does not properly drain, the brain can push against the skull, causing brain damage UNIT B TO PREVIOUS SLIDE Section 12.3 Chapter 12: Nervous System

6 UNIT B TO PREVIOUS SLIDE Section 12.3 Chapter 12: Nervous System 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.

7 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 UNIT B TO PREVIOUS SLIDE Section 12.3 Figure 12.8 Spinal cord. a. The spinal cord passes through the vertebral canal formed by the vertebrae. Chapter 12: Nervous System

8 Central canal: contains the cerebrospinal fluid Grey matter: centrally located, shaped like the letter H o 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 UNIT B TO PREVIOUS SLIDE Section 12.3 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. Chapter 12: Nervous System

9 White matter: surrounds grey matter o Contains ascending tracts taking information to the brain and descending tracts taking information from the brain o 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 UNIT B TO PREVIOUS SLIDE Section 12.3 Figure 12.8 Spinal cord. c. Photomicrograph of a cross section of the spinal cord. Chapter 12: Nervous System

10 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 o 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 o 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 UNIT B TO PREVIOUS SLIDE Section 12.3 Chapter 12: Nervous System

11 The Brain The brain has four major parts: Cerebrum (two lateral ventricles) Diencephalon (third ventricle) Cerebellum (fourth ventricle) Brain stem (fourth ventricle) UNIT B TO PREVIOUS SLIDE Section 12.3 Chapter 12: Nervous System

12 UNIT B TO PREVIOUS SLIDE Section 12.3 Chapter 12: Nervous System 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.

13 The Cerebrum The cerebrum is the largest part of the brain in humans Communicates with and coordinates activities of other parts of the brain UNIT B TO PREVIOUS SLIDE Section 12.3 Chapter 12: Nervous System

14 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 UNIT B TO PREVIOUS SLIDE Section 12.3 Chapter 12: Nervous System Figure 12.9 The human brain. The cerebrum has left and right cerebral hemispheres, which are connected by the corpus callosum.

15 UNIT B TO PREVIOUS SLIDE Section 12.3 Chapter 12: Nervous System 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.

16 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) UNIT B TO PREVIOUS SLIDE Section 12.3 Chapter 12: Nervous System

17 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 UNIT B TO PREVIOUS SLIDE Section 12.3 Chapter 12: Nervous System

18 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 UNIT B TO PREVIOUS SLIDE Section 12.3 Chapter 12: Nervous System

19 Occipital Lobe Primary visual area: involved in vision Visual association area: associates new visual information with previous visual information (e.g., facial recognition) UNIT B TO PREVIOUS SLIDE Section 12.3 Chapter 12: Nervous System

20 UNIT B TO PREVIOUS SLIDE Section 12.3 Chapter 12: Nervous System 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.

21 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 UNIT B TO PREVIOUS SLIDE Section 12.3 Chapter 12: Nervous System

22 The Diencephalon The diencephalon is a region that encircles the third ventricle. UNIT B TO PREVIOUS SLIDE Section 12.3 Chapter 12: Nervous System

23 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 UNIT B TO PREVIOUS SLIDE Section 12.3 Chapter 12: Nervous System

24 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 UNIT B TO PREVIOUS SLIDE Section 12.3 Chapter 12: Nervous System

25 The Cerebellum The cerebellum is located under the occipital lobe of the cerebrum. UNIT B TO PREVIOUS SLIDE Section 12.3 Chapter 12: Nervous System

26 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 o Receives sensory input from the joints, muscles, and other sensory pathways about the position of body parts o 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) UNIT B TO PREVIOUS SLIDE Section 12.3 Chapter 12: Nervous System

27 The Brain Stem The brain stem contains the midbrain, the pons, and the medulla oblongata. UNIT B TO PREVIOUS SLIDE Section 12.3 Chapter 12: Nervous System

28 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 UNIT B TO PREVIOUS SLIDE Section 12.3 Chapter 12: Nervous System

29 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) UNIT B TO PREVIOUS SLIDE Section 12.3 Chapter 12: Nervous System

30 Check Your Progress 1.Summarize the functions of the spinal cord. 2.Identify the four major parts of the brain and describe the general functions of each. 3.Describe the types of symptoms you would expect to see in a person who has sustained damage to the cerebellum, medulla oblongata, or RAS. UNIT B TO PREVIOUS SLIDE Section 12.3 Chapter 12: Nervous System

31 UNIT B TO PREVIOUS SLIDE Section 12.3 Chapter 12: Nervous System

32 UNIT B TO PREVIOUS SLIDE Section 12.3 Chapter 12: Nervous System


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