RAP 7 CH 12 - 14 - This is the study guide for an in class quiz PDF

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This is the study guide for an in class quiz...

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.Study Guide for BMSP 2135 – Readiness Assurance Test 7 – Part 1 of 3 Chapter 12 – The Central Nervous System Module 12.1 Overview of the Central Nervous System Overview of CNS Functions This should mostly be a review of 11.1 which was an overview of the nervous system. It give a brief, sweeping overview of the CNS. Basic Structure of the Brain and Spinal Cord You should know the basic divisions of the brain and their functions (see figure 12.1 on page 426). You should also know what composes white matter and gray matter and where each is located in the brain and spinal cord (see figure 12.2 on page 426). You should also be familiar with terminology related to white and gray matter: nuclei (bundles of gray matter), tracts (bundles of white matter).    

Cerebrum: higher mental functions and interprets sensory stimuli, plans movement Diencephalon: process and integrates info, maintains homeostasis, regulates rhythms Cerebellum: monitors and coordinates movement Brain stem: maintains homeostasis, controls reflexes, monitors movement, integrates info

Overview of CNS Development You can skip this section Module 12.2 The Brain The Cerebrum You should know that the cerebrum has two hemispheres separated by a longitudinal fissure. You should know the terms gyri (singular is gyrus) and sulci (singular is sulcus). What is the reason for the surface of the brain to have so many wrinkles? Increase surface area Label the five lobes of the cerebrum. Frontal, Parietal, temporal, occipital, and insulas What structure separates the frontal lobe and parietal lobe? What is the name of the gyri on either side of it? (Use the names to help you remember!) central sulcus What separates the temporal lobe from the frontal and parietal lobes? Lateral fissure See figure 12.4 on page 428.

Gray Matter: Cerebral Cortex Cortex means “bark” how does this relate to its location? Covers cerebral hemispheres What is an association area? Areas of the cerebral cortex that integrate different types of info Where is the primary motor cortex located? Precentral gyrus What is the function of the primary motor cortex? Plans and executes movement Where is the premotor cortex located? On temporal lobe before precentral gyrus What is the function of the premotor cortex? Planning, guidance, coordination, and execution of movement What is the primary somatosensory cortex? It is a sensory cortex Where is the primary somatosensory cortex located? Postcentral gyrus What is the function of the primary somatosensory cortex? Interprets somatic sensory info What is the function of the primary visual cortex? Interprets and processes visual stimuli Where is the primary visual cortex located? Occipital lobe What area surrounds the primary visual cortex? Where is the primary auditory cortex located? Temporal lobe What is the function of the primary auditory cortex? Process auditory stimuli Where is the prefrontal cortex located? Frontal lobe What is its function? Planning, personality, higher cognitive functions What is the function of Broca’s area? Language production What is the function of Wernicke’s area? Language comprehension What are basal nuclei? Nuclei within the cerebral hemisphere What is their collective function? Initiation of movement and the prevention of inappropriate movement Name three basal nuclei: caudate nucleus, putamen, and globus pallidus Cerebral White Matter Name the three types of white matter in the cerebrum: commissural, association, and projection fibers ,Recognize each type in figure 12.7

Structures of the Limbic System What role does the limbic system play in the brain? Participates in learning, memories, emotion, and behavior Know two parts of the limbic system: hippocampus and amygdala If shown an image similar to figure 12.9, recognize that the structures are the limbic system. (You do not need to know all the individual structures). The Diencephalon What are the four parts of the diencephalon? Thalamus, hypothalamus, epithalamus, and subthalamus Thalamus Why is the thalamus called the “main entrance” or the “gateway” to the cerebral cortex? All info destined for cerebral cortex is processed here first; regulates the info Recognize the thalamus in figure 12.10 on page 434.

Hypothalamus The hypothalamus is shaped like a funnel. It is an important part of the brain and the endocrine system. Recognize the hypothalamus in figure 12.10c on page 434. What are some primary functions of the hypothalamus? Regulates autonomic nervous system (body temperature, wake/sleep, hunger) Which of the functions listed above are related to homeostasis? All of them Which endocrine organ is connected to the hypothalamus? What is the name of the connecting stalk? Pituitary gland and infundibulum What structures connect the hypothalamus to the limbic system? Mammillary bodies They are fairly prominent in an inferior view of the brain. They are highlighted in this image:

The thalamus and the hypothalamus are the most important parts of the diencephalon. The only thing you should know about the other two parts is that they contain the pineal gland. The Cerebellum Where is the cerebellum located? Posterior and inferior part of the brain What connects the two hemispheres of the cerebellum? vermis What are the ridges called in the cerebellum? folia Where is the gray matter located in the cerebellum? Cerebellar cortex What is the name given to the white matter in the cerebellum? Cerebellar peduncles What is the function of the cerebellar peduncles? Connect cerebellum to the brainstem The Brainstem What are the primary functions of the brainstem? Homeostatic functions (HR and breathing) What are the three subdivisions of the brainstem? Pons, Medulla Oblongata, Midbrain Identify the three divisions in figure 12.13. Midbrain What is the name of the channel that runs through the middle of the midbrain? Cerebral aquaduct What are the four protrusions from the posterior side of the midbrain? Two pairs of superior/inferior colliculi What is the structure visible in a cross section whose name means “black substance”? subtantia nigra Predict what would occur if this “black substance” did not function properly. Movement would be out of control

Pons What are some important functions of the pons? Reflexes, breathing, movements Medulla Oblongata What are the elevated ridges on the anterior surface of the pons? pyramids These ridges (they look like baseball bats to me) contain motor neuron fibers. Reticular Formation Where are the nuclei of the reticular formation located? Core of the three brainstem divisions What are some primary functions of the reticular formation. Sends output info to brain and spinal cord Putting It All Together: The Big Picture of Major Brain Structures and Their Functions Label the structures in figure 12.17 on page 442. Module 12.3 Protection of the Brain Name four things that help protect the brain: Cranial meninges, cerebrospinal fluid, blood-brain barrier, skull The Cranial Meninges List the three cranial meninges from outermost to innermost. What are the three spaces related to the meninges? Where is each located? Which is a potential space? Dura, subdural space, arachnoid mater, subarachnoid space, pia mater Potential because normally dura is tightly bound to bone with only blood vessels between See figure 12.18a. Dura mater What are the two layers of the dura mater? Periosteal and Meningeal dura Which layer functions as a periosteum and is fused to bone? Periosteal What is formed in locations where the two layers of the dura separate? The dural sinuses What do dural sinuses drain from the brain? CSF and deoxygenated blood

Where is the falx cerebri located? What structure forms the falx cerebri? Between right and lef cerebral hemispheres; lies in longitudinal cerebral fissure Where is the falx cerebelli located? Separates right and lef cerebellar hemispheres Where is the tentorium cerebelli locates? How did it get its name? Between the cerebellum and occipital lobe; “tent” covering the cerebellum See figure 12.18 B

Arachnoid Mater How did the arachnoid mater get its name? Like a spider web What are arachnoid trabeculae? Inward extensions that anchor to pia mater Located the arachnoid granulations (also known as arachnoid villi) in figure 12.18. Pia Mater Where is the pia mater located? Physically touches the brain The Ventricles and Cerebrospinal Fluid What is a ventricle? Cavities Which cells line ventricles? Ependymal What fluid is found within ventricles? CSF

What are the four ventricles? Label figure 12.19 on page 445. Right and Lef, Third and Fourth Which structures are found on either side of the third ventricle in figure 12.19b? Two lobes of the diencephalon The fourth ventricle is located between which two structures in figure 12.19a? Pons and the cerebellum What structure connects the lateral ventricles and the third ventricle? Interventricular foramen What structure connects the third ventricle to the fourth ventricle? Cerebral aquaduct Name four important functions of CSF. Removes wastes, cushions brain, maintains temperature, increases buoyancy Where is CSF formed? What structure forms CSF? Within each of the four ventricles via choroid plexuses Describe the formation and flow of CSF. 1. 2. 3. 4.

Fluid and electrolytes leak out of capillaries of the choroid plexuses Ependymal cells secrete CSF into the ventricles CSF circulates through and around brain and spinal cord in the subarachnoid space Some of the CSF is reabsorbed into the blood in the dural sinuses via arachnoid granulations

The Blood-Brain Barrier What is the function of the blood-brain barrier (BBB)? Keeps CSF and extracellular fluid separate from the blood; protects brain from substances Read the ConceptBOOST on page 447. Where is the BBB located? Within the brain What is the name of the cells that line all capillaries? Capillary endothelial cell

Name two ways that these cells are different in the brain. They have more tight junctions than most cells of capillaries and they limit endo/exocytosis Which microglia is involved in the BBB? Explain how the following substances cross the BBB: Oxygen & lipid-based molecules freely permeable Glucose & amino acids protein channels or carriers, also polar Module 12.4 The Spinal Cord Explain the two primary roles of the spinal cord. Relay station between body and brain: receives incoming and outgoing information Processing station: spinal reflexes The meninges of the spinal cord are continuous with that of the brain. Name two differences. Dura mater lacks a periosteal layer and consists only of a meningeal layer Spinal pia helps anchor the spinal cord in the vertebral cavity How is the epidural space different in the spinal cord compared to the brain? What is found in the epidural space in the spinal cord? Only exists between the meningeal dura and the walls of the vertebral foramina; filled with veins and adipose tissue What is found in the subarachnoid space? Thin layer of CSF External Spinal Cord Anatomy The spinal cord is continuous with the medulla oblongata of the brain. Name the bony structure that marks where the two meet. What are the names of the indentations running along the front and the back of the spinal cord? Which is larger? Anterior median fissure and posterior median sulcus Where does the spinal cord end? Lumbar enlargement

What is the name of the cone-shaped end of the spinal cord? Conus medullaris

What anchors the end of the spinal cord to the coccyx? What membrane forms this structure? Filum Terminale; pia mater The spinal cord bulges in two locations. What are the names of these bulges? What is the reason for the bulges? Cervical and lumber enlargements; attachment for spinal nerves

What is the name of the bundle of spinal nerve roots extending from the end of the spinal cord? (How did it get its name?) Cauda equina = horsetail

Internal Spinal Cord Anatomy What is the name of the channel that runs through the middle of the spinal cord? What is the name of the fluid found in the channel? Central canal; CSF

What cells line the channel?

The shape of the gray matter in the spinal cord is said to resemble what insect? butterfly

What is the name of the central gray matter that links the “wings” together? Gray commisure

What is the gray matter composed of?

What is the white matter composed of?

What is found in the anterior horn? Cell bodies of motor neurons The nerve roots attach spinal nerves to the spinal cord. What type of nerve fibers are found in the anterior root? motor

What types of nerve fibers are found in the posterior root? sensory What type of information is carried by ascending tracts in the spinal cord? (This should make sense to you!) sensory info What type of information is carried by descending tracts in the spinal cord? motor

Module 12.5 Sensation Part I: Role of the CNS in Sensation What is the difference between a sensation and a perception? Sensation is perceiving sensory stimuli; perception is a conscious awareness of the sensation What are the special senses? Vision, hearing, equilibrium, smell, and taste What are the general senses? Stimuli detected by skin, organ walls, or muscles What do the general somatic senses involve? Skin, muscle, joints What do the general visceral senses involve? Internal organs General Somatic Senses What is a first-order neuron? The sensory neuron that detects the initial stimulus in the PNS Sensory first-order neurons are typically pseudounipolar. What is a pseudounipolar neuron?

First order neurons synapse with second order neurons in the spinal cord or brainstem. Where do second-order neurons typically end? Thalamus/brainstem Second order neurons typically synapse with third order neurons. Where do third-order neurons typically end? Cerebral cortex

Role of the Cerebral Cortex in Sensation Third-order neurons end in the cortex. In particular, in the primary somatosensory cortex. What is the name of the gyrus where this cortex is located? Postcentral gyrus

What is the abbreviation for this cortex? S1 Where would sensation arriving from the lef should be perceived in the brain? Right

Why would the lips have a greater proportion of the gyrus dedicated to sensation than the arm? More nerve endings Introduction to the Special Senses The thalamus acts as the “gateway” for which special senses? Visual Where is the primary visual cortex located? Occipital lobe In which lobe is the primary auditory cortex located? Temporal Which sense goes to the limbic system for initial processing? (This sense is particularly tied into emotion and memories) Olfaction

Module 12.6 Movement Part I: Role of the CNS in Voluntary Movement Name four components of the CNS that are critical for coordinated movement. Cerebral cortex, basal nuclei, cerebellum, and spinal cord Name the three types of neurons directly involved in eliciting a muscle contraction. Upper motor neurons, interneurons, and lower motor neurons See figure 12.29 on page 458. Where are the somas of upper motor neurons located? Motor areas of the cerebral cortex Where do most upper motor neurons decussate? Medullary pyramids Where do most upper motor neurons end? Anterior horn Where are the somas of lower motor neurons located? Anterior horn Where do most lower motor neurons end? Skeletal muscle they innervate Role of the Brain in Voluntary Movement What is a motor program? Group of neurons selected to perform a given action Role of the Cerebral Cortex Explain why the hands of the motor homunculus are so large. (i.e. what exactly are they proportional to?) Movement initiated from the cerebral cortex along is jerky and uncoordinated. Input from which additional structures is needed for smooth, fluid movement? Basal nuclei and cerebellum Role of the Basal Nuclei How do the basal nuclei (and the substantia nigra in the midbrain) help inhibit involuntary movement? By modifying the activity of … thalamus Role of the Cerebellum The cerebellum determines the motor error for ongoing movements. What is the motor error? The difference between the intended movement and the actual movement Think about it – what type of input would be required to calculate motor error? What process can decrease motor error? Motor learning

What type of input does the cerebellum receive? (Did you predict these correctly in the questions above?) input from motor areas Where is the primary location where the cerebellum sends output to correct motor error? The motor cortices Module 12.7 Homeostasis Part I: Role of the CNS in Maintenance of Homeostasis Define homeostasis: maintenance of relatively stable internal environment in ever changing conditions What two systems in the body are key for maintaining homeostasis? Nervous and endocrine Which system works more quickly? Nervous Within the CNS, which two structures are key in maintaining homeostasis? Reticular formation and hypothalamus Homeostasis of Vital Functions What system is largely responsible for homeostasis of vital functions such as heart rate, blood pressure, and digestion? Autonomic nervous system What part of the CNS acts as a “boss” of the ANS? hypothalamus Body Temperature and Feeling Where is the thermostat located in the body? Hypothalamus What structure initiates changes to bring temperature down if it increases above normal? hypothalamus What structure in the brain helps regulate feeding? Hypothalamus What is a potential anatomical explanation for feeling “Hangry” (angry when hungry). The same area of the hypothalamus that mediates hunger also mediates aggression and rage Sleep and Wakefulness What is the definition of sleep? A reversible and suspension of consciousness Why do we need sleep? Energy restoration function

What is a circadian rhythm? Biological process that follows a set pattern over a 24 hours day What structure in the body controls our “biological clock”? Hypothalamus What hormone is released from the pineal gland? Melatonin That hormone depressed the activity of which structure? Reticular formation The reticular formation lowers the rate at which signals are sent from the ___reticular formation__ to the __thalamus___. (the gateway is closed, so to speak)

Module 12.8 Higher Mental Functions Cognition and Language What is cognition? Mental function; processing and responding to complex external stimuli, recognizing related stimuli, processing internal stimuli and planning responses to stimuli Which area is responsible for the cognition that results in a person’s character or personality? Prefrontal cortex Cerebral Lateralization What is meant by cerebral lateralization? An unequal distribution of cognitive functions in the right and lef hemispheres Name four functions that are largely lateralized. Emotion, Attention, Facial recognition, and language-related recognition Language Language is more complex than just understanding the meaning of words. Here is an example:

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