Bio 201 Lab 9 Essay

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Lab Report: Exercise 10: Organization of Nervous Tissue Purpose: What is the purpose of this exercise? Are there any safety concerns associated with this exercise? If so, list what they are and what precautions should be taken. To understand the structure and function of multipolar neuron,unipolar and bipolar neurons. Also to identify the structures of a nerve. There are no safety concerns for this lab. Step 1: Relates to Lab Exercise 10/Activity 1, 3, and 4. Assignment 1: Write a brief description of the three slides (Neuron, Spinal Cord Smear and C.

S of Myelinated Nerve Fibers) as though you were explaining it to someone who cannot see the slide. Neuron- There is a reddish rounded shape with lighter thin looking branches these are probably the axon terminals or dendrites. I am thinking this is a multipolor neuron. The reddish rounded figure is the nucleus. There are smaller darker dot, which I am guessing could be the axons. Spinal Cord Smear- A large purple figure with bundles of darker spots, which I believe to be chromatin. The cytoplasm is visible as well as darker purple scattered Nissl bodies. I am not sure I can identify the axon.

C. S of Myelinated Nerve Fibers- There an alternating patterns of blue and pink sheaths running horizontally. There is red nuclei. The lighter area I can identify is the vesicular myelin. Assignment 2: Answer to the questions in Lab Report: Exercise 10: Organization of Nervous Tissue- Activity 1 ,3 AND 4. You can skip answering questions for activities 2 ! Activity 1: Multipolar Neurons Observations: Sketch your observations through the microscope of the neuron, the ox spinal cord smear, and the teased myelinated nerve Please describe what you observed on each slide. Questions: A.

What is the function of a neuron? A neuron secretes chemicals to stimulate other cells. Its function is to produce and transmit action potentials B. What is the difference between a neuron and a nerve? A nerve is a bundle of axons. A neuron is the basic cell of the nervous system and is made of the cell body, dendrites, and an axon. C. What gives a multipolar neuron its name? The multiple fibers that come off of the cell body. D. What are the functions of the dendrites and axons? Axons conduct electrical impulses away fro the body and Dendrites conduct electrical impulses toward the cell body.

Activity 3: The Neuroglia and Supporting Cells ??????? Activity 4: Structure of a Nerve Questions: A. Describe the functions of the following parts of a nerve: Endoneurium: The connective tissue that encloses the myelin sheath of a nerve fiber within fascicullus. Epineurium: This is the most outer layer that surround the peripheral nerve. Perineurium: This is the protective sheath that surrounds bundled fascicles. Fascicle: Bundle of nerve fibers, enclosed by perineurium. B. What is a nerve? A nerve is bundle of peripheral axons carrying sensory to CNS and motor from CNS. C.

Why are the connective tissue wrappings an important part of nerve structure? Because it connect the spinal cord with peripheral nerves. D. Differentiate the central nervous system from the peripheral nervous system. The PNS is all the neural structures except the brain and spinal cord. It includes sensory receptors, peripheral nerves, and motor endings. It also provides links to and from the external environment. The PNS can regenerate some and myelination is done by schwann cells. The CNS contains the brain and spinal cord. It incapable of regeneration and myelination in the CNS is accomplished by oligodendrocytes.

The major inhibitory neurotransmitter in the CNS is gamma-aminobutyric acid (GABA), while in the PNS it is glycine Conclusions: Describe the structure of nervous tissue and relate it to its function. There two main cells types in nervous tissue neurons are excitable cells that transmit electrical signals and supporting cells that surround and wrap the neutrons. There are armlike extentions from the soma tacts in in the CNS and nerves in the PNS. The dendrites resembel short branches they are the input regions of the neuron. The axons are slender processes of uniform diameter arising from the hillock.

There is usually only one unbranched axon per neuron. Step 2: Define terms related to nervous tissue Click on the Loyola University/ Part 6: Nervous Tissue. For each of the following terms, find at least one example slide containing the term. Identify the slide by number and define the term in your own words. 1. Axon is a singular fiber that carries information away from the soma to the synaptic sites of other neurons. 2. Dendrite are the receptive region of the neuron. They conduct electrical impulses toward the cell body. 3. Axon Hillock is a cone shaped area on the side of the soma and is where the axon arise. 4.

Soma is the control center of the neuron. 5. Nissl bodies are in the soma of the nucleus and are made up ofrough ER. 6. Axodendritic Synapse axons that connect the axon to the dendrite. 7. Myelin Sheath whitish fatty segmented sheath around most long axons. It protects the axon, electrically insulates fibers from one another , and increases the speed of nerve impulse transmition. 8. Muscle spindle are sensory receptors in the muscle. They can detect changes in muscle length and then communicate it to the central nervous system. 9. Pacinian Corpuscles connective tissue wrapped around a nerve ending located in the deep layers of skin. 0. Astrocyte most abundant, versatile, and highly branched glial cell. They support and brace neurons, anchor neuron to their nutrient supplies, guide migration of young neurons, and control the chemical environment. 11. Microglial Cell small ovid cells with spiny processes. phagocytes that monitor the health of neurons. 12. Nodes of Ranvier gaps in the myelin sheath between adjacent schwann cells. They are sites where axon collaterals can emerge. Lab Report: Exercise 11: Gross Anatomy of the Central Nervous System Step 4: Relates to Lab Exercise 11/Activity 1 and 2

Assignment-1: For each of the the following sections of the brain, describe in detail the location and structure of that section. Also, identify what body activities are controlled by each of the listed sections. 1. medulla oblongata is the most inferior part of the brain stem. It forms the ventral wall of the 4th ventricle along with the pons. It contains a choroid plexus of the 4th ventricle. pyramidsare the two longitudinal ridges formed by the coricospinal tracts. The decussation of the pyramids is the crossover points of the corticospinal tracts.

It controls the autonomic functions such as breathing, digestion, heart and blood vessel function, swallowing and sneezing. Motor and sensory neurons from the midbrain and forebrain travel through the medulla. 2. pons is the bulging brainstem region between the midbrain and the medulla oblongata. It forms part of the anterior wall of the 4th ventricle. Fibers of the pons connect higher brain centers and the spinal cord. They relay impulses between the motor cortex and the cerebellum. It is the origin of cranial nerves III, VI, and VII. Also contains the nuclei of the reticular formation.

The pons is responsible for arousal, assisting in controlling autonomic functions, relying sensory information between the cerebrum and cerebellum and sleep. 3. mid brain is located between the diencephalon and the pons. The midbrains main structures in cluse the Cerebral crus the two bulging structures that contain desending pyramidal motor tracts, the cerebral aqueduct the hollow tube that connects the 3rd and 4th ventricles, and the various nuclei. The mid brain controls visual and auditory systems as well as eye movement. 4. cerebellum located dorsal to the prons and medulla.

It protrudes under the occipital lobes of the cerebrum. It makes up 11%of the brains mass and provides precise timing and appropiate patterns of skeletal muscle contraction. 5. reticular formation is composed of three broad columns along the length of the brain stem. It is made up of the raphe nuclei, medial cell group, and lateral cell group. It has far flung axonal connections with the hypothalamus, thalamus, cerebellum, and spinal cord. The reticular formation controls levels of arousal and attention (consciousness). 6. thalamus paired ovid shaped masses that form the superolateral walls of the third ventricle.

It is connected at the midline by the intermediate mass. It contains four groups of nuclei anterior, ventral, dorsal and posterior. The nuclei project and receive fibers from the cerebral cortex. The thalamus is involved in sensory perception and regulation of motor functions. 7. hypothalamus is located below the thalamus, it caps the brainstem and forms the inferolateral walls of the 3rd vesicle. It plays a vital role in homeostasis due to its connections with structures of the endocrine and nervous systems. It is the control center for many autonomic functions of the PNS.

The release of 8 major hormones by the hypophysis, and is involved in temperature regulation, control of food and water intake, sexual behavior and reproduction, control of daily cycles in physiological state and behavior, and mediation of emotional responses. 8. epithalamus is located at the most dorsal portion of the diencephalon and forms the roof of the third ventricle. The pineal gland extends from the posterior border and secretes melatonin. Melatonin is the hormone involved with sleep regulation and mood. The choroid plexus secretes cerebrospinal fluid. 9. erebrum and cerebral cortex- The cerebral cortex is the superficial gray matter that accounts for 40% of the mass of the brain. It enables voluntary movements, understanding, communication, processes of thought, perception and memory, social abilities, language, and problem solving. functional behavior requires the entire cortex because functional area acts alone. 10. limbic system structures are located on the medial aspects of the cerebral hemispheres and diencephalon. It includes the rhinencephalon, amygdala, hypothalamus, and anterior nucleusof the thalamus. The cingulate gyrus plays a major role in expressing emotions by using gestures.

Assignment 2: 1. Label the diagrams on Lab Report: Exercise 11: Gross Anatomy of the Central Nervous System -Activity 1. You need not have to submit these diagrams. 2. Answer to the questions on Lab Report: Exercise 11: Gross Anatomy of the Central Nervous System- Activity 2. Purpose: What is the purpose of this exercise? Are there any safety concerns associated with this exercise? If so, list what they are and what precautions should be taken. To identify and understand the Functions of the structures of the brain using diagrams and dissection. Also compare the sheep brain with the human brain, and know cranial and spinal nerves.

Safety concerns would be contamination as well as proper use of instruments during dissection. Activity 1: Structures of the Brain 1. Label the Lateral View of the Brain at right using the table from the Procedures. Central Sulcus, Spinal Cord, Frontal Lobe, Cerebellum, Temporal Lobe, Occipital Lobe, Pons, Parietal Lobe, Medulla Oblongata 2. Label the Mid Sagittal View of the brain below using the table from the Procedures. Spinal cord, Pineal gland, Cerebellum, Thalamus, Medulla oblongata, Hypothalamus, Fourth ventricle, Mammillary body, Pon,s Corpus callosum, Cerebral aqueduct

Label the Ventral View of the brain at right using the table from the Procedures 3. Label the Brain Association and Cortical Function Areas on the diagram at right using the table from the Procedures. Activity 2: The Sheep Brain Dissection Questions: A. Which of the four major areas of the brain (cerebrum, diencephalon, cerebellum and brain step) was obviously much larger in the human brain diagram then in the sheep brain? Why do you suppose these structures differ so dramatically? The human cerebrum larger than sheep. I think this is because the human brain has higher level of function.

B. What is the significance of the size difference in the olfactory bulbs between humans and sheep? Humans are more visual than the sheep and do not have a high need for olfactory sensation. Sheep have more of a need for their sense of smell so have a high need for olfactory sensation C. The human cerebellum is split in half while the sheep cerebellum is one mass. Why do you suppose this structural difference exists? Humans are more complex and require a greater level of functioning. D. What is the significance in the size difference between the sheep and human brain stems?

The human brain is much bigger because humans have more complex sensory & motor requirements. E. In your own words, explain how (if) this exercise helped you better understand brain anatomy. I think this exercise has helped increase my level of understanding on how the brain functions. I believe this is because being able to use the diagrams as well as dissect the brain gave me a better understanding. Step 5: Cranial and spinal nerves/ Relates to Lab Exercise 11-Activity 3 and 4. Perform activity 3 and 4. The abducens and glossopharyngeal are spelled wrong in page 104 picture of cranial nerves in the manual.

Assignment-1: Answer to the following questions. 1. Which cranial nerve(s) is (are) needed to perform each of the following? (0. 5 points each) a. crying because you broke a present CNVII b. chewing holiday treat CNVII, CNIX, CNXII, CNX c. seeing snowflakes CNII d. smiling for a family picture CNVII e. bowing your head CNXI f. listening to your favorite music CNVIII g. singing Christmas carols CNX h. raising the eyelids in surprise CNVII, CNIII, CNIV i. having a tooth-ache from eating too many cherry chocolates CNIX j. focusing the lens of your eye so you can read this assignment CNII, CNIV 2.

Which spinal nerve might be damaged in each of the following situations? (0. 5 points each) a. unable to extend the leg femoral nerve b. unable to flex the leg Tibial nerve c. pain in the medial thigh femoral nerve d. difficulty opposing thumb and fingers to pick up objects Ulnar nerve e. crutch paralysis/arm paralysis while using crutches radial nerve f. carpal tunnel syndrome median nerve g. tingling that results when you hit your “funny bone” ulnar nerve h. paralysis of diaphragm phrenic nerve Assignment-2: Answer to the questions for Lab Report: Exercise 11: Gross Anatomy of the Central Nervous System- Activity 3 and 4.

Activity 3: The Cranial Nerves Questions: A. Fill in the following information about the twelve cranial nerves: ????????????? B. Which cranial nerves would be involved in the following activities? Smelling a flower: Olfactory nerve Shrugging your shoulders: Accessory nerve Tasting freshly baked cookies: Facial nerve, . Glossopharyngeal nerve, Vagus nerve Slowing your heart rate: Vagus nerve Activity 4: The Spinal Cord and Spinal Nerves Questions: A. Label the numbered structures below using the diagram from the Procedures or your textbook as reference. B.

Fill in the table with the names of the major spinal nerves that serve the areas indicated. ?????????? C. Define a plexus. A plexus is a network of intersecting and interweaving nerves Conclusions: Explain the significance of having two hemispheres in the brain. Step 6: Narrative about the lab activity Write a brief narrative of what you have learned from this activity. Try to include the following: ·How might this information assist you in your career? ·Please include any other thoughts. ·Comment about drawing slides? Lab Report Submission Grading You should have a the following items in your lab submission: ?????????

Cell Function Location (CNS/PNS) astrocytes Support and brace neurons to nutrient blood capillaries CNS Microglia Provide protection and sense neuron injuries. Can be phagocytic. CNS Ependymal cells Ciliated cells found in the cavities of the brain. Help to circulate cerebrospinal fluid. CNS Oligodendrocytes Makes the myelin sheath in the central nervous system. CNS Satellite cells Surround neuron cell bodies with ganglia. Function is mostly unknown. PNS Schwann cells Produces the myelin sheath in the peripheral nervous system PNS Cranial Nerve Function Is it Sensory/Motor/Both? I. Olfactory nerve smell sensory II.

Optic nerve vision sensory III. Oculomotor nerve eye movements, opening of eye lid, pupillary constriction, focusing motor IV. Trochlear nerve eye movements motor V. Trigeminal nerve touch, temperature, and pain on face both motor- mastication VI. Abducent nerve lateral eye movement motor VII. Facial nerve taste, facial expression, secretion of tears saliva and nasal and oral mucus both VIII. Auditory nerve hearing and equilibrium sensory IX. Glossopharyngeal nerve taste, touch, pressure, pain, and temperturer- sensations from toung and outer ear- regulates respiration and blood pressure- salivation, swallowing, gagging both

X. Vagus nerve taste, sensation of hunger, fullness, gastrointestinal discomfort, swallowing speech, deceleration of heart, bronchoconstriction, gastrointestinal secretion and motility both XI. Accessory nerve swallowing head and neck and shoulder movements motor XII. Hypoglossal nerve toung movements of speech, food manipulation, and swallowing motor Nerve Area of the body served cervical plexus Head, neck, shoulders (plexus only) Phrenic nerve Diaphragm sciatic nerve Posterior thigh femoral nerve Anterior thigh radial nerve Arm muscles musculocutaneous nerve Anterior forearm umbar plexus Abdominal wall ulnar nerve Medial side of the hand fibular and tibial nerves Leg and foot Item Description Points Step 1 Description of 3 slides 6 Step 2 Identification and definition of 12 terms 12 Step 3 Answer to the two questions No points allotted. No submission needed. Step 4 Description about the structure of brain 12 Step 5 Naming the cranial and spinal nerves 8 Step 6 1/2-page reflection of what you have learned during this lab 2 Manual Lab report for exercises 10 and 11. You need not have to submit the labeled diagrams for activity 1 35 (15+20) Total Points 75

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