Lab 10 Nervous System Brain and Spinal Cord

Anatomy & Physiology 1 Lab Lab 10: Nervous System: Brain and Spinal Cord Objectives for this Lab: 1. 2. 3. 4. 5. 6. 7. 8. Determine what structures are designed to protect the brain. Identify the 4 major parts of the brain and describe what their primary functions are. Identify on classroom models the structures listed in your lab manual for the 4 parts of the brain. List the 12 Cranial Nerves and determine what type of information they are carrying. Identify the Cranial Nerves on classroom models and pictures. Locate the structures listed for the external spinal cord anatomy on classroom models. Differentiate between the material that composes white versus gray matter in the spinal cord. Describe what a reflex is and the steps within its pathway. Overview: The nervous system is the primary communication system in the body. It controls and regulates homeostasis by detecting changes in our internal and external environment, analyzing that information and initiating the appropriate response. It is comprised of the central nervous system, which includes the brain and the spinal cord, and the peripheral nervous system, which includes the spinal nerves, ganglia and cranial nerves. Nervous tissue is composed of two types of cells, neurons and glial cells. Neurons are able to initiate and transmit electrical signals and glial cells provide support and protection for those neurons. In lab today, we will be looking at the brain, spinal cord and cranial nerves. The brain consists of 4 primary regions: the cerebrum, cerebellum, brainstem and diencephalon. We will be identifying those regions on models in the lab and on a sheep brain and briefly discussing their important functions. We will also be naming and identifying the 12 cranial nerves and discussing what information they are carrying. At the end, we will be looking at the gross anatomy and a cross-sectional view of the spinal cord. 157 Anatomy & Physiology 1 Lab Pre Pre-La -La -Lab bQ Que ue uestio stio stions ns ns:: 1. The innermost meningeal layer that is directly attached to the brain is the ________________________. 2. Where does cerebrospinal fluid flow? meningeal part of the brain? ______________________________________________________________ 3. Which of the following structures are part of the brainstem? (check all that apply) _✔_ pons _ _ corpus callosum _ _ thalamus _ _ medulla oblongata _✔_ midbrain _ _ epithalamus 4. Which portion of the brain controls balance, equilibrium and proprioception? ________________________________ 5. What white matter structure connects the two cerebral hemispheres? ________________________________ 6. Check all of the following statements that are true about the Cranial Nerves: they are part of the Central Nervous System there are 12 pairs of Cranial Nerves they may carry sensory and/or motor information they are part of the Peripheral Nervous System they carry information to the upper extremities 7. The lumbosacral enlargement of the spine contains neurons that innervate the the lower extremities ______________________________. 8. What is the bundle of spinal nerves that extend beyond the spinal cord? cauda equina ___________________________ 158 Anatomy & Physiology 1 Lab neuronal cell bodies, dendrites, glial cells and unmyelinated axons 9. The gray matter of the spine contains ____________________________________ myelinated axons organized into tracts and the white matter contains __________________________________________. reflex 10. A quick involuntary response to a stimulus is called a _______________________. 159 Anatomy & Physiology 1 Lab Lab Exercises: Exe Exerci rci rcisse 10.1: Ide Identi nti ntify fy the p paart rtss o off tth he br brai ai ain n llis is istted b belo elo elow w on th the e ffull ull br braain o o o o o Gyri Sulci Cerebrum Cerebellum Medulla Oblongata Gyri sulci cerebrum medulla oblongota 160 cerebellum Anatomy & Physiology 1 Lab Exe Exerci rci rcisse 10.2: IId dent entify ify the part artss of the brai ain no on n tthe he m mod od odels els in cla class ss aand nd in tthe he pi picctur ture e listed be below low us using ing a sag agitta itta ittall ssect ect ection ion o Cerebral hemisphere o Cerebellum o Corpus callosum o Lateral ventricle o Thalamus o Epithalamus o Hypothalamus o Midbrain o Pons o Medulla Oblongata corpus callosum Cerebral Hemisphe Thalamus epithalamus midbrain Lateral Ventricle Hypothalamus pons cerebellum medulla oblongata 161 Anatomy & Physiology 1 Lab Exe Exerci rci rcisse 10.3: IId dent entify ify the follo ollowi wi wing ng Cra rani ni nial al N Ner er erves ves o on n tthe he m mod od odel el o o o o Olfactory Nerve (CN I) Optic Nerve (CN II) Oculomotor Nerve (CN III) Trigeminal Nerve (CN V) Olfactory Optic Trigeminal Oculomotor 162 Anatomy & Physiology 1 Lab Exe Exerci rci rcisse 10.4: Lab abel el th the e 112 2 Cran Cranial ial Nerve rvess. Olfactory Optic Trochlear Oculomotor Abducens trigeminal facial glossopharyngeal vestibulocochlear hypoglossal vagus cranial accessory Modified/ © Lynch, Jaffe 1/ Wikimedia Commons / CC-2.5 163 Anatomy & Physiology 1 Lab Exe Exerci rci rcisse 10.5: IId dent entify ify an and d lab abel el the ffo ollo llowin win wingg sstru tru tructu ctu cture re ress o off the spin pinal al co cord rd o o o o Cervical Enlargement Lumbosacral Enlargement Conus Medullaris Cauda Equina cervical enlargement lumbosacral enlargement conus medullaris cauda equina 164 Anatomy & Physiology 1 Lab Exe Exerci rci rcisse 10.6: LLabe abe abell tthe he ssttruc ructur tur tures es on a cr cro ossss-sec sec sectio tio tional nal vie iew w of the spina inall cco ord o o o o o o Gray Matter White Matter Dorsal Root Ventral Root Spinal Nerve Anterior, Lateral and Posterior Horns of the Gray Matter dorsal root gray matter posterior horn of gray matte lateral horn of gray matter spinal nerve anterior horn of gray matte ventral root white matter 165 Anatomy & Physiology 1 Lab Exe Exerci rci rcisse 10.7: D Disse isse issectio ctio ction n of a Sh Sheep eep B Brain rain Follow the instructions of your lab instructor in performing a sagittal section on a sheep brain. Identify the following structures on the sheep brain: o Cerebrum o Cerebellum o Pons o Medulla Oblongata o Corpus callosum o Thalamus 166 Anatomy & Physiology 1 Lab Pos Post-L t-L t-Laab Quest estion ion ions: s: 1. If an individual’s corpus callosum was damaged and rendered non-functional, what limitations might they have? interrupts steady flow of info between right and left side of brain epilepsy 2. What is dysdiadochokinesia? impaired ability to perform rapid alternating movements This may be the result of damage to what part(s) of the brain? cerebellum 3. Heart rate and respiratory rate are controlled by what region of the brain? medulla- regulates involuntary life sustaining function such as breathing, swallowing & heart rate 167 Anatomy & Physiology 1 Lab 4. What is Bell’s Palsy? sudden weakness in the muscles on one half of the face 7th cranial nerve- facial nerve Which cranial nerve does this involve? ________________________________ 5. A patient presents to your clinic and you suspect they have Cauda Equina Syndrome. Why is this considered a medical emergency? -compression of spinal Nerve roots -need emergency treatment to prevent lasting damage leading to incontinence and possibly permanent paralysis of the legs 168