Bio 207 - 242 Lab 8_Brain and Cranial Nerves

Laboratory Exercise 8 Brain Objectives: 1. Identify the parts of the brain and know their functions 2. Identify the cranial nerves and their functions 3. Perform a sheep brain dissection and locate the parts listed Lab Activities: 1. Using the brain model and the picture in the book, identify the following parts and learn their functions. Part Function Number/Marking on the Model Cerebrum: frontal, parietal, temporal and occipital lobes Conscious thought processes Central sulcus Separates frontal lobe from parietal lobes Postcentral gyrus Primary somatosensory cortex Precentral gyrus Primary motor cortex Thalamus Relay center for sensory information Hypothalamus Autonomic control center, body temperature regulation, regulation of hunger and thirst and sleep/wake cycles, control of endocrine functions Pituitary gland Anterior lobe secretes six principal hormones (FSH, LH, PRL, ACTH, TSH, GH) and the posterior lobe stores and releases two hormones produced by the hypothalamus (OT, ADH). Cerebellum Coordinates movements Pons Bridge to the motor cortex and cerebellum Medulla oblongata Contains the cardiovascular and respiratory centers Corpus callosum Connects the right and lef hemispheres Longitudinal fissure Divides the brain into right and lef hemispheres Pineal gland Helps regulate biological cycles Optic chiasm Where optic nerves cross Lateral ventricles Produce cerebrospinal fluid Third ventricle Produce cerebrospinal fluid Fourth ventricle Produce cerebrospinal fluid Choroid plexus Formation of CSF Cerebral aqueduct Channel for CSF to travel from 3 rd to 4 th ventricle

Corpora quadrigemina Visual and auditory reflex centers Arbor vitae (tree of life) 2. Perform the sheep brain dissection afer observing external features on the intact brain: Cerebrum, longitudinal fissure, cerebellum, pons medulla oblongata, corpora quadrigemina, optic chiasm, olfactory bulbs Then make a sagittal incision following the longitudinal fissure and observe internal features: Corpus callosum, lateral ventricles, third ventricle, fourth ventricle, thalamus, hypothalamus, pineal gland, arbor vitae, choroid plexus, and cerebral aqueduct. 3. Using the brain model and the picture in the lab book, locate the cranial nerves and learn their functions. Cranial Nerve Number or Marking on the Model Type/ General Function Specific Function Mnemonic for Name Mnemonic for type Olfactory/CNI Sensory Smell Oh Some Optic/CNII Sensory Vision Once say Oculomotor/CNIII Motor Eye movement One marry Trochlear/CNIV Motor Eye movement Takes money Trigeminal/CNV Both Face sensation, mastication The but Abducens/CNVI Motor Eye movement Anatomy my Facial/CNVII Both Taste, facial expression Final brother Vestibulocochlear/ CNVIII Sensory Hearing and equilibrium Very says Glossopharyngeal/ CNVIII Both Taste, swallowing and speech Good bad Vagus/CNX Both Sensation and visceral regulation Vacations business Accessory/CNXI Motor Neck muscle movement Are marry Hypoglossal/CNXII Motor Swallowing, sticking tongue out Heavenly money