2021 CHI202 W1 Prosection Laboratory Notes - Answers PDF

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2021 CHI202 Week 1 Prosection Laboratory Notes Gross Anatomy and Functionality of Cranial Nerves I - XII

Exercise / Quiz 1 Review and identify the bones of both the neurocranium and viscerocranium. Neurocranium 1. Frontal bone 2. Parietal bone 3. Ethmoid bone 4. Sphenoid bone 5. Temporal bone 6. Occipital bone Viscerocranium 7. Zygomatic bone 8. Nasal bone 9. Maxilla 10. Mandible

Identify the unique aspect of the bone identified as 3? The cribriform plate and crista galli are considered to be neurocranial whereas the remaining bone is viscerocranial. Have all the viscerocranium bone been identified in the image above, if not identify the bones not included on the two image below? ______________________ vomer, inferior nasal conchae, palatine bone, lacrimal bone

Exercise / Quiz 1 Identify the anatomical names of the sutural joints that join: Bones 1 and 2 together:____________________________________________ Coronal or Frontal Suture Bones 2 and 2 together:____________________________________________ Sagittal Suture Bones 2 and 3 together:____________________________________________ Squamosal Suture Bones 2 and 4 together:____________________________________________ Lambdoidal Suture

Develop a brief anatomical narrative that describes the associations and structural relationships of the four bones in the red circle in the image above. ___________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________

The cranium is the skeleton of the head, develop an anatomical narrative that describe the anatomical difference between the neurocranium and the viscerocranium? _____________________________________________________________________________________ The neurocranium forms the cranial vault that surrounds and protects the brain and brainstem. The neurocranium consists of the occipital bone, two temporal bones, two parietal bones, the sphenoid, ethmoid and frontal bone. They are articulate through fibrous joints know as sutures. The viscerocranium is one of the two areas that make up the skull. The viscerocranium comprises several bones, vomer, 2 inferior nasal conchae, 2 nasals, maxilla, mandible, palatine, 2 zygomatic bones, and 2 lacrimal bones.

Exercise / Quiz 2 On these anatomical models of the skull identify the following structures A to E, then apply your answers to the associated questions below. A. Optic Canal B. Foramen Rotundum C. Foramen Oval D. Jugular Foramen E. Stylomastoid Foramen

Following the identification of the exit apertures A to E, identify the cranial nerves that exit through A to E. A. Optic Nerve B. V2 Maxillary Nerve C. V3 Mandibular Nerve D. Glossopharyngeal, Vagus, Spinal Accessory Nerves E. Facial Nerve

Following the identification of the cranial nerves that exit through A to E. Identify these nerves on the anterior, posterior and lateral aspects of the brainstem.

Anterior Aspect

Posterior Aspect

Lateral Aspect

Exercise / Quiz 2 The olfactory receptor neurons enter the cranium through a specific structure in a neurocranial bone, identify the specific structure and the bone? ______________________________ Cribriform Foramina, Ethmoid Bone

After reviewing the adjacent image outline why, the olfactory receptor neurons are anatomically unique? ________________ The olfactory receptor neurons reside in the olfactory mucosa in the roof of the nasal cavity.

Identify on the adjacent image the exit apertures that CN XII passes through to exits the cranial vault? __________________ Hypoglossal Canal

Identify on the adjacent image the internal acoustic meatus and indicate the cranial nerves that exit the cranial vault through this exit aperture? __ Vestibulocochlear nerve and facial (intermediate) nerves exit the cranium through the internal acoustic meatus. Note: CN VII has two component the facial and intermediate nerves both classified as CN VII. Distinguish the cranial nerve that exit the cranial vault through the internal acoustic meatus and has a relationship with the stylomastoid foramen? _____________________________The facial nerves finally exit point is through the stylomastoid foramen. The superior orbital fissure is the exit point for several cranial nerves, identify the nerves that exit through this fissure? _________________________ Oculomotor, Trochlear, Abducent and Ophthalmic (V1) Nerves _____________________________________________________________________________________

Identify and label on the adjacent diagram the nerves that exit the superior orbital fissure are involved with eye movement? _________________________ Oculomotor, Trochlear, Abducent Nerves

Exercise / Quiz 3 On the anatomical model of the internal inferior surface of the cranial vault identify the following nerves A to E, then apply your answers to the associated questions below. A. Optic Nerve B. Trigeminal Nerve C1. Vestibulocochlear Nerve C2. Facial Nerve C3. Intermediate Nerve D1. Glossopharyngeal Nerve D2. Vagus Nerve D3. Spinal Accessory Nerve E. Hypoglossal Nerve

The table below consists of three columns (1) cranial nerves as roman numerals, (2) the anatomical names of the cranial nerves and (3) their exit apertures. Using a marker link all three columns correctly, the roman numeral - the anatomical name – the exit aperture.

CN (1) CN XI CN VI CN V1 CN VII CN II CN VIII CN I CN XII CN V2 CN IX CN III CN X CN V3 CN IV

Name (2) Trochlear n. Glossopharyngeal n. Olfactory n. Abducent n. Mandibular n. Hypoglossal n. Spinal Accessory n. Vagus n. Vestibulocochlear n. Maxillary n. Facial n. Oculomotor n. Ophthalmic n. Optic n.

Exit Aperture (3) Jugular Foramen Internal Acoustic Meatus Superior Orbital Fissure Foramen Rotundum Hypoglossal Canal Jugular Foramen Internal Acoustic Meatus Superior Orbital Fissure Jugular Foramen Optic Canal Superior Orbital Fissure Cribriform Foramina Superior Orbital Fissure Foramen Oval

Exercise / Quiz 3 Examine the area contained within the red circle on the left side of the sella turcica, overlayed on this anatomical model. Following identification answer the following questions with respect to this area.

What significant neural structure resides within this area? ____________________________________ Trigeminal Ganglion

The neural structure identified in the previous question is located in specific anatomical structure. Develop an anatomical narrative that describes the relative anatomy located in the identified structure. Include in your narrative the adjacent significant anatomical structures, Moore pg. 1064. __________ Trigeminal Cave. The trigeminal cave is situated in the trigeminal impression located near the anterior medial apex of the petrous part of the temporal bone. The trigeminal cave is a dura mater pouch containing cerebrospinal fluid that envelops the trigeminal ganglion.

The cavernous sinus is one of the dural venous sinuses of the head. It is a network of veins residing within this dural venous sinus it dimensions approximately 1 x 2 cm in size in an adult. Identify and describe the locational relationship the cavernous sinus has to the structure you described above. _______________ The cavernous sinus is anatomically located slightly anterior and medial to the trigeminal cave and lateral to the pituitary gland.

Exercise / Quiz 3 Apart from the blood which passes through the venous sinus, several anatomical structures, including several cranial nerves and their branches also pass through the cavernous sinus. Develop an anatomical narrative that describes the cranial nerves that pass through and have close association with the cavernous sinus? ________ Neural structures within the lateral wall of the cavernous sinus from superior to inferior are the Oculomotor nerve, Trochlear nerve, Ophthalmic nerve and Maxillary nerve. The neural structures passing through the medial aspect of the cavernous sinus is the Abducens nerve. _____________________________________________________________________________________

Identify the artery that pass through the cavernous sinus? _____________________ Internal carotid artery What cranial nerve lies superior and outside the cavernous sinus? ___________________ The optic nerve

Identify the 3 structures that lay within the red circles on this skull? Superior Circle: _______________ Supra-orbital Notch / Foramen Middle Circle: __________________________ Infra-orbital Foramen Inferior Circle: ______________________________ Mental Foramen

Identify the anatomical relevance of the 3 structures identified on the adjacent skull?

______ The 3 structures representing the supra-orbital notch, infra-orbital foramen and mental foramen are the 3 exit points of the divisions of the trigeminal n. transitioning from the bony skull into the superficial soft tissue of the skull. The 3 divisions are the ophthalmic n., maxillary n. and mandibular n., respectively.

Exercise / Quiz 4 On the anatomical model of the brain stem identify the following cranial nerves, A to E, then apply your answers to the associated questions below. A. Oculomotor Nerve B. Trochlear Nerve C. Abducens Nerve D. Hypoglossal Nerve E. Spinal Accessory Nerve

Identify the nerve that innervates the intrinsic ocular muscles? _________________________ Oculomotor Nerve

The nerve identified in the previous question innervates two involuntary (smooth muscle) parasympathetic structures, indicate and identify these two structures on the image below? _____________________ Ciliary Body & Sphincter Pupillae

Pupil size can vary from a normal pupil size to a maximum constriction (miosis) then to a maximum dilation (mydriasis). Identify these three pupil sizes below.

_______________

_______________

_______________

Exercise / Quiz 4 Cranial Nerves: Easy Identification

Using the diagram above as a template can you reproduce this simple diagram using only the cranial nerve numbers? It is important you can visualise the cranial nerve locations quickly as you may need to sketch this diagram in an examination to answers questions concerning cranial nerve locations in relation to the brain stem.

Begin to develop your understanding related to the functions that each cranial nerve performs?

CN I CN II CN III CN IV CN V CN VI CN VII CN VIII CN IX CN X CN XI CN XII

Exercise / Quiz 5 On the anatomical model of the right bony orbit and the extraocular muscles identify the following cranial nerves, A to E, then apply your answers to the associated questions below. A. Oculomotor Nerve B. Trochlear Nerve C. Ophthalmic Nerve D. Maxillary Nerve E. Abducens Nerve

Using this model identify the extra-ocular muscles and the muscle of the superior eyelid. Determine the cranial nerves that innervate each muscle and complete the table below? Muscle

Cranial Nerve Innervation

Superior Rectus

CN III

Medial Rectus

CN III

Inferior Rectus

CN III

Inferior Oblique

CN III

Levator Palpebrae Superioris

CN III

Superior Oblique

CN IV

Lateral Rectus

CN VI

Identify the above muscle on the images below which indicate the extraocular muscles in the right orbit.

Exercise / Quiz 5 Identify the gland in this model, located in the superior lateral aspect of the bony orbit, develop an anatomical narrative related to this gland, include the innervating cranial nerve its associated ganglion and fibre type? ________ Lacrimal Gland: CN VII, parasympathetic innervation via the pterygopalatine ganglion which contains post ganglionic neurons.

Identify the ganglion that is located on the lateral aspect of the optic nerve. develop an anatomical narrative related to this ganglion, indicate the cell type contained within this ganglion and their actions of the structures innervated by the cells in the ganglion? ___________________ The Ciliary Ganglion contains post ganglionic neurons that innervate the Pupillary Sphincter and Ciliary Body.

Exercise / Quiz 6 On this anatomical model of the right lateral aspect of the skull identify the following neural structures, A to E, then apply your answers to the associated questions below. A. Ciliary Ganglion B. Pterygopalatine Ganglion C. Chorda Tympani D. Otic Ganglion E. Submandibular Ganglion

Structures A, B, D and E all contain involuntary postsynaptic parasympathetic cell bodies develop an anatomical narrative that identifies the cranial nerves that supplies the presynaptic parasympathetic motor fibres while describing their specific target organs and relative actions. _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________

Exercise / Quiz 7 On this brain prosection identify the following cranial nerves, A to E, then apply your answers to the associated questions below. A. Olfactory Nerve B. Trigeminal Nerve C. Abducens Nerve D. Facial Nerve E. Vestibulocochlear Nerve

Cranial nerve D is unique as it encompasses one small named nerve, identify this nerves name? _____________________________________________________________________ Intermediate nerve

The nerve identified above carries special sensory fibres (taste) sensation, identify the name of the nerve that carries this taste? _______________________ The chorda tympani a branch of the intermediate nerve that originates from the vallate papillae (taste buds) on the anterior 2/3rds of the tongue. It runs through the middle ear and carries taste messages to the brain. Refer to the adjacent diagram to assist you answering the questions above. Moore: Fig 10.11

Notes: ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________

Exercise / Quiz 8 On this brain prosection identify the following cranial nerves, A to E, then apply your answers to the associated questions below. A. Oculomotor Nerve B. Abducens Nerve C1. Vestibulocochlear Nerve C2. Facial Nerve D1. Glossopharyngeal Nerve D2. Vagus Nerve D3. Spinal Accessory Nerve E. Hypoglossal Nerve

Specific cranial nerves identified above are involved in the following response. In the space provide below discuss the special sensory fibres responsible for taste sensation, sensory fibres transmitting general (somatic) sensation and tongue movement. In your answer develop a response that describe among other things the cranial nerves involved with taste (regions of tongue), general sensation of the tongue and the muscles that produce movement of the tongue as an anatomical narrative? _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ Moore: Fig 8.91

Exercise / Quiz 9

On the brain prosection and plastic model identify the following cranial nerves and structural features, A to E, then apply your answers to the associated questions below. A. Identify the bony feature within the large red circle: Petrous part of the temporal bone B. Auditory tube, Eustachian tube, Pharyngotympanic tube C. Identify this exit aperture: Internal acoustic meatus D1. Vestibulocochlear Nerve D2. Facial Nerve E. Trigeminal Nerve

The structure you identified as B connects two anatomical areas, identify the two areas connected by B? __________________________________ The Auditory tube connects the middle ear to the nasopharynx

What is the function of B? ____________ It controls the pressure within the middle ear (tympanic cavity), making it equal with the air pressure outside the body, thus the tympanic membrane can vibrate effectively.

Identify all the anatomical structures A to I in the diagram below, write your answers on the next page?

Moore: Fig 8.114

Exercise / Quiz 9 Anatomical structures A to I A.

B.

C.

D.

E.

F.

G.

H.

I. (only CN required)

Identify why nerve I is important within this cavity? _________________________________ Sensory Fibres: General (Somatic) Sensation for the lining of the tympanic cavity (middle ear) and auditory tube.

Muscles of Scalp and Face Voluntary (striated) muscle motor fibres innervate the muscles of facial expression.

Identify all the neural structures 1 to 6 in the diagram above?

1. Posterior auricular branch 2. Temporal 3. Zygomatic 4. Buccal 5. Marginal mandibular 6. Cervical

Moore: Fig 8.16

In the space provide below discuss the relationship CN (G) has with the neural structures 1 to 6, in your answer develop a response that describes the cranial nerves as an anatomical narrative? _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________

Exercise / Quiz 10 On this prosection identify the following structures, A to E, then apply your answers to the associated questions below. A. Temporalis B. Masseter C. Parotid Gland D. Sternocleidomastoid E. Genioglossus Two muscles where not identified that are identified on the adjacent diagram, identify each muscle.

1. The muscle that attaches to the inferior lateral aspect of the condylar process of the mandible? ______________________ Lateral Pterygoid

2. The muscle that attaches to the medial aspect of the mandibles ramus ? ___________________________________ Medial Pterygoid

Do these two muscles attach to the viscerocranium’s palatine bone or the neurocranium’s sphenoid bone? ________________________________________________________________________ Sphenoid bone The mandibular nerve (CN V3) is the inferior and largest division of the trigeminal nerve. It is the only division of to carry motor fibres. Branches of the mandibular nerve innervate the muscles of mastication. Complete the table below with the help of an anatomy text.

Develop an anatomic narrative to describe the pathological effect of a unilateral CN XII lesion. _______________...