Dissection 10 Flashcards
Scalp Layers
Skin Dense subCutaneous tissue Galea Aponeurotica Loose connective tissue Pericranium
Scalp Proper
Skin
Dense subcutaneous tissue
Galea aponeurotica
Placodes
Thickenings of the surface ectoderm caused by neural tube contact; form nerves of special senses
Optic vesicle
Expansion of the forebrain
Lens Placode
Forms the lens of the eye
Nasal Placode
Forms olfactory nerves
Otic Placode
Forms auditory nerves
Paraxial Mesoderm
Mesoderm in head organized into somites
Preotic Somites
Form the extraocular muscles
Postotic Somites
Form muscles of the tongue
What do neural crest cells form in the head?
Sensory ganglia and 4 parasympathetic ganglia
Skeletal elements like mandible and middle ear osicles
Smooth muscle associated with thymus, heart, parathyroid, thyroid
What nerve provides sensory innervation of the face?
Cranial Nerve V
Main sensory nerves of the face
- Supraorbital Nerve
- Infraorbital Nerve
- Mental Nerve
Main facial expression muscles
- Orbicularis Oculi (closes eye)
- Orbicularis Oris (closes lips)
- Occipital Frontalis (raises eyebrows)
- Platysma (tightens neck)
- Buccinatory (compresses cheeks)
What innervates the muscles of facial expression?
Cranial Nerve VII
What are the main facial expression nerves?
- Temporal- Frontalis
- Zygomatic- Orbicularis oculi
- Buccal- Buccinator and Orbicularis oris
- Marginal Mandibular- Orbicularis oris
- Cervical- Platysma
Where does the facial nerve exit the skull?
Stylomastoid Foramen
What is the parotid gland innervated by?
Cranial Nerve IX (Glossopharyngeal)
Bell’s Palsy
Facial nerve paralysis
Main vessels of the face
Facial Artery
Facial Vein
External Carotid Artery
Superficial Temporal Artery
Two main triangles of the neck
Anterior Cervical Triangle
Posterior Cervical Triangle
What is located in the anterior cervical triangle?
Common carotid artery
internal jugular vein
What is located in the posterior cervical triangle?
CN XI
Cutaneous branches of cervical plexus
Fascial layers of the neck
Cervical investing fascia Prevertebral Fascia Carotid Sheaths Pretrachial fascia Buccopharyngeal fascia
Retropharyngeal Space
Continuous with posterior mediastinum. Susceptible to infections.
Superficial veins of the neck
External jugular vein
Anterior jugular vein
Superficial to investing facia
Cervical Lymph Nodes
Jugulodigastric
Supraclavicular
Sternocleidomastoid
Innervated by CN XI
Flexes neck
Rotates head
Spinal Accesory Nerve (CN XI)
Branchiomotor only
C1-C5/6
Sensory fibers from cervical spinal nerves
Torticollis
Shortened sternocleidomastoid
Head tilted to bad side
Abnormal muscle tone
Hyoid Muscles
Swallowing and speaking
Supra and infrahyoid
Suprahyoid Muscles
Mylohyoid (CN V3) Digastric (Anterior, V3; Posterior, VII) Stylohyoid (CN VII) Geniohyoid (C1) Elevate hyoid and depress mandible
What fibers does the cervical plexus have?
Sensory and Sympathetic
What dermatomes does the cervical plexus innervate?
C2, C3, C4
What muscles does the cervical plexus innervate?
Geniohyoid
Infrahyoid
Ansa Cervicalis Nerve
Motor portion of cervical plexus to C1-3
Infrahyoid muscles
Scalene Muscles
Anterior, Middle, and Posterior
Lateral Neck
What does the first pharyngeal cleft form?
External auditory meatus
External lining of the eardrum
What lines the internal surface of the branchial arches?
Endoderm
What does the thyroid gland form from?
Pouch tissue from a branchial pouch
First Pharyngeal Pouch
Tympanic or middle ear cavity
Auditory tube
Second Pharyngeal Pouch
Fossa for palatine tonsil
Third Pharyngeal Pouch
Inferior parathyroid gland
Thymus
Fourth Pharyngeal Pouch
Superior parathyroid gland
Fifth Pharyngeal Pouch
Ultimobranchial body (calcitonin cells of thyroid)
Cranial nerve associated with pharyngeal arch 1
V Trigeminal
Muscles innervated by pharyngeal arch 1
Lateral pterygoid Medial pterygoid masseter Temporalis Tensor tympani Tensor veli palatini Mylohyoid Anterior belly of the digastric
Bones associated with pharyngeal arch 1
Maxilla
Mandible
Malleus
Incus
Cranial nerve of pharyngeal arch 2
VII Facial
Muscles associated with pharyngeal arch 2
All muscles of facial expression
Posterior belly of the digastric
Stylohyoid
Stapedius
Bones associated with pharyngeal arch 2
Stapes
Styloid Process
Lesser horn of hyoid
Cranial nerve of pharyngeal arch 3
IX Glossopharyngeal
Muscles from pharyngeal arch 3
Stylopharyngeus
Bones from pharyngeal arch 3
Greater horn of hyoid
Cranial nerve of pharyngeal arch 4
X Vagus (Superior laryngeal)
Muscles of pharyngeal arch 4
Levator veli palatini
Intrinsic muscles of soft palate
Cricothyroid
Constrictors of the pharynx
Bones of pharyngeal arch 4
Thyroid cartilage
Cranial nerve of pharyngeal arch 6
X Vagus
Muscles of pharyngeal arch 6
Intrinsic laryngeal muscles
Bones of pharyngeal arch 6
Cricoid cartilage
Name the four parasympathetic ganglia of the head
Ciliary
Pterygopalatine
Otic
Submandibular
Which nerve do postsynaptic parasympathetic fibers of the face follow?
CN V
What does ectoderm form in the head?
Neural tube and neural crest cells
What does mesoderm form in the head?
Skeletal elements
Muscles of the somites and pharyngeal arches
What does endoderm form in the head?
Lining of the pharynx and pharyngeal pouches
What does the first pharyngeal cleft form?
External auditory canal
General somatosensory fibers of the head
Pain, temp, and touch
Skin, oral/nasal cavities, pharynx, larynx, middle ear
General viscerosensory fibers of the head
Sensation from head organs (gut)
Special somatosensory fibers of the head
Lens and otic placodes
Special viscerosensory fibers of the head
Taste and smell
Branchiomotor fibers of the head
Skeletal muscles derived from branchial arches
Three divisons of Cranial Nerve V
Opthalmic division- Supraorbital nerve
Maxillary division- Infraorbital nerve
Mandibular division- Mental nerve
Where are the cell bodies of CN V?
Trigeminal ganglion outside the brainstem
What nerve innervates facial expression muscles?
Cranial Nerve VII (Facial)
What are the two bellies of the epicranius muscle?
Frontalis
Occipitalis
Joined by galea aponeurotica, raise eyebrows
What muscle (hard) closes the eyes?
Orbicularis oculi
What muscle flattens and protrudes the lips?
Orbicularis oris
What muscle helps with chewing, compresses the cheeks, and helps with drinking through a straw?
Buccinator
What muscle draws down the corners of the mouth and depresses the mandible?
Platysma
What muscle does the parotid duct pierce?
Buccinator
What is enclosed by the prevertebral fascia?
Prevertebral muscles
What is enclosed by the visceral/pretrachial fascia?
Thyroid gland
Trachea
Esophagus
What does the carotid sheath enclose?
Common carotid artery
Internal jugular vein
Vagus nerve
Borders of the anterior cervical triangle
Mandible
Neck midline
Anterior border of sternocleidomastoid muscle
Borders of the posterior cervical triangle
Clavicle
Posterior border of sternocleidomastoid muscle
Anterior border of trapezius
Name the two triangles within the anterior cervical triangle. What divides them?
Carotid triangle
Muscular triangle
Superior belly of the omohyoid muscle
What would you see with CN XI lesion?
Ipsilateral shoulder droop
Weakness turning head to contralateral side
What two branchial arches does the digastric muscle develop from? What innervates it?
1 and 2
Anterior- CN V3
Posterior- CN VII
(Depresses the mandible)
Location, innervation, and origin of Mylohyoid muscle
Floor of the mouth
Inferior alveolar branch of V3
Branchial arch 1
Location, innervation, and origin of Stylohyoid muscle
Styloid process to hyoid bone
Branchiomotor CN VII
Branchial arch 2
Location, innervation, and origin of Geniohyoid muscle
Mandible back to hyoid bone, deep to mylohyoid
C1 spinal nerve that runs with CN XII
Head somite?
What nerves innervate the Infrahyoid Muscles?
Ansa Cervicalis
EXCEPT for thyrohyoid- C1
Scalenus Anticus Syndrome
Cervical Rib Syndrome
Thoracic Outlet Syndrome
Cervical plexus and subclavian artery are compressed
Adson’s test produces obliteration of pulse
What nerves make up the cervical plexus?
Ventral rami from C1-C4
What lymph nodes drain the back of the scalp?
Retroauricular
Parotid
What lymph nodes drain the lateral face?
Parotid
Superficial cervical
What lymph nodes drain the chin and middle part of the lower lip?
Buccal
Submandibular
Submental
What are all the lymph nodes that drain the face and scalp called?
Cervical collar of nodes
What lymph node drains the tongue and palatine tonsil?
Jugulodigastric
What lymph nodes are known as the sentinel nodes and why?
Supraclavicular nodes
They are swollen if there is a problem in the upper limb, head/neck, and thorax.
