Head and Neck II Flashcards
Why are the rectus capitis anterior and longus capitis clinically relevant?
They are often weak and found in patients suffering from lots of headaches. This is because the suboccipital muscles are often too tight.
What are the prevertebral muscles? (X4)
Rectus capitis lateralis, Rectus capitis anterior, Longus colli, Longus capitis, Anterior, middle, and posterior scalenes
What prevertebral muscle runs from vertebral body to vertebral body?
Longus colli
What is a large, general function of the scalene muscles?
Give stability to the neck.
What emerge through the scalene muscles? Specifically which of the two?
The roots of the brachial plexus (specifically through the anterior and middle scalenes.
What are the three ganglion of the sympathetic trunk?
Superior cervical ganglion, middle cervical ganglion, and the stellate ganglion.
What makes up the stellate ganglion?
A combination of the inferior cervical and superior thoracic ganglion.
True or false:
The inferior cervical sympathetic ganglion is bound up within a membrane with the superior thoracic sympathetic ganglion.
True. This is what makes up the stellate ganglion.
What is the function of the sympathetic (peri-arterial) plexus?
It is what gets sympathetic fibers to the head.
Where do the fibers to the peri-arterial plexus arise from?
The T1 to T3/4 cord levels.
True or false:
The fibers from the peri-arterial plexus synapse with the cervical sympathetic ganglia as they ascend to the head.
False. They do not synapse with the cervical sympathetic ganglion.
How do the fibers from the peri-arterial plexus ascend to the destinations in the head?
They hitchhike on the carotid vasculature and their branches.
What type of outflow does the sympathetic nervous system have?
A thoracolumbar outflow.
True or false:
The sympathetic nervous system distribution is more widespread in distribution and function as compared to the parasympathetic nervous system.
True.
In terms of sympathetic innervation, what is the thorax innervated by?
Pulmonary and cardiac nerves and plexuses.
In terms of sympathetic innervation, what is the foregut innervated by?
Greater thoracic splanchnic nerve (T5-T9)
In terms of sympathetic innervation, what is the midgut innervated by?
Lesser thoracic splanchnic nerve (T10-T11)
In terms of sympathetic innervation, what is the hindgut innervated by?
Least thoracic splanchnic nere (T12) and the lumbar splanchnic nerves.
In terms of sympathetic innervation, what is the pelvis and pernineum innervated by?
Pelvic splanchnic nerves
Which of the communicans is located more laterally? More medially?
Lateral= white rami communicans
Medial=grey rami communicans
Describe the pathway for sympathetic fibers to their effector organs.
Exit the IML grey cell column (lateral horn) at C8-L2/3 levels, out the ventral root, through the spinal nerve, through the white rami communicans (pre-ganglionic fibers), into the sympathetic trunk to their 3 options.
What are the 3 options for sympathetic fibers to choose after exiting the sympathetic trunk?
1) Synapsing at the same level & joining the spinal nerve
2) Ascending/descending and then synapsing and joing the vessels or spinal nerves at that level
3) Pass through without synapsing as thoracic splanchinc nerves(pre-ganglionic) and then synapse in the ganglia to innervate the
What do the sympathetic fibers of the peri-arterial plexus hitch-hike on?
Internal and external carotid arteries.
What is innervated by the peri-articular plexus?
Eye
Mucousal lining of the mouth
Salivary glands
Vasculature
What is the isthmus of the thyroid gland?
The connection between the two lobes
What is the pyramidal lobe of the thyroid gland?
The finger-like superior projection extending off the gland
What two types of cells make up the thryoid gland tissue? What does each of these cells secrete?
Follicular cells (iodine containg hormones--throxine (T3) and triiodothronine (T4)) Parafollicular cells (calcitonin)
What thryoid hormones are important in metabolism? Blood calcium levels?
T3 and T4; calcitonin
What other hormone does calcitonin work with to help regulate blood calcium levels?
PTH (parathryoid hormone)
Where are the parathryoid glands located? How many are there usually?
Embedded in the thyroid gland. Typically 4 but can have 2-6.
True or false:
The parathyroid glands are essential to life.
True
What does the parathyroid glands produce? What does it do?
PTH (parathyroid hormone) that helps regulate blood calcium levels.
PTH is important for regulating blood calcium levels. This is because function of four things need these levels regulated for normal function. What are the four things?
Heart
Nervous system
Kidneys
Bone
What type of feedback runs PTH?
Negative feedback–so as the blood calcium levels rise, the higher levels will cause a stop in secretion of the hormone.
What nerve runs close to the carotid?
Vagus nerve
What does the superior laryngeal nerve branch off from?
Vagus nerve
What innervates the muscles of the larynx?
Recurrent laryngeal nerves
What does the superior thyroid artery branch off from? Then what does it do?
External carotid; it gives off the superior laryngeal artery and then continues as the superior thyroid artery.
Where does the superior thyroid artery run to?
Thyroid gland
What runs with the superior laryngeal artery?
The internal branch of the superior laryngeal nerve
What does the external branch of the superior laryngeal nerve run with?
The superior thyroid artery
What does the superior laryngeal artery pierce?
The thryo-hyoid membrane (the membrane between the hyoid bone and thyroid cartilage
What does the left recurrent laryngeal nerve wrap around?
Ligamentum arteriosus
What does the right recurrent laryngeal nerve wrap around?
Right subclavian artery
What does the inferior thyroid artery come from?
It branches off the thryocervical trunk (with is a branch of the subclavian)
What are the three major lymph nodes that the doctor palpates during a visit?
Jugulo-digastric
Subparotid
Internal jugular (superior deep lateral cervical lymph node)
What is the flap that covers the top of the larynx?
Epiglottis
What are the two cartilagtes of the larynx?
Thyroid and cricoid cartilage
Name the outer structures of the larynx from superior to inferior. (x6)
Epiglottis Hyoid Bone Thryohyoid membrane Thyroid cartilage Cricothyroid membrane Cricoid cartilage
What are the intrinsic muscles of the larynx?
Cricothyroid
Arytenoid (transverse, oblique, & ary-epiglottic parts)
Crico-arytenoid (lateral & posterior parts)
Thryo-arytenoid
Vocalis
What muscle makes up the anterolateral aspect between the cricoid and thryoid cartilages?
Cricothyroid muscle
What is the action of the cricothyroid muscle?
Lengthens the vocal ligaments to increase tension on the cords
What is the action of the posterior part of the crico-arytenoid muscle?
Abduct the vocal ligaments to allow more airflow in
What is the action of the lateral part of the crico-arytenoid muscle?
Adduct the vocal ligaments to decrease the amount of airflow in
What is the action of the transverse and oblique parts of the arytenoid muscle?
Adduct the vocal ligaments/folds to decrease the amount of airflow in
What is the action of the vocalis and thryo-arytenoid muscles?
Shorten the vocal ligaments to decrease tension on the cords
What does tightening the vocal cords do? What about lengthening them?
Higher tones; lower tones
Tightening the vocal cords occurs by stretching and lengenthing them; loosening the vocal cords occurs by allowing them to slack
What innervates all the intrinsic laryngeal muscles except the cricothryoid?
Recurrent laryngeal nerve
What innervates the cricothyroid muscle?
External branch of the superior laryngeal nerve
What does the internal branch of the superior laryngeal nerve innervate?
It supplies sensory to the mucousal linings superior to the vocal cord
What does the external branch of the superior laryngeal nerve innervate?
Cricothyroid muscle and the inferior pharyngeal constrictor muscle (which is not an intrinsic laryngeal muscle)
Which is the tough, fibrous outermost layer of the meningeal layers?
Dura mater
What meningeal layer encases the venous sinuses?
Dura mater
Where is the epidural space?
Between the dura mater and the bone of the cranium
Where is the sub-arachnoid space?
Between the arachnoid mater and the pia mater
Where is the subdural space located?
Between the dura mater and the arachnoid mater
Which of the meninges is a thin, transparent membrane that is deep to the dura?
Arachnoid mater
What is the arachnoid villa?
Projections of the arachnoid mater that project though the dura mater (as arachnoid granulations) into the venous sinuses
What are the venous sinuses encases by?
Dura mater
What are the tuft like collections of arachnoid villa that project through the dura?
Arachnoid granulations
What are the fovea granularis?
Pits in the bone caused by the projections of the arachnoid granulations that go through the dura mater and into the periosteum
Where is CSF located?
Subarachnoid space
True or false:
The arachnoid granulations protrude into the dural sinuses.
True because the project through the dura and the dura is what encases the venous sinuses
True or false:
The dura mater reflects and folds to form the dural (venous) sinuses
True
What is the largest infolding of the dura mater?
Faux cerebri
What does the faux cerebri do? What does it attach to?
It is located between the two cerebral hemispheres and attaches to the crist gali of the ethmoid bone (anteriorly) and the internal occipital protuberance posteriorly. It is continuous with the tectorium cerebelli
What does the tectorium cerebelli do?
Separates the occipital lobes from the cerebellum.
What are the dura venous sinuses?
Endothelium-lined spaces between the periosteal and meningeal layers of the dura mater. They form where the dural septa attach along the free edge of the faux cerebri. Large veins from the surface of the brain drain into these.
What is the confluence of the sinuses?
A convergence of four dural sinuses (superior sagittal, occipital, straight, and transverse) located at the posterior aspect of the occipital
What runs in the borders of the dural folds?
Dural venous sinuses
Name the dural sinuses (x7)
Superior sagittal Inferior sagittal Sigmoid Superior petrosal Inferior petrosal Transverse Straight
What sinus is located at the same level as the inferior nuchal line?
Transverse
Where does the inferior sagittal sinus end?
In the straight sinus
What is the straight sinus formed by?
The union of the inferior sagittal sinus and the great cerebral vein
What two sinuses are associated with the rocky portion of the temporal bone?
Superior and inferior petrosal (rocky) sinuses
What two sinuses drain into the sigmoid sinus?
Superior and inferior petrosal
What does the sigmoid sinus drain into?
Transverse sinus
What houses the pituitary gland?
Sella tursusica
What dural folding extends around the occipital bone?
Tectorium cerebelli
What is special about the petrosal portion of the temporal bone?
The ossicles are located here
What are the dural sinuses continuous from? Why is this significant?
From the internal jugulars vein to the branches of the facial vein and the vertebral vein plexus. There is the possibility for infections to spread from the cutaneous tissues of the face into the dural sinuses.
What are the two branches of the facial vein?
Superior and inferior ophthalmic veins
How could a cutaneous infection travel into the cavernous sinus? Why is this bad?
Via the ophthalmic veins..the cavernous sinus houses the cranial nerves therefore the infection could spread into the nervous system
Where are the internal arteries and the cranial nerves bathed in venous blood?
Cavernous sinus
What can be found in the cavernous sinus?
Internal carotid arteries and cranial nerves 3, 4, V1, V2, and 6,
Where does and epidural hemorrhage typically occur?
Unilateral and adjacent to a fracture site…usually in the temporal or parietal bones
True or false:
Epidural hemorrhages cross suture lines.
False, subdural hematomas cross suture lines.
90% of epidural hemorrhages are this…
Arterial
From what structure does epidural hemorrhages typically occur?
Middle meningeal artery