Anatomy Flashcards
What are the endocrine glands found in the cranial cavity?
- Hypothalamus
2. Pituitary gland (hypophysis cerebri)
what are the endocrine glands in the neck?
- thyroid glands
2. four parathyroid glands
what are the endocrine glands in the abdomen?
- Pancreas
2. two adrenal (suprarenal glands)
what are the endocrine glands found in the pelvis for females?
the two ovaries in broad ligaments
what are the endocrine glands found in the perineum?
two testes in the scrotum
what does the diencephalon of the brain contain?
- Thalamus
2. Hypothalamus
what is the role of the diencephalon?
forms the central core of the cerebrum with connection to right and left cerebral hemispheres and midbrain
what does the brainstem consist of?
midbrain
pons
medulla oblongata
spinal cord - inferior continuation of brainstem
how is the hypothalamus attached to the pituitary gland?
it is anatomically and functionally connected via the infundibulum or pituitary stalk
what is the anterior lobe of the piuitary gland known as?
adenohypophysis
what does the anterior lobe of the pituitary gland contain?
Pars distalis
Pars tuberalis
pars intermedia
what is the role of the anterior lobe of the pituitary gland?
Responsible for synthesis and release of most pituitary hormones (GH,TSH,ACTH,FSH,LH and PRL)
what is the posterior lobe of the pituitary gland know as?
neurohypophysis
what does the posterior lobe of the pituitary gland contain?
Pars nervosa
which is an extension of the brain posterior or anterior lobe of the pituitary gland?
posterior
anterior is an independent gland
what does the posterior lobe of the pituitary gland release?
ADH and oxytocin - synthesised in the hypothalamus
where is the pituitary gland found and its anatomical relationships?
it is a midline structure in the pituitary fossa (depression) of sphenoid bone
the pituitary fossa lies in the sella turcica
pituitary gland lies immediately inferior to the optic chiasma
diaphragma sella covers the pituitary gland (immediately superior to it)
Surrounded on either side by: from medial to lateral and then superior to inferior for the nerves
- Internal carotid artery
- Right/left oculomotor nerve (CN III)
- Right/left trochlear nerve (CN IV)
- right/left opthalmic division of trigeminal nerve (CN v1)
- Right/left maxillary division of the trigeminal nerve (CN v2)
- Right/left abducent nerve (CN VI)
what is the optic chiasma formed by?
right and left optic nerves (CN II)
right and left optic tracts pass posteriorly from the chiasma true or false?
true
how do axons in the chain pass through to the visual cortex in the occipital lobe?
optic radiation
what are the early clinical effect of the pituitary tumour has on the visual pathway?
- initial midline compression of optic chiasma
- disrupts transmission of action potentials from nasal retina bilaterally
- patient loses ability to see sturctures in temporal side of visual field bilaterallly
- results in bitemproal hemianopia
how do you surgically access the pituitary fossa?
Transcranial approach: subfrontal - inferior to frontal love
Transsphenoidal approach: via nasal cavities and sphenoid sinus (more common)
what is the osteology of the the nasal septum?
- Perpendicular plate of ethmoid bone ( superior part of nasal septum)
- Vomer bone (inferior part)
which bone is the roof of the nasal cavity?
cribriform plate of the ethmoid bone
which bone mainly makes up the hard pallate in the oral cavity?
maxilla
what is the role of the nasal conchae?
makes up the lateral wall of the nasal cavity
remember superior and middle nasal concha are apart of the ethmoid bone while the inferior is a separate bone on its own
what are the 4 paranasal sinuses?
ii. what are they lined with?
- frontal bone (frontal sinuses)
- maxillae (maxillary sinuses)
- ethmoid bone (ethmoidal air cells)
- sphenoid bone (sphenoid sinuses
ii. mucus secreting respiratory mucosa
which paranasal sinus does the transphenoidal transnasal approach pass through?
surgical fracture is carried out on the nasal septum and floor and roof of sphenoid sinuses
what is a le fort fracture?
Le Fort fractures are fractures of the midface, which collectively involve separation of all or a portion of the midface from the skull base (3 types)
when may a le fort fracture be used surgically?
le fort 1 down-fracture approach to the nasal cavities provides better access in more complicated cases
how many cranial nerves?
12 ( n.b. 3 divisions of the trigemenial nerve CNV)
What is the dura mata?
the outer thick fibrous layer of the brain and cranial cavity
what is the diaphragma sellae?
tough sheet of dura mater forming roof (diaphragm) over pituitary fossa
what is the tentorium cerebelli?
tough sheet of dura mata “tenting” over cerebullum in posterior cranial fossa but has a central gap to allow brainstem to pass through
what are the dural venous sinuses?
venous channels within the dura mater which drain most of venous blood from cranial cavity (including brain) into internal jugular veins at the jugular foramina
they dont have conventional wall like typical veins but act like them
what is the role of the anterior inter cavernous sinus?
connects right and left cavernous sinuses anterior to pituitary gland
which sinuses surround the pituitary gland?
cavernous and intercavernous sinuses
which arteries pass through the cavernous sinuses?
internal carotid arteries
what is the role of the optic chiasma?
conducts action potentials bilaterally from nasal retinae
what may happen if the optic chiasma is injured via pituitary gland tumour or due to iatrogenic reasons?
bitemporal hemianopia
What is the role of the oculomotor nerve (CN III)? (
- motor to muscles that move eyeball
2. parasympathetic to contrictor pupilae of iris
what may happen if the oculomotor nerve is injured via pituitary gland tumour or due to iatrogenic reasons?
severe eye movement deficits
dilated pupil
What is the role of the trochlear nerve (CN IV)?
motor to superior oblique muscle that moves eyeball
what may happen if the oculomotor nerve is injured via pituitary gland tumour or due to iatrogenic reasons?
difficulty looking inferiorly and laterally
what is the role of the trigeminal nerve (CNV)?
sensory to mosy of face
motor to muscles of mastication?
what may happen if the trigeminal nerve is injured via pituitary gland tumour or due to iatrogenic reasons?
paraethesia of face
difficulty masticating
what is the role of abducent nerve (CN VI)?
motor to lateral rectus muscle which moves the eyeball
what may happen if the abducent nerve is injured via pituitary gland tumour or due to iatrogenic reasons?
difficulty abducting eye
what is the role fo the cavernous sinus?
drains venous blood
what may happen if the cavernous sinus is injured via pituitary gland tumour or due to iatrogenic reasons?
venous haemorrhage
what is the role of the internal carotid artery?
supplies arterial blood to brain and orbit (includes eyeball)
what may happen if the internal carotid artery is injured via pituitary gland tumour or due to iatrogenic reasons?
catastrophic haemorrhage
what is the role of the dura mater?
protects structures of the cranial cavity
what may happen if the dura mater is injured via pituitary gland tumour or due to iatrogenic reasons?
CSF leak
what is the medical term for adam’s apple?
Laryngeal prominence of the thyroid cartilage
which nerve supplies the the sternocleidomastoid and trapezius?
CN XI
which bones does the the superior part of the trapezius attach to?
- attaches inferiorly to spine of scapula
2. Attaches inferiorly to lateral end of scapula
How many heads does the sternocleoidomastoid have and what do they bind to?
- Sternal head - attaches to manubrium of sternum
- Clavicular head - attaches to medial end of clavicle
both also pass superiorly to attach to mastoid process of the temporal bone
Where is the external jugular vein found?
ii. what does it drain into?
superficial fascia
ii.drains in subclavian vein
where is the anterior jugular vein found?
superficial fascia
ii. external jugular vein
what are the layers of the neck from superficial to deep?
- skin
- superficial fascia (platysma muscle found here)
- investing fascia (deep) - encloses all neck fascial compartments.
encloses:
both trapezius and sternocleidomastoid. quiet fibrous
- Prevertebral fascia (deep) - located MAINLY POSTERIOR to vertebral. I know its confusing.
encloses:
the postural muscles and cervical vertebrae
- Carotid sheath (2 of them) (deep) - tube like bilateral compartments. both sheaths joined by alar fascia. sheaths are located anterolateral and is posterolateral to thyroid gland.
encloses:
deep cervical lymph nodes
vagus nerve
common carotid artery then internal carotid artery
internal jugular vein
- Pretracheal fascia (deep) - located anteriorly however has posterior layer too.
encloses:
oesophagus
trachea
thyroid gland
strap muscles
recurrent laryngeal nerves
which nerves innervate the platysma muscles?
cranial nerve vii (facial nerve)
part of the the muscles of facial expression
why are fascia clinically important?
ii. what happens if infections reaches retopharyngeal space in the neck?
prevents spread of infection
ii. risk of spreading to mediastinum
where does the carotid sheaths attach to?
attach superiorly to base of skull (around jugular foramen and entrance to carotid canal)
what is the most superficial muscle of the neck?
Platysma
what are the four strap muscles?
- superficial - sternohyoid and omohyoid ( most lateral)
2. deep - sternothyroid and thyrohyoid
where does the thyroid gland develop?
midline epitherlial proliferation at junction between anterior two thirds and posterior one third of tongue ( this will soon be formaen caecum)
then migrates inferiorly while remaining to tongue via thyroglossal duct
when does the thyroid gland reach its final position?
ii. what is the remanent of the thyroglossal duct if it doesnt disappear?
7th week
ii thyroglossal duct cysts or ectopic thyroid tissue - it is a pyramidal love
what does the thyroid gland consist of?
two lateral lobes (right and left)
isthmus - narrow connecting band
what do the thyroid gland lobes bind to?
Lateral aspects of thyroid and cricoid cartilages and to the trachea
where does the isthmus of the thyroid gland lie?
anterior to 2nd and 3rd cartilages of trachea
what is a goitre?
enlarged gland
where are the four parathyroid glands located?
posterior surfaces of thyroid gland lateral lobes
what are the four 4 parathyroid glands
2 superior
2 inferior
where do most pyramidal loves of thyroid gland attach to?
superiorly to thyroid cartilage
some can extend all the the way to hyoid bone
most commonly originate from left lateral lobe
what is the blood supply of the thyroid and parathyroid glands?
- superior thyroid artery (divides into posterior and anterior branches) - branch of external carotid artery
- inferior thyroid artery (branch of subclavian artery)
- left common carotid artery
- thyroidea ima - it is present in 10% of patients - usually a branch of brachiocephalic, left common carotid or arch of aorta
All are branches of
what is the the venous drainage of the thyroid and parathyorid glands?
- superior thyroid vein - drain into internal jugular vein
- middle thyroid vein - drain into internal jugular vein
- inferior thyroid vein - drains directly into left brachiocephalic vein
what is the lymphatic drainage of thyroid and parathyroid glands?
contain superior deep cervical lymph nodes
contain inferior deep cervical lymph nodes ( lymph drains into)
- lymph fluid can pass superiorly into pre laryngeal lymph nodes and laterally into superior deep cervicial lymph nodes
- lymph can pass laterally into inferior deep cervical lymph nodes
- lymph can pass inferiorly inferiorly into pretracheal and paratracheal nodes
ALL lymph is returned via:
right lymphatic duct to right venous angle
or
thoracic duct to left venous angle
what are the anatomical relations of the thyroid gland?
- pretracheal fascia
- trachea
- parathyroid glands
- recurrent laryngeal nerves
- oesophagus
- carotid sheaths
what is the route of CN X (vagus nerve)?
Neck:
- emerge from medulla oblongata
- exit cranium via jugular foramen
- descend in carotid sheath
Thorax:
- Right CN X - lateral to trachea
- Left CNX - left side of aortic arch
- both posterior to lung hilum and around oesophagus ( form oesophageal plexus)
Abdomen:
- both vagus nerves pass through diaphragm with oesophagus
- divide into their terminal branches on surface of stomach; parasympathetic supply to abdominal organs
what does the left recurrent laryngeal nerve wrap around?
arch of aorta
what does the right recurrent laryngeal nerve wrap around?
subclavian artery
what occurs in a classical thyroidectomy incision
- A “collar” incision is made within a natural skin crease or in the direction of Langer’s lines
- Incision should be just superior to clavicles and jugular notch (optimal aesthetics with scar hidden by clothing and reduced risk of keloid formation)
- The incision is made through skin and platysma
what happens if a recurrent nerve injury occurs?
Recurrent nerve injury results in paralysis of vocal cord
- Unilateral injury causes “hoarseness” or weakness of voice and weak cough
- Bilateral injury causes aphonia (inability to produce sound) and inability to close rima glottidis (opening between vocal cords), to prevent aspiration, or to produce good cough, which requires closure of rima glottidis
what is the vertebral level of the thyroid gland?
C5-T1
what is superficial to the submandibular gland?
Platysma
deep fascia
mandible
Submandibular lymph nodes
Facial vein (facial artery near mandible)
Marginal mandibular nerve
Cervical branch of the facial nerve
what is deep in relation the submandibular gland?
Facial artery (inferior to the mandible)
Mylohoid muscle
Sub mandibular duct
Hyoglossus muscle
Lingual nerve
Submandibular ganglion
Hypoglossal nerve
what innervates the submandibular glands?
Sympathetic innervation- Derived from superior cervical ganglion
Parasympathetic innervation- Submandibular ganglion via lingual nerve
what is the arterial and venous supply for the submandibular glands?
Facial artery
anterior facial vein
