Anatomy Flashcards
Name five parts of the body where endocrine glands can be found
- cranial cavity - neck - abdomen - pelvis - perineum
State four endocrine glands in the head and neck
hypothalamus, pituitary gland, parathyroid, thyroid glands
What two endocrine glands are found int he abdomen?
adrenal glands (above kidneys) & pancreas
Name the two different endocrine glands in males & females
ovaries & testes
What is the name for the thalamus and hypothalamus combined?
Diencephalon
What is the purpose of the diencephalon?
Core of the cerebrum - connects to right/left hemispheres and midbrain
Label this diagram
- T- thalamus
- H - hypothalamus
- midbrain
- pons
- medulla oblongata
MPM make up the brain stem
Describe the location of the pituitary gland in relation to the hypothalamus
It hangs off the hypothalamus by the infundibulum which connects to the posterior lobe
What is another name for the posterior lobe?
Neurohypophysis
How are hormones transported from the hypothalamus to the posterior lobe?
In the cytoplasm of axons (axoplasm) within the infundibulum
Which hormones does the hypothalmus send to the posterior pituitary lobe?
Vasopressin (ADH) & Oxytocin
What does the posterior pituitary lobe do with the hormones?
Neurosecretion - from nerves to blood stream. Posterior lobe regulates levels of hormone in the blood
What is another name for the anterior lobe?
adenohypophysis
Describe step 1 in the anterior lobe pathway
hypothalmic neurons secrete either releasing hormones or inhibiotory
Describe the pathway of which the hormones travel from the hypothalamus to the anterior lobe and beyond
- Hypothalamus secretes stimulatory/inhibitory hormones to capillary bed
- hypophyseal portal veins carry hormones to anterior lobe
- anterior pituitary cells respond to the signal by releasing hormones into the capillary
- these hormones travel in hypophyseal veins to the superior vena cava
What hormones do the anterior pituitary cells secrete?
- growth hormone
- prolactin
- thyroid stimulating hormone
- adrenocorticotrophic intensing hormone
- follicle stimulating hormone
- luteinizing hormone
Where is the pituitary fossa found?
Within the sella turcica of the sphenoid bone.
Which nerves are embedded in the cavernous sinus?
- occulomotor
- trochlear
- trigeminal (V1&V2)
- abducent
Describe the position of the nerves & arteries within the cavernous sinus
Nerves are in the lateral aspect while the internal carotid arteries run more medially
What structure lies directly superiorly to the pituitary gland?
Optic chiasm
If light comes from temporal field of vision describe its path
- temporal field of vision
- nasal retina
- optic chiasm & crosses over to opposite tract
- opposite thalamus and radiation
- opposite visual cortex
If light comes from the nasal field of vision describe its path
- nasal field of vision
- temporal retina
- optic chiasm & same side tract
- same side thalamus & radiation
- same side visual cortex
Define paranasal sinuses
air filled spaces within the bones surrounding nasal cavities lined with respiratory mucosa
name four bones where paranasal sinuses can be found
- frontal
- maxillae
- ethmoid
- sphenoid
What structure lines the entire cranial cavity?
Dura mater - adherent to interal aspects of all bones of the cranial vault
Give two examples of dura mater and describe where it lies within the skull
- tentorium cerebelli (within the posterior cranial fossa over the cerebrum with a central gap from the brain stem to pass through)
- diaphragm sellae (roof over the pituitary fossa)
Which direction are pituitary tumours most likely to grow and why?
laterally due to the thick sheet of diaphragm sellae above
What is the purpose of dura venous sinuses?
Venous channels within the dura mater that drain blood from the cranial cavity to the internal jugular veins
Where do the dura sinuses drain into the jugular veins?
Jugular foraminae
What eight structures are at risk during pituitary surgery?
- optic chiasm
- oculomotor nerve
- trochlear nerve
- trigeminal nerve
- adbducent nerve
- cavernous sinus
- internal carotid artery
- dura mater
Name two surgical approaches for pituitary tumours
- transcranial
- transsphenoidal
How will injury to the optic chiasm present?
bitemporal hemianopia
How will injury to the oculomotor nerve present?
Dilated pupil
How will injury to the trochlear nerve present?
Inability to look down/out
How will injury to the trigeminal nerve present?
sensory symptoms & difficultly chewing
What will injury to the abducent nerve result in?
inability to abduct eyes
Injury to the cavernous sinus will result in what?
Venous haemorrhage
If the internal carotid artery is injured what will happen?
Arterial haemorrhage
How will injury to the dura mater present?
CSF leak
Describe the location of the thyroid gland
Attaches to the lateral aspects of the thyroid and cricoid cartilage and the isthmus lies directly in front of the 2nd & 3rd cartilage of the trachea
What is the name for an enlarged thyroid gland?
Goitre
Where can the parathyroid glands be found? How many are there?
posterior surfaces of the thyroid glands lateral lobes, there are four - two superior and two inferior on each side
What is a common variant in the thyroid gland?
pyramidal lobe - most attach to the left lobe and superiorly to the thyroid cartilage
Where does the thyroid gland originate from embryologically?
Tongue - it migrates down via the thyroglossal duct
What is the name of the muscles located immediately deep to the skin?
Platysma muscles
What is the nerve supply to the platysma muscles?
Facial nerve (CNVII)
Name the four fascial compartments of the neck
- prevertebral
- investing
- carotid sheaths
- pretracheal
What can be found int he prevertebral fascia?
- postural neck muscles
- cervical vertebrae
Name the muscles found in the investing fascia
- trapezius
- sternocleomastoid
What can be found within the carotid sheaths?
- vagus nerves
- deep cervical lymph nodes
- carotid arteries
- internal jugular vein
Name the structure that joins the two carotid sheaths
alar fascia
What can be found in the pretracheal fascia?
- oesophagus
- trachea
- thyroid gland
- strap muscles
- recurrent laryngeal nerve
Describe the blood supply to thyroid/parathyroid glands
Inferior thyroid artery (comes from the subclavian artery)
Superior thyroid artery (comes from external carotid artery)
Describe the venous drainage of the thyroid/parathyroid glands
superior & middle veins –> internal jugular & brachiocephalic
inferior –> brachiocephalic
both then go to SVC
What is the lymphatic drainage of the thyroid gland?
- superior deep cervical lymph nodes
- (right) inferior deep cervical lymph nodes
- tracheal lymph nodes (pre and para tracheal)
Describe the pathway of the vagus nerve
- medulla oblongata
- jugular foramen
- carotid sheath
- right - lateral to trachea, left - left side of aortic arch
- terminal branches on stomach (to organs and distal midgut)
Describe the pathway of the recurrent laryngeal nerves
left - recurs under the arch of the aorta
right - recurs under the subclavian artery
Name the four strap muscles
- thyrohyoid
- sternothyroid
- sternohyoid
- omohyoid
What is the nerve supply to the strap muscles?
ansa cervicalis (C1-3)
except thyrohyoid - C1 runs with the hypoglossal nerve
Where is the incision made for a thyroidectomy?
superior to the clavicles & jugular notch along natural skin crease or langer’s lines - made through the skin & platysma
What is the risk of a thyroidectomy?
Injury to the right recurrent laryngeal nerve
Describe the purpose of the right recurrent laryngeal nerve
Provides motor supply to most of skeletal muscles that move the right vocal cord
What will unilateral injury to the right recurrent laryngeal nerve result in?
hoarseness/weakness of the voice & weak cough
What will bilateral injury to the right recurrent laryngeal nerve result in?
aphonia (inability to produce sound) and inability to close rima glottidis to prevent aspiration or produce a good cough
