202 ES - Anatomy Flashcards
Which structure is located inferiorly to the pituitary gland?
Sphenoid sinus
What structure can become compressed in a pituitary adenoma, leading to problems with vision?
Optic chiasm
What part of the anterior pituitary gland is mainly responsible for hormone secretion?
Pars anterior
Anatomical relations of the pituitary gland
Anteriorly – sphenoid sinus Posteriorly – dorsum sellae Superiorly – optic chiasm Inferiorly – sphenoid sinus Laterally – cavernous sinus
Function of pituitary gland
Secretes hormones that control the actions of other endocrine organs and various tissues around the body
3 parts of adenohypophysis
Pars anterior
Pars intermedia
Pars tuberalis
Which 2 hormones does the neurohypophysis (posterior lobe of pituitary gland) secrete?
ADH
Oxytocin
What supplies the anterior pituitary?
Superior hypophyseal artery
What supplies the posterior pituitary?
Superior hypophyseal artery
Infundibular artery
Inferior hypophyseal artery.
The superior, middle and inferior thyroid veins are responsible for the venous drainage of the thyroid gland. Where does the inferior thyroid vein empty into?
Brachiocephalic vein
- The inferior thyroid vein empties into the brachiocephalic vein. The superior and middle thyroid veins drain into the internal jugular vein.
Which embryological remnant might explain a central neck lump which ascends on tongue protrusion?
Thyroglossal cyst
- A thyroglossal cyst arises from a failure of the thyroglossal duct to regress during development. It typically presents as a midline lump in the anterior neck which rises on tongue protrusion.
During a thyroidectomy, the inferior thyroid artery is identified and ligated. Which vessel directly gives rise to the inferior thyroid artery?
Thyrocervical trunk
- The inferior thyroid artery arises from the thyrocervical trunk, which is branch of the subclavian artery
A child in seen in primary care with midline neck lump. A thyroglossal cyst is suspected. What is the role of thyroglossal duct in development?
Marks the decent of the thyroid gland into the neck
- The descent of the developing thyroid gland forms the thyroglossal duct – an epithelialised tract that connects the gland to its origin at the foramen cecum.
Function of the thyroid gland
Regulating metabolic rate of the body
Where does thyroid gland span?
C5-T1 vertebrae
Anatomical relations of thyroid gland
Anteriorly – infrahyoid muscles (sternothyroid, superior belly of the omohyoid & sternohyoid)
Laterally – carotid sheath, containing the common carotid artery, internal jugular vein and vagus nerve
Medially –
Organs – larynx, pharynx, trachea and esophagus;
Nerves – external laryngeal and recurrent laryngeal
Which 2 arteries supply the thyroid gland?
Superior thyroid artery (1st branch of external carotid artery)
Inferior thyroid artery (arises from thyrocervical trunk - branch of subclavian artery)
Venous drainage of thyroid gland
Superior, middle, and inferior thyroid veins - form a venous plexus around the thyroid gland.
Superior & middle veins → internal jugular vein
Inferior → brachiocephalic vein
Innervation of thyroid gland
Branches of sympathetic trunk
What controls the secretory function of thyroid gland?
Regulated by pituitary gland
Lymphatic drainage of thyroid gland
To the paratracheal & deep cervical nodes
Embryological origin of anterior pituitary gland
Rathke’s pouch
Embryological origin of pituitary stalk & posterior pituitary gland
Infundibulum
Isthmus
Connects the 2 lateral lobe of thyroid gland
Crosses trachea just below cricoid cartilage
