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
A surgeon is performing a minimally invasive parathyroidectomy for primary hypercalcaemia. Which surface of the thryoid are the parathyroid glands located?
Posterior
Which embryological structure gives rise to the superior parathyroid glands?
4th pharyngeal pouch
What is the main arterial supply to the parathyroid glands?
Inferior thyroid artery
Venous drainage of parathyroid gland
Superior, middle, and inferior thyroid veins
Lymphatic drainage of parathyroid gland
Drain to paratracheal & deep cervical nodes
Shape of right adrenal gland
Pyramidal
Shape of left adrenal gland
Semi-lunar
What is the embryonic origin of the adrenal cortex?
Mesoderm
- The adrenal cortex is derived from mesoderm. The medulla is derived from neural crest cells.
Where is the adrenal gland located?
Posterior abdomen
between superomedial kidney & diaphragm
Relations of right adrenal gland
Anterior - IVC, right lobe of liver
Posterior - right crus of diaphragm
Relations of the left adrenal gland
Anterior - stomach, pancreas, spleen
Posterior - left crus of diaphragm
Which 2 hormones does the adrenal cortex secrete?
Corticosteroids
Androgens
3 functional regions of adrenal cortex (superficial to deep)
Zona glomerulosa
Zona fasciculata
Zona reticularis
Function of zona glomerulosa (adrenal gland)
Produce & secretes mineralocorticoids - aldosterone
Function of zona fasciculata (adrenal gland)
Produce & secretes corticosteroids - cortisol
Function of zona reticularis (adrenal gland)
Produce & secretes androgens - DHEA
What cells does adrenal medulla contain?
Chromaffin cells
Function of chromaffin cells
Secrete catecholamines (adrenaline) in response to stress
Catecholamines have a role in ______ response
fight-or-flight
Which 3 arteries supply the adrenal gland?
Superior, middle, inferior adrenal artery
Venous drainage of the adrenal gland
Right adrenal vein → IVC
Left adrenal vein → left renal vein
Innervation of the adrenal gland
Coeliac plexus
Greater splanchnic nerves
Sympathetic innervation of the adrenal gland
Myelinated pre-synaptic fibres from T10 to L1
Lymphatic drainage of adrenal glands
Lumbar lymph nodes via adrenal lymphatic vessels
