Anatomy pre-practical Flashcards
How much does the pituitary gland weigh?
0.5g
In what part of which bone is the pituitary gland found?
Hypophysial fossa in the sella turcica of sphenoid bone
What dural fold envelops the pituitary gland?
diaphragma sellae
What can happen following an enlarged pituitary gland?
Due to its proximity to the optic chiasma, it can cause bitemporal hemianopia
What is another name of the anterior pituitary?
adenohypophysis
What is another name of the posterior pituitary?
neurohypophysis
Which lobe of the pituitary gland is bigger?
Anterior pituitary lobe
What connects the hypothalamus to the posterior pituitary?
Infundibulum a.k.a. the pituitary stalk
Which lobe of the pituitary gland stains darker with H&E staining?
Anterior pituitary
What are the three cell types of the anterior pituitary lobe, and how do they stain differently?
o Acidophilic – stains pink
o Basophilic – stains light purple
o Chromophobic – do not take up stain, appear pale
What artery supplies the anterior pituitary?
The superior hypophysial artery enters into the substance of the hypothalamus before breaking up into capillaries to form the hypophysial portal system, which supplies the anterior pituitary gland
Whats the name of the portal system that supplies the anterior pituitary?
Hypophysial portal system
What artery supplies the posterior pituitary?
The inferior hypophysial artery supplies the posterior pituitary gland
Between what vertebral levels is the thyroid gland found?
C5-T1
Where is the thyroid gland in relation to the pharynx?
Thyroid is inferior to the larynx
Where is the thyroid gland in relation to the trachea?
Thyroid is anterior to the trachea
Between what tracheal rings is the isthmus of the thyroid gland found?
The isthmus lies opposite the 2nd to 4th tracheal ring
Describe the arterial supply of the thyroid gland and their sources
- Superior thyroid artery – 1st branch of ECA
* Inferior thyroid artery – branch of subclavian artery
Describe the veins of the thyroid gland and what they drain into
- Superior - drains into IJV
- Middle - drains into IJV
- Inferior - drains into Brachiocephalic
What 3 strap muscles overlie the thyroid gland?
o Sternohyoid
o Omohyoid (anterior belly)
o Sternothyroid
What is the external laryngeal nerve a branch of?
Branch of the superior laryngeal nerve
What two nerves run close to the thyroid arteries?
External laryngeal nerve - near superior thyroid artery
Recurrent laryngeal nerve - near inferior thyroid artery
What happens if the external laryngeal nerve (branch of the superior laryngeal nerve) becomes damages?
Hoarseness, inability to produce high-pitched voices
What happens if the recurrent laryngeal nerve becomes damages?
Hoarseness (if U/L) and if B/L aphonia (inability to speak) and breathing difficulties
What type of hormones are released from the thyroid gland?
Peptide hormones
What cells in the thyroid gland produced calcitonin?
Clear parafillicular C cells secrete calcitonin
What hormones are produced by the thyroid gland?
o Triiodothyronine (T3) o Thyroxine (T4) a.k.a thyroid hormone o Calcitonin
How are the adrenal glands peritonised?
Retroperitoneal
What are the two components of the adrenal glands?
Outer cortex
Inner medulla
What does the cortex arise from, and what does it secrete?
Outer cortex – arises from mesodermal epithelium, secretes steroid hormones
What does the medulla arise from, and what does it secrete?
Inner medulla – arises from neuroectoderm, secretes adrenalin and noradrenalin from large ovoid chromaffin cells
What are the three zones of the medulla and what do they each produce?
Outer thin zona glomerulosa – secretes mineralocorticoids e.g. aldosterone
Middle thick zona fasciculata – secretes glucocorticoids e.g. cortisol, corticosterone
Inner zona reticularis – secretes androgens e.g. sex hormones
Describe the three pairs of adrenal arteries and from where they arise from
o Superior - from inferior phrenic
o Middle - directly from aorta
o Inferior - from renal arteries
Describe the two adrenal veins and from where they drain into
o Right suprarenal vein – drains into IVC
o Left suprarenal vein - drains into L renal vein
How is the pancreas peritonised?
Retroperitoneal
What are the 4 types of endocrine cells in the pancreas and what do they produce?
o Alpha cells - glucagon
o Beta - insulin
o Delta - somatostatin
o F cells – pancreatic polypeptide
