Anatomy Flashcards
Where is the pituitary found?
In the sella turcica in the body of the sphenoid within the middle cranial fossa
What type of tissue is the pituitary gland?
Ant = True epithelial tissue Post = Neural tissue (extension of the Hypothalamus)
How’d you differntiate ant/post pituitary on histology?
Ant stains dark
Post stains light
What would you see on close histology of the ant pituitary?
Two different cell types:
- Acidophils (Stain lighter)
- Basophils (stain heavily)
What types of cells are acidophils, and what do they make?
- Somatotrophs (GH)
- Mammotrophs (Prolactin)
What types of cells are basophils and what do they make?
- Corticotrophs [ACTH & MSH]
- Thyrotrophs [TSH]
- Gonadotrophs [LH & FSH]
What hormones are secreted by the post pituitary?
Oxytocin
ADH (Vasopressin)
Describe the arterial supply of the pituitary?
ICA
-> Sup & Inf Hypophyseal arteries
Sup -> Hypophyseal portal system
Inf -> Post Pituitary
How does the hypothalamus communicate with the pituitary?
Ant - Through hypophyseal portal system
Post - Neurons in the infandibulum
Venous drainage of the pituitary?
Hypophysial veins into cavernous sinus
Describe the locaiton of the thyroid?
C5-T1
Thyroid cartilae to 6th tracheal ring
Where is the thyroid isthmus found?
Between tracheal rings 2 & 4
What 3 strap muscles overlie the thyroid?
Omohyoid
Sternohyoid
Sternothyroid
[NOT THE Thyrohyoid]
What nerves supply the thyroid & where are they found?
Recurrent Laryngeal Nerve (between trachea/oesophagus)
Sup Laryngeal Nerve (Close to Sup Thyroid Art)
Describe the arterial supply of the thyroid?
Sup Thyroid artery - ECA
Inf Thyroid Art - Subclavian
Describe the venous supply of the thyroid?
Sup & Middle Thyroid Vein - IJV
Inf Thyroid Vein - Brachiocephalic Vein
Where does lymph drain from the thyroid?
Deep Cervical Lymph nodes
Describe the histological structure of the thyroid?
Cuboidal epithelial cells arranged in circles forming Follicles
C or Clear cells interspersed
What is found within thyroid follicles?
Glycoprotein called colloid bound to the thyroid hormones
What do C cells do?
Secrete Calcitonin
What 2 hormones do thyroid follicles secrete?
T3 - Triodothyronine
T4 - Thyroxine
Where are the parathyroid glands found?
Lateral half of the post surface of each thyroid lobe. External to the fibrous capsule.
At what level are the parathyroid glands found?
Sup - Inf border of cricoid
Inf - Inf poles of thyroid
Blood supply of parathyroid glands?
Arterial - Inf Thyroid Arteries (Subclavian Art)
Venous - Sup/Middle Thyroid Veins (IJV)
Describe the histological appearance of the parathyroids?
Two main cell types:
- Chief Cells (numerous and pale staining)
- Oxyphil cells (Less common & darker)
How are the suprarenal glands peritonised?
Retroperitoneal
Embryology of the suprarenal glands?
Cortex - Mesodermal epithelium
Medulla - Neuroectoderm
Arterial supply of the adrenal gland?
Inf Phrenic –> Sup Suprarenal Arts
Aorta –> Middle Suprarenal Arts
Renal Arts –> Inf Suprarenal Arts
Venous drainage of the adrenal gland?
Suprarenal Vein
Drains into IVC on right and the renal vein on left
What are the layers of the adrenal gland and what do they secrete?
Outside in:
- Fibrous capsule
- Zona Glomerulosa (Mineralocorticoids)
- Zona Fasciculata (Glucocorticoids)
- Zona Reticularis (Sex Steroids)
- Medulla (Catecholamines e.g. epinephrine)
How is the pancreas peritonised?
Retroperitoneal
Except tail which is intraperitoneal
Describe the arterial supply of the pancreas
Splenic Art gives off pancreatic branches
Coelic trunk –> Common hepatic –> Gastroduodenal –> Sup Pancreaticoduodenal
Sup Mesenteric –> Inf Pancreaticoduodenal
Cell types of the endocrine pancreas?
Alpha - glucagon
Beta - Insulin
Delta - Somatostatin
F - Pancreatic Polypeptide
All found in islets of langerhans (lightly stained and non-acinar)
