The Endocrine Glands Flashcards
Where is the pituitary gland located?
Sell turcica (sphenoid bone) in middle cranial fossa
extends from the hypothalamus infundibulum
Where is the pituitary gland located?
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Pituitary gland structure:
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Pituitary Gland:
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Infundibulum: Tissue:
extension of neural tissue
ends at posterior lobe
Pituitary: Anterior Lobe:
- glandular tissue
- adrenohypophysis = anterior
- secretes multiple hormones:
- Adrenocorticoptrophic (ACTH)
- TSH
- LH
- FSH
- Prolactin (PRL)
- Growth hormone
Pituitary: Posterior Lobe:
- neural extension
- neurohypophysis
- secretes: ADH, oxytocin
Posterior Pituitary - Neural Connection:
- neural cells site within the infundibulum
- hormones transported via axons into
posterior lobe of pituitary - hormones are then directly secreted into
capillary bed in posterior lobe
Posterior Pituitary - Neural Connection:
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Anterior Pituitary - Vascular Connection:
- Hormones secreted into the primary
plexus in the infundibulum - travel into via the hypophyseal vein into
the secondary plexus - leave the pituitary gland via the efferent
hyophyseal veins - into the cavernous sinus
Anterior Pituitary - Vascular Connection:
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Anterior Pituitary-Vascular Connection: low levels of T3 and T4:
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67 year old male with fat deposits around face, thinning of skin, weight gain, red/purple stretch marks on thighs, stomach and progressive ophthalmoplegia
- Cushing’s
- visual problems -> pituitary gland
- enlarged pituitary gland
- pushing on optic chiasm (upwards)
- results in bitemporal hemianopia
- affects ACTH
- hence adrenal gland issue as well
- can also affect internal carotid artery in
cavernous sinue - CN3, 4, V1,V2, 6 in cavernous sinus
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What lies within the cavernous sinus?
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What is the most common treatment for pituitary tumours?
Surgery, via nasal cavity
Disruption to the following hormones results in?
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Adrenal Glands:
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Adrenal Cortex: Secretions:
- aldosterone
- cortisol
- androgens
Adrenal Medulla: Secretions:
- adrenaline
- noradrenaline
Because adrenaline and noradrenaline is released via sympathetic system, the adrenal medulla is
effectively specialised sympathetic ganglion
preganglionic sympathetic fibers synapse in the medulla instead of the sympathetic chain
What are the three layers of the adrenal cortex?
Zona Reticularis
Zone Fasciculata
Zona Glomerulosa
deep to superficial
Which layer of the adrenal cortex secretes androgens?
- testosterone precursor
- zona reticularis
Which layer of the adrenal cortex secretes glucocorticoids?
-> cortisol
- zona fasciculata
Which layer of the adrenal cortex secretes mineralocorticoids?
-> aldosterone
Zona Glomerulus
Adrenal Cortex
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Adrenal Glands: Location:
- lie on top of fat layer which lies on top of
kidneys - not functionally related
- right = pyramidal, contact with liver and
IVC - left = crescent shaped, contract with
spleen, stomach and pancreas
Adrenal Glands: Blood Supply:
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- superior suprarenal arteries (6-8), arise
from inferior phrenic from abdo aorta - middle suprarenal artery (1/2), arise from
abdo aorta near superior mesenteric
artery - inferior suprarenal artery (1/2) arising
directly from renal artery
Adrenal Glands: Venous Drainage:
- into large suprarenal vein
- right drains into the inferior vena cava
- left drains into the left renal vein and then
into the inferior vena cava
left gonadal vein drains into left renal vein
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30yr old male, growth in neck which moves with swallowing
Following a hemithyroidectomy, he suffers from dysphonia for 3 months
Recurrent laryngeal nerve is likely damaged
supplies vocal cords
causes hoarsness
hyperthyroidism/goitre
mindful: trachea, muscles, recurrent laryngeal nerve, ima thyroid artery, parathyroid glands
Thyroid Gland: Surface anatomy:
- thyroid cartilage above cricoid cartilage
- cricoid cartilage above thyroid gland
What muscles overly the thyroid gland?
Infra-hyoid muscles:
- thyrohyoid
- sternothyroid
- sternohyoid (superficial)
- omohyoid (superficial)
Muscles overlying the thyroid gland
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Thyroid Gland: Structure:
- C5-T1
- left and right lobe connected by isthmus
- pyramidal lobe, embrylogical remnant of
development in the oral cavity - highly vascular
Thyroid Gland:
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Thyroid Gland: Arterial Supply:
- superior thyroid artery arises from
external carotid artery - inferior thyroid artery arises from the
thyrocervical trunk (subclavian) - thyroid ima artery arises from
braciocephalic trunk but variable found in
1-%
Thyroid Gland: Venous Drainage:
- Superior thyroid vein drains into internal
jugular vein - middle thyroid vein drains into internal
jugular vein - internal jugular joins subclavian to form
braciocephalic trunks which form SVC - inferior thyroid vein drains into
braciocephalic veins
Thyroid Gland: Arterial Suppky:
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Thyroid Gland: Venous Drainage:
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Where are parathyroid gland located?
- 4 glands
- posterior side of thyroid gland
- share blood supply with the thyroid gland
- controls Ca2+ in blood
Recurrent Laryngeal Nerve:
- vagus nerve runs in carotid sheath
- recurrent laryngeal branches off the vagus
- runs posterior to the thyroid gland
- supplies the vocal cords and intrinsic
muscles of the larynx - left loops under arch of the aorta
- right loops under the right subclavian
Within which compartment does the trachea, oesophagus, thyroid gland and infrahyoid muscles lie in?
Pre-tracheal fascia
Anatomical division of the pre-tracheal fascia:
- muscular = encloses infrahyoid muscles
- visceral = thyroid, trachea and oesophagus
enclosed
Pre-tracheal fascia
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58 year old experiences severe pain in the epigastric region of the abdomen, which radiates to the back and is worse upon eating fatty foods. He complains of oily, smelly stools (steatorrhea) and is visibly jaundiced.
gallstone in major duodenal papilla
inflammation of pancreas
might result in diabetes too
Pancreas Function:
- exocrine: secretion of digestive enzymes
into the small intestine - endocrine: release of insulin and glucagon
into the bloodstream to determine how
the body uses food for energy
Pancreas: Structure:
uncinate process inferior, head, neck, tail (spleen)
duodenum ->head
Pancreas:
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Pancreas: Blood Supply:
- develops as two separate parts hence
blood supply from coeliac trunk and
superior mesenteric artery - coeliac trunk, splenic artery runs along
superior border, grate pancreatic vessels,
dorsal pancreatic vessels = upper part of
tail - on the right coeliac trunk, common
hepatic, gastro-duodenal branch, posterior
superior pancreaticoduodenal branch - superior mesenteric artery, posterior
inferior pancreaticoduodenal artery,
anterior inferior pancreaticoduodenal
artery - SMA gives off transverse pancreatic artery
running along the inferior border of the tail - superior and inferior anastamose
- transverse branches anastomose with
splenic artery
Pancreas: Blood Supply:
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What hormones are secreted by the pancreatic islets?
- glucagon
- insulin
- somatostatin
- pancreatic polypeptid
Pancreatic Islets: Cell Types:
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Exocrine Structures of the Pancreas:
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Exocrine Structures of the Pancreas:
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Where can gallstones be found?
- gall bladder
- cystic duct -> blocks bile from gb -> pain
following meals -> biliary colic - common bile duct - blocks bile from gb
and liver ->billirubin not broken down ->
accumulates causing jaundice and biliary
colic - common bile and hepatic meeting point ->
block bile and pancreatic enzymes ->
biliary colic, jaundice and pancreatitis
What is the master endocrine gland?
pituitary gland
Which sinus are hormones from pituitary released into?
cavernous sinus
