Embryology & Histology: Endocrine- Reynolds Flashcards
(23 cards)
What is the primary function of the endocrine system?
Aid in establishment and maintenance of homeostasis
What is the speed of onset for the endocrine system?
Seconds to hours
What is the duration of the endocrine system?
Can range from hours to weeks even if the secretion ceases
What is a horomone?
A long distance chemical secreted into the blood and transported to specific receptor sites and affects the function of the cell/tissue
Describe the three main functions of the hypothalamus
Direct innervation of the adrenal gland
Secrete oxytocin and ADH
Indirect control through regulation hormones
What is the hypothalamus mainly composed of and where is it located?
Nervous tissue
Base of the brain
Where is the pituitary gland located?
At the base of the hypothalamus
What is the anterior pituitary gland (adenohypophysis) made of and what is its function?
Glandular epithelium
Contains chromophobes and chromophils in pars distalis
Secretes hormones
What is the posterior pituitary gland (neurohypophysis) made of and what is its function?
Nervous epithelium
Contains Herring bodies (extensions from the hypothalamus)
Acts as a reservoir for the hypothalamus and contains capillaries to transport hypothalamus horomones
Developmentally, where did the anterior pituitary (adenohypophysis) come from?
Rathke’s pouch
Made from ectoderm
Invagination of the stomatodeum
Developmentally, where did the posterior pituitary (neurohypophysis) come from?
Infundibulum
Made from ectoderm
Extension of the diencephalon
Where was the parathyroid derived from?
The 3rd (inferior) and 4th (superior) pouch
Where was the thymus derived from?
The 3rd pouch
Where was the parafollicular cells derived from and what structure do they belong to?
The 4th pouch
Thyroid
In development they are also known as ultimopharyngeal bodies
What do parafollicular cells secrete?
calcitonin
What does the thyroid gland make and where is it located?
Calcitonin, T3, and T4
Underneath the larynx
Activated by TSH from the anterior pituitary
What are the two types of cells associated with the thyroid?
Follicular- T3 and T4
Parafollicular- calcitonin
What are the associated cells of the parathyroid?
Cheif/Principle Cells and Oxyphil Cells
They secrete PTH
Signal the production of osteoclast stimulating factor
What are the parts of the adrenal glands and what are the functions of each
Medulla- catecholamines
Cortex- steroid hormones
How do the parts of the adrenal glands develop?
Cortex first starts out as the primidium cortex and then gets engulfed by the definitive cortex (mesoderm)
Medulla is from migrating neural crest cells and migrates towards the center of the cortex (ectoderm)
What is unique about the pancreas?
It is both exocrine and endocrine
Describe the development of the pancreas
Dorsal bud and Ventral bud fuse off of the duodenum
Ventral contains two buds
Annulus pancreas is when the two ventral buds migrate opposite directions around the duodenum
What are the associated cells of the pancreas?
Islets of Langerhans
Alpha- glucagon
Beta- insulin (most)
Delta- somatostatin (least)
