histology: endocrine organs Flashcards
(64 cards)
How does the endocrine secrete it’s secretion
Directly into the vascular system
What is the type of blood vessels in the endocrine system
Fenestrated or sinusoidal
What endocrine gland does not have fenestrated blood vesels
Testes
What is the effects of the endocrine system
Stimulatory or inhibitory
What system works closely with the endocrine system
Nervous system
What does the nervous system use to communicate
Neurotransmitters that are released locally & bind to receptor on target cell
What does the endocrine system use to communicate
Hormones that circulate & bind to receptor on target cell
What are the two types of hormones
- Lipid soluble: binds to receptors in target cells (diffuse into cell)
- Water soluble: bind to receptor on exterior surface of target cells (cascade of events)
What is the speed of communication of the nervous system vs the endocrine system
Nervous system: rapid communication
Endocrine system: delayed communication
What is the two feedback loops
- Physiological response
- Endocrine axis
What is the two parts of the pituitary gland & origins
- Neurohypophysis from hypothalamus
- Adenohypophysis from roof of mouth
What is another name for pituitary gland
Hypophysis
How does the pituitary form
- Neurohypophyseal bud projects downwards while roof of mouth projects upwards
- Roof of mouth forms the Rathke’s pouch that connect with neurohypophyseal bud
- Roof of mouth loses connection & pituitary is formed
What is the hypothalamohypophyseal portal system
The blood vessels of the anterior pituitary
What regulates secretions of the anterior pituitary
- Neurosecretory cells in hypothalamus
- Negative feedback loops
What is the capillary system of the hypothalamohypophyseal portal system
Fenestrated capillaries
What is the benefit of the hypothalamohypophyseal portal system
System bypasses the heart meaning quicker transport & higher hormone concentration
What connects the anterior & posterior pituitary
Pars intermedia
What is three disorders of the pituitary gland
- Adenoma: under/over production of hormones
- Somatotrophs adenoma: secrete excess GH causing gigantism & acromegaly
- Prolactinomas: deficiency of GnRH leading to infertility
What three tissues are the anterior pituitary composed of
- Cords of epithelial cells
- Minimal supporting connective tissue stroma
- Fenestrated capillaries/sinusoids
What is the two cell types of the anterior pituitary
- Chromophobes: resist stain & undifferentiated chromophils
- Chromophils: important cells
What is the two types of chromophils
- Acidophils
- Basophils
What is the two acidophils cells & what do they secreted
- Somatotrophs: secrete human growth factor hormone/somatotropin
- Lactotrophs: secrete prolactin
What is the three basophil cells & what do they secreted
- Gonadotrophs: secrete FSH & LH
- Thyrotrophs: secrete thyroid stimulating hormone/thyrotropin
- Corticotrophs: secrete ACTH/corticotropin