Lesson 11 Endocrine system Flashcards
This is the coordinating center of the endocrine system, consolidates signals derived from thoughts, feelings, autonomic function, environmental cues, and peripheral endocrine feedback.
Hypothalamus
This is a pea-sized organ located in the center of the brain, is called the master gland because it regulates all the body’s endocrine glands. It can be compared to a dispatcher because, in response to a signal from the hypothalamus, it releases one of its many tropic hormones
pituitary
this secretes growth hormone (GH), prolactin (PRL), ACTH, thyroid-stimulating hormone (TSH), follicle-stimulating hormone (FSH), and luteinizing hormone (LH).
Anterior pituitary
This synthesizes ADH and oxytocin (OXT), which are stored and released by the posterior pituitary. ADH is also called arginine vasopressin (AVP), and GH is also called somatotropin.
hypothalamus
This stores and releases ADH and oxytocin (OXT)
posterior pituitary
this regulates each of the hypothalamic-pituitary-hormone axes, a process that maintains hormone levels within a narrow range.
Negative feedback
When an individual is running in a marathon, the hypothalamus receives signals from the body that the muscles and organs have extra metabolic needs. The hypothalamus secretes _________1________. which stimulates the ____2______ gland. This then secretes ______3______, which stimulates the adrenal gland to secrete the hormone _____4_____. These levels in the blood rise, the pituitary senses increased level and shuts off stimulus to ___5____. this is an example of _____6____.
- corticotrophin-releasing factor (CRF)
- pituitary
- ACTH
- cortisol
- adrenal gland
- endocrine negative feedback system
For instance, prolonged, excessive stimulation of an endocrine gland often results in receptor insensitivity and may decrease its number of receptors in a process known as what?
Downregulation of receptors (caused by excessive, prolonged dose of glucocorticoid drugs)
What is the most common reason for upregulation of receptors?
a reduction in the receptor stimulation by hormones.
what are the 2 categories of endocrine gland dysfunction?
hypofunction and hyperfunction
This dysfunction caused by the endocrine gland itself
Primary endocrine disorder
This dysfunction caused by abnormal pituitary activity
secondary endocrine disorder
This dysfunction caused by a hypothalamic origin
tertiary endocrine disorder
These tumors can cause such problems as growth disturbances, electrolyte imbalances, and infertility. They classically cause visual disturbances because of their proximity to the optic chiasm in the brain.
pituitary tumors
These are the etiologies for what?
tumors, cranial radiation, traumatic brain injury, subarachnoid hemorrhage, infectious and inflammatory disorders, and postpartum pituitary necrosis (Sheehan’s syndrome). The pituitary adenoma, a benign, epithelial neoplasm, is the most common tumor of the pituitary gland.
hypopituitarism
These hormones are secreted by which part of the pituitary gland?
*Thyrotropin, or TSH
* Gonadotropins, or FSH and LH
* Somatotropin, or GH
* Corticotropin, or ACTH
* Prolactin, or PRL
Anterior pituitary
What is unique about the posterior pituitary? (how is it different from the anterior?)
does not produce its own hormones; it stores hormones. The hypothalamus produces ADH (also referred to as AVP) and OXT. These two hormones are released into the hypothalamic–hypophyseal tract to the posterior pituitary, where they are stored.
How is the endocrine system impacted by hypopituitarism?
results in secondary failure of the target endocrine glands
What are the most serious concerns for hypopituitarism?
drenal insufficiency, hypothyroidism, and diabetes insipidus (DI), the last of which occurs because of a lack of posterior pituitary secretion of ADH.
What are the clinical presentations in the neonate and infant?
dwarfism, developmental delay, various visual and neurological symptoms, seizure disorder, and a number of congenital malformations.
How do adults present for hypopituitarism
radual symptoms of hypothyroidism, adrenal insufficiency, and ADH deficiency. The clinical presentation may be weakness, weight loss, and hypotension caused by adrenal insufficiency, or weight gain, sluggishness, and depression caused by hypothyroidism. Lack of ADH causes excessive urination and dehydration, a syndrome known as DI.
What are the clinical presentations when hypopituitarism is acute
a rapidly deteriorating state of hypotension; severe dehydration; neurological deficits; and abnormalities in electrolyte levels, glucose levels, body temperature, and heart rate.
What are the diagnostic findings for someone with hypopituitarism
low serum levels of pituitary tropic hormones, such as TSH, ACTH, FSH, LH, GH, PRL, and ADH, and low corresponding endocrine organ hormones, such as thyroxine (T4), cortisol, and estrogen.
How is hypopituitarism treated?
varies depending on which tropic hormones are lacking. Hormone replacement and surgical excision of the tumor, if present, are the treatment measures.