HORMONES
This is a long range chemical messenger carried in the blood.
What is a hormone?
This produce hormones and lack ducts.
What is endocrine glands?
Most hormone levels in the body are controlled by this type of feedback, where a hormone’s effect shuts off its own production.
What is negative feedback?
Unlike the pituitary, hypothalamus, and pineal glands, this endocrine gland is not located in the central nervous system and regulates metabolism.
What is the thyroid gland?
This hormone, produced by the pancreas, lowers blood glucose by promoting uptake into cells.
What is insulin?
This “master gland” controls many other glands and secretes growth hormone, prolactin, and ACTH.
What is the pituitary gland?
A patient presents with fatigue, weight gain, and cold intolerance. Lab tests show low levels of T3 and T4 and high TSH. Which gland is malfunctioning, and what condition does this indicate?
The thyroid gland; condition is hypothyroidism.
Hormones made from cholesterol, like cortisol and estrogen, belong to this class.
What are steroids?
This class of hormones, released by the adrenal medulla, plays a key role in the body’s “fight-or-flight” response to stress by increasing heart rate, blood pressure, and blood glucose.
What are catecholamines (epinephrine and norepinephrine)?
Secreted by the adrenal medulla, this hormone is responsible for the “fight or flight” response, increasing heart rate and blood pressure.
What is epinephrine (adrenaline)?
This butterfly-shaped gland in the neck regulates metabolism and requires iodine to produce its hormones.
What is the thyroid gland?
A 12-year-old girl presents with excessive thirst and frequent urination. Blood tests reveal elevated blood glucose levels. Which endocrine organ is most likely involved, and what is the probable diagnosis?
The pancreas; probable diagnosis is type 1 diabetes mellitus (insulin deficiency).
This part of the brain controls the pituitary gland and releases hormones like TRH and CRH.
What is the hypothalamus?
The kidneys produce erythropoietin, a hormone that stimulates the red bone marrow to produce this type of blood cell.
What are red blood cells (erythrocytes)?
This hormone, produced by the thyroid gland, requires iodine for its synthesis and regulates basal metabolic rate.
What is thyroxine (T4)?
This small gland in the brain regulates circadian rhythm by producing melatonin. Also it is often referred to as the "third eye".
What is the pineal gland?
A 35-year-old patient has high blood pressure, muscle weakness, and a “moon face.” Blood tests reveal high cortisol levels regardless of time of day. What condition is suspected, and which gland is involved?
Cushing’s syndrome; the adrenal cortex is overproducing cortisol.
Hormones that act on intracellular receptors are typically of this chemical class.
What are lipid-soluble hormones (steroids and thyroid hormones)?
Ipamorelin is a peptide that mimics growth hormone–releasing hormone. When administered, it may cause this effect in the body by stimulating the release of growth hormone.
What is increased growth hormone secretion, leading to effects such as increased muscle mass, bone growth, and fat metabolism?
This hormone from the anterior pituitary triggers cortisol release from the adrenal cortex and is regulated by negative feedback from cortisol levels.
What is adrenocorticotropic hormone (ACTH)?
This gland is located in the chest, is large in children, shrinks in adults, and plays a role in T-cell maturation for the immune system.
What is the thymus gland?
A patient experiences severe fatigue, low blood pressure, and hyperpigmentation of the skin. Lab tests reveal low cortisol and aldosterone levels, but high ACTH levels. Which gland is failing, and what is the diagnosis?
Adrenal cortex failure; diagnosis is Addison’s disease (primary adrenal insufficiency).
This type of hormonal regulation occurs when one hormone triggers the release of another hormone from a different gland. This type of stimulus involves changes in blood levels of ions or nutrients directly triggering hormone release. This rare type of control occurs when nerve fibers stimulate hormone release, such as during the fight-or-flight response.
What is a hormonal stimulus? What is a humoral stimulus? What is a neural stimulus?