Endocrine system Flashcards
Endocrine system features
releases hormones and is responsible for metabolic activities (e.g., growth hormone [GH] is most abundantly produced by the pituitary gland)
Endocrine system Key structures
Hypothalamus
Pineal gland
Pituitary gland
Thyroid
Parathyroid
Thymus
Adrenal
Pancreas
Ovaries
Testes
Hypothalamus
The main role of this gland is to maintain homeostasis. It either stimulates or inhibits heart rate, blood pressure, body temperature, fluid and electrolyte balance, thirst, appetite, body weight, glandular secretions of the stomach and intestines, the release of substances influencing the pituitary gland, and sleep cycles.
Electrolyte
Electrolytes are minerals in the body that have an electric charge.
Pineal gland
The only hormone this gland is known to secrete is melatonin.
Pituitary gland
Pituitary hormones control other parts of the endocrine system, including the thyroid gland, adrenal glands, ovaries, and testes.
Thyroid
The main function of the thyroid is to regulate metabolism.
Parathyroid
There are four parathyroid glands that help regulate calcium levels in the body.
Thymus
The thymus is only active until puberty. Before puberty, it stimulates the development of T lymphocytes, which play a role in the lymphatic system’s defense against illness and infection.
Adrenal
The adrenal glands are attached to the kidneys and are made up of the adrenal cortex and adrenal medulla. Hormones secreted by the adrenal cortex are essential to life. Those secreted by the adrenal medulla are not.
Pancreas
The main role of the pancreas is to maintain blood glucose balance.
Ovaries
The ovaries secrete hormones essential for female reproductive development and fertility.
Testes
The testes are responsible for maintaining male reproductive health.
Hormones
chemical messengers stored, created, and released by endocrine glands
Endocrine glands
ductless glands releasing hormones that remain within the body
ENDOcrine glands produce substances that remain within the body
Exocrine glands
glands that produce and release substances through ducts or openings on the body’s surface
EXOcrine glands secrete substances that EXIT the body
Testosterone
A steroid hormone found in both males and females
Controls muscle size; increases number of red blood cells; decreases body fat; promotes male sex characteristics
Growth hormone (GH)
A hormone released by the pituitary gland that stimulates growth in animal cells
Increases protein synthesis
Increases fat breakdown
Increases collagen synthesis
Decreases glucose utilization
Insulin-like growth factor
A protein similar to insulin that stimulates the growth of cells
Limited production when GH is absent
Insulin
A hormone produced in the pancreas to regulate blood sugar
Insulin promotes the uptake of glucose into target cells. Insulin = IN the cells
Cortisol
A catabolic hormone released in response to physical and emotional stress
Can be good or bad based on how long it remains elevated
Short-term cortisol elevation:
Increases blood sugar (glucose) levels
Enhances the brain’s use of glucose
Reduces inflammation
Reduces unnecessary bodily functions during the fight-or-flight response
Extended-duration cortisol elevation:
Increases appetite
Increases blood pressure
Promotes weight gain
Contributes to type 2 diabetes
Catecholamines
Hormones released by the adrenal glands into the blood as a result of stress
Key
Anabolic
the process of creating larger molecules from smaller units
Catabolic
metabolic activity involving the breakdown of molecules such as proteins or lipids into smaller units
Protein synthesis
the process of arranging amino acids into protein structures
