Endocrine System Flashcards
What two systems work together to maintain homeostasis?
nervous and endocrine systems
How does the nervous system regulate physiological activities?
neurotransmitters (short-term, specific responses to stimuli)
How does the endocrine system regulate physiological activities?
Hormones (long-term regulation of metabolic processes)
Five ‘pure’ endocrine glands
- Pituitary
- Pineal
- Thyroid
- Parathyroid
- Adrenal
Four organs containing endocrine cells:
- Pancreas
- Thymus
- Gonads
- Hypothalamus
Endocrine cells release hormones directly into _______ , _______ , or _______ .
- Interstitial fluids
- Lymphoid systems
- Blood
Where is the pituitary gland located?
sella turcica
Which gland is controlled by the hypothalamus?
Pituitary gland
The two lobes of the pituitary gland
- Adenohypophysis (anterior lobe)
- Neurohypophysis (posterior lobe)
Hormones stored and released by the neurohypophysis
- Oxytocin
- Antidiuretic Hormone (ADH)
What condition results from an inability to produce ADH?
Diabetes insipidus
Functions of oxytocin
- Cause uterine contractions
- Milk letdown in lactation
Hormones released by Adenohypophysis (anterior lobe)
- Adrenocorticotropic hormone (ACTH)
- Thyroid-stimulating hormone (TSH)
- Growth hormone (GH)
- Prolactin (PRL)
- Follicle-stimulating hormone (FSH)
- Luteinizing hormone (LH)
Three hormones released by the adenohypophysis that target other glands (Tropic)
- Thyroid-stimulating hormone (TSH)
- Adrenocorticotropic hormone (ACTH)
- Gonadotropic hormone
Three hormones released by the adenohypophysis that do not affect other glands (Non-tropic)
- Melanocyte-stimulating hormone (MSH)
- Growth hormone (GH)
- Prolactin (PRL)
Hormone that has both tropic and non-tropic effects
Growth hormone (GH)
A disorder that results from a lack of growth hormone during childhood
Pituitary dwarfism
A disorder results from excess growth hormone during childhood
Gigantism
A disorder results from excess growth hormone in adulthood
Acromegaly
Two main thyroid hormones involved in metabolism
- Thyroxine (T4)
- Triiodothyronine (T3)
Hormone involved in calcium homeostasis
Calcitonin
Connects the two main lobes of the thyroid gland
Isthmus
Mineral that is essential for thyroid hormone production
Iodine
Also known as severe hypothyroidism in adults; characterized by lethargy, weight gain, loss of hair
Myxedema
Severe hypothyroidism during development resulting in short stature, stocky body type, and mental retardation.
Cretinism
Hyperthyroidism causing exophthalmic goiter (bulging eyes due to edema), hyperactivity, and arrhythmias
Grave’s disease
Functions of Parathyroid Hormone (PTH)
- Stimulates osteoclasts
- Decrease calcium secretion by kidneys
- Activates vitamin D
Happens as a result of removal or destruction of parathyroids
Hypocalcemia
What happens to the blood calcium levels when parathyroid hormones are released
Increases
Hormones that aid in the development of T-cells of the immune system
Thymosins
Endocrine gland that is most active during childhood and atrophies as one ages
Thymus gland
Hormone produced by the pineal gland
Melatonin
Parts of the Adrenal Glands
- Cortex (outer)
- Medulla (inner)
Hormones released by the adrenal medulla
- Epinephrine
- Norepinephrine
A part of the adrenal gland that is a neurosecretory structure
Medulla
A part of the adrenal gland that is under the control of ACTH
Cortex
Two main hormone groups produced by the adrenal cortex
- Mineralocorticoids
- Glucocorticoids
Hormones that regulates salt and water balance; aids in regulation of blood volume and pressure
Mineralocorticoids
Regulates carbohydrate, protein, and fat metabolism; causes increase in blood glucose
Glucocorticoids
The adrenal cortex also produces small amounts of _______ .
Sex hormones (Sex steroids)
Disorder caused by accumulation of ACTH leading to skin bronzing
Addison’s Disease
Disorder caused by hypersecretion of adrenal cortex and excess cortisol leading to Diabetes mellitus, subcutaneous fat deposition in midsection, and high blood pressure
Cushing’s Syndrome
Organ that contains endocrine and exocrine cells
Pancreas
________ form most of the Pancreas; secretes digestive enzymes into the small intestine
Exocrine acinar cells
Regions of pancreas that contain the endocrine cells
Pancreatic islets or Islets of Langerhans
Each pancreatic islet contain four major cells:
- Alpha cells (Glucagon)
- Beta cells (Insulin)
- Delta cells (somatostatin-GH inhibiting hormone)
- F cells (Pancreatic polypeptide)
Hormone that stimulates uptake of glucose
Insulin
Hormone that increases blood glucose levels
Glucagon
The primary cause of type 2 diabetes mellitus
Insulin-resistance
Hormone that slows the maturation of sperm, oocytes, and reproductive organs
Melatonin
Pine-cone shaped gland that contains neurons, glial cells, and special secretory cells
Pineal Gland
Special secretory cells found in the Pineal gland
Pinealocytes
