Endocrine Flashcards
What are the major glands of the Endocrine System
Hypothalamus
Pituitary
Thyroid
Parathyroid
Pancreas
Adrenal
Ovaries/testes
Pineal
What are target cells
A specific cell with receptors that responds to specific hormones
How many hormones are in target cells
2,000 - 100,000
What are 3 lipid soluble hormones
Steroid hormones
Thyroid hormones
Nitric oxide
What are 2 water soluble hormones
Amino acids
Where is the hypophyseal Portal Vein contained in
The infundibulum
What allows for the transfer of hormones from the hypothalamus to the anterior pituitary gland
Hypophyseal Portal Vein
Secretion of anterior pituitary hormones is stimulated/suppressed by
Releasing hormones and suppressed by selective inhibiting hormones
Follicle Stimulating Hormone (FSH) release is stimulated by
GnRH
FSH is suppressed by
Elevated levels of estrogen in females and testosterone in males
Luteinizing Hormone (LH) has what function in females
Trigger ovulation
Stimulate corpus luteum to secrete progesterone
What is the function of LH in males
Promotes testes to release testosterone
Prolactin releasing hormone function
Initiates and maintains milk production by the mammary glands
Prolactin-Inhibiting Hormone (PIH) has what function
Suppresses the release of prolactin
What is Adrenocorticotropic Hormone (ACTH)
Controls the production and secretion of Glucocorticoids
What are the functions of the Posterior Pituitary
Stores 2 hormones
Does not synthesize hormones
Contains neurosecretory cells
What is released in large quantities prior to childbirth to enhance contractions
Oxytocin
What is the function of Oxytocin in breasts
Stimulates ejection of milk
What is T4
Thyroxine
What is T3
Triiodothyronine
What are the 2 Islets cells
Alpha cells - secrete glucagon
Beta cells - secrete insulin
What are the 2 adrenal gland regions
Adrenal cortex
Adrenal medulla
What are the 3 zones of the adrenal cortex
Zona Glomerulosa - secretes aldosterone
Zona Fasciculata - secretes glucocorticoids, cortisol
Zona Reticularis - secretes androgens
Glucocorticoid functions
Protein breakdown
Glucose formation
Breakdown triglycerides
Anti-inflammatory
Depress immune response
What are the gamete’s in males
Sperm
What are the gametes in females
Oocyte
What hormone produced by the placenta increases the flexibility of pubic symphysis and uterine cervix during labor
Relaxin
What hormone is produced and secreted by the pineal gland
Melatonin
What hormone stimulates the secretion of cortisol
HgH
What gland secretes cortisol
Adrenal cortex
What peptide hormone lowers plasma calcium levels
Calcitonin
The C-cells of what gland produce calcitonin
Thyroid
What cells are responsible for secreting PTH
Chief cells
What hormone is essential for the stress response
CrH
What hormone inhibits the release of prolactin
Prolactin inhibiting hormone (PIH)
What hormone is a stimulus for sperm production and ovarian follicle maturation
FSH
Zona Glomerulosa primarily produces what hormone
Aldosterone
What promotes reabsorption of sodium and potassium
Aldosterone
What is the insulin pathway
Pancreas -> pancreatic islets -> B cells
What is the progesterone pathway
GnRH -> anterior pituitary -> LH -> ovaries -> corpus luteum
What is the cortisol pathway
Hypothalamus -> corticotropin releasing hormone -> anterior pituitary -> ATCH -> adrenal cortex
What is the growth hormone pathway
Hypothalamus-> GnRH -> Anterior pituitary
What is the adrenaline pathway
Adrenal Medulla -> Epinephrine or norepinephrine
What is the testosterone pathway
Hypothalamus -> anterior pituitary -> LH -> testes
What is the oxytocin pathway
Hypothalamus -> posterior pituitary -> uterus or mammary glands
What gland produces a hormone called insulin
The pancreas
What are the 9 hormones of the hypothalamus
Gonadotropin releasing hormone
Growth hormone releasing hormone
Growth hormone inhibiting hormone
Prolactin releasing hormone
Prolactin inhibiting hormone
Corticotropin releasing hormone
Oxytocin
Antidiuretic hormone
Thyroid releasing hormone
What are the 2 hormones stored in the posterior pituitary
Oxytocin and Antidiuretic hormone
What is tropic hormone
Hormone that stimulates endocrine gland to grow and secrete hormones
What are the 5 tropic hormones
Human growth hormones
Thyroid stimulating hormone
Follicle stimulating hormone
Luteinizing hormone
Adrenocorticotropic hormone
What are 2 direct acting hormones
Prolactin
Melanocyte stimulating hormone
What is the main function of the human growth hormone
Promote synthesis and secretion of hormone insulin like growth factor
- stimulate protein synthesis
- help maintain muscle and bone mass
What is the most abundant thyroid hormone
T4
What are the 4 actions of the thyroid hormone
Stimulate protein synthesis
Increase use of glucose and fatty acids for ATP
Breakdown triglycerides and andante cholesterol secretion
Assist in stimulating body growth
What is calcitonin produced by
The parafollicular cells of the thyroid gland
What is the function of calcitonin
Decreases the level of calcium in the blood by inhibiting the action of osteoclasts, the cells that break down bone
What does the parathyroid hormone regulate
Calcium, magnesium, and phosphate
What is the function of the parathyroid hormone function in the kidneys
Slows rate of calcium and magnesium loss
Increases loss of hydrogen phosphate from blood
Promote formation of calcitrol
What is a flattened organ located in the curve of the duodenum
Pancreas
What are resistance reaction hormones
Corticotropin releasing hormone
Growth hormone releasing hormone
Thyrotropin releasing hormone
What gland stimulates development of the ovarian follicle
Pituitary
What gland controls blood glucose levels
Pancreas
What gland influences the rate of growth and development
Thyroid
What gland stimulates the growth of long bones
Anterior pituitary
What gland stimulates absorption of water in kidney tubule
Hypothalamus (produced) and posterior pituitary (stored)
What gland prepares the body for fight or flight
Adrenal
What gland affects glucose, protein, and fat metabolism
Thyroid
What gland prepares the body for emergency situations
Adrenal
Hormones act at specific target organs because these organs contain what
Target cells
Growth hormone is secreted by what gland
Anterior pituitary
Intermediary proteins that stimulate growth of bones
IGF
Where is the lipid soluble hormone receptor located
Located in the nucleus and changes gene expression
Where is the receptor located for water soluble hormones
On plasma membranes and causes changes
Hormones influence their target cells by doing what
Chemically binding to specific protein receptors
How many atoms do T4 contain
4 atoms of iodine are in Thyroxine
How many atoms are in T3
Triiodothyronine contains 3 atoms of iodine
What is the most abundant Thyroid hormone
T4
T4 converts to what after entering the cell
T3
The thyroid hormones stimulate what
Protein synthesis
Increase the use of glucose and fatty acids for ATP production
Increase the breakdown of triglycerides
Enhance cholesterol excretion reducing blood cholesterol
DONE THROUGH NEGATIVE FEEDBACK
Actions of the pancreas: he main action of glucagon is to increase blood glucose when what occurs
When blood glucose falls below normal
Actions of the pancreas: Insulin helps glucose move into cells, especially muscle fibers which do what
Lower blood glucose level when it is too high
Actions of the pancreas: the level of blood glucose controls secretion of both glucagon and insulin via what
NEGATIVE FEEDBACK
Where does adrenal crisis typically occur
In the adrenal cortex - Zona fasciculata
What hormone is secreted from the pineal gland
Melatonin
Melatonin contributes to what
Setting the body’s biological clock (circadian rhythm)
As we age, human growth hormone decreases which is the cause of what
One cause of muscle atrophy
As we age thyroid hormones (T3, T4, and calcitonin) decrease which causes what
Decreased metabolic rate, increased body fat, and hypothyroidism
As we age, parathyroid hormone rises which causes what
The rise in PTH and the fall in calcitonin decrease bone mass leading to osteoporosis
As we age, insulin is released more slowly causing what
Blood glucose levels to increase faster
As we age, estrogen decreases causing what
As the ovaries decrease in size, they no longer respond to gonadotropins which leads to conditions such as osteoporosis, high blood cholesterol and arethrosclerosis
The hypothalamus is known as the master switchboard because it’s the part of the brain that controls what
The endocrine system
What is a stalk like structure that is attaches the pituitary gland to the hypothalamus
The infundibulum
What hormone is secreted by the hypothalamus and stimulates HGH and IGF
GHRH - growth hormone, releasing hormone
What hormone is secreted by the hypothalamus that inhibits HGH and IGF
GHIH - growth hormone, inhibiting hormone
What stimulates protein synthesis, helps maintain muscle and bone mass, and promotes healing of injury and tissue repair
Human growth hormone - hGH
What stimulates the synthesis and secretion of thyroid hormones by the thyroid gland
Thyroid-stimulating Hormone - TSH
What initiates the development of ovarian follicles in females
Follicle-Stimulation Hormone - FSH
What controls the production and secretion of hormones called Glucocorticoids by the cortex (outer portion) of the adrenal gland
Adrenocorticotropic hormone - ACTH
What causes constriction of arterioles, thus causing an increase in blood pressure
Antidiuretic Hormone - ADH
The walls of each follicle consists of cells called what that produce the two thyroid hormones
Follicular cells
What are the two types of follicular cells
T4- thyroxine
T3- triiodothyronine
What is produced by the parafollicular cells of the thyroid gland
Calcitonin - CT
What is the parathyroid gland
Small round masses of glandular tissue that are partially embedded in the posterior surface of the thyroid gland
Within the parathyroid glands are secretory cells called what
Chief cells: which release PTH
PTH is the major regulator of the levels of what
Calcium, magnesium, and phosphate ions in the blood
PTH produces a change in the kidney that promotes formation of what hormone
Calcitrol
Alpha cells secrete the hormone glucagon which release is stimulated by what
Sympathetic division of the autonomic nervous system
Beta cells secrete the hormone insulin which release is stimulated by what
The parasympathetic division of the ANS
The outer zone of the adrenal cortex is also known as what and secretes what hormone
Zona Glomerulosa and secretes aldosterone
The middle zone of the adrenal cortex is also known as what and secretes what hormone
Zona Fasciculata and secretes cortisol
The inner zone of the adrenal cortex is also known as what and secretes what hormone
Zona Reticularis and releases androgens (male and female sex hormones)
Secretion of aldosterone occurs as part of what pathway
Renin-angiotensin-aldosterone pathway
Conditions that initiate the renin-angiotensin-aldosterone pathway include what
Dehydration
Sodium (Na+) deficiency
Hemorrhage
Which decreases blood pressure and blood volume
The most abundant glucocorticoid is cortisol and glucocorticoids have what actions
Protein breakdown
Glucose formation
Breakdown of triglycerides
ANTI-INFLAMMATORY EFFECTS
Depression of immune response
What also produces inhibin, a protein hormone that inhibits the secretion of follicle-inhibiting hormone (FSH)
The ovaries
What produces testosterone , the primary androgen or male sex hormone
Testes
Testosterone regulates what for the action of the testes
Production of sperm
Stimulates the development and maintenance of masculine characteristics such as beard growth and deepening of the voice
What is the structure of the pineal gland
A small endocrine gland attached to the roof of the third ventricle of the brain at the midline
What is a stress response and how many stages are involved
Stress response is a sequence of bodily changes that can progress through stages:
First stage - an initial fight-or-flight response
Second stage - a slower resistance reaction
Third stage - exhaustion
During the second stage of the stress response, what reduces inflammation
Cortisol
During the exhaustion phase of the stress response, prolonged exposure to high levels of cortisol and other hormones involved in the resistance reactions causes what
Wasting of muscles
Suppression of the immune system
Ulceration of the gastrointestinal tract
Failure of pancreatic beta cells
Pathological changes may occur
What is the blood glucose measured to diagnose with hypoglycemia
<70mg/dl = abnormal
When do symptoms begin for a hypoglycemic patient
At plasma glucose levels in the range of 60 mg/dl and impairment of brain function at approx. 50 mg/dl
Spontaneous hypoglycemia in adults is of what principal types
Fasting and postprandial
Postprandial hypoglycemia is relatively acute and is often heralded by what symptoms
Sweating
Palpitations
Anxiety
Tremulousness
Mainly seen in patients after surgery
What lab(s) can be performed to diagnose a patient with hypoglycemia
Finger stick blood glucose
What is the treatment for a patient with hypoglycemia
Immediate treatment involves provision of glucose - patients able to eat or drink can drink juices, sucrose water, or glucose solutions; eat candy or other foods; or chew on glucose tablets when sx occur
**can be done if member has NO altered mental status
What are the essentials of diagnosis for a patient with prediabetes
Impaired fasting glucose ranging from 100 - 125 mg/dl ***
What are the risk factors of a pre-diabetic
Family history/genetic predisposition
Obesity
*DIET
Physical inactivity
Race
Women who delivered a baby weighing 9lb or grater or had previous sx of gestational diabetes
What medications can cause a patient to present as a pre-diabetic
**Corticosteroids
Antibiotics
Beta-blockers
HCTZ
What is the first-line of treatment for a patient with prediabetes
Weight loss if overweight/obese & increased physical activity/exercise
What is the nest line of treatment for prediabetes if first-line treatment fails
Metformin
What will the plasma glucose be in a patient presenting with diabetes mellitus
126 mg/dl or higher AFTER an overnight fast, documented on more than one occasion
What clinical findings will be present for a Type 1 diabetic patient
3 P’s: polyuria, polydipsia, polyphagia
Higher prevalence of certain infections, especially candidal vaginitis and balanitis, recurrent/severe urinary tract infections, recurrent skin infections, and malignant otitis externa
What are some complications of type 1 diabetes
Insulin overdose
Insulin overdose treatment
Neuropathy
Nephropathy
Heart disease
Ophthalmology
What is macrosomia
High birth weight for mothers who have untreated gestational diabetes may give birth to these babies
What is the treatment for gestational diabetes
Nutrition counseling, strict DIET CONTROL can prevent need for use of insulin
When is insulin used for women with gestational diabetes
Those with persistent fasting hyperglycemia despite strict diet control
What are the essentials for diagnosis of diabetic Ketoacidocis (DKA)
**Hyperglycemia > 250 mg/dl
Acidosis with blood pH less than or equal to 7.3
Serum bicarbonate less than or equal to 15 mEq/l
Serum positive for ketones
What are clinical findings for DKA
3 P’s
Dehydration, possible stupor
**raid deep breathing and a “fruity” breath odor of acetone (nail polish remover)
Hypotension with tachycardia
Mild hypothermia
What is the initial management priority to treat a patient for DKA
4-5 L of 0.9% normal saline within the first hour (lactated ringer’s is fluid of choice if available)
What is the most common cause of endemic goiter
Iodine deficiency
What is endemic goiter a sign of
Thyroid disorder
What are the essentials of diagnosis for hypothyroidism
Menorrhagia, delayed DTR, serum free thyroxine (T4) low, TSH elevated in primary hypothyroidism
What are the causes of hypothyroidism WITH goiter
Autoimmune
Subacute
Iodine deficiency
Genetic thyroid enzyme defects
HEP C
Drugs
What are the causes of hypothyroidism WITHOUT goiter
Thyroid surgery, irradiation
Deficient pituitary TSH
Severe illness
Drugs
Radiation therapy
“Subclinical” hypothyroidism
What are the clinical findings for hypothyroidism: Early Sx
Cold intolerance
Constipation
Menorrhagia
What are the clinical findings of hypothyroidism: Late Sx
Amenorrhea or menorrhagia
Galactorrhea
What are some clinical findings for hypothyroidism: Early signs
Thin, brittle nails
Thinning of hair (Think HEENT)
Pallor
Delayed DTR
What is the treatment for a patient with hypothyroidism
Levothyroxine (T4)
What are some complications for a patient with hypothyroidism
Myxedema coma
Adrenal crisis
What is the most common cause of hyperthyroidism
**Graves’ disease
Hashimoto’s thyroiditis
High serum human chorionic gonadotropin levels n first 4 months of pregnancy
What is a common clinical finding of the thyroid in a patient with hyperthyroidism
Goiter (often with a bruit) in Graves’ disease
What is a common clinical finding of the eyes in a patient that has hyperthyroidism
Stare and lid lag
Opthalmopathy (chemo sis, conjunctivitis, and mild protosis) in 20-40% of patients with Graves’ disease
What is the treatment for Graves’ disease in hyperthyroidism
Radioactive iodine
Propranolol (generally used for symptomatic relief)
What are some common clinical findings in patients with a thyroid nodule
Toxic multinodular goiter and hyper functioning nodules can cause hyperthyroidism
Sweating, weight loss, anxiety, loose stools, heat intolerance, tachycardia, tremor
Malignancy of a thyroid nodule is suggested by what
Hoarseness or vocal cord paralysis
Nodules in men or young women
Nodule that is solitary, firm, large, or adherent to trachea or strip muscles
Vocal cord paralysis
Enlarged lymph node(s)
Distant metastatic lesions
What is the preferred method of lab/image findings of a thyroid nodule
Ultrasound is preferred over CT and MRI because of its accuracy
What is the treatment for a patient with thyroid nodule(s)
Ultrasound guided fine-needle aspiration biopsy of suspicious nodules after referral to endocrinology
What are some essentials of diagnosis for a patient in adrenal crisis
Weakness, abdominal pain, fever, confusion, vomiting
Low blood pressure, dehydration
skin pigmentation may be increased
What is another name for acute adrenal crisis
Adrenocorticotropic insufficiency
What is the treatment for a patient in acute adrenal crisis
If symptomatic adrenal insufficiency is suspected, treat with hydrocortisone100-300 mg IV and saline
*or deximethizone
What is an etiology for chronic adrenal insufficiency
Autoimmune destruction of the adrenals is the most common cause of Addison disease in the US
*TB is a leading cause of Addison disease (rare in US), decreased since 1960s
What is Addison disease
An uncommon disorder caused by destruction or dysfunction of the adrenal cortices
