Test 2 (Endocrine Glands) Flashcards
-Regulate organic metabolism and water
-Induce adaptive changes to help body cope
-Promotes sequential growth
-Control reproduction
regulate RBC production
Endocrine system functions
Secrete chemical signals into the blood
Endocrine glands
Chemical signals released into circulation that broadcast throughout the body to every organ
Hormones
Derived from fatty acids/cholesterol
Lipid hormones
Estrogen, progesterone, testosterone, aldosterone
Steroids
Functions in inflammatory response
Prostaglandins
Chains of amino acids
Peptide hormones
Protein bound to one or more carbohydrate group
Glycoprotein hormones
Derived from the AA tyrosine and tryptophan
Amine hormones
Long-chained precursors to hormones (ex insulin produced from proinsulin)
Prohormones
Molecules that are inactive until converted into the active forms of hormones (ex thyroxine secreted)
Prehormones
Occurs when two or more hormones work together to produce a particular effect. Effects may be additive or complementary
Synergistic effects
Occurs when one hormones makes the target cell more responsive to a second hormone
Permissive effects
Occurs when hormones work in opposite directions with the goal of maintaining homeostasis
Antagonistic effects
Increases levels on calcium in the blood if they get too low
PTH
Decreases the release of calcium into the blood if levels are too high
Calcitonin
Stimulates fat storage
Insulin
Stimulates fat breakdown
Glucagon
What controls the secretion of hormones?
Changes in ions or nutrients
Neurotransmitters
Other hormones
What are the hormonal control systems?
- Ions/nutrient concentrations (Humoral Control)
- Neurotransmitters (neural control)
- Hormonal Control
Endocrine cells monitor concentrations of certain ions or nutrients
Humoral control
Neurons from the ANS can influence hormone release from adrenal medulla and other endocrine glands
Neural Control
Neurons from CNS affect hypothalamus, which in turn influences hormone release
Neural Control
Hormone that stimulates the secretion of a second hormone
Tropic hormone
Stimulates and maintains their endocrine target tissues
Tropic hormones
Mechanism of action
- Hormones bind to receptors on or in target cells
- Hormones bind to receptors with a high affinity
- -Hormones can saturate receptors
Hormone receptors are in the cytoplasm or nucleus
Lipophilic hormones
Hormone receptors are on the outer surface of the plasma membrane
Water-soluble hormone receptors
too little hormone
Hyposecretion
Too much hormone
Hypersecretion
Enough hormone, but ineffective response
Hyporesponsiveness
Too much response
Hyperresponsiveness
Defect in the cells that secretes the hormone that is causing problems
Primary secretion disorder
Problem is with too much or to little tropic hormone
Secondary Secretion Disorder
Part of the diencephalon and controls release of pituitary hormones
Hypothalamus
Extends from the interior surface of the hypothalamus and has two distinctive lobes
Pituitary gland
Composed of nervous tissue
Posterior pituitary
Where are hormones synthesized?
Hypothalamus
What are the posterior pituitary hormones?
- ADH
- Oxytocin
Increases reabsorption of H20 by kidneys
ADH
Stimulates uterine contraction during childbirth and milk letdown during breast feeding
Oxytocin
What are some hormones released by the anterior pituitary gland?
- Follicle Stimulating Hormone (FSH)
- Luteinzing Hormone (LH)
- Thyroid Stimulating Hormone (TSH)
- Adrenocorticotropic Hormone (ACTH)
- Growth hormone
- Prolactin
Promotes gamete production and stimulates estrogen production
Follicle Stimulating Hormone
Stimulates sex hormone secretion
Luteinizing Hormone
Stimulates secretion of glucocorticoids
Adrenocorticotropic Hormone
Promotes protein synthesis and growth
Growth hormone
Promotes milk production
Prolactin
Hormones released by the hypothalamus and pituitary
Gonadotropin Releasing Hormone (GnRH)
- Growth Hormones releasing Hormone (GHRH)
- Somatostatin (SS)
- Thyrotropin Releasing Hormone (TRH)
- Dopamine
- Corticotropin (CRH)
Stimulates release of FSH
GnRH
Stimulates release of GH
GHRH
Inhibits secretion of GH
SS
Stimulates release of TSH
TRH
Inhibits secretion of Prolactin
Dopamine
Stimulates release of ACTH
CRH
A principle means of regulating the effects of a hormone
Negative feedback inhibition
High secretion of a hormone leads to a response that inhibits further secretion of that hormone
Negative feedback inhibition
Hyposecretion in childhood that results in a short stature
Pituitary dwarfism
Hypersecretion in childhood usually caused by tumor on the anterior pituitary which results in excessive growth
Gigantism
Hypersecretion in adulthood which results in excessive growth especially in cranial and facial bones, hands and feet
Acromegaly
Located on the superior aspect of each kidney composed of the adrenal cortex and adrenal medulla
Adrenal glands
Outer portion of adrenal glands that secretes steroid hormones
Adrenal cortex
Inner portion of the adrenal glands which secretes catecholamines
Adrenal medulla
Consists of mineralocorticoids, glucocorticoids and androgens which secrete different hormones
Adrenal cortex
Consists of mainly aldosterone and influences mineral balance
Mineralocorticoids
Primarily consists of cortisol/hydrocortisone and plays a major role in glucose metabolism and protein and lipid metabolism
Glucocorticoids
- Stimulates gluconegenesis
- stimulates protein degration
- facilitates lipolysis
- plays key role in adaption to stress
- anti-inflammatory and immunosuppresive effects
Cortisol/hydrocortisone
What are some of the causes of Cushing’s syndrome?
overstimulation of adrenal cortex
adrenal tumors
taking meds with high glucocorticoid concentrations
What are signs and symptoms of Cushing’s syndrome?
Abnormal fat distribution
Effects of thyroid hormones
- main determinant of basal metabolic rare
- influences synthesis and degradation of carbs, fat and protein
- increases heart rate
- essential for normal growth
- crucial role in development of nervous system
Primary causes of Hypothyroidism
Failure of thyroid gland
Inadequate dietary supplement of iodine
Symptoms of Hypothyrodism
Low BMR, weight-gain, letharrgy
Goiter
enlarged thyroid
Cretinism
Hypo secretion during first few months of life
Graves disease
Autoimmune disease
Hyper secretion of thyroid hormones
Symptoms of Graves disease
agitation, nervousness, bulging eyes
Treatment of Graves disease
Surgical removal or a portion of the over-secreting thyroid or orbital decompression
Four small organs located on posterior surface of the thyroid
parathyroid glands
What does the parathyroid secrete
PTH
- increases blood Ca2+ levels if they get too low
- Increases breakdown of bone matrix and inhibits Ca2+ secretion from the kidneys
parathyroid hormone
Both an endocrine organ and digestive exocrine organ
Pancreas
What are the two cell types in the pancreas
Alpha and Beta cells (secretes glucagon and insulin)
Encourages cellular growth
Anabolic hormones
Induces glucose uptake and utilization by cells which promotes removal of glucose from blood and lowers blood glucose levels
Insulin
Characterized by lack of insulin secretion and results in blood sugar level monitoring and regular insulin injections
Type 1 diabetes
Characterized by normal or even increased insulin secretion but reduced sensitivity of insulin target cells
Type II diabetes
What are additional endocrine organs
Gonads
Pineal gland
Stomach and small intestine
