Endocrine Ch 17 Flashcards
What are the endocrine glands?
Pituitary, thyroid, parathyroid, adrenal, pineal, thymus
What two organs produce both hormones and exocrine products?
Pancreas
Gonads
What are endocrine, exocrine, and neuroendocrine organs?
Endocrine-ductless glands/dump hormone directly into capillaries
Exocrine- non hormonal substances routed to membrane surface by duct
Neuro-hypothalamus controls pituitary gland hormones
Differentiate autocrines and paracrines.
Auto- chemicals that exert effects on same cell that secrete
Para-locally acting chemicals that affect cells other than those secreting (blood clotting chems)
What are three types of hormones?
Amino acid based (proteins)
Steroid (cholesterol/lipid)
Eicosanoids-active lipid with local hormone like activity
What are some examples of amino acids (protein) hormones?
Amines, thyroxine, peptide, and protein
Insulin, glucagon
Name some examples of steroid (cholesterol/fat) hormones.
Gonadal (testosterone, estrogen, progesterone), adrenocortical:(aldosterone,cortisol))
(Gonads and adrenal)
What are two ways hormones alter target cell?
Second messengers -amino acids bases (except t3 t4 thyroid)
Direct gene activation- steroid
*response depends on type of target cell and type of hormone
How do steroid hormones work?
Enter nucleus and alters gene expression, prompting DNA transcription to produce mRNA.
Which is translated into proteins.
Endocrine system is the body’s second great controlling system which influences ________ activities of cells by means of _________.
Metabolic
Hormones
What receptors are found on the adrenal cortex cells?
ACTH
Thyroxine receptors are found on nearly all cells of _________.
The body
What are the three factors of target cell activation?
Blood levels of the hormone.
Relative number of receptors on target sale.
The affinity of those receptors for the hormone.
What is up and down regulation?
Up– Target cells for more receptors in response to hormones. Affects gets bigger.
Down – target cells lose receptors in response to hormones. Affects get smaller.
Hormones circulate the blood and what two forms?
Free or bound.
*Steroids and thyroid hormone are attached to plasma lipoprotein’s.
All others are encumbered.
Hormones are removed from the blood by…
Degrading enzymes
the kidneys
liver enzyme systems
What are the three types of hormone interaction at target cells?
Permissiveness
synergism
antagonism
What is permissiveness? (Hormone/Target cell interaction)
Hormone cannot exert its effects without another hormone being present.
Thyroid hormone/growth hormone
What is synergism? (hormone/target cell interaction)
More than one hormone produces the same affects on a target cell.
(Glucagon epinephrine Cortisol)
What is antagonism? (Hormone/target cell interaction)
One or more hormones opposes the action of another hormone.
insulin/glucagon, parathyroid hormone/calcitonin, GHRH/GHIH
Hormones are synthesized and released in response to…
Humoral stimuli
Neural stimuli
hormonal stimuli
What is humoral stimuli?
Secretion of hormones in direct response to changing blood levels in ions and nutrients
What is neural stimuli?
Nerve fiber stimulate hormone release
Adrenal Medulla
What is hormonal stimuli?
Release of hormones in response to hormones produced by other endocrine organs.
- hypothalamus—>anterior pituitary—> target recep.
What can override normal endocrine controls?
The nervous system.
The pituitary gland is a two lobed organ that secretes nine major hormones.
Name the two parts and their function.
Neurohypophysis-posterior lobe (neural tissue) and infundibulum. Receives stores and releases hormones from hypothalamus
Adenohypophysis-anterior lobe, (glandular tissue)
Synthesizes and secretes a number of hormones
Nuclei of the hypothalamus synthesize
________ and ________.
Oxytocin and antidiuretic hormone
What is the vascular connection between the hypothalamus and anterior lobe of pituitary? (Adenohypophysis)
Hypophyseal portal system (portal vein)
The hypothalamus sends a chemical stimulus to the anterior pituitary. What two types of hormones?
Releasing hormones – stimulate the synthesis and release of hormones.
Inhibiting hormones – shut off the synthesis and release of hormones.
What are the seven hormones made by the hypothalamus that act on the anterior pituitary?
Growth hormone releasing hormone Growth Hormone inhibiting hormone Corticotropin releasing hormone thyrotropin releasing hormone gonadotropin releasing hormone Prolactin releasing hormone prolactin inhibiting hormone
What are the tropic (hormones that trigger other hormones) hormones of the anterior pituitary? (4)
Thyroid stimulating hormone adrenocorticotropic hormone
follicle-stimulating hormone
luteinizing hormone
What are two other anterior pituitary hormones?
Growth hormone and prolactin
Hypersecretion of GH results in?
Gigantism and acromegaly
Hyposecretion Of GH results in?
Achondroplasia and hypopituitary dwarfism
TSH stimulates the normal development and secretory activity of the? And is triggered by?
Rising blood levels of thyroid hormones act on it to Terry and hypothalamus to block the release of?
Thyroid
Hypothalamic peptide TRH
TSH
What stimulates the adrenal cortex to release corticosteroids?
Adrenocorticotropic hormone (ACTH)
What can trigger the release of CRH (corticotropin releasing hormone)?
Internal/External factors: fever, hypoglycemia, and stressors
What are the anterior pituitary gonadotropins?
Follicle-stimulating hormone (FSH) and Luteinizing hormone (LH)
What is the function of LH in females and males?
FEMALES:
LH works with FSH to cause maturation of the ovarian follicle.
Triggers ovulation, promote synthesis and release of estrogen and progesterone.
MALES:
Stimulates interstitial cells of testes to produce testosterone
What is PRL?
Prolactin
Prh-releasing
Pih-inhibiting
The posterior pituitary drug oxytocin is regulated by? Intensifies? And triggers?
Regulated by positive feedback to oxytocin in the blood.
Intensifies uterine contractions.
Triggers milk ejection in milk producing women.
What hormone helps to avoid dehydration or water overload?
Antidiuretic hormone ADH
- with high solutes ADH preserves water (Dehydration ), with low solutes ADH is not released causing water loss (pee often)
What does ADH deficiency lead to? And symptoms.?
Diabetes insipidus
Copious urine (polyuria), intense thirst (polydipsia) * don't make ADH
Hypersecretion of ADH results in? Symptoms?
Syndrome inappropriate ADH secretion (SIADH)
Fluid retention- (not purging water through urination)
headache/disorientation (cerebrospinal fluid buildup)
hypo osmolarity of blood (02 delivery impaired)
What is the largest endocrine gland and the tissue that connects each side called?
Thyroid gland
Isthmus
What do the follicles of the thyroid gland produce?
Glycoprotein thyroglobulin
What is thyroid gland colloid?
Thyroglobulin and iodine. Fills the lumen of the follicles and is the precursor of TH
What is thyroxine and triiodothyronine called and made up of?
T3-has 2 tyrosine molecules and four iodine (DIT + DIT)
T4-has 2 tyrosine a and 3 iodine atoms (DIT + MIT)
Thyroid hormones T3 and T4 are concerned with what three things?
Glucose oxidation
increasing metabolic rate and calorigenic heat production
(Normal body temp)
Besides what thyroid hormones are concerned with, they play a role in what four things?
Maintaining blood pressure.
Regulating tissue growth.
Developing skeletal and nervous systems.
Maturation and reproductive capabilities.
What do T3 and T4 bind to which is produced by what?
Which one is more active? Mechanisms are similar to what? Regulation is by what?
Thyroxine-binding globulin (TBGs) by liver
T3 is 10 times more
Similar to steroids (directly alter in nucleus)
Negative feedback elation
What is hypothyroid syndromes results?
Myxedema-mucus swelling
Symptoms:
Low metabolic rate
feeling chilled
Endemic goiter
Cretinism-prenatal
Hyperthyroid syndrome results in?
Graves’ disease
Symptoms: Elevated metabolic rate Rapid heart rate Weight loss Exophthalmos (large eye look)
What is calcitonin and its function?
Peptide hormone produced by the parafollicular cell.
Targets skeleton where it inhibits osteoclast activity. stimulates calcium uptake and incorporation into bone matrix.
*Regulated by humoral negative feedback.
Chief cells are in what gland and secrete what?
What does this hormone do?
Parathyroid gland
PTH
regulates calcium levels in the blood
PTH _______ calcium in blood by?
Increases
- osteoclasts digest bone
- reabsorption of calcium and the secretion of phosphate by kidneys
- increases absorption of calcium from food
- rising calcium in blood inhibits PTH release
- antagonist to calcitonin
Hyperparathyroidism is rare but leads to?
Osteitis fibrosa cystica
Symptoms: hypercalcemia
Hypoparathyroidism is rare but leads to?
Tetany and convulsions.
Symptoms hypocalcemia
What are the two layers of the adrenal gland and their anatomical difference?
Adrenal Medulla – neural tissue that acts as part of the SNS (produces catecholamines)
Adrenal cortex – glandular tissue derived from embryonic mesoderm (produces steroid hormones corticosteroids)
What are three layers of the adrenal cortex, the hormone class and specific majority hormone produced?
Zona Glomerulosa-mineralocorticoids (Aldosterone)
Zona fasciculata-glucocorticoids (cortisol)
Zona reticularis – gonadocorticoids (androgens)
What is the function of mineralocorticoids and specifically Aldosterone?
Regulate electrolytes (mineral salts) in extracellular fluid
- maintain sodium balance by reducing excretion of sodium in the body.
- stimulates reabsorption of sodium by the kidneys
Aldosterone is stimulated by?
Dehydration make potassium concentration appear high.
Which means sodium in the blood is low and blood volume and pressure is decreased.
Aldosterone stimulated, then sodium increases, then water increases, then potassium concentration normal.
What are the four mechanisms that regulate aldosterone secretion?
Renin angiotensin mechanism.
Plasma concentration of sodium and potassium.
ACTH.
Atrial natriuretic peptide (ANP)
Explain the renin angiotensin system.
Decrease blood pressure alerts kidney to secrete renin. An enzyme converts to angiotensinogen, ace converts angiotensin I to angiotensin II. Which has three effects:
vasoconstrictor.
Aldosterone production.
ADH production
Explain atrial natriuretic peptide in aldosterone regulation.
Inhibits activity of the Zona Glomerulosa; inhibits renin angiotensin mechanism.
*Second messenger. Put sodium to the urine because pressure and volume too high.
What are the three drug classes that can be used to decrease blood pressure?
Ace inhibitors
beta blockers
calcium channel blocker’s
How do ace inhibitors work?
Blocks the production of angiotensin II. Increase urine output
decreased blood volume
How do beta blockers work?
Blocks beta epinephrine receptors. Decreases heart rate
decreases heart contraction force
How do chemical channel blockers work?
Blocks calcium channels in heart.
Weakens heart
What is the function of glucocorticoids?
Resist stress by keeping blood sugar levels constant. Maintaining blood volume and preventing water shift into tissue.
Cortisol provokes what?
Gluconeogenesis (muscle and fat turn to new sugar)
Glycogenolysis (breakdown of glycogen not new sugar
Raises in blood glucose, fatty acids, and amino acids.
Excessive levels of glucocorticoids can do what?
Depressed cartilage and bone formation (healing slower).
Inhibit inflammation.
Depressed immune system (infection prone).
changes in cardiovascular, neural and gastrointestinal function (fat storage).
What disease can be caused by glucocorticoid excess?
Cushing’s disease.
Symptoms:
Hyperglycemia.
Loss in muscle and bone protein.
Moon face Buffalo hump
Glucocorticoid hyposecretion results in what disease?
Addison’s disease.
Symptoms:
Hypoglycemia
weight loss
sodium levels fall while potassium levels rise
dehydration and hypertension darkening of skin
Most Gonadocorticoid secreted are ___________, and contribute to?
Most important one is ___________.
Androgens: onset of puberty and rapid growth. Appearance of secondary sex characteristics. Sex Drive in females.
Testosterone
Androgen hyper secretion results in?
Adrenogenital syndrome
Symptoms and young people:
boys- early mature of repo organs earlier appearance of sex charac.
Girls-develop male hair, clit resems small penis
Adrenal medulla is made up of _______ cells that secrete _______ and __________.
Chromaffin
Epinephrine and norepinephrine
Secretion of epinephrine and norepinephrine causes:
Blood glucose levels to rise.
Blood vessels to constrict.
Heart beat faster.
Blood diverted to brain, heart, skeletal muscle.
