Endocrine Pharmacology - Test 4 Fall 2011

Front 1

What 2 major regulating systems are involved in maintaining homeostasis?

Back 1

nervous system
endocrine system

Front 2

How do the nervous and endocrine systems maintain homeostasis?

Back 2

these systems regulate the body's response to a changing internal and external environment
ie: ability to regulate body temp

Front 3

What is the purpose of the endocrine system?

Back 3

regulation of behavior, growth, metabolism, fluid status, development, and reproduction

Front 4

How do endocrine glands work?

Back 4

secrete their hormone products directly into surrounding extracellular fluid - to venous system

Front 5

What are the 7 major endocrine glands?

Back 5

pituitary gland
thyroid gland
parathyroid glands
adrenal glands
pancreas
ovaries and testes
placenta

Front 6

What are the 3 types of hormones that mediate endocrine function?

Back 6

proteins or peptides
amines or amino acid derivatives
steroids

Front 7

describe endocrine function

Back 7

transmission of MINUTE quantities of a hormonal signal through the bloodstream to a distant target cell

Front 8

define paracrine function

Back 8

hormone signal acting on a neighboring cell of a different type

Front 9

define autocrine function

Back 9

secreted hormone acts on the producer cell itself or on neighboring identical cells

causing a reaction of this cell to release a hormone

Front 10

Give examples of peptide or protein hormones

Back 10

insulin
growth hormone
vasopressin
angiotensin
prolactin
erythropoietin
calcitonin
somatostatin
ACTH
oxytocin
glucagon
parathyroid hormone

Front 11

Where are Peptide / protein hormones made, processed, and stored

Back 11

synthesized in endocrine cells

processed by the cell and stored in secretory granules within the endocrine gland

released as needed (most are increased during SNS stimulation for fight / flight)

Front 12

Give examples of amines or amino acid derivatives

Back 12

serotonin made from amino acid tryptophan

thyroid hormone and catecholamine hormones are derived from amino acid tyrosine

Front 13

Steroids are derived from

Back 13

Cholesterol - all steroids are derived from cholesterol

Front 14

Give examples of steroid hormones

Back 14

cortisol
aldosterone
estrogen
progesterone
testosterone

Front 15

How is the adrenal cortex involved with cortisol and aldosterone?

Back 15

these steroid hormones are stored in the adrenal cortex and with stimulation are released directly into venous circulation

why they will block venous circulation first when taking out a tumor that produces steroids

Front 16

Describe steroid hormone secretion and degredation

Back 16

NOT stored in secretory cells but are in the endocrine cell and released into the extracellular fluid by simple diffusion

metabolized and eliminated mediated by the liver and kidneys (rarely in the cell)

Front 17

Describe target cells and endocrine function

Back 17

binding specific target cell receptors is the primary event that initiates a hormone response

some hormones act on widespread target sites and others act on one target tissue

Front 18

describe hormone receptor activation

Back 18

hormone receptors are located either on the surface of inside of the cell - an if inside then the hormone must be very lipid soluble (i.e.: steroid hormones)

every hormone has a specific onset and duration of action - i.e.: epi and norepi are very short acting hormones and once you block a tumor you will see a decrease within 5 minutes

hormonal effects may be generated in seconds to minutes or several hours to days - i.e.: epi and norepi act within seconds resulting in increase in HR and BP, thyroid hormones may take a coupe of days to get the full effect of what is released, and growth hormone will take hours to days to have an effect

Front 19

How are hormone receptors regulated?

Back 19

receptors are constantly being destroyed and replaced (up and down regulation)

receptor destruction may be part of a normal endocrine response or part of an acquired or genetic disease state

receptor number is usually inversely related to the concentration of the circulating hormone

number of receptors in a target cell usually changes from day to day

Front 20

How is hormone secretion regulated?

(3 general control mechanisms)

Back 20

neural controls

biorhythms - most productive part of the day is 6am - 10 am then see decreases (have lunch and blood is diverted to gut and decrease productivity) and 330-700 pm then decreases hormones to increase GABA (sleepy) hormones

Feedback mechanisms: positive and negative

Front 21

Pituitary Gland

Back 21

master gland also known as the hypophysis

Front 22

what is the function of the pituitary gland?

Back 22

secrete hormones that have far reaching effects on various homeostatic, developmental, metabolic, and reproductive functions of the body - releasing hormones that target other endocrine glands to release hormones

Front 23

Where is the pituitary gland located?

Back 23

base of the brain enclosed within the sella turcica, connected to the overlying hypothalamus by the hypophyseal stalk (hypothalamus is located below the thalamus), behind the optic chasm and between the optic tracts

so - if you have a tumor of the pituitary the patient will start to experience double vision due to pressure on the optic chasm

Front 24

How does the brain regulate pituitary function?

Back 24

via the hypothalamus which collects and integrates information from all parts of the body and uses this information to control the secretion of vital pituitary hormones

Front 25

how are pituitary hormone secretions regulated?

Back 25

feedback mechanisms - both positive and negative

Front 26

name the 2 distinct divisions of the pituitary gland

Back 26

anterior lobe = adenohypophysis

posterior lobe = neurohypophysis

Front 27

name the blood supply to the pituitary gland

Back 27

anterior = superior hypophyseal artery

posterior = inferior hypophyseal artery

Front 28

The anterior pituitary (adenohypophysis) secretes which 6 PRIMARY hormones?

Back 28

Growth Hormone (GH)

Adrenocorticotrophic hormone (ACTH)

Thyroid stimulating hormone (TSH)

Follicle stimulating hormone (FSH)

Luteinizing hormone (LH)

Prolactin

**several other less important or less well defined hormones are secreted but not significant for homeostasis

Front 29

How is synthesis of adenohypophysis hormones regulated?

Back 29

signals from the hypothalamus

hypothalamic neurohomes are released into a capillary bed of the hypothalamus and eventually locate and bind specific target cell type having an inhibitory or stimulatory effect on corresponding anterior pituitary target cells

synthesis and release of most anterior pituitary hormones depend on positive stimulatory signal from a given hypothalamic hormone

Front 30

What are some causes of hyposecretion of anterior pituitary disorders

Back 30

large pituitary rumors

postpartum shock (Sheehan's Syndrome)

irradiation of head

trauma

hypophysectomy (removal of pituitary gland)

however - PANHYPOPITUITARISM is more common and see with aging because of a decrease in the release of all of these hormones

Front 31

what are important effects of panhypopituitarism

Back 31

decrease in thyroid function due to decrease in TSH

depression of flucocorticoid production by adrenal cortex causing a decrease in blood pressure - so patients on steroids need dose of solu-cortef because unable to counteract the stress response - if pt not responding to pressers you could add a dose of solu-cortef or decahedron to replace the glucocorticoids to increase the blood pressure

suppression of sexual development and reproductive function

macro adenomas may cause the panhypopituitarism

Front 32

what are surgical implications for hypo secretion pituitary disorders?

Back 32

control bleeding - large tumors can disrupt blood vessels causing bleeding

decompression or removal of pituitary tumor - most neuro tumors are sucked out with suction - not cut out as one large mass because there is good brain tissue you don't want to disrupt

may require thyroid hormone replacement and corticosteroid coverage in the preoperative period

Front 33

what is the most popular surgical approach for pituitary removal and why

Back 33

trans-sphenoidal approach - across the sphenoid sinuses, access through the nose or mouth allowing the surgeon to get to the tumor and prevent going through any brain tissue

Anesthesia Concerns:
preventing coughing on ETT because it will increase ICP and arterial pressure causing bleeding in the brain

you will need smooth extubation and rapid neurological assessment is desirable making sure no swelling in the areas that will cause problems (pressure on optic chasm and decreased blood flow can lead to blindness)

oral ray tube is a good idea because you will be at the foot of the bed and this will decrease the likelihood of kinking off the tube

Front 34

What are the 3 most common hormones produced from hyper secreting pituitary tumors?

Back 34

prolactin
ACTH
Growth hormone

usually caused by hyper functioning pituitary adenoma

first line treatment is medical therapy

if suboptimal response to medical therapy then benefit from microsurgical removal of the tumor

Front 35

How is growth hormone synthesized?

Back 35

synthesized and secreted by somatotroph cells of the anterior pituitary lobe (adenohypophysis) under dual control of the hypothalamus

Front 36

Describe the timing of growth hormone

Back 36

generally increased in childhood, followed by further increase in adolescence, plateau in adulthood, and declining levels in older age

Front 37

how is growth hormone affected?

Back 37

stimulated by stress, hypoglycemia, exercise, and deep sleep -

important for teens to get adequate exercise and sleep for adequate hormone secretion

inhibited by hyperglycemia and increased plasma free fatty acid levels - juvenile diabetes will be smaller than peers because of decreased growth hormone production during formative years

Front 38

where does growth hormone work?

Back 38

functions through almost all tissues of the body

promotes growth and development of most tissues that are capable of growing

most obvious to skeletal frame

Front 39

how is growth hormone regulated?

Back 39

negative feedback mechanism

Front 40

What results from hypo secretion of growth hormone?

Back 40

dwarfism- insufficient bone maturation and short stature (especially of long bones)

most dwarfs have normal thoracic cavity but long bones are stunted during growth

Front 41

what results from hyper secretion of growth hormone?

Back 41

acromegaly - produced by sustained hyper secretion of growth hormone FOLLOWING ADOLESCENCE - after the time you would normally see plateau of growth hormone

Gigantism - hyper secretion of growth hormone PRIOR TO PUBERTY

excessive production of GH enhances growth of periosteal bone

bones are produced that are massive in size and thickness and soft tissue changes are prominent

Front 42

Describe physical signs of Acromegaly

Back 42

overgrowth of internal organs

increased lung volumes

limited exercise tolerance - because it compresses the heart and it has to pump against additional vascular beds and tissue causing patient to develop cardiomyopathy and cardiomegaly

cardiomyopathy, hypertension, and accelerated atherosclerosis can lead to symptomatic cardiac disease early in life

ECG changes - LONG PR interval, LONG QRS interval, tissues don't depolarize nearly as quickly

treatment aimed at restoring normal growth hormone levels

Front 43

Describe anesthetic implications for acromegaly and gigantism

Back 43

preanesthetic assessment should include careful exam of airway - really key because all structures are large - plan to use a larger blade, tissues will be more dense and harder to move out of the way

endotracheal intubation may present a challenge - increased tissue in neck and difficult to get a good sniffing position - may be difficult to line up the axis

consider fiberoptic guided intubation (awake)

preanesthetic cardiac evaluation - really want to illicit any symptoms of cardiac disease - developed much quicker than general population

perioperative monitoring of blood glucose levels - tend to be hyperglycemic

consider glucocorticoid therapy and thyroid replacement - so will need additional medications (100 of solu-cortef or 10 mg of decadron)

Allen's test prior to radial artery catheter insertion - occlude the ulnar and radial artery simultaneously and open and close hand, then release ulnar and look for good circulation - if you don't have good circulation you will not place the art line (good cir

Front 44

What type of hormone is Adrenocorticotrophic hormone (ACTH) and what does it do?

Back 44

peptide based hormone, that regulates growth of the adrenal cortex and regulates release of cortisol (steroid) and adrogenic hormones

Front 45

what makes ACTH?

Back 45

corticotrophs

Front 46

What is the target site for ACTH?

Back 46

adrenal gland -

ACTH is synthesized and released from anterior pituitary in response to corticotrophin releasing hormone (CRH) that is released from the hypothalamus

stress leads to the hypothalamus releasing ACTH which travels in the blood to the adrenals and causes release of epinephrine and norepinephrine (all stimulated by the hypothalamus, the master gland)

Front 47

What type of hormone is Thyroid Stimulating Hormone (TSH) and what does it do?

Back 47

peptide hormone that controls growth and metabolism of the thyroid gland, controls secretion of thyroid hormones (T3 and T4)

Front 48

How is TSH made and where does it work?

Back 48

synthesized by throtrophs

target site = thyroid gland

second messenger is cAMP

Front 49

What is FSH and what does it do?

Back 49

Follicle stimulating hormone (FSH)

stimulates ovarian follicle development in females to stimulate egg production

stimulates spermatogenesis in males to stimulate sperm production

Front 50

How is FSH made and where does it work?

Back 50

synthesized by gonadotrophs

target site = gonads (sex glands)

Front 51

What is LH and what does it do?

Back 51

Luteinzing hormone (LH)

induces ovulation and the corpus luteum development in females

induces testes to produce testosterone in males

Front 52

How is LH made and where does it work?

Back 52

synthesized by gonadotrophs

target site is gonads

cAMP dependent

Front 53

What does Prolactin do?

Back 53

promotes mammary gland development and milk production in females

little to no use in males but abnormal mammary production have abnormal prolactin production and often will see in plastic surgery for breast tissue removal

target site is obviously breast tissue

prolactin receptors are UNIQUE = RESTRAINED

Front 54

What are the 2 hormones secreted by the posterior pituitary (neurohypophysis) and what type of hormone are they?

Back 54

Antidiuretic Hormone
Oxytocin

peptide hormones

Front 55

What does ADH control?

Back 55

water excretion and reabsorption in the kidney and is major regulator of serum osmolarity

Front 56

Describe oxytocin function

Back 56

stimulates contraction of myoepithelial cells of breast milk for ejection during lactation and stimulates uterine smooth muscle contraction during labor and postpartum

give oxytocin injection at the end of anesthetic to stimulate muscle to tighten down at the end of delivery where uterus is still boggy and you want muscles to tighten to decrease bleeding

Front 57

How do hormones from the neurohypophysis work?

Back 57

communicate with the hypothalamus through the neural pathway

hormones are synthesized OUTSIDE of the pituitary gland but stored here

nerve fibers arise from these hypothalamic nuclei transport ADH and oxytocin down the pituitary stalk to the posterior lobe where they are stored - don't produce anything just store and release

Front 58

Where is ADH synthesized?

Back 58

supraoptic nucleus

Front 59

where is oxytocin synthesized?

Back 59

paraventricular nucleus

Front 60

Where does ADH act and how does it work?

Back 60

principle preserver of water balance acting on collecting tubules to increase absorption of solute free water from kidney tubules

without ADH the collecting ducts are impermeable to water reabsorption

DI = constant urine output getting hypovolemic very quickly and don't reabsorb water because they secret it

Front 61

Describe how ADH effects osmolarity (serum and urine) and blood volume

Back 61

urine osmolarity = increased
serum osmolarity = decreased
blood volume = increased

Front 62

What results from high levels of ADH?

Back 62

potent systemic vasoconstriction, especially in coronary splanchnic, and renal vascular beds

Front 63

how is ADH secretion triggered?

Back 63

secreted in response to an increase in plasma osmolarity or plasma sodium ion concentration, a decrease in blood volume or a decrease in blood pressure

water deprivation initiates signals in the hypothalamic osmoreceptors that cause ADH release from the pituitary gland

plasma osmotic threshold for ADH release is approx 285 mOsm / L

ADH release causes reabsorption of most fluid from the distal convoluted tubules

ADH promotes hemostasis

Front 64

What is a 2nd line of defense for water balance?

Back 64

thirst - part of the mechanism is to signal the individual that they have low fluid volume status

Front 65

What disease process results from deficiency of ADH?

Back 65

Diabetes insipidus (DI)

inadequate ADH secretion from neurohypophysis or the inability of the renal collecting duct receptors to respond to ADH

Front 66

What are common causes of neurogenic DI?

Back 66

severe head trauma

neurosurgical procedures
infiltrating pituitary lesions - tumors of pituitary that stimulate release of neurohormones

brain tumors that push on the pituitary

Front 67

What drugs can cause DI?

Back 67

ethanol
phenytoin
chlorpromazine
lithium

all inhibit the action of ADH or its release

Front 68

What are hallmark signs of DI?

Back 68

serum osmolarity > 290 mOsmo/L

serum sodium concentration > 145 mEq/L

thirst mechanism is significantly important

Front 69

what are the treatment protocols for DI?

Back 69

various ADH preparations such as vasopressin

different that what is given for cardiac

Front 70

What results from hyper secretion of ADH?

Back 70

Syndrome of Inappropriate Antidiuretic Hormone (SIADH)

disorder characterized by high circulating vasopressin level relative to plasma osmolarity and serum sodium concentration

kidneys continue to reabsorb water despite the presence of hyponatremia (<130 mEq/L) and plasma hypotonicity (<270 mOsm/L)

Front 71

What is caused by hormone induced water reabsorption?

Back 71

expansion of intracellular and extracellular fluid volumes

hemodilution

weight gain

shift of fluid from intravascular to interstitial then to intercellular causing edema - if uncorrected you have the shift to the cell and apoptosis results

urine output is low and urine is hypertonic relative to the plasma

Front 72

What are clinical manifestations of SIADH?

Back 72

water intoxication
dilutional hyponatremia
brain edema - fluid does eventually cross BBB causing confusion -can cause delayed awakening

best place to look for edema is the sclera b/c loose connective tissue and will see swelling here

HYPERTENSION
PITTING EDEMA (3+)

Front 73

What are the treatment modalities for SIADH?

Back 73

mild SIADH not associated with hyponatremia - may not be decrease in sodium but it is decreased relative to water - dilution

patients with profound hyponatremia and acute neurological symptoms are critical and must stimulate excretion quickly

demeclocycline administered to antagonize the effects of vasopressin on the renal tubules

definitive treatment directed at underlying disorder

Front 74

What are anesthetic implications and considerations for SIADH?

Back 74

preoperative evaluation - pt hypertensive and will react differently to anesthetics, have larger volume of distribution so the normal amount of proposal may not put the patient to sleep because more volume for it to diffuse to

perioperative fluid management - reduce the amount of fluid you administer to the patient and make the patient more hypertonic to pull fluid back into the vascular system

CVP and PA cath measurements are usually very important