EXAM 2 Flashcards
What is hyperglycemia?
High blood glucose
Effects of hyperglycemia
Low energy
Polyuria
Polydipsia (excessive thirst)
Polyphagia (excessive eating)
Exocrine (pancreas)
99% of cells in pancreas
Acinar cells that produce enzyme rich juices that are carried to the small intestine
Endocrine (pancreas)
1% of cells
Scattered among the acinar cells; secrete pancreatic hormones
Endocrine Pancreas (Islets of Langerhans) secretion by (4)
Insulin: secreted by beta cells
Glucagon: secreted by the alpha cells
Somatostatin: secreted by delta cells
Pancreatic polypeptide: secreted by F cells
Endocrine Pancreas (Islets of Langerhans) regulates
glucose
lipid
protein metabolism
Stimulation of Pancreatic Hormone Secretion (Glucagon) (3)
- sympathetic nervous system stimulation
- rising amino acid levels (following protein-rich meal)
- falling blood glucose levels
Stimulation of Pancreatic Hormone Secretion (Insulin) (3)
- parasympathetic release of acetylcholine
- rising plasma levels of amino acids and fatty acids
- rising levels of blood glucose
What is hyperglycemia?
high blood glucose
Cellular Use of glucose (3)
- Used for current energy needs
- converted into glycogen (stored)
- converted into fat
Insulin is what kind of hormone?
anabolic hormone
Insulin metabolizes 3 diff things…
- fat metabolism
- protein metabolism
- carbohydrate metabolism
Fat metabolism
promotes triglyceride storage
Protein metabolism
conversion of amino acids into proteins
Carbohydrate metabolism
conversion of glucose into glycogen
Insulin Lowering Blood Glucose (mech) 3 HINT: EII
- enhances membrane transport of glucose into body cells (eg=.g. muscle and fat cells)
- inhibits breakdown of glycogen to glucose
- inhibits the conversion of amino acids or fats to glucose
Activation of the insulin receptor promotes
cellular uptake of glucose
What kind of receptor does insulin use?
tyrosine kinase
Insulin promotes the translocation of
GLUT channels to the cell membrane
Metabolic Effects of Insulin (Energy storage) (3) HINT: LPI
- Liver
- promotes anabolism
- inhibits catabolism
Liver: Anabolism (insulin) (3) HINT: IIP
- inhibits glycogen breakdown
- inhibits gluconeogenesis
- promotes glycolysis (breakdown of glucose)
Liver: Inhibiting catabolism (insulin)
decrease hepatic glycogenolysis, ketogenesis and gluconeogenesis
Metabolic Effects of Insulin (Skeletal Muscle) (3)
- promotes protein synthesis
- increases glucose transport into muscle cells
- promotes glycogen synthesis
Glucagon (3) what kind of hormone, what does it do, and what does 1 molecule do?
- counter-regulatory hormone
- increased blood glucose concentration (hyperglycemic)
- one molecule releases 100 million molecules of glucose into the blood (amplification)
Effects of Glucagon (mech)
- breakdown of liver glycogen (glycogenolysis) via activation of cAMP 2nd messenger using amplification mech (each product is greater than one before)
- Increase gluconeogenesis in the liver
Glucagon major target
liver
Glucagon promotes (3)
- breakdown of glycogen to glucose
- gluconeogenesis
- release of glucose to the blood (from liver cells), causing blood glucose levels to rise
Glycogenolysis what is
breakdown of glycogen to glucose
Glucagon suppressed by
rising blood glucose, insulin, and somatostatin
Glucose homeostasis
normal blood glucose range 80-110mg/100mL (4.4-6.1mM)
Pancreas continuously adjusts
glucagon and insulin secretion to balance blood glucose
Hypoglycemia
low blood glucose levels
below 45-55mg/100mL or 2.5mM
Diabetes Mellitus results from
hyposecretion of insulin or hypoactivity (insulin resistance)
Diabetes Mellitus (what’s happening)
deficiency in insulin secretion (Type 1 diabetes)
Type 2 diabetes
Deficiency in insulin secretion (Type 1 diabetes)
-pancreatic beta cell destruction
- require insulin replacement therapy
Type 2 diabetes
mostly associated with insulin resistance
Counter regulatory hormones known as (blood glucose)
hyperglycemic hormones
What do hyperglycemic hormones do?
counter the effects of insulin which increase blood glucose levels
Counter regulatory hormones (examples) (5)
glucagon
epinephrine
growth hormone
thyroxine
glucocorticoids like cortisol
High Blood glucose occurs and stimulates beta cells to secrete…
insulin
- blood glucose levels fall
Low blood glucose occurs and stimulates alpha cells to secrete…
glucagon
- blood glucose levels rises to normal
The adrenal glands also called
suprarenal glands
The two endocrine glands in the adrenal gland
Adrenal cortex
adrenal medulla
Adrenal cortex is the
outer section of the adrenal gland
Adrenal medulla is the
inner part of the adrenal gland
The adrenal glands synthesizes over one dozen
steroid hormones collectively called corticosteroids
Mineralocorticoids, Glucocorticoids, and Androgens are located where?
Mineralocorticosteroids in the outermost layer
Glucocorticosteroids in the middle
Androgens in the inside
Aldosterone comes from what part of the Adrenal Cortex
Zona glomerulosa
Mineralocorticoid
Mineralocorticoids (Aldosterone) are responsible for
maintaining homeostatic levels of extracellular Na+ and K+ which increases transcription of sodium-potassium ATPase enzyme
Physiological effects of Aldosterone (4) HINT: IIIE
- increased transcription of the sodium-potassium ATPase protein
- increases reabsorption of sodium and secretion of potassium
- increases reabsorption of sodium in sweat and salivary glands
- enhances sodium reabsorption in the intestines, particularly the colon
Regulators of Aldosterone Secretion (4) RPAA
- renin-angiotensin mechansim
- Plasma concentrations of potassium (K+)
- Adrenocorticiotropic hormone (ACTH)
- Atrial natriuretic peptide (ANP)
Renin-Angiotensin Mechanism
regulates blood volume and blood pressure by stimulating aldosterone secretion
Plasma Concentrations of Potassium K+ (aldosterone)
increased blood concentrations of K+ stimulate aldosterone secretion
Adrenocorticotropic hormone (ACTH) (aldosterone)
extreme stress increases hypothalamic secretion of CRH, which increases ACTH, increasing aldosterone secretion
Atrial natriuretic peptide (ANP) (aldosterone)
inhibits the renin-angiotensin mechanism therefore also decreases aldosterone
overall effect: decrease blood pressure by increasing urinary sodium excretion
Hypersecretion of aldosterone
aldosteronism
Aldosteronism (3)
- usually results from adrenal tumors
- hypertension and edema due to excess NA+ and water retention
- accelerated excretion of potassium ions - can lead to muscle weakness and paralysis
Hyposecretion of aldosterone
Addison’s disease, affects all of the adrenal cortex
Signs/symptoms: hypoglycemia, autoimmunity
What will cause the GREATEST INCREASE in hormone secretion by the zona glomerulosa cells? Which hormone will be secreted as a result?
Hyperkalemia (excessive potassium ion); aldosterone
What zone produces glucocorticoids and the major one?
zona fasciculata
cortisol
Zona fasciculata reposible for
- resisting stress
- secretion is regulated by negative feedback within the hypothalamic-pituitary-adrenal axis
Glucocorticoids are essential for
influencing energy metabolism of most body cells
Physiological effects of Cortisol (3) (IIA)
- ultimately increases blood glucose concentrations
- increases amino acids and fatty acids
- all these for energy during time of stress
Costisol has some ____ activity during conditions of cortisol excess
mineralocorticoid
Glucocorticoids (cortisol) attributes (2) HINT: SM
- stimulate production of glycogen
- maintain blood glucose concentration
Glucocorticoids (cortisol) targets these body parts (3) HINT: MFL
muscle
fat
liver cells
What are normal circulating levels?
Cortisol secretion is increased in response to…
approx 6-20 ug/ml
STRESS
Effects of cortisol in the body (muscle) (3)
-inhibits protein synthesis
-stimulates proteolysis
-produces free amino acids
Effects of cortisol in the body (adipose) (2)
- inhibits lipogenesis
- stimulates lipolysis (triglycerides converted to FFAs)
Effects of cortisol in the body (Liver) (2)
- AAs and FFAs converted to glucose
- stored as glycogen
What is the role of cortisol in preparing the body to deal with stress? HINT: GPFS (4)
- gluconeogenesis
- protein mobilization
- fat mobilization
- stabilizes lysosomes
Cortisol has ____effects
anti-inflammatory effects
Glucocorticoid excess leads to (disease)
cushing’s syndrome
Cushing’s syndrome can be due to these two things
- due to clinical administration of pharmacological doses of cortisol (anti-inflammatory)
- ACTH-releasing tumors (pituitary, lung, pancreas, kidney)
Signs and symptoms of cushing’s syndrome
- elevated blood glucose levels
- loss in muscle and bone
- water and salt retention
- moon face
- fat redistribution to the abdomen and posterior neck
Diabetic tendency with muscle protein metabolism and deposition of fat in the upper body and midsection is a sign of
Cushing’s syndrome
Weak androgens are produced by what zone?
zona reticularis
Zona reticularis produces 2 main androgens
DHEA
androstenedione
Zona reticularis is also known as what kind of secreting area
sex hormone secreting area
Zona reticularis secretion is regulated partially by
ACTH and cortical androgen-stimulating hormone
Overproduction of adrenal androgens can result in
masculinization in women (facial hair)
Adrenal Medulla made of _____ derived from the _____
chromaffin cells; neural crest
Chromaffin cells are
modified neurons, cell bodies without axons or dendrites
____is secreted in response to chronic stress while ____ is/are normally released in response to acute stress
cortisol
epinephrine
What is not a physiological (normal level) action of cortisol?
increased sodium reabsorption
Norepinephrine’s direct effect
increased renal reabsorption of water
Excessive concentrations of this hormone cause muscle wasting, centripetal adiposity, and diabetic tendency. What is the hormone? What type of hormone is it?
cortisol
glucocorticoid
Hyperglycemic hormones are known as ____ because they are ____ to insulin
counter-regulatory
antagonsitic
Effect of blood glucose level: insulin
decrease
Effect of blood glucose level: glucagon
increase
Effect of blood glucose level: growth hormone
increase
Effect of blood glucose level: Thyroxine
increase
Effect of blood glucose level: epinephrine
increase
Effect of blood glucose level: norepinephrine
increase
Effect of blood glucose level: aldosterone
no change
Effect of blood glucose level: angiotensin
no change
Polyuria
excessive urination
Polydipsia
excessive thirst/drinking
Glucosuria
sugar in urine
polyphagia
excessive eatinf
hyponatremia
low sodium in the blood
Signs/Symptoms: hypertension, hyperglycemia
Type I diabetes mellitus
Signs/Symptoms: weight loss, tachycardia
Hyperthyroidism
Signs/Symptoms: hyperglycemia, insulin resistance
Type II diabetes mellitus
Signs/Symptoms: hypoglycemia, autoimmunity
Addison’s disease
Signs/Symptoms: hyperglycemia, autoimmunity
Type 1 diabetes mellitus
Signs/Symptoms: weight gain, cold intolerance
hypothyroidism
Signs/Symptoms: hirsutism, weight gain
cushing’s syndrome
Signs/Symptoms: cretinism, depression, constipation
hypothyroidism
Body’s physiological response: hyperglycemia
increase in insulin sympathetic acitivity
Body’s physiological response: hypotension
increase in sympathetic activity
Body’s physiological response: hypertension
increase in parasympathetic activity
Body’s physiological response: increase in stress
increase in sympathetic activity
The adrenal medulla is functionally an
extension of the sympathetic nervous system
The Adrenal Medulla secretes
epinephrine and norepinephrine
Epinephrine aka
adrenaline
norepinephrine aka
noradrenaline
Approx 80% of the adrenal medulla is
epinephrine
The adrenal medulla stimulates…
lipolysis and increases blood fatty acid concentration; this allows their availability for energy
The adrenal medulla stimulates____ in the liver
glycogenolysis
Axons of the preganglionic splanchnic nerve terminate on the chromaffin cells, releasing…
acetylcholine
The adrenal medulla is stimulated by what kind of neurons
sympathetic
Adrenal Medulla: Acetylcholine (ACH) binds to…
cholinergic receptors and this leads to the secretion of NE (norepinephrine) and E
Secretion of E and NE is stimulated by
release of ACH (acetycholine) (ach binds to cholinergic receptors) from the preganglionic sympathetic neuron
Chromaffin Cells (NE and E, stress reponse) (2)
- store them in secretory vesicles
- secrete them into the bloodstream
Release of Catecholamines (3)
- release of ACH (ach binds to cholinergic receptors) from the preganglionic sympathetic neuron
- allows opening of calcium channels and depolarization of chromaffin cells
- stimulates release of NE and E into blood to travel to target cells
Catecholamines bind to
adrenergic receptors
Adrenergic receptors are
singly polypeptide proteins with seven hydrophobic membrane-spanning regions GPCRS
Adrenergic receptors: B1 receptors found in
the heart
Adrenergic receptors: B2 receptors found in
the blood vessels supplying the skeletal and cardiac muscle
Adrenergic receptors: a1 receptors are found
in blood vessels innervating the visceral organs
As an extension of the sympathetic nervous system, adrenomedullary hormones…(2)
- divert resources to muscles, brain, and heart to allow animals to respond to acute stress
- decrease blood supply to the nonessential (visceral) organs
What is a counter-regulatory hormone?
a hormone that opposes the action another
Hormone (s) secreted by zona reticularis
DHEA
Androstenedione
What is the stimulus for secretion of NE and E?
fight/flight response, when body is under extreme stress
Discuss the role of the kidneys in regulation of blood pressure (3) LSD
- long term regulation
- slower mechanism
- kidneys secrete ‘renin’, an enzyme that triggers a series of events to increase blood pressure
List different enzymes and hormones that are activated/secreted by the kidneys (3)
renin: responsible for increase in blood pressure (angiotensinogen)
kallikreins (serine proteases): vasodilation (bradykinin)
Prostaglandins: facilitate secretion of renin, vasoconstriction
What is mean atrial pressure (MAP)?
pressure that propels towards the tissues
What factors regulate MAP?
- regulated by cardiac output and peripheral resistance
Effects of Epinephrine and NE (Flight/Flight response) (6)
- increase in heart
- increase in the force of contraction
- results in increased blood pressure
- increase blood glucose and fatty acids
- dilate airways to the lungs
- increase blood flow to heart, liver, skeletal muscles, adipose tissues
Short-term stress hormones and which adrenal part?
- catecholamines (epinephrine and norepinephrine)
- adrenal medulla
Long-term stress hormones and which adrenal part?
- mineralocorticoids and glucocorticoids
- adrenal cortex
Short-term stress response (4)
- increase heart rate
- increased blood pressure
- dilation of bronchioles
- increased metabolic rate
Long-term stress response (Gluc/Min)
Gluco: proteins/fats converted to glucose or broken down for energy, increased blood glucose, suppression of immune system
Mineral: retention of sodium and water by kidneys, increased blood volume and blood pressure
Erythropoietin (2)
- stimulates erythropoiesis (red blood cell formation)
- secreted by interstitial cells within the kidneys
The proportions of cells secreting erythropoietin increase in response to
hypoxia
hypoxia
oxygen not available in sufficient amounts at the tissue level to maintain adequate homeostasis
Erythropoietin and RBC formation (mech)
- Anemia (Low rbc)
- low oxygen carrying capacity of blood, decreased tissue oxygenation
- kidney increases secretion of EPO, increased EPO stimulates production of red blood cells
What is blood pressure?
the pressure that the blood exerts against the inner walls of the blood vessels
- its force keeps blood circulating continuously between heart beats
Blood pressure is regulated by the actions of the
nervous system in the short-term
Hormones exert what effects on blood pressure
short and long term
The ____ are important regulators of blood pressure (long-term)
kidneys
Short-term regulation (adjusting vascular resistance, control of BP) (3) CNH
- counteract the moment-to-moment changes in blood pressure by altering peripheral resistance
- neural control (baroreceptor reflex)
- hormonal control: RAAS
Short-Term Hormonal control of MAP (4) IIVI
epinephrine and norepinephrine (adrenal medulla)
- increase heart rate
- increase force of contraction of cardiac muscle (B1 adrenergic receptors)
- vasoconstriction of the arterioles (a1 adrenergic receptors)
- increase MAP
RAAS (Renin-angiotensin-aldosterone system) (3)
- promotes secretion of aldosterone
- Angiotensin II
- short term control of MAP
How does RAAS affect blood pressure? (3) HINT: VSS
Angiotensin II (Short-term control of MAP)
1. Vasoconstriction (like EP and NP)
2. stimulation of thirst centers (increase blood volume)
3. stimulates secretion of Anti-diuretic hormone (vasopressin)
Vasopressin - vasoconstriction
Hormonal control of BP in the Short-Term (3) hint: EAV
achieved through changing peripheral resistance
1. Epinephrine/NE: also affects cardiac output)
2. Angiotensin II: vasoconstrictor
3. vasopressin: vasoconstrictor
How does aldosterone affect blood pressure?
increase blood pressure by acting on the kidneys to stimulate the reabsorption of salt and water, sodium as well
How does angiotensin II affect blood pressure?
increases blood pressure by acting directly on blood vessels stimulating vasoconstriction
- acts on adrenal gland to stimulate release of aldosterone
How does ADH/vasopressin affect blood pressure?
increases blood pressure by causing vasoconstriction in blood vessels and increased blood volume from kidneys (fluid retention)
How do catecholamines affect blood pressure? (3) HINT: PUMPS
increases heart rate, BP, increased stroke volume (how much blood is ejected during pumps)
How does atrial natriuretic peptide (ANP) affect blood pressure? (3)
lowers blood pressure by being an inhibitor of aldosterone secretion, reduction in blood volume, general vasodilation
Which of the following actions can be attributed to the effects of aldosterone?
increased transcription of the sodium-potassium ATPase protein
Condition with symptom: Adrenal insufficiency
hypertension
Adrenal androgens are relative ___compared to testosterone. However, when excessive adrenal androgens are secreted, they have the following effect in women:
weak; hirsutism
Preganglionic sympathetic neurons stimulate secretion of the catecholamines by the ____ cells in the _____
chromaffin cells; adrenal medulla
Which of the following effects are likely due to the actions of the catecholamines?
vasoconstriction of the splanchnic arterioles
Hormones of the adrenal medulla act rapidly during the flight or fight response to increase blood glucose for use by the:
kidneys
Renin (function)
activation of angiotensin
Prostaglandin (function)
vasoconstriction
Angiotensin II (function)
thirst
Thyroxin (function)
increase in basic metabolic rate
A short-term increase in blood pressure is accomplished by ____ while long-term elevation in blood pressure is due to ____ .
- vasoconstriction
- increase in blood volume
What will cause a transient (short-term) decrease in blood pressure?
increase in parasympathetic innervation
How do catecholamines cause an increase in blood pressure?
by increasing heart rate and cardiac muscle contractility
Which of the following accurately describes the role of angiotensin II in the regulation of mean arterial pressure?
Angiotensin II causes vasoconstriction which leads to an increase in mean arterial pressure
What accurately describes the role of vasopressin in regulating blood pressure?
It causes vasoconstriction and water reabsorption
Which enzymes are involved in the activation of angiotensin?
renin and ACE
Hormone with its DIRECT effect: Vitamin D
stimulates intestinal absorption of calcium
Which of the following hormones play BOTH short-term and long-term roles in the regulation of blood pressure?
vasopressin, angiotensin II, and atrial natriuretic peptide
Which of the following signs/symptoms are consistent with hypoaldosteronism?
diarrhea
The nervous system can regulate blood pressure by using a minute-by-minute (short-term) mechanism. This mechanism is called the ____. If someone experiences blood loss/hemorrhage, which branch of the nervous system will become activated to regulate blood pressure?
baroreceptor reflex; sympathetic
Term with appropriate description: Adrenal cortex secretes only…
steroid hormones
Term with appropriate description: Adrenergic receptors activate by
binding of catecholamines
Term with appropriate description: mineralocorticoids increase
blood volume
ACE converts
angiotensin I to angiotensin II causing an increase in blood pressure
Term with appropriate description: epinephrine
hormone that increases blood pressure quickly
Term with appropriate description: acetylcholine
activates cholinergic receptors in the adrenal medulla
Term with appropriate description: Goiter caused by
excessive TSH
Term with appropriate description: Primary hypothyroidism
low thyroxine, high TSH
Under physiological (normal) conditions, which of the following hormones affect blood volume directly and/or indirectly?
Angiotensin II, aldosterone, ADH
The following conditions cause primary hypothyroidism… (4)
- inactivity of the follicular cells in the thyroid gland
- iodine deficiency
- an autoimmune condition that damages the thyroid gland
- elevated TSH
The following signs/symptoms are consistent with hypothyroidism…(5) WCDCS
weight gain, constipation, depression, cretinism, short stature
Which of the following scenarios will cause a transient (short-term) decrease in blood pressure?
increase in parasympathetic innervation
Calcium and phosphate are
the most abundant inorganic elements in humans
Calcium regulating hormones (3)
- vitamin D
- parathyroid hormone
- calcitonin
Vitamin D
primary stimulation of intestinal absorption of CA2+ and phosphate
Parathyroid hormone (2) SI
supports the synthesis of vitamin D, increases blood CA2+
Calcitonin (3) ODA
- opposes effects of PTH
- decreases blood CA2+
- a polypeptide stimulated by high blood Ca2+
What roles does calcium play in the normal body function? (4) MBNM
- muscle contraction
- bone structure
- normal cell function
- membrane stability
Effects of PTH on bone, kidneys, and intestine (3) SII
- stimulates osteoclasts (bone-resorbing cells) in the bones
- increases Ca2+ reabsorption in the kidneys
- indirectly increases Ca2+ absorption in the GIT (activates vitamin D)
Role of vitamin D in calcium homeostasis (3) SPI
- stimulates the absorption of dietary calcium (and phosphate)
- promotes mineralization of bone matrix, bone resorption
- increases intestinal absorption of calcium
What is the most important hormone that regulates calcium levels in the blood?
PTH, parathyroid hormone
Which form of calcium is the biologically active form?
free ionized calcium (Ca2+)
What other mineral is regulated in conjunction with calcium?
phosphate
Where is calcium stored in the body? (3)
- intestine
- bone
- kidney
Parathyroid hormone secreted by
chief cells in the parathyroid gland
Affecting blood volume is short-term or long-term?
long term
Affecting blood dilation (vasoconstriction)
short term
Calcitonin and calcium homeostasis (2) HINT: IS
- inhibits osteoclasts activity
- stimulates calcium ion uptake into the bone matrix (bone-sparing effect)
What is the active form of vitamin D?
calcitrol
Which hormones play a direct role in calcium homeostasis? (3)
- parathyroid hormone
- calcitriol
- calcitonin
Hypocalcemia (signs/symptoms) (3)
- irritability, depression
- fatigue
- seizures
Hypercalcemia (causes) (2)
- parathyroid gland tumor
- excessive vitamin D
Hypercalcemia (signs/symptoms) (3)
- excessive thirst and urination
- weak (and painful) muscles and bones
- palpitations, fainting, cardiac arrhythmia
Hypoparathyroidism (what is, signs/symptoms)
- PTH deficiency
- hypocalcemia, convulsions, neurons become more excitable ‘tingling’ sensation
Hyperparathyroidism (what is, signs/symptoms)
- excessive PTH
- hypercalcemia, weak skeletal muscle, calcium deposits throughout the body
BP Medication: ACE inhibitor (3)
- blocks formation of angiotensin II
- lowers BP
- reduces vascular resistance
BP Medication: Vasodilator (3)
- blocks calcium channels
- lowers contraction
- lowers peripheral resistance
BP Medication: Diuretic (3)
- lowers sodium, water reabsorption
- lowers blood volumes
- increases urination
BP Medication: Adrenergic Receptor blockers (4)
- Opposes the effect of catecholamines
- lowers heart rate
- relax blood vessels
- lowers blood pressure
Increasing blood pressure involves (4)
- vasoconstriction
- stimulates thirst center, more drinking
- stimulates aldosterone secretion, increases sodium and water retention
- stimulates ADH
