Chapter 13 PPT : Endocrine Flashcards
What are endocrine glands?
They are ductless and secrete hormones into the bloodstream. Act only on target cells
What are exocrine glands?
Glands that secrete into ducts or tubes that lead to a body surface
Exocrine glands deliver their products directly to a
specific site
What glands secrete messenger molecules?
Paracrine Secretions (Affect Nearby Cells) and Autocrine secretions (affect cells that secrete the substances)
Endocrine glands secrete hormones into
body fluids
Exocrine glands secrete substances into
outside environment
What two systems function in communication?
Nervous and Endocrine
Nervous system releases
neurotransmitters into synapsees
Endocrine system secretes
hormones into bloodstream
Nervous and Endocrine communicate via
chemicals that bind to receptor molecules
Cells of the Nervous System?
Neurons
Cells of the Endocrine System?
Glandular Epithelium
Chemical Signal of Nervous System?
Neurotransmitter
Chemical Signal of Endocrine System?
Hormone
Specificity of Action of Nervous system?
Receptors on Postsynaptic Cell
Specificity of Action on Endocrine System?
Receptors on target cells
Speed of onset for nervous system?
1 second
Speed of onset for endocrine system?
seconds to houors
Duration of action for nervous system?
Very brief, unless neuronal activity continuees
Duraction of action for endocrine system
May be brief or may last for days even if secretion ceases
Endocrine system is ___ in that only ______
precise,
target cels respond to a specific hormone
Target cells contain particular
receptors for the hormone. These receptors are not present on other cells
Many hormones are produced by what larger endocrine glands?
Hypothalamus Pituitary Gland Thyroid Gland Adrenal Gland Pancreas
Small Group of cells that produce hormones?
Ovary, Testis, Kidney, Pineal Gland
What are the two types of hormones?
Steroid or Steroid-Like Hormones
Non-Steroid Hormones
What are steroids?
Lipids containing complex rings of carbon and hydrogen atoms
All steroid hormones are produced from
cholesterol
Examples of Steroids?
Sex Hormones (Testosterone, Estrogens), and Adrenal Cortex Hormones (Cortisol, Aldosterone)
Four types of Non-Steroid Hormones?
Amines
Proteins
Peptides
Glycoproteins
What are Amines?
Derived from Tyrosine (Epinephrine, Norepinephrine)
What are Proteins?
Composed of long chains of amino acids (growth hormones)
What are Peptides?
Short chains of amino acids (oxytocin)
What are glycoproteins
Carbohydrates joined to proteins (TSH)
Examples of Peptides?
ADH, OT, TRH, SS, GnRH
Examples of Proteins?
PTH, GH, PR
Examples of Glycoproteins?
FSH, LH, TSH
Examples of Steroids?
Estrogens, Testosterone, Aldosterone, Cortisol
Hormones exert effects by
altering metabolic processes
Hormones may alter
enzyme activity and alter rate of membrane transport of a substance
Hormones deliver messages by
binding to their receptors on/in target cell
Hormones can affect changes in
target cells, even in extremely low concentration
Hormones: Number of receptors determines
strength of response, and can be changed to alter the response
What is Upregulation?
Increase in number of receptors on target cell in response to a decrease in hormone level
What is downregulation?
Decrease in number of receptors on target cell, due to an increase in hormone level
Steroid and Thyroid hormones have poor
water-solubility
Steroid hormones can diffuse through
lipid bilayer of cell membranes
Thyroid hormones are thought to enter cell by
specific transport methods. They bind to receptors inside cell
Nonsteroid hormones cnanot penetrate the
lipid bilayer of cell membranes
Nonsteroid hormones bind to
receptors on the target cell membrane
Nonsteroid Hormone is considered a
first messenger
Chemical that induces changes leading to hormone effect is considered a
second messenger
Many nonsteroid hormones use
cyclic adenosine monophosphate (cAMP) as a second messenger
The entire process of chemical communication, from outside cells to inside, is called
signal transduction
What is Erythropoietin used for?
Used to increase the number of red blood cells and oxygen delivery to muscles
Prostaglandins are what type of substances?
Paracrine
Prostaglandins potency?
Very potent in small amount
Prostaglandins are not stored in cells, but synthesized just
before release
Prostaglandins; what happens after use?
rapidly inactivated?
Prostaglandins regulate
cellular responses to hromones
Prostaglandins can activate or inhibit
adenylate cyclase;
to control cAMP product and alter a cells response to hormones
Prostaglandins have a wide variety of effects such as
contracting or relaxing msooth muscle
stimulating or inhibiting secretion
regulating blood pressure
controlling movement of h20 and Na+ in kidneys
promoting inflammation
Hormone secretion is primarily controlled by
negative feedback mechanisms
Hormones effects can be (time duration)
short-lived or may last for days
Hormone secretiosn are precisely
regulated
Hormones are excreted in the
urine after exerting their effects
Hormones can be broken down by
enzymes, mainly from the liver, to stop their effects
A small number of cases of hormone control involve
positive feedback, mainly in reproductive system
What is negative feedback?
A control mechanism in which rising level of a hormone leads to a decrease in hormone secretion
What are the 3 methods in which negative feedback controls hormone secretion
Tropic Hormones
Nervous System Control
Changes in Composition Of Internal Environment
What is a Tropic Hormone?
Hormones that act on other glands, to regulate their hormone secretion
What is a Nervous system Control?
Nervous system directly stimualtes some glands to secrete their hormones (Via nerve impulseS)
What is a Changes in composition of internal environment?
Changing levels of a specific substance in the blood (ion, glucose) stimiulates or inhibits secretion or certain hormones
Pituitary gland lies at the
base of the brain, in the sella turcica of spenoid bone
Pituitary Gland attached to
hypothalamus by pituitary stalk (infundibulum)
Pituitary Gland consists of 2 distinct portions
Anterior Lobe and Posterior Lobe
Pituitary Gland: How does Anterior Lobe Regulation work
Hypothalamic releasing hormones are transporting through the Hypophyseal Portal System, and stimulate cells of anterior lobe to release hormones
Pituitary Gland: How does Posterior Lobe Rgulation work?
Nerve impulses from the hypothalamus travel through the infundibulum and stimulate nerve endings in posterior libe to release hormones
The hypothalamus, which is an endocrine gland, controls hormone secretion from
peripheral endocrine glands via 3-step pathways
Each hypothalamic releasing hormone acts on
specific hormone-secreting cells in the anterior pituitry gland
Anterior pituuitary hormone acts on cells in a
peripheral endocrine gland, to stimulate its secretions
Anterior lobe of the Pituitary Gland consists of
glandular epithelial tissue
Anterior Pituitary Hormones are produced in the
anterior lobe by 1-5 types of secretory cells
Each anterior lobe hormone is released in response to a releasing hormone from teh hypothalamus, some are inhibited by
inhibiting hormones form the hypothalamus
What are Some Anterior Pituitary Hormones?
Growth Hormone (GH) Prolactin (PRL) Thyroid-Stimulating Hormone (TSH) Adrenocorticotropic Hormone (ACTH) follicle-Stimulating Hormone (FSH) Lutenizing Hormone (LH)
Growth hormone targets what?
Bone
Muscle
Adipose Tissue
Prolactin targets what?
Mammary Gland
Adrenocorticotropic Hormone targets what?
Adrenal Cortex
Lutenizing Hormone targets what
Ovary
Follicle Stimulating Hormone targets what?
Testis
What does the growth hormone do?
Stimualtes cells to enlarge and divide rapidly, increases amino acid uptake and protein synthesis, decreases rate fo carbohydrate usage, increase rate of fat useage
What does Prolactin do?
Promotes milk production in females, uncertain function in males
What does Thyroid-Stimulating Hormone do?
Stimulates secretion of thyroid hormones (T3 and T4)
What does Adrenocorticotropic Hormone do?
Stimulates secretion of cortisol and other glucocorticoids from adrenal cortex
What does Follicle-Stimulating Hormone do?
Causes growth and development of ovarian follicles in females, sperm production in males
What does Lutenizing Hormone cause?
Causes ovulation in females, sex hormone production in both genders
How is TSH controlled?
Controoled by level of TRSH from the hypothlamus Also controlled by negative feedback
How does Hypopituitary Dwarfism occur?
Caused by deficiency of growth hormone during childhood.
Short stature, but body proportions and mental development are normal
What is Gigantism?
Caused by oversecretion of GH during childhood.
Height may exceed 8 feet. Often caused by pituitary tumor
What is Acromegaly?
Caused by oversecretion of GH during adulthood, after epiphyseal ossification, bones thicken.
Enlargement of tongue, nose, hands, feet, jaw, heart, thyroid gland
Posteroid lobe of pituitry gland consists of nerve fibers from
hypothalamus and neuroglia, unlike glandular epithelium of anterior lobes
Posterior Pituitary Hormones : 2 Hormoens are produced yby
neurons in the hypothalamus, and stored and released by this
Posterior Pituitary Hormones The two hormones are transported to the posterior pituitary gland via the
pituitary stralk
Posterior Pituitary Hormones
ADH, Vasopressin and OXxytocin
What does ADH/Vasopressin do?
Decreases urine production by reducing volume of H2O the kidneys excrete, also causes vasoconstriction to increase bp
What does Oxytocin do?
Causes muscle conraction in uterine wall during childbirth, milk ejection during lactation, has no known functions in males
Thyroid Gland has the special ability to remove
idoine from blood
Thyrid Gland produces
T4 (Thyroxine)
T3 (Triiodothyronine)
Calcitonin
What cells product T3 and T4
Follicular
What produces Calcitonin?
Extra or Parafollicular Cells
Thyroid is composed of round secretory units called
follicles
Each follicle is surrounded by
a single layer of follicular cells
What does T4 do?
Increases rate of energy released from carbohydrates
increases rate of protein synthesis
accelerates growth
necessary for normal nervous sytem maturation
T4 source of control?
TSH from the anterior pituitary gland
What does T3 do?
Same as T4, but five times for potent
T3 source of control?
TSh form teh anterior pituitary gland
What does Calcitonin do?
Lowers blood calcum and phosphate ion contentration by inhibiting release of calcium and phosphate ions form bones and by increasing the rate at whcihc alcium and phosphate ions are deposited into bones
increases secretion of calcium by the kidneys
Calcitonin source of control?
Elevated blood calcium ion concentration,, digestive hormones
Hyperthyroid diseases?
Hyperthyroidism
GRaves Disease
Hypothyroid Diseases?
Hashimoto Disease
Hypothyroidism (Infantile)
Hypothyroidism (Adult)
Simple Goiter
What is Hyperthyrodism
High metabolic rate
sensitivity to heat
restlessness
hyperactivity
weight loss
What is Graves Disease?
Autoantibodies bind to TSH receptors on thyroid cell membranes
What is Hashimoto disease?
Autoantibodies destroy thyroid cells
What is Hypothyroidism (infantile)
stunted growth, abnormal bone formation, intellectual disability
What is Hypothyroidism (adult)
Low metabolic rate
Sensitivity to cold
Sluggishness
Poor Appetite
What is Simple Goiter?
Deficiency of thyroid hormones due to iodine deficiency
Parathyroid glands located on
posteiror surface of the thyroid gland
Parathyroid Glands secretes what hormone?
PTH (Parathyroid Hormone)
PTH regulates
Ca and PO4 concentrations in blood
Actions of PTH: Ca and Po4
Increase level of blood Ca
Decrease level of blood PO4
Actions of PTH: EXerts these effects by acting on
bone, kidneys and intenstines
Actions of PTH: Indirectly stiualtes absorption of
Ca by stimulating a step in Vitamin D metabolism
PTH acts on kidney to cause final step in production of
Active Vitamin D
Hyperparathyroidism Symptoms
Fatigue
Muscular Weakness
Painful Joints
Altered Mental Status
Depression
Hyperparathyroidism Cause
Tumor
Hyperparathyroidism Treatment
Remove tumor, correct bone deformities
Hypoparathyroidism Symptoms
Muscle Cramps and Seizures
Decreased PTH secretion reduces osteoclast activity
Diminishing Blood Calcium Ion Concentration
Hypoparathyroidism Cause
Inadvertent surgical removal, injury
Hypoparathyroidism Treatment
Calcium salt injections, massive doses of Vitamin D
Adrenal glands are also called
suprarenal glands
Adrenal glands are closely associated with the
kidneys
Adrenal glands sit like
cap on each kidney
Adrenal Glands: Hormones secreted from what two areas?
Adrenal Cortex
Adrenal Medulla
Adrenal Glands: How many hormones secreted ere?
Numerous
Adrenal Glands: Play roles in maintaining
blood sodium levels and responding to stress. They also include certain sex hormones
Adrenal Cortex makes up
outer portion of gland and secretes steroid hormones
Adrenal medulla makes up
central portion of gland, and secretes amine hormones
What two hormones does the adrenal medulla secrete?
Epinephrine and Norepinephrine
Epinephrine affect on heart
Heart Rate increases, force of contraction increases
Epinephrine affect on blood vessels
vasodilation, especiall important in skeletal muscle at onset of fight of flight
Epinephrine affect on systemic blood pressure
some increase due to increased cardiac output
Epinephrine affect on airways
dilation
Epinephrine affect on reticular formaiton of brainstem
activated
Epinephrine affect on liver
Promotes breakdown of glycogen to glucose , increasing blood sugar level
Epinephrine affect on metabolic rate
increases
Norepinephrine effect on heart
heart rate increases, force of contraction increases
Norepinephrine effect on blood vessels
vasoconstriction in skin adn viscera shifts blood flow to other areas such as exercising skeletal muscle
Norepinephrine effect on systemic blood pressure
some icnreased due to increased cardiac output and vasoconstriction
Norepinephrine effect on airways
some dilation
Norepinephrine effect on reticular formation of brainstem
little effect
Norepinephrine effect on liver
little effect on blood glucose level
Norepinephrine effect on metabolic rate
increases
Adrenall Cortex produces
steroid hormones
Some of the Adrenal Cortex hormones are vital to
maintaining life
Most important hormones of the adrenal cortex are
Aldosterone, Cortisol
Aldosterone action
Helps regulate the concentraiton of extracellular electrolytes by conserving sodium ions adn excreting potassium ions
Aldosterone factors regulating secretion
Plasma potassium and sodium ion cocnentrations and reninangiotensin system
Cortisol Action
Decrease protein synthesis, increases fatty acid release, adn stimulates glucose sythesis from noncarbohydrates
Cortisol factors regulating secretion
CRH from the hypothalamus and adrenocorticotropic hormone (ACH) fromt he aterior pituitary gland
Adrenal Androgen Action
Supplement sex hormones form the gonads; may be converted into estrogens
Adrenal Androgens Factors Regulting Secretion
Adrenocorticotropic hormone (ACTH) from the anterior pituitary plus unknown factors
Three zones of the Adrenal Cortex?
Zona Glomerulosa
Zona Fasciculata
Zona Reticularis
Where is the Zona Glomerulosoa located?
Outer Zone
What does the Zona Glomerulosa produce?
Aldosterone and other mineralocorticoids
Where is the Zona Fasciculata located?
Middle Zone
What does the Zona Fasciculata produce?
Cortisol and OTher Glucocorticoids
Where is the Zona Reticularis located
Inner Zone
What does the Zone Reticularis produce?
Produces male sex hormones
What does the RAAS system do?
Helps maintain normal blood pressure
What does Angiotensin II do?
Increases blood pressure, and promotes secretion of aldosterone
What does aldosterone conserve?
Na, and H2O is retained by osmosis.
Addison disease is due to
insufficient hormone secretion from adrenal cortex
Addison disease results in
electrolyte and glucose imbalances, dehydration, low blood pressure, fatigue, nausea, and increased skin pigmentation
Addison disease can be
fatal, due to severe electrolyte imbalance
Cushing Syndrome due to
hypersecretion of cortisol, because of adrenal tumor, or excess secretion of ACTH by anterior pituitary
Cushing Syndrome results in
muscle wasting, loss of bone, elevated blood glucose, Na+ retention, H2O retention by osmosis, increased blood pressure, puffy skin, abnormal deposition of adipose tissue in face and back
Pancreas has how many major types of secretory tissue?
2
Pancreas is what type of gland?
Endocrine and Exocrine
Endocrine function
Secretes hormones into body fluids
Exocrine Function?
Secrete digestive juices through a ducr
How many and what hormones are secreted from endocrine cells?
Alpha, Beta, Delta
Alpha cells secrete
glucagon
Beta cells secete
insulin
Delta cells secrete
somatostatin
What does the pancreas look like?
Elongated, flattened organ
Pancres location?
Posterior to the stomach
What does the pancreatic duct transport?
Digestive juice to the duodenum
Endocrine portion of Pancreas consists of
groups of cells called Pancreatic islets (islets of Langerhans)
Glucagon Action?
Stimulates the liver to break down glycogen and convert noncarbohydrates into glucose ; stimulates breakdown of fats
Glucagon source of control
Blood glucose concentration
Insulin Action
PRomotes formation of glycogen from glucose, inhibits conversion of noncarbohydraes into glucose, and enhances movement of glucose through adipose and muscle cell membranes, decreasing blood glucose concentration
Insulin source of control
Blood glucose concentration
Somatostatin Action?
Helps regulate glucose metabolism by inhibiting secretion of insulin and glucagon
Somatostatin source of controlled?
Not known
Simple Insulin action?
Decreases blood glucose, when it is too high
Glucagon simple action definition
Increase blood glucose, when it is too low
Diabetes Mellitus results from lack of
insulin or inability of cells to recognize insulin
Diabetes Mellitus : Elevated blood glucose can damage
eyes, heart, kidney, nerves
Diabetes Mellitus : Results in
disturbances in carbohydrate, protein, and fat metabolism
Diabetes Mellitus : Insulin promotes
glucose uptake by adipose and muscle cells
Diabetes Mellitus In diabetes, carbohydrates cannot enter
cells in normal quantities
Diabetes Mellitus , without carbohydrates, what does this result in?
Hyperglycemia , or high blood glucose
Diabetes Mellitus : Signs of this?
Weight decline, hunger increases, fatigue increases, wounds do not heal well, growth stops in children
Diabetes Mellitus: Glucose spills into
urine, and H2O follows by osmosis leading to dehydration and thirst
Type I usually begins before
age of 20
Type 1 Diabetes is what type of disease?
Autoimmune disease, with immune system destroying beta cells of pancreas
Type 1 results in a lack of
insulin production
PErcentage of cases in Type 1
5-10%
What happens in Type 2 diabetes?
Insulin produced, but body cells are unable to recognize it
Type 2 Milder than
Type 1
Type 2 complications include
coronary artery disease, erve or retinal damage
Type 1 administration requires administration of
insulin
Insulin cn be obtained from
pigs and cows
Human insulin can be synthesized using
recombinant DNA technology; insulin is producecd by genetically altered bacteria
Type 2 Diabetes treatment?
Low carbohydrates, high protein diet
Regular exercise
Gastric bypass surgery
Has you grow older, endocrine glands
decrease in size
As you get older, what happens to ADH?
ADH levels increase increase due to slower elimintion by liver and kidneys
As you get older, what happens to Calcitonin?
Decrease, increasing risk of osteoporosis
What does the Pineal Gland do?
Secretes melatonin
Regulates circadian rhythms
What does the Thymus gland do?
Secretes thymosins
Promotes development of T-Lymphocytes
Important in role of immunity
What do the ovaries produce?
Estrogens and Progesterone
What do the Testes produce?
Testosterone
What does the Placenta produce?
Estrogens, Progesterone, and a Gonadotropin
When sensory receptors detect changes, they send
nerve impulses to the hypothalamus
The hypothalamus activates
sympathetic nervous sytem and increases secretion of adrenal hormones
Factor capable of initiating this response is a
stressor
Stress is the condition produced in response to
stressors
Hypothalamus controls
response to stress
Response is called
General Adaptation
General Stress Syndrome
What are teh two stages of General Stress Syndrome?
Alarm Stage
Resistance Stage
What is the Alarm Stage?
Immediate/ Fight or Flight
Epinephrine intensifies and prologns these responses
What is the Resistance Stage?
Long-Term
Increased cortisol spares glucose for brain
Glucagon and GH mobilize energy sources for other tissues
ADH and Renin cause water retention
