CH.16 Endocrine system Flashcards
Water Soluble Hormones (1st messenger) Binds to extracellular receptors.
Why not intracellular?-
IT cannot pass through the lipid bilayer of the cell membrane.
What does Insulin do?
-Binds to receptors on target cells = turn on glucose transporters
-Blood glucose levels fall fast
-
Are thyroid hormones water soluble?
(T3/ T4)
No
(Bind to intracellular receptors)
LIPID SOLUBLE
Amino acid Based Hormones (Water-Soluble) rely on extracellular or intracellular
rely on extracellular receptors to send signals inside the cell using second messengers (like cAMP or calcium).
epinephrine, glucagon, insulin are
WATER orLIPID SOLUBLE HORMONES
Bind to EXTRACELLULAR or INTRACELLULAR RECEPTORS?
WATER SOLUBLE HORMONES
Bind to EXTRACELLULAR RECEPTORS
Step 1:
Water-soluble hormones affect target cells by binding to __________.
EXTRACELLULAR RECEPTORS
plasma membrane receptors
What are Lipid Soluble Hormones called?
(INTRACELLULAR RECEPTORS)
Steroid Hormones + Thyroid Hormones
Cortisol
Estrogen
Testosterone
Progesterone
Aldosterone
Thyroxine (T4)
Triiodothyronine (T3)
Steroids are lipid-soluble hormones derived from______.
(INTRACELLULAR RECEPTORS)
cholesterol
Steroids are lipid-soluble hormones derived from cholesterol and are synthesized by
(INTRACELLULAR RECEPTORS)
What Lipid Soluble Hormones is derived from Cholesterol?
(INTRACELLULAR RECEPTORS)
Steroid Hormones
****
Cortisol
Estrogen
Testosterone
Progesterone
Aldosterone
What Lipid Soluble Hormones is derived from Amino Acids?
(INTRACELLULAR RECEPTORS)
Thyroid Hormones
*****
Thyroxine (T4)
Triiodothyronine (T3)e
What type of hormone enter the cell, bind to an intracellular receptor, activate genes in the nucleus, and increase protein production
lipid-soluble hormones
After a lipid-soluble hormone is bound to its intracellular receptor, what does the hormone complex do?
acts as a transcription factor and binds to DNA, activating a gene
Which hormone’s receptor is always bound to DNA, even when the receptor is empty?
insulin
thyroid hormone
Do amino based acids produce slow or rapid responses?
What’s an example of this?
Rapid
What’s an example of a carrier mediated facilitated diffusion?
Glucose
Why do steroid and thyroid hormones bind intracellularly
they are (fat-soluble) and can easily diffuse through the cell membrane, which is composed of a lipid bilayer.
What hormone helps regulate blood sugar levels by raising glucose when it gets too low?
Glucagon - regulated by negative feedback
Is blood sugar regulation positive or negative feedback
Negative
( negative feedback maintains stability, while positive feedback amplifies a process until an endpoint is reached.)
What hormone lowers blood glucose
Insulin
- bloodglucose low
2.___WHAT___ releases glucagon???
- Liver breaks down glycogen and releases glucose to the blood
Pancreas
What Molecule stores glucose in the Liver
Glucagon
Why do we crave something sweet after a meal?
- After meal = blood sugar rise
- Body releases Insulin 2 Lower
- slight dip in blood sugar levels after the initial rise
- Body craves quick sources of energy
Cause:
Autoimmune disease destroys insulin-producing cells in the pancreas.
-No insulin production; requires insulin injections.
TYPE 1 O R 2?
Type 1 Diabetes
Cause: Insulin resistance
- Insulin is produced but the body cant secrete/Use
TYPE 1 O R 2?
Type 2 Diabetes
What refers to high blood sugar levels
-Consequence of Diabetes
Hyperglycemia
How would abnormal or missing insulin receptors cause hyperglycemia?
Hyperglycemia= too much glucose
-Insulin can’t tell cells to take in glucose.
-glucose stays in the blood
Where Are Insulin Receptors Normally located on target cells?:
Liver, Muscle, Fat
What bony feature of the skull encloses and protects the pituitary gland?
Sella Turcica
What is the bony depression in the sphenoid bone where the pituitary gland sits, and what is its commonly known term?
sella turcica, commonly known as the “Turk’s saddle.
Made of glandular epithelium, developed from an upward projection from the roof of the mouth.
Anterior lobe
Where does the posterior pituitary develop from, and what is it composed of?
develops from the hypothalamus and is composed of axons and axon terminals.
What hormones are secreted by the posterior pituitary, and where are they synthesized?
Oxytocin and ADH (antidiuretic hormone),
-synthesized in the hypothalamus.
How are oxytocin and ADH transported to the posterior pituitary?
hypothalamic-hypophyseal tract from the hypothalamus to the posterior pituitary.
When are oxytocin and ADH secreted into the blood?
They are secreted when neurons in the hypothalamus fire action potentials.
Posterior Pituitary Hormones:
Which hormone stimulates the milk letdown reflex?
(Positive Feedback)
Oxytocin
Posterior Pituitary Hormones: stimulates the milk letdown reflex
Is oxytocin, POSITIVE or NEGATIVE feedback
Positive
promotes water conservation by preventing excessive water loss in urine (diuresis).
antidiuretic hormone (ADH)
Posterior Pituitary Hormones:
Posterior Pituitary Hormones:
Antidiuretic Hormone (ADH)
What happens when there is hyposecretion of ADH?
Diabetes insipidus
Posterior Pituitary Hormones::
What is the excessive production of urine.
Diuresis
What triggers the release of Antidiuretic Hormone (ADH)?
Dehydration detected by the hypothalamus
Which hormone increases water reabsorption in the kidneys back into the bloodstream
ADH
Posterior Pituitary Hormones:
What kind of feedback mechanism regulates ADH release?
A negative feedback loop, which
(stops ADH release once hydration is restored)
What happens if too little ADH is made?
The kidneys don’t save water, causing lots of urine and dehydration.
What does the hypothalamus do in ADH release?
It detects dehydration and tells the posterior pituitary to release ADH.
How does alcohol affect ADH?
Alcohol blocks ADH, so you pee more and get dehydrated.
What happens to the kidneys if there’s no ADH?
They don’t reabsorb water, so you lose more in urine.
Why can a head injury cause diabetes insipidus?
Can damage the hypothalamus/ pituitary, =
stopping ADH release = causing excessive urination.
What type of hormones are Oxytocin and ADH?
They are neurohormones.
Where are Oxytocin and ADH synthesized (made)?
They are made by neurons in the hypothalamus.
How are Oxytocin and ADH transported?
Through the hypothalamic-hypophyseal tract (a bundle of axons).
Where are Oxytocin and ADH released from?
secreted from the axon terminals in the posterior pituitary
Tropic hormones for what gland?
TSH – Stimulates the thyroid
FSH – Stimulates gonads (ovaries/testes)
LH – Stimulates gonads (ovaries/testes)
ACTH – Stimulates the adrenal cortex
What are the four tropic hormones of the anterior pituitary?
Anterior Pituitary Hormones
Why doesn’t a neural tract run from the hypothalamus to the anterior pituitary?
The anterior pituitary is a gland, not nerve tissue, so it gets signals through blood vessels (hypophyseal portal system) instead of nerves.
Which two anterior pituitary hormones are not tropic?
Growth Hormone (GH) & Prolactin (PRL) – They do not target other endocrine organs
(non tropic anterior pituitary hormone)
GH and PRL are
produced and secreted by what?
Acidophils
(non tropic anterior pituitary hormone)
What does GH do to metabolism?
GH makes more fatty acids and glucose available for growth.
(non tropic anterior pituitary hormone)
What does GH stimulate to promote growth?
liver and other tissues to produce insulin-like growth factors (IGFs).
(non tropic anterior pituitary hormone)
How do IGFs contribute to growth?
stimulate cell growth, protein synthesis, and tissue repair, especially in bones, cartilage, and skeletal muscles.
What role do IGFs play in bone growth?
promote the lengthening of long bones by stimulating the epiphyseal plates.
Why are IGFs important during adolescence?
y support rapid growth by stimulating bone lengthening, cartilage expansion, and muscle development.
How do long bones grow to adult size?
endochondral ossification. Growth hormone (GH) stimulates growth indirectly through insulin-like growth factors (IGFs).
What happens with HYPERsecretion of GH
(often due to a tumor in the anterior pituitary)
gigantism,
What happens with HYPOsecretion of GH
Pituitary dwarfism
Is Acromegaly hyper or hypo secretion of GH
Hypersecretion
Oxytocin is released from the posterior pituitary then what happens ?
Let-down reflex
Milk is ejected through ductsof nipples.
Positive feedback
Anterior pituitary Hormone
- Anterior pituitary secretes prolactin into blood
- Prolactin targets what?
Prolactin targets mammary glands
of breasts
= MILK PRODUCTION
which gland has tropic hormones?
Anterior pituitary
was once known as the
“master endocrine gland”
* Secretes numerous
hormones
Why is the term “master endocrine gland” no longer accurate for the Anterior pituitary
Anterior pituitary is not in charge of the endocrine system, but instead is regulated by hormones from the hypothalamus
How does the hypothalamus control the anterior pituitary? (What does it release)
Hypothalamus releases neurohormones that regulate the secretion of hormones from the anterior pituitary
(Neurohormones control the secretion of anterior pituitary hormones.)
What is the role of neurohormones from the hypothalamus?
Neurohormones from the hypothalamus control the secretion of anterior pituitary hormones.
What neumonioc helps remember the hormones secreted by basophil cells in the anterior pituitary:
B - Basophils
F - FSH
L - LH
A - ACTH
T - TSH
B-FST
Anterior
pituitary gland
Gonadotropins that target the ovaries and testes, stimulating the production of sex hormones and the development of sex cells.
FSH + LH
(secreted by basophil cells)
What triggers the release of anterior pituitary hormones? List the hypothalamic hormones that regulate them.
Hypothalamus-Pituitary-Gonadal Axis
Thyroid and adrenal hormones are regulated by what ?
hypothalamic neurohormones and anterior pituitary tropic hormones.
A, C
What endocrine gland is located:
Anterior to the trachea
Inferior to the larynx
Thyroid gland
What are the structural features of the thyroid gland?
Has lobes composed of hollow spherical follicles
What do follicle cells in the thyroid gland produce?
thyroglobulin protein.
What is formed when iodine atoms attach to thyroglobulin
Colloid
What are the two related compounds of thyroid hormone (TH)?
T3 (Triiodothyronine)
T4 (Thyroxine):
What hormone triggers thyroid hormone secretion in anterior pituitary
by TSH (thyroid-
stimulating hormone).
(anterior pituitary tropic
hormone)
Secretion of TSH is stimulated by
TRH
What disease
Hypersecretion of Thyroid Hormone (TH)
(Too much) (HyperThyroid)
Graves Disease
Symptoms:
Exophthalmos
Proptosis and Goiter are symptoms of what disease?
—
Graves Disease
Treatment:
- Surgical removal of the
thyroid gland
-Radioactive iodine to destroy thyroid cells, followed by life- long thyroid hormone replacement.
Treatment:
- Surgical removal of the
thyroid gland
-Radioactive iodine to destroy thyroid cells, followed by life- long thyroid hormone replacement.
for what DIsease?
Graves Disease
What Disease?
Excessive glucocorticoidsecretion
-caused by an
ACTH-secreting tumor of anterior pituitary
* Causes high blood glucose levels
* Promotes water and salt retention; redistribution of fat
Cushing’s syndrome
CORTIOCOID- CUSHING
What disease?
Cushing’s syndrome
Due to
HYPER or HYPOthyroidism
(untreated Hyorthyroidism)
Myxedema
Goiter is due to what
Iodine Deficieny
Hyposecretion of ADH
Diabetes Insipidus
Diabetes Mellitus
💡 What hormones does the adrenal medulla produce, and what triggers their release?
CRH – corticotropin-releasing
hormone causes the release of what
Severe hypothyroidism in infant:
Cretinism
What are the direct effects of Growth Hormone (GH) on metabolism,
Part of Adrenal Gland that helps with long term stress
Adrenal Cortex
Part of Adrenal Gland that helps with SHORT term stress
Adrenal Medulla
What does Adrenal Medulla secrete ?
epinephrine, norepinephrine
What are the Amino acid derived Hormones?
Epinephrine, Insulin, Dopamine
Fat Soluble Derived Hormones
Which one is Fast vs Slow
Water- Fast (extra)
Fat-Slow (inta)
Alderostone is secreted by what Gland?
Adrenal Cortex
Alderostone function
(Hyposecretion)
Condition where Adrenal glands fail to produce sufficient amounts of the hormones cortisol and aldosterone
Addisons Disease
Hormones travel through blood
Hormones sent by nerves
A: Anterior/Posterioir
Function of Erythropoietin (EPO
(Secreted from Kidney)
Where is Erythropoietin (EPO) Secreted from?
Identify
Sella Turcica
Q: What pathway is used by the posterior pituitary?
A: The hypothalamo-hypophyseal tract.
How does the posterior pituitary transport hormones?
Through nerve fibers (action potentials).
What pathway is used by the anterior pituitary?
The hypophyseal portal system.
Thyroid Axis = Hypothalamus → TRH → Anterior Pituitary → TSH → Thyroid → T3/T4
Adrenal Axis = Hypothalamus → CRH → Anterior Pituitary → ACTH → Adrenal Glands → Cortisol
When is the worst time to give a patient insulin?
When their blood sugar is already low (hypoglycemia) or if they are not eating.
How does alcohol affect antidiuretic hormone (ADH) and hydration?
inhibits the release of ADH, Which helps the kidneys retain water. Without ADH, the kidneys produce more urine, leading to increased urination and dehydration.
What does the Zona Fasciculata of the adrenal cortex secrete?
Glucocorticoids, such as cortisol and cortisone.
Q: What does the Zona Reticularis of the adrenal cortex secrete?
Gonadocorticoids, which are adrenal sex hormones, such as testosterone.
What does the adrenal medulla secrete?
Norepinephrine and epinephrine (also known as adrenaline and noradrenaline).
What are the key elements needed to make thyroid hormones?
Iodine and tyrosine
most abundant of all of the formed elements
RBC
Leukocytes
Platelets
Complete Cells
Leukocytes
What secrete
factors that initiate
blood clotting
Platelets
What has Immune defense against microorganisms.
Which WBC Targets bacteria.
Neutrophil
Target allergens and release histamine.
Basophils
Target parasites and help in allergic reactions.
Eosinophils
Target viruses; include T-cells and B-cells.
Lymphocytes
