Module 6: Endocrinology Flashcards
There are … relay molecules in a signal transduction pathway.
3
List the 3 stages of cell signaling
- Reception
- Transduction
- Response
Is synaptic signaling local or long-distance signaling?
Local signaling
Is paracrine signaling local or long-distance signaling?
Local signaling
Is endocrine signaling local or long-distance signaling?
Long-distance signaling
What is paracrine signaling?
A secreting cell acts on nearby target cells by secreting molecules of a local regulator.
What is synaptic signaling?
A nerve cell releases neurotransmitter molecules into a synapse, stimulating the target cell, such as a muscle or nerve cell.
What is endocrine signaling?
Specialised endocrine cells secrete hormones into body fluids, often blood. Hormones reach virtually all body cells, but are bound only by some cells.
T or F
Endocrine signaling can trigger responses in virtually any part of the body.
T
Provided the body part has the appropriate endocrine receptors for the signal.
The secreted molecules in neuroendocrine signaling are called…
neurohormones
T or F
Neuroendocrine signaling can trigger responses in virtually any part of the body.
T
Provided the body part has the appropriate neuroendocrine receptors for the signal.
In paracrine signaling, secreted molecules diffuse locally through the …
extra cellular fluid (ECF)
What is autocrine signaling?
Secreted molecules diffuse locally, triggering a response in the cell that secreted them.
T or F
The secreted molecules in autocrine signaling are always local regulators.
T
The secreted molecules in endocrine signaling are …
hormones
Animals regulate their internal environment in one of what two ways?
Animals either regulate their internal environment despite the external environment (homeostasis).
OR
Animals internal conditions conform to the external environment.
Organisms use homeostasis to maintain a…
steady state
T or F
An animal’s steady state changes depending on the external environment that animal is in.
F
T or F
Endocrine cells in various organs and tissues release chemicals (‘hormones’) that are distributed
into the bloodstream.
T
T or F
Hormones act on target cells as ‘messengers’
T
T or F
Hormones cannot change the way a cell behaves or functions.
F
Hormones tell the cells how to behave and act.
In endocrinology, what is meant by the term ‘specificity’?
Even though hormones circulate in the bloodstream they target a limited number of cells or tissues based on the presence of a specific receptor.
T or F
Lipid-soluble hormones are hydrophilic
F
They are hydrophobic
T or F
Water-soluble hormones are hydrophilic
T
Are polypeptides lipid-soluble or water-soluble?
Water-soluble
Are Steroids lipid-soluble or water-soluble?
Lipid-soluble
Water-soluble hormone receptors are located in a cells…
plasma membrane
Lipid-soluble hormone receptors are located in a cells…
nucleus or cytoplasm.
T or F
Water-soluble hormones exit a cell via exocytosis whereas lipid-soluble hormones exit via passive diffusion.
T
T or F
Adrenaline is a water-soluble hormone.
T
What kind of receptor does adrenaline bind to?
A GPCR
Adenylyl cyclase transforms … into ATP.
GTP
Adenylyl cyclase transforms ATP into …
cAMP
Which molecule acts as a second messenger in GPCR reactions?
cAMP
cAMP acts as a second messenger on what protein?
Protein kinase A
When activated, what effects does protein kinase A have on a cell?
It inhibits glycogen synthesis and promotes the breakdown of glycogen.
Is oestradiol water or lipid-soluble?
lipid-soluble
T or F
Thyroid hormones regulate homeostasis
T
T or F
Thyroid hormones do not regulate development
F
T or F
One hormone can have multiple functions depending on what receptor it binds to.
T
What effect does adrenaline have on liver cells?
Glycogen breaks down and glucose is released from the cell. Blood glucose lvl increases.
What effect does adrenaline have on smooth muscle cells in the wall of blood vessels that supply skeletal muscles?
Blood vessels dilate increasing flow to skeletal muscle
What effect does adrenaline have on smooth muscle cells in the wall of blood vessels that supply the small intestine?
Blood vessels constrict, decreasing flow to the intestines.
What two systems are the body’s long-distance regulators?
The nervous system and the endocrine system.
Signals from the … system initiate and regulate endocrine signals.
nervous
T or F
Homeostasis occurs via positive feedback
F
via negative feedback.
Put the following in order according to the negative/positive feedback arrow.
Hormone <-
Response |
Endocrine Gland | -/+
Stimulus |
Target Tissue -
Stimulus <-
Endocrine Gland |
Hormone | -/+
Target Tissue |
Response -
What are some examples of hormone cascade pathways?
When the body is cold the hypothalamus secretes TRH in the blood which travels to the anterior pituitary which secretes TSH to the thyroid vis the blood which then secrets T3 and T4 which travel to body tissues and increase cellular metabolism.
The … cells of the pancreas release glucagon into the blood.
alpha
The … breaks down … and releases glucose into the blood.
liver
glycogen
Homeostasis occurs via the action of … pairs of hormones.
antagonistic
The … cells of the pancreas release insulin into the blood.
beta
T or F
The liver takes up glucose and stores it as glucagon.
F
as glycogen
What is the difference between glycogen and glucagon?
Glycogen is a stored form of glucose. Glucagon is a hormone that triggers liver glycogen to convert back into glucose and to enter your bloodstream so that your body can use it for energy.
Which type of diabetes (I or II) is insulin-dependent?
Type I
Which type of diabetes (I or II) is an autoimmune disorder?
Type I
What causes Type II diabetes mellitus?
insulin deficiency or reduced response of target cells due to change in insulin receptors.
What causes Type I diabetes mellitus?
an autoimmune disorder in which the immune system destroys pancreatic beta cells.
What does RAAS stand for?
Renin-Angiotensin-Aldosterone System
T or F
Renin is an enzyme.
T
T or F
Angiotensin II and Aldosterone are enzymes.
F
They are hormones
What can cause blood pressure or blood volume to drop?
Dehydration, blood loss
Where is the juxtaglomerular apparatus (JGA) located?
Near the distal tubal in the kidneys.
The juxtaglomerular apparatus (JGA) releases what enzyme?
Renin
Sensors in the juxtaglomerular apparatus sense what?
a decrease in blood pressure or volume.
Which organ secretes angiotensinogen?
The liver
What two things come together to form Angiotensin I?
Renin from the kidneys and Angiotensinogen from the liver
Which enzyme converts angiotensin I to angiotensin II?
Angiotensin-converting enzyme (ACE)
Angiotensin II stimulates the secretion of … in the adrenal glands.
aldosterone
How does aldosterone help return blood pressure to steady-state?
Aldosterone causes more Na+ and H2O to be reabsorbed by the distal tubules in the kidneys, increasing blood volume.
What effect does angiotensin II have on the arterioles?
It causes arterioles to constrict, increasing blood pressure.
List the organs containing endocrine cells
Thymus, heart, liver, stomach, kidney and small intestine
List the major human endocrine glands
The thyroid gland, parathyroid glands, adrenal glands, ovaries, testes, pineal gland, hypothalamus, pituitary gland and the pancreas.
(PPATHPPOT)
List the endocrine glands in the human brain
The pineal gland, hypothalamus and pituitary gland
What hormones are secreted from the posterior pituitary?
Oxytocin and vassopressin (ADH)
The … cells of the hypothalamus produce and release neurohormones that affect the secretion or hormones in the pituitary.
neurosecretory
… in the hypothalamus trigger the release of ADH from the … pituitary.
Osmoreceptors
posterior
The … generates thirst.
hypothalamus
T or F
Drinking water reduces blood osmolarity.
T
What is considered normal blood osmolarity?
300 mOsm/L
T or F
The ADH receptor activates a second messenger
T
Which second messenger does the ADH receptor activate?
cAMP
(in relation to ADH receptors) cAMP affects which protein?
Protein kinase A
What causes a hangover?
alcohol can inhibit ADH release, excess urine and
dehydration (“hangover”)
What are tropic hormones?
Hormones that regulate the function of other endocrine cells or glands
… and … stimulate the activities of
the male and female gonads
LH
FSH
LH and FSH are …
gonadotropins
ACTH stimulates the production and secretion of …. by the ….
steroid hormones
adrenal cortex
TSH acts on the … to stimulate the release of ….
thyroid
thyroid hormones
What are nontropic hormones?
Hormones that target nonendocrine tissues
What hormones does the anterior pituitary release?
ACTH, prolactin, MSH, GH, TSH, FSH and LH
Which anterior pituitary hormone produces both tropic and non-tropic effects?
GH
Which anterior pituitary hormones produce tropic effects?
FSH, LH and ACTH
Which anterior pituitary hormones produce nontropic effects?
MSH and prolactin
What does the hormone prolactin do in mammals?
Stimulates mammary gland growth and milk synthesis.
What does the hormone prolactin do in freshwater fishes?
Regulates salt and water balance
What does the hormone prolactin do in amphibians?
Delays metamorphosis
What does the hormone prolactin do in birds?
Regulates reproduction
Which hormones regulates activity of pigment-containing cells in
skin (of fishes, some amphibians, reptiles) and acts on neurons in the brain inhibiting hunger (mammals)?
MSH
T or F
Growth Hormone exerts diverse metabolic effects to lower blood glucose
F
raise
GH acts on the liver to release …., which circulate in blood and directly stimulate bone and cartilage growth
Insulin-like Growth Factors
(IGFs)
FSH and LH affect what organ/s?
ovaries or testes
ACTH affects what organ/s?
Adrenal cortex
TSH affects what organ/s?
Thyroid
Prolactin affects what organ/s?
Mammary glands
GH affects what organ/s?
Liver, bones & other tissues
MSH affects what organ/s?
Melanocytes
