Item 9 Flashcards
REad Endocrine overview: 6th edition: Ch.5: 124-134, 137-145 (5th edition: Ch. 5: 125-133, 136-144)
Hypothalamus and pituitary: 6th edition: Ch 6: 148 153, Ch 19: 541 543, Ch 22: 661 663 , Ch 21: 619 623 (5th edition: Ch6: 149 153 , Ch 19: 541 543, Ch 22: 662 663 , Ch 21: 619-623)
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35
32
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Cell-to-cell communication that is direct involves small ions and small molecules that use _ _ via connexons
gap junctions
Cell-to-cell communication that is indirect via chemical messenger involves a secretorycell sending a chemical messenger that reaches the receptor of a target cell. The target cell’s receptor needs to be present as well as be _ to the messenger
specific
growth factors, clotting factors and cytokines are examples of _ chemical messenger signaling
paracrine
Paracrines diffuse a _ distance through extracellular fluid, from a secretory cell and binds to adjacent cells
short
Neurotransmitters are released from neurons at synapses, which are specifically labelled as _ and _ cells
presynaptic and postsynaptic
Can neurotransmitters be sent far distances?
yes, provided the axon is super-long
Hormone signalling involves a secretory cell or _ cell which uses a hormone that is a chemical cellular that is released into _ fluid into the blood stream though gaps in capillaries.
endocrine;
interstitial/extracellular
Hormone signalling uses _ capillaries to travel into the blood
fenestrated
Do hormones use receptors?
yes, otherwise they do not respond to hormones
T or F: Hormones are released into the bloodstream and can reach both near and far targets
true
Neurohormones secrete from neurons, and they are released from the ending of the neuron into the blood and will only act on cells with _
receptors to the particular neurohormone
Krinein means to _ or _
secrete or separate
The endocrine system secretes hormones into the bloodstream and have …
target cells which express receptors for the hormone, responsible for hormone function
The organs that secrete hormones are:
- glands
- cells embedded in _
tissue
Primary endocrine glands are meant to…
secrete hormones
Secondary endocrine organs are meant to…
have a main function, but can also release hormones
Primary endocrine organs include:
glands:
- pineal
- hypothalamus
- pituitary
- thyroid
- parathyroid
- thymus
- _ gland
- pancreas
- ovaries (placenta) / testes
adrenal gland
Secondary endocrine organs include:
- heart
- stomach
- liver
- kidney
- small intestine
- _
skin
Functions of the endocrine system:
metabolism
growth and development
reproduction
…
water and electrolyte balance
digestive and circulatory systems - regulation
responses to stress
Regulation of hormone secretion (stimulate or inhibit):
1. neurotransmitters - interaction with _ system
2. other hormones
3. metabolites - glucose (high - insulin), amino acids (insulin, glucagon)
4. ions (potassium, calcium, etc.)
5. …
hormonal feedback - regulation of the actual hormone being secreted - keeps homeostasis in check
Type I diabetes means that, without insulin, the child cannot…
absorb nutrients
Disorders with _ hormone predict an incredibly small or an incredibly large size
growth
Classification of hormones:
_ hormones, which are water soluble (can dissolve in plasma)
hydrophilic
Hydrophilic are lipophobic, and cannot…
cross plasma membranes
Peptide and protein hormones and catecholamines (adrenaline, etc.) are examples of _ hormones
hydrophilic (cannot cross the plasma membrane)
Steroid and thyroid hormones are _ hormones, readily crossing the plasma membrane (lipophilic)
hydrophobic
Hydrophilic hormones are secreted by _, moving into the blood vessel and are dissolved by messengers
exocytosis
Hydrophobic hormones are secreted by _, and are transported in the blood by carrier proteins, although less than 1% can be ‘free’ or without a carrier protein
diffusion
Two types of hormone receptors are _ and membrane-bound
intracellular
Intracellular receptors bind with hydro_ hormones, which are considered cytoplasmic/cytosolic or nuclear receptors
hydrophobic
Intracellulr receptors directly alter gene transcription, and are _ responses
slower
Membrane-bound receptors include G-protein linked receptors, and ligand-gated ion channels, and bind hydro_ hormones.
hydrophilic
Membrane-bound receptors offer _ responses to hormone signals
rapid
What makes a cell responsive to a particular hormone?
a. the chemical properties of the hormone
b. the presence of a receptor for that particular hormone
c. the site where the hormone is secreted
d. the location of the target cells in the body
b. the presence of a receptor for that particular hormone
Hydrophobic hormones require a hydrophobic messenger that diffuses across the plasma membrane into the target cell, where is can then bind to a cytoplasmic receptor, or move into the nucleus, forming with a _ receptor.
Cytoplasmic receptors and the hydrophobic messenger can join, creating hormone-receptor complex that allows them to…
enter the nucleus through a nuclear pore
The hormone-receptor complex forms with the DNA, creating a hormone _ _ (HRE), enabling a subset of genes that would be activated when this binds
hormone receptor element
If the hormone-receptor complex binds to DNA, it binds as a HRE, which activates the transcription of that particular gene, producing _, which leaves the nucleus and binds to ribosomes where the message is translated into proteins which cause a biological effect
mRNA (messenger RNA); the messenger part of it creates proteins made in the cell
The creation of _ into ion channels, enzymes, created structures for the cell, etc. are instigated by the mRNA, a reaction from the hormone-receptor complex binding to DNA as a hormone response element (HRE), a process of hydrophobic hormones
proteins
Hydrophilic hormones use membrane-bound receptors, specifically - linked receptors
G-protein
G-protein linked receptors can act on _ _ or alter enzyme activity e.g., cAMP second messenger system
ion channels
G-protein linked receptors are associated with _, which is a G protein that has an alpha, beta, and gamma component
GDP
When the G protein is BOUND, it includes alpha, beta and gamma subunit proteins that are connected to GDP
unbound
when the messenger binds to the receptor, the G-protein complex will be UN/BOUND
unbound/separation
GDP is BOUND/RELEASED, and GTP is BOUND/RELEASED when a hydrophilic messenger activates a membrane-bound receptor
released;
bound
When a hydrophilic hormone activates a membrane-bound receptor, its result could be the GTP bind to an alpha subunit protein, activating …, which requires no further energy
an ion channel
When a hydrophilic hormone activates a membrane-bound receptor, its result could be the GTP bind to an alpha subunit protein, which can move to an enzyme, i.e., _ _
adenylate cyclase
When a hydrophilic hormone activates a membrane-bound receptor, its result could be the GTP bind to an alpha subunit protein, which can move to an enzyme, i.e., adenylate cyclase.
The activation of adenylate cyclase thereby catalyses the conversion of _ to cAMP, a second messenger, which binds to another protein in the cell
ATP
When a hydrophilic hormone activates a membrane-bound receptor, its result could be the GTP bind to an alpha subunit protein, which can move to an enzyme, i.e., adenylate cyclase.
The activation of adenylate cyclase thereby catalyzes the conversion of ATP to cAMP, a second messenger, which binds to another protein in the cell, protein _ _, and activates it.
kinase A
When a hydrophilic hormone activates a membrane-bound receptor, its result could be the GTP bind to an alpha subunit protein, which can move to an enzyme, i.e., adenylate cyclase.
The activation of adenylate cyclase thereby catalyzes the conversion of ATP to cAMP, a second messenger, which binds to another protein in the cell, protein kinase A, and activates it.
This causes protein kinase A, an enzyme, that phosphorylates a subset of proteins in the cell, i.e., …
change the activity of those proteins, altering the activity of the cell, creating a biological response in the cell
When a hydrophilic hormone activates a membrane-bound receptor, its result could be the GTP bind to an alpha subunit protein, which can move to an enzyme, i.e., adenylate cyclase.
The activation of adenylate cyclase thereby catalyzes the conversion of ATP to cAMP, a second messenger, which binds to another protein in the cell, protein kinase A, and activates it.
This causes protein kinase A, an enzyme, that phosphorylates a subset of proteins in the cell, by the use of _, creating Protein-P + ADP, creating a response in the cell
ATP
One purpose of cAMP as a second messenger in hydrophilic hormones is creating a…
greater biological response in the cell or amplification
Put the following steps in the cAMP second messenger pathway in the correct order:
- G-protein is activated
- hormone binds to receptor located in plasma membrane
- cellular proteins are phosphorylated
- protein kinase A is activated
- cAMP is synthesized
- activity of adenylate cyclase increases
- hormone binds to receptor located in plasma membrane
- G-protein is activated
- activity of adenylate cyclase increases
- cAMP is synthesized
- protein kinase A is activated
- cellular proteins are phosphorylated
Hormones simply relay info to cells through receptors, but do not themselves…
carry out a target effect
Receptor response is dependent on receptor shape and quantity, which can be _
dynamic
Hormonal responses vary depending on strength and _ of stimuli
type
Cell-cell communication in the endocrine system:
- endocrine cells _ and release a hormone
synthesize
Cell-cell communication in the endocrine system:
- endocrine cells synthesize and release a hormone
- determined by _ nature of hormone
chemical
Cell-cell communication in the endocrine system:
- endocrine cells synthesize and release a hormone
- determined by chemical nature of hormone
- determined by chemical nature of hormone and _ of receptor
availability
Cell-cell communication in the endocrine system:
- endocrine cells synthesize and release a hormone
- determined by chemical nature of hormone
- determined by chemical nature of hormone and availability of receptor
- this can be impacted by response-specific _of information transfer
termination
Cell-cell communication in the endocrine system:
- endocrine cells synthesize and release a hormone
- determined by chemical nature of hormone
- determined by chemical nature of hormone and availability of receptor
- this can be impacted by response-specific termination of information transfer - signal _
amplification
Cell-cell communication in the endocrine system:
- endocrine cells synthesize and release a hormone
- determined by chemical nature of hormone
- determined by chemical nature of hormone and availability of receptor
- this can be impacted by response-specific termination of information transfer - signal amplification
- hormone and target cell-specific _
response
Hormones are _ messengers that produce responses in target cells by binding to specific receptors
chemical
Different hormones have different chemical characteristics, i.e., hydro_ or _
philic or phobic
T or F: cells can have receptors for more than one hormone
true
There is more than one type of receptor for a given hormone. This results in the activation of different…
intracellular signalling pathways
The pituitary gland is composed of the anterior (front) and posterior (back) pituitary, attached to the hypothalamus by the _
infundibulum
Neurosecretory cells project into _ pituitary, release hormones into bloodstream
posterior
Nucleus in neurons, means …of neurons
cluster of cell bodies of neurons
Cluster of neurons in _ nucleus secrete oxytocin, whereas the _ nucleus secrete antidiuretic hormone
supraoptic - oxy
paraventricular - ADH