physio exam 1

level 1 critical thinking

yes/no thinking; basic thinking

level 2 critical thinking

memorization of textbook material

level 3 critical thinking

thinking of possibilities; why/how

level 4 critical thinking

the what if scenarios

level 1

is Na+ charged? name the type of critical thinking

level 2

How many Na ions and K ions are pumped through the Na+/K+ pump? name the type of critical thinking

level 3

what is one possibility that would lower the concern of sodium outside the cell? name the type of critical thinking

level 4

what would happen if you used alprazolam for anxiety?

universal structure of thought

1. Purpose of thinking >> within a point of view >> based on assumptions >> leading to implications/consequences (if correct)
2. Data and facts >> make inferences/judgement >> based on concepts/theories >> answer question/problem solve

thinking (eight structures)

1. Generate purpose
2. Raise question
3. Use information
4. Utilizes concepts
5. Makes inferences
6. Makes assumptions
7. Generates implications
8. Embodies point of view

purpose

Goal, objective, function

point of view

Frame of reference, orientation

question of issue

problem, issue

information

data, facts, evidence, observations

Interpretation/inference

Conclusions, solutions

concepts

Theories, definitions, laws

Implications/consequence

That which follows logically, effects

assumptions

Presuppositions, axioms

Question/premise (aim)

State the question/premise (laying out the problem)

Information/data (aim)

What information is needed? Is it relevant, accurate, sufficient?

Inferences (aim)

Is the inference (interpretation) logical, follow the data, plausible?

Assumptions (aim)

Did I take anything for granted, make wrong assumption? Are my assumptions one-sided, biased?

Concepts (aim)

What is the hypothesis? What are the main distinctions? What are the basic principles involved?

Point of view (aim)

What is being looked at? What are other perspectives to be considered?

Implication (aim)

How significant are the implications of the decision? If "X", what impact does that have?

clarity

Understandable, the meaning can be grasped.

* can you elaborate further?
* could you give an example?
* could you illustrate what you mean?

precision

Exact to the necessary level.

* could you be more specific?
* could you provide more detail?
* could you be more exact?

accuracy

Free from error or distortion.

* how would you check that?
* how could you find if that's true?
* how could you verify?

relevance

Relating to the matter at hand.

* how does it relate to the problem?
* how does it bear on the question?
* how does it help with the issue?

depth

Containing complexities/interrelationships.

* what factors make it a difficult issue?
* what are the complexities of the question?
* what difficulties need to be dealt with?

breadth

Encompassing multiple viewpoints.

* do we need to look at it from another point of view?
* do we need to consider other viewpoints?
* do we need to look at it differently?

significance

Focusing on the important.

* is this the most important problem to consider?
* is this the central problem to focus on?
* which facts are most important?

fairness

Justifable, not self-serving.

* do i have a vested interest in the issue?
* am i sympathetically representing the view points of others?

logic

Parts make sense together, no contradictions.

* does it all make sense together?
* does what you say fit the evidence?
* does the first line of thought fit the last?

argument

Connected series of statements/premises intended to establish a proposition/claim/conclusion. Each statement/premise has a truth value either being "true" or "false"

deductive reasoning

Directionally link premises with a conclusion.

inductive reasoning

Specific observations that lead to general conclusion with a certain level of probability. Occam's razor/law of parsimony: simple solutions are more likely correct than complex ones. Formulation of a hypothesis.

sound

Valid and all premises are true.

cogent

Strong and all premises are true.

first messenger

what messenger systems are only extracellular?

examples of first messengers

hormones or neurotransmitters

negatively charged

proteins have what charge?

ligands

what are first messengers considered?

ligand

something that binds to a binding site

example of a ligand

growth hormone binds to the GH receptor

agonist or antagonist

what two ways can first messengers/ligands act as?

multiple hormones without changing the whole protein but rather cut sections to form different hormones

what can be derived from one precursor protein?

agonist

gives physiologic response directly

antagonist

blocks physiologic response

example of agonist

acetylcholine binds to ACTH receptor to cause an action potential

example of antagonist

atropine which blocks parasympathetic and only allows sympathetic

categories of first messengers

autocrine, endocrine, paracrine

autocrine

cell releasing a hormone is stimulated by the same hormone that was released

paracrine

cell releasing a hormone stimulates a cell that is nearby

hormone has a half life where they can only travel a short distance and still be effective

what is a characteristic about a hormone from paracrine?

endocrine

cell releasing a hormone stimulates a cell far away

endocrine

type of first messenger system where a hormone can go through the bloodstream and the hormones have a long half life?

* neurons can release neurotransmitters to affect another neuron that is similar to paracrine
* neuroendocrine secretion

what ways can neurons release neurotransmitters?

neuroendocrine

neuron can release a hormone into the blood stream

receptor protein

what is needed on a lipid bilayer?

first messengers are charged, so they are hydrophilic and not lipid soluble so they need receptors to allow those messengers to enter the cell

why do first messengers need protein receptors to interact with the cell?

it is hydrophobic and lipid soluble and its embedded through the membrane

what does it mean when membrane bound receptors are neutral?

amino acid derived first messengers

* Tyrosine and O2 form DOPA with the help of tyrosine hydroxylase that catalyzes the formation of DOPA where it is also the rate limiting step


* when the CO2 is removed from the DOPA, it will convert into dopamine
* adding oxygen to dopamine converts it to norepinephrine NT, a sympathetic post ganglionic neuron
* adding a methyl group to the norepinephrine NT forms epinephrine where it converts a neurotransmitter into a hormone
* cells can modify the steps to get what it needs

rate determining step

always the first step in a mechanism

basal ganglia

where is the neurotransmitter dopamine found?

protein derived first messengers

* multiple hormones derived from one protein
* proteins are put into vesicles for post-translational modification
* pro-opiocortin is broken down in response to stress where the alpha and beta melanocyte SH is released to lower stress coming from sun burn
* ACTH releases cortisol which adjusts the body’s metabolism to help deal with stress

* one hormone at a time ( example the pre-proinsulin will form only insulin
* pro-opiocortin forms multiple different hormones at once from that protein

2 ways of post-translation modification

large protein that is broken down in the RER and golgi

pro-opiocortin

adrenocorticotropic hormone (ACTH)

causes release of cortisol from adrenal cortex

endogenous opiates

act as negative feedack for pain

cholesterol-derived first messenger

* squalene can be used to make cholesterol
* cholesterol used to make vitamin D and steroids like progesterone
* cholesterol is passed through the kidney and liver where when it is hit with UV radiation, it will convert to vitamin D
* cholesterol can also form to pregnenolone with cholesterol desmolase which is the RDS
* pregnenolone is then converted to progesterone which then with the usage of 21-hydrolase, it can be made into glucorticoids and mineralocorticoids

example on pregnenlone

like a river system where if you have a mutation in the enzyme, it is like a dam and accumulates precursor hormone that causes issues

function of vitamin D

absorbs calcium in the intestine

function of progesterone

* first messenger that functions to maintaining the uterine lining
* used to make other steroid derived first messengers

glucocorticoids

* example: cortisol
* involved with glucose metabolism and availability under stress

mineralocorticoids

* example: aldosterone
* responsible for maintaining and regulating Na+, K+, and acid levels in the body

what can progesterone make besides the corticoids?

* can form androgens for makes to allow the formation of the male reproductive tract and give male secondary sex characteristics
* can also form estrogen from androgens to allow ovulation in females and spermatogenesis in males

* progesterone cannot be converted to glucocorticoids or mineralcorticoids which results in increased levels of androgens

what happens when 21-hydrolase is mutated?

* in females it causes development of male sex characteristics and organs
* in males, it can cause precocious puberty (early)

what happens when there is an increased level of androgen?

secondary messenger

* used only if the first messenger are hydrophilic where a receptor protein is required
* all signaling that happens within the cell that can alter a cell’s function

example of a secondary messenger system with the nicotine receptor/Na+

* acetylcholine (ACH) acts a ligand to bind to the nicotine receptor
* when the ACH binds to the receptor, it changes the shape of the receptor to allow the Na+ to enter the cell to cause action potential
* ACH is an agonist to cause physiologic change and Na+ is the secondary messenger

* ACH is an agonist as it confused a physiologic change to allow action potential
* Na+ is the secondary messenger to move intracellularly to alter the cell function and alter the membrane potential

what does the ACH and Na+ do in the Na+/nicotine receptor?

second messenger with G-proteins

* agonist ligand binds to extracellular receptor which causes the alpha G-protein subunit with GTP to break off
* the alpha G-protein with GTP activates the adenylate cyclase enzyme to convert GTP to GDP
* The activated adenylate cyclase to convert ATP to cyclicAMP
* cAMP can go on to activate protein kinase A
* activated protein kinase A can phosphorylate a target protein to turn on or off such as tyrosine

G-proteins

secondary messengers and are made up of 3 subunits (alpha, beta, and gamma) where the alpha subunit is associated with GTP

Inhibitors (GI-proteins) or stimulatory (GS-proetein)

What can G proteins be?

* after adenylate cyclase is activates, the alpha subunit will have GDP attached
* the alpha subunit will break off the GDP and attach a new GTP molecule
* the alpha subunit with new GTP will go back and attach to the rest of the G protein

in the second messenger with G protein, what happens during the recirculation of the alpha subunit?

* when the adenylate cyclase turns off, the cell needs to eliminate excess cAMP to prevent activation of protein kinase-A
* cAMP phosphodiesterase ( made from calmodulin) breaks down excess cAMP

what happens when we need to eliminate excess cAMP?

* alpha subunit with GTP activates phospholipase-C
* the phospholipase-C can break down phospholipids, like PIP2 to form IP3 (inositol) and DAG
* IP3 binds receptor on smooth ER and opens calcium channels within it to either pump in calcium or pump out
* calcium and DAG activates protein kinase-C
* protein kinase C will then phosphorylate the target protein such as serine or threonine

what steps can occur when a ligand binds receptor to cause the alpha subunit to break off in relation to phospholipase C

* calcium released from the smooth ER will also activate a protein called calmodulin
* activation of calmodulin will increase the activity of cAMP phosphodiesterase
* cAMP phosphodiesterase is responsible for eliminating excess cAMP in the other G-protein pathway
* an increase in cAMP phosphodiesterase can also equal a decrease in cAMP to inhibit other G-protein pathways

example of two second messenger systems working against each other

adds phosphate to tyrosine found on the protein

what does protein kinase A do?

adds phosphate to serine or threonine found on protein

what does protein kinase C do?

second messenger system with receptor kinases

* ligand binds to receptor kinase such as insulin or a growth factor
* receptor kinase phosphorylates the target protein by asdding a phosphate to tyrosine

insulin and growth factor

types of receptor kinase

* ligand such as growth factor binds to 2 receptor pieces to have them pulled together
* once the receptor is pulled, the receptor will pull two kinase pieces to add a phosphate in a tyrosine
* this can also be known as Janus J4K

second messenger system to involve growth factor, receptors, and kinases

the embryonic GI tract derives from the endoderm

as it develops, it creates finger like structures that eventually break off to form endocrine glands

the finger like projection is the diverticulum which is attached to the GI tract

when the diverticulum stays attachd, it will for ma duct into the GU tract and the diverticulum will become an exocrine gland

diverticulum for the pituitary is the ratkes pouch

what is the development of the endocrine system?

* occurs at the embryologically roof of the mouth
* the diverticulum for the pituitaru is called the rathke’s pouch
* and extension of the hypothalamus grows out towards rathke’s pouch
* when the hypothalamus and rathkes piuch come together, the patkes puch pinches off and attaches to the hypothalamus extension creating a pituitary gland
* the hypothalamus will then create the posterior pituitary

whar is the development of the pituitary gland?

posterior pituitary gland or neurohypophysis

what does the hypothalamus extension create?

anterior pituitary and adenohypophysis

what does the rathke’s pouch form?

* two neurons that extend from the hypothalamus to the posterior pituitary
* 2 hormones are released form the psoterior pituitary

what happens in the posterior pituitary?

antidiuretic hormone (ADH)/vasopressin and oxytocin

what are the 2 hormones released from the posterior pituitary?