Module 1 Flashcards
physiology
-body functions
-multiple organs work together
-“why” & “how”
integrative system - unifying separate organs
what is the human body made up of?
water
water is inside and out of cells. what are the biological terms for this?
intracellular - inside cells
extracellular - outside cells
what does it mean for the body to be in homeostasis?
normal range/state of balance
ability of organisms to keep relatively stable internal environment in face of changing external conditions
what throws the body off balance?
variable
what is counter response and how does it play into negative feedback?
variable is what throws the body off balance. counter response is a reply to the variable - negative feedback is all about bringing the body back to normal range and the counter response aids min that.
what maintains homeostasis in the body?
negative feedback
what are the extreme low and high levels of ph?
low: acidic
high: alkaline
what are the ranges for blood glucose
hypoglycemia 0 hyperglycemia
how is body temperature an example of homeostasis?
body temperature is an example of homeostasis because the body senses a change in temperature above or below 37 C and alerts the hypothalamus to bring it back to the original set point.
how is blood staying within a certain ph range a form of homeostasis?
explain how blood glucose is regulated when it’s too high.
glucose is sugar.
when you eat, blood glucose rises.
when blood sugar is too high, insulin is released (“feed me”) so that it can make cells take in glucose, stores glucose in muscles, liver & fat for later energy use.
explain what happens when blood glucose is too low
glucagon is released, causes liver to release glucose into blood - prevents from blood glucose from dropping too low.
explain how blood glucose is an example of homeostasis
blood glucose is either regulated by insulin or glucagon. glucagon helps prevent it from dropping too low and bringing it back to the set point by causing liver to release glucose into the blood and insulin is released when there’s too much blood glucose and forces cells to take in the glucose to be stored for later usage. together, the hormones glucagon and insulin control blood sugar levels and keep them within the set point.
what are sensors, stimulus and effectors?
sensors: sense change / effectors: cause response
stimulus: center that compares current conditions to the set point
stimulus is measured by sensor (input) - often neurons that measure chemicals & temperature.
what is positive feedback?
does not keep the body in homeostasis; amplifies the stimulus
less common in body, amplifies effect of disturbance, response makes initial stimulus greater, drives system to an extreme
difference between stimulus and sensor
explain how the body would react in extreme Texas heat (high body temperature) and explain whether this is negative or positive feedback
1) nerves (sensors) - heat detection
2) brain is notified and sent signals to counteract variable
3) sweat glands: activated & heat lost as sweat evaporates off skin
4) skin turns red
5) blood vessels dilate to get rid of heat
body temp lowered!
this is negative feedback because the original variable threw the body off of balance and the counter response brings the body temp back to 37 C
explain how AC blasting relates to homeostasis and what type of feedback it is
1) sweating profusely so AC helps to stop the sweating
2)muscle contractions (tightening, shortening muscles when you hold/pick up something, stretch, or exercise with weights) - shivering caused and it generates heat
3) blood vessels - constrict to conserve heat to make it hard to escape
body temp brought back to stable point!
this is a form of negative feedback because the variable originally was throwing the body out of balance because it’s too hot and the counter response of the outside variables (AC) would serve as the counter response and help bring the body to a stable body temperature.
how does a baby being born relate to homeostasis and what type of feedback is it?
1) pressure on the cervix
2) pressure & hormones cause contractions of uterus
therefore, more hormones cause more contractions & pressure —- releasing more hormones and more contractions & pressure - hence it is positive feedback because it is amplifying the variable
cellular respiration
series of chemical reactions that break down glucose to produce ATP
explain Type 1 Diabetes
pancreas makes hormones but for patients that have diabetes, there is no proper hormone production - therefore insulin (which is a hormone) is not released so blood sugar is not able to go into cells. blood sugar (glucose) outside of cells cannot be used in cellular respiration (chemical reaction that break down glucose to produce ATP) - ATP is the energy produced from cellular respiration breaking down glucose.
so because cells have to take in glucose to make ATP energy in cellular respiration - diabetic patients don’t have the hormone insulin present to make that process work. therefore, patients have to give themselves insulin and monitor their glucose because negative feedback doesn’t work the way that they should.
diabetic patients monitor blood sugar because too much glucose can cause damage to organs over time. low blood sugar is typically treated by eating fast acting carbs (sugars) like juice, soda, candies. type 1 diabetics only inject glucagon if it’s extremely low
solution for type 1 diabetes patients: give themselves insulin and monitor blood sugar cuz negative feedback doesn’t work as it should.
what does anatomy answer
“what”
purpose of concept maps
organize thoughts & connections between different ideas and concepts
organ systems
made up of different organs and tissues working together for one major function
difference between external environment and internal environment
external: parts of the body directly connected to the outside
internal: material from external environment brought into body across epithelial cells, & into blood vessels which circulate material to rest of the body. This is also how body removes waste from internal environment.
epithelial cells: type of cell that covers the inside and outside of surfaces of your body.
external: gastrointestinal, respiratory, urinary, skin & reproductive
internal: endocrine, nervous, cardiovascular, immune, muscles
why is gastrointestinal part of the external environment?
digestive open from mouth to anus. when you eat - if it’s digested but not absorbed into cell, it passes through the mouth, esophagus, stomach, intestines and out the anus.
it stays in external environment part of the intestines.
when a molecule is absorbed on outside into the body, it crosses into one of the cells.
how does the body regulate the internal environment?
through negative feedback to maintain homeostasis even as external environment changes
what does the total body water consist of?
def: all of the water in all the body’s internal compartments (not including digestive tract and other external components)
total body water - inside cells (intracellular fluid) ICF & outside cells (extracellular fluid) ECF
within ECF: plasma (liquid in blood) & interstitial fluid (fluid outside other cells like neurons and muscles)
interstitial fluid - not in cell or blood vessel - basically everything else
why is interstitial fluid considered to be part of the internal environment?
what is interstitial space?
because it is OUTSIDE of the cells but still inside the body. don’t confuse this with intracellular fluid because that’s talking about being INSIDE the cells.
the area outside of cells is interstitial space
how much of the total body water (TBW) is in ICF?
2/3
reproductive system
generate offspring
gastrointestinal system
breaks down food and absorbs into body
urinary system
filters blood to regulate acidity, blood volume and ion concentrations
eliminates waste
respiratory system
O2 into body
CO2 out
cardiovascular system
transports molecules throughout body in bloodstream
helps move material from 1 part of body to another
musculoskeletal system
supports body
allows voluntary movement
facial expressions
immune system
defends body against pathogens and abnormal cells
pathogens: organisms causing disease to its host
integumentary
protects body from external environment
endocrine system
provides communication between cells of body through release of hormones into bloodstream
regulates all biological processes from conception to old age like metabolism, growth, sexual function, heart rate, blood pressure, appetite, body temp, sleep & waking cycles
uses hormones to send messages to target cells through blood
nervous system
uses electrical impulse to send messages through neurons
neurotransmitters: body’s chemical messengers. carry messages from one nerve cell to next nerve, muscle or cell. these messages help you move your limbs, feel sensations, keep heart beating, and take in and respond to all information your body receives from other internal parts of body and environment
difference between nervous and endocrine system
endocrine: produce hormones - involuntary - transmitted through blood vessels - hormones can be either
nervous: send signals in form of nerve impulse - can be both voluntary and involuntary - transmitted by nerve cells called neurons - nerve impulse are short-lived efforts - involved in transmitting and interpreting sensory information (endocrine isn’t)
mass balance / input & output / law of mass balance
def: balance what comes into and leaves body & helps body maintain homeostasis of water & solutes
solutes: substance that is dissolved in a solution
purpose: to maintain constant level, output must equal input
ex) amount of water that comes in is same amount that goes out
mass balance consists of input and output
input: intake through intestine, lungs, skin (through what we eat, breathe etc) - leading to metabolic production (diff chemicals produced in bodies through chemical reactions)
output: excretion by kidneys, liver, lungs, skin (urine, feces, sweat) - process: metabolism to a new substance (chemicals going through more chemical reactions to become more substances)
law of mass balance:
mass balance = existing body load + intake (metabolic production) - excretion (metabolic removal)
why does homeostasis act in particular on extracellular fluid?
to maintain correct amount of water & molecules outside of cells - which allows cells to function properly
normal range of body
37 C (98.6 F) but remember that it’s within a range. 37 is ideal but can fluctuate a couple diseases but that’s normal
-regardless of outside weather
-body temp always fluctuates
-if body temp too high, body has a way of bringing it back to normal range (ex of neg.)
negative feedback
maintains homeostasis & opposes stimulus
keeps parameters steady
decreases effect of initial disturbance
if something increases, body acts to decrease it
explain how cruise control of a vehicle is an example of negative feedback
1) setting speed as “set point”
2) car goes up hill
3) stimulus: speed goes down because of having to go up - engine senses error hence more gas flow to engine increases
4) speed increases (response) - error signal decreases - car goes back to set point
this is an example of response opposing stimulus — notice how stimulus and response are opposites. in positive feedback, the stimulus increases, hence it stays the same.
summary:
stimulus: car slows down below set point
response: car goes faster to return to set point
example of temperature control in a fish tank if temperature drops and if it rises
include sensors, integrating center,
1) fish tank set to desired temperature
2) sensors (thermometer) - that sense the temperature
3) control box (integrating center) - compares current temperature to set point and initiates response if temp below set point - control box turns on heater to warm up temperature.
integrating center gets information from the sensor.
effectors: cause response
drops:
heater turned on to get back up to set point since temperature has dropped
effector: heater (physical object)
response: heating up water
^^ this is an act of opposing the initial stimulus because the temperature was again brought back to the original desired set point.
rises:
temperature goes above set point, heater turns off to let water cool down - because the control box is only able to generate heat and not cool air.
why do our bodies control internal parameters in both directions?
so that we can always stay near set point
how do effectors in human body change response levels
as dials - refer to image.
effectors: cause response - dials in body to sense change by sensors and effectors actually do something about it.
key components of negative feedback
1) input: stimulus measured by sensor (often neurons that measure)
2) integration: something needs to take information from sensor and compare it to set point
integrating center typically in nervous and endocrine systems
3) response: integrating center relays signals to cells/tissues (effectors: cause response) to bring about final response
(effectors are objects & response is action)
thermostat example - seeking to increase the room temperature
if room temp is lower than set point, heater turned on.
how? - thermostat senses low temperature than set point, therefore turn on.
once the temperature returns to desired set point, the heater will be turned off
sensor: thermometer
thermostat: integrating center
measuring: room temperature
stimulus: lowering temperature
effector: heater - because it’s causing the response
response: heat goes up
(refer to picture)
regulation of body temperature on a cold day and the 3 responses generated - and how this is an example of negative feedback where the response opposes the stimulus
stimulus: low body temperature
^^^ sensed by: sensors (thermo-receptors in skin and hypothalamus) which are neurons
hypothalamus function: keeping body in homeostasis and is located in brain
sensors are able to sense that the body temperature is lower than the set point - so sensors alert the hypothalamus which is the integrating center because it is comparing the current conditions of low body temperature to the set point and the hypothalamus has sensed that something needs to be done. therefore, it can generate 3 responses.
1st response: effector: skeletal muscles contract - this is an effector because muscles are an object - causing a response: shivering which generates heat by using a lot of ATP - leading to high body temperature - hence opposing the stimulus of low body temperature
remember: During aerobic cellular respiration, glucose reacts with oxygen, forming ATP that can be used by the cell. ATP is essentially stored energy
2nd response: you put a coat on because you are cold - this is an example of changing behaviors but if you didn’t have a coat, 1st response would happen most likely
3rd response: blood vessels get smaller (remember this is effector because vessels are an object) - response: vessels vasoconstrict because it will create less heat loss through skin because vessels are preserving heat by becoming smaller. vessels are contacted because heat is carried in blood. typically heat leaves blood through skin but vasoconstriction helps you to hold onto the heat.
why does your body generate a fever when you’re sick? and how is this an example of negative feedback?
purpose of having a fever: controlling body temperature to help kill off infection. high temp kills viruses and bacteria
hypothalamus: keeps body in homeostasis
when sick, set point changed by hypothalamus to higher level to kill off functions
body initiates warming behaviors to help produce higher temperature and fever by causing shivering and vasoconstriction
once infection is gone, set point wants to go back to normal but you’re hotter than usual so people typically get fever breaks where sweating and vasodilation is caused to generate cooling behaviors
example of running but passing out due to past burns
pt’s body temp was too high so they passed out - but found out that pt has burns from 5 years ago so the body no longer has sweat glands so they’re unable to cool off, hence causing a heat stroke and causing passing out
why do you get warmer during running
muscles require a lot of energy during contraction (tightening of muscle)
contractions:
muscles rely on ATP (stored cellular energy from process of cellular respiration) … ATP is made by breaking down glucose (body’s main source of energy, comes from the food you eat) … leading to heat production and body is able to do that because of the energy stored
so during runs, muscles make lots of ATP, causing lots of heat
which later causes sweating that lowers body temperature back to normal
why do we shiver when we’re cold
muscles contract, helping to produce heat with ATP - to help higher up body temperature with stored energy (ATP)
what is ATP responsible for
cellular movement, muscle contractions, nerve impulse transmissions, protein synthesis
requires O2, produces CO2
Cellular respiration converts ingested nutrients in the form of glucose (C6H12O6) and oxygen to energy in the form of adenosine triphosphate (ATP). CO2 is produced as a byproduct of this reaction.
heat exhaustion vs heat stroke
heat exhaustion: get too hot - excessive sweating - causes faint, dizzy, sweating, cool skin, n&v, weak pulse, muscle cramps - cooler environment helps, water, & cold showers
heat stroke: too much heat, but body isn’t responding - hence no sweat, so body is unable to cool down - medical attention necessary. heat stroke causes headache, confusion, no sweating, 103 F, red skin, vomit, strong pulse and loss of consciousness - solutions: don’t drink anything, cool bath, cooler place
regulation of osmolarity by kidney
baroreceptor reflex to maintain blood pressure
if blood pressure increases above normal, baroreceptors in major arteries detect the change and send signals to brain.
certain areas of the brain then send signals to nerves that control heart and blood vessels to make heart beat slower and blood vessels increase in diameter, which in turn reduce the blood pressure.
baroreceptors: send signals to the brain and the signals are interpreted as a rise in blood pressure. The brain sends signals to other parts of the body to reduce blood pressure such as the blood vessels, heart and kidneys.
negative feedback
heart rate
controls how much blood leaves heart & how much blood goes to other tissues
why would we want to increase blood flow during exercise?
sympathetic nervous system: network of nerves that helps body activate fight or flight & activated when stressed, in danger or exercising
when you exercise, sympathetic nervous system is activated - releasing epinephrine into blood (adrenaline)
adrenaline makes your heart beat faster and lungs breathe efficiently - causing blood vessels to send more blood to brain & muscles, increases blood pressure, makes brain more alter, and raises sugar level in blood to give energy and adrenaline also delivers more oxygen to muscles
blood vessels
keep blood flowing, supplying tissues with oxygen and nutrients and keep organs such as the heart healthy
regulation of heart rate during exercise
1) active muscles (use oxygen) - when cells are active they need oxygen to make ATP, which is used for energy for our muscles.
2) oxygen decreases, CO2 increases (stimulus) cuz stimulus is decreased O2 since muscles are using O2
(there are sensors that can measure oxygen and carbon dioxide)
3) brain - integrating center
4) activate sympathetic nervous system (“fight or flight”)(object so it’s effector)
there can be multiple effectors in this scenario:
heart because heart rate goes up
epinephrine because heart rate goes up
sympathetic nervous system because we release epinephrine
(it all depends on which part of the pathway we’re looking at)
5) sympathetic system release epinephrine, increased heart rate -> increased blood flow -> more oxygen to active muscles because oxygen is carried in blood on red blood cells -> something is happening (response)
example of negative feedback because response opposes stimulus
how to count resting pulse rate: count pulse for 30 seconds. multiply by 2
how to count heart rate after exercise: after exercising, count pulse for 30 second and multiply by 2
heart rate increases during exercise because
-increasing O2 delivery to muscles (this is the purpose)
-adrenaline rush (epinephrine) signals for heart beat faster (this is the mechanism for signaling the heart to beat faster)
LH surge causes ovulation (+)
LH: hormone that signals ovaries to release estrogen (sex hormone responsible for development and regulation of female reproductive system) (estrogen is a hormone that travels in blood and signals other cells)
pituitary (releases several hormones that carry out bodily functions like growth, development and metabolism)
estrogen signals pituitary to release more LH - both LH & estrogen increase rapidly
increase in LH and estrogen cause egg to be released from ovary once a month during menstrual cycle - causing ovulation (release of egg in fallopian tubes)
if consuming birth control: affects this whole system because it inhibits (prevents) pituitary. birth control contains estrogen and progesterone. but estrogen is at a low concentration. prevents pituitary from releasing LH in the first place.
if your body is above the set point
blood flow to skin will increase via vasodilation of blood vessels because it’s trying to get rid of the heat
wouldn’t start shivering because you’re not preserving the heat
you can technically bring it down by going to the shade as that is a form of changing behaviors but blood vessels dilating to get rid of heat is better
you will not definitely have a heat stroke because you don’t always have heat strokes, that only happens if your body isn’t able to respond properly
positive feedback example - hormone regulation of uterine contractions during birth because you need more hormones, contractions and pressures to push baby out
not insulin regulation of blood glucose levels because insulin
not body temperature regulation when you go from a very hot environment into a very cold room because body temp is brought back to a stable point
We learned that fever is not a failure of homeostasis, in fact it demonstrates how well the body can control body temperature. What causes a fever? - C
a) sensors become effectors as well. no because sensors sense change and effectors cause change. it can never be the same thing.
b) hypothalamus becomes less active - no because hypothalamus is in charge of homeostasis
c) set point becomes higher - YES because set point which is the body’s normal temperature of 37 C becomes higher by the hypothalamus to kill off fever
d) sensors no longer send signals to integrating center -
water in red blood cells
intracellular
water that surrounds blood cells
plasma
what 3 places is water found in
intracellular, extracellular and —
which environment does homeostasis care about
internal - not external
internal because it’s making sure that the body has enough water, right levels of ions and sugars, right temp
reproductive system - external or internal
external
what does the digestive tract consist of
mouth to anus - part of external
why is mouth part of external
inside of mouth is same as air outside
fluid inside blood cells is intracellular. how
because it is INSIDE of a cell.
ex) when you take a blood test, doctors spin it to separate plasma from cells
what environment is extracellular apart of
internal because it is inside of the body. external is everything out of the body. extracellular is fluid outside of cells
what is almost always the center
neurons (nerve cells) - they can be from the brain, skin
can be endocrine cells - hormones
integrating center almost always going to be the brain - hypothalamus is a major center
negative feedback: regulating blood pressure
something happens and our blood pressure goes up
baroreceptors that sense blood pressure that sends signals to cardiovascular center in medulla (brainstem)
medulla: regulates heartbeat, blood pressure, and breathing
medulla activates parasympathetic nervous system and tells the heart rate to decrease, which leads to decreasing blood pressure
stimulus: high blood pressure
response: lowered blood pressure
effector: parasympathetic nervous system (effector causes response of decreased heart rate and decreased blood pressure)
(heart rate and high blood pressure cannot be an effector because it is not an object.)
sensors: baroreceptors (sensors send information to integrating center)
cardiovascular center in medulla: integrating center (medulla would be the set point because it regulates blood pressure and it senses that something’s wrong)
parts of negative feedback
-stimulus sensed by sensors
-information sent to integrating center (activates, inhibits effector)
-effector causes response
negative feedback of pressing brake on car when going over speed limit
sensor: speedometer and eyes
driver: integrating center (know the set point of area)
sensory input from speedometer
effector; foot and brake
response: slow down
examples of positive feedback
hormone #1 causes release of hormone #2, which stimulates release of #1 (estrogen and LH)
exponential growth of human population - more people you have, more children you’ll have and so one
a broken heater that is always on, even during summer (why is this not either negative or positive feedback)
it’s not responding to any type of stimulus, it’s just broken,
during a blood clot, platelets release ADP, which stimulates platelet aggregation, causing platelets to release more ADP
blood clots: break blood vessel open but you don’t bleed out because blood clots form to block off energy
ADP: signal
platelets release ADP, causing platelets to aggregate and release more ADP
positive feedback
at the time of birth, uterine contractions push baby towards cervix. receptors in cervix detect the pressure caused by the baby and cause the release of a hormone called oxytocin. this hormone stimulates stronger uterine contractions, which push more on the baby, causing an increase in pressure and another increase in oxytocin. the cycle continues until the baby is delivered from the mother.
positive feedback
consumption of caffeine increases urine output causing dehydration
neither
you consume caffeine. caffeine is a diuretic, produces urine output and become dehydrated. there’s no responses or stimulus.
but if the problem had said that you become thirsty, leading to drinking more caffeine, causing more dehydration - that could possibly be a form of positive feedback
