Test 3 Flashcards
How do we find the rate of air flow
Difference in pressure between atmosphere and intra-alveolar pressure
divided by the resistance of airways
What causes air to move into the lungs
when the pressure in the lungs is less than the pressure of the atmosphere
How does the diaphragm cause inspiration
the diaphragm contracts decreasing pressure in the thorax, causes the lungs to expand, which causes the pressure to go down, and air rushes in
How does the diaphragm affect inspiration
it relaxes, increasing pressure in the thorax, which causes the lungs to shrink, increasing pressure, forcing air out
What is boyles law
p1v1 = p2v2
The greater the pressure the less the volume
the less the volume the greater the pressure
less pressure = more volume
more volume = less pressure
How do the intercostals affect breathing
contraction leads to increased rib cage = increase volume of lungs = decrease pressure = inspiration
relaxation = decreased rib cage size = less volume in lungs = more pressure = expiration
contraction of the abdominals does what to inspiration and expiration
contraction leads to expiration, relaxation leads to inspiration.
What is pneumothorax, what happens
when air gets into the plural cavity, it gets rid of the negative intrapleural pressure in the pleural sac. so the increase in pressure there causes the lung to collapse
what is the primary way to regulate air flow into the lungs
the radius of the conducting airway
what controls the radius of the conducting airway
the autonomic nervous system
sympathetic - relaxation of smooth muscle = bronchodialation
parasympathetic = contraction of smooth muscle = bronchoconstriction
What is compliance
distensability - the ease with which lungs expand under pressure
(The lungs must be compliant for inspiration)
What is elasticity
Tendancy to return to size after being stretched
lungs must be elastic for expiration
What is it that makes the lungs elastic
the high content of elastin in the lungs
how often are the lungs under elastic tension
constantly, it increases with inspiration and decreases with expiration but it never goes away
what happens as lungs become less compliant
they become harder to expand and therefor it requires more work to inflate them
What is surfactant
A fluid secreted by the lungs that decreases the surface tension within the alveoli
Where does surfactant come from
type II alveolar cells
What is the result of surfactant decreasing the surface tension within the alveoli
it leads to increased compliance and decreased tendency to recoil
Why is it bad to not have surfactat
the lungs become really hard to inflate because of low compliance, the lungs will often collapse
What is respiratory distress syndrome
surfactant is produced late in fetal developpment, so often premature infants don’t have enough surfactant and thier lungs are hard to inflate and often collapse
What is a spirogram
The thing that measures lung volumes, inspiration and expiration
What is tidal volume TV
the amount of air inspired and expired during normal breathing (Middle portion on spirogram)
What is inspiratory reserve volume IRV
how much more you could breath in more than how much you normally do ( big peak )
What is expiratory reserve volume ERV
how much more you could breath out than you normally do. (big dip)
What is residual volume (RV)
the difference between 0 volume in the lungs and how much you have when you do a maximal expiration. (between bottom of graph and low dip)
What is Inspiratory capacity IC
how much you can breath in, includes tidal volume and max inspiratory volume (IRV + TV)
What is Vital capacity VC
the maximum amount of air that can be inhaled and exhaled ( tidal volume + IRV + ERV)
What is functional reserve capacity FRC
the difference between no volume in the lungs to the bottom of tidal volume ( ERV + RV)
what is total lung capacity
the total amount of air the lungs can hold, from 0 to top of max inspiration (IRV + TV + ERV + RV)
What is FEV1
Forced expiratory volume
the maximum amount of air that can be expired in one second after max inspiration
What is anatomical dead space
the air passageways (150 ml)
what is minute respiratory volume
and how do you find it
the amount of air inhaled or exhaled during one minute of breathing
MRV = TV * Rate of breathing
what is minute alveolar ventilation
the amount of new air entering the alveoli per minute
how do you find minute alveolar ventilation
MAV = Rate * (TV - Dead space)
rate is # of breaths per minute
what happens to minute alveolar ventilation after exercise
it increases
What is obstructive lung disease
an increase in resistance in air pathways
causes dificulty in expiration
What are two types of obstructive lung diseases
Asthma
Chronic Obstructive pulmanory disease (COPD)
What is asthma
airway obstruction due to inflammation, mucous secretion, brachoconstriction
what can cause asthma
allergic reaction
exercise
infection
What are the two main types of COPD
Emphysema
Chronic Bromchitis
what is emphysema
desctuction of alveoli = larger but fewer alveoli
this leads to decreased area for gas exchange and can lead to the bronchiolies collapsing
(caused by smoking)
What is chronic bronchitis
lower airways are chronically inflammed
airways swell, thicken and produce mucus. the mucus doesn’t move because the cillia are damaged
(Caused by smoking, pollution, and allergins)
what does obstructive lung diseases do to the spirometer
it decreases FEV1, and just ERV
What do restrictive lung diseases do to the spirometer
they decrease IRV, FEV1 is normal
what do restrictive lung diseases do
they decrease compliance and make inspiration dificult
What is an example of a restrictive lung disease
Pulmonary fibrosis
what is pulmonary fibrosis
it’s caused by inhaling smoke, pollution, and irritants and it causes scar tissue to build up in the lungs. this decreases compliance and diffusion of gasses
how much of our energy expenditure is used for quiet breathing
3%
When is energy expenditure for breathing increased
when pulmonary compliance is decreased (NRDS)
When resistance is increased (COPD)
When elastic recoil decreases (EMPHYSEMA)
when more ventilation is needed (exercise)
What is partial pressure
the amount of pressure each substance is contributing to the whole pressure
how to calculate partial pressure
take the percentage .05 and times it by the total pressure
What does the dorsal respiration group do
it stimulates the phrenic to incite breathing
what does the ventral respiration group do
it helps in breathing when its heavy
What does the central pattern generator do
it helps build the breathing rythym
what does the pontine respiratory group do
helps transistion between inspiration and expiration
what receptors are the most important in regulating breathing rate
chemoreceptors
what are the chemicals that are the most important in signaling to help regulate breathing rate
CO2 and H+
What are pulmonary receptors for
detect irritants - leads to caughing
to prevent excessive stretching
during normal expiration what fraction of lung volume is exchanged
1/7
what are the two ways to transport O in the blood
It can bind to hemoglobin, or it can be dissolved in the blood
What is oxygen carrying capacity
how much O the blood can hold
how does Hemoglobin affect the oxygen carrying capacity
each molecule of hemoglobin can carry some Oxygen, more hemoglobin = more oxygen
how does the % satuation of HB change
the higher the pressure of O in the blood the higher the %saturation of HB
how do you calculate the oxygen content of blood
you find the oxygen carrying capacity (how much each molecule of HB can hold)
how much HB there is in the blood then figure out the %saturation of HB and multiply capacity by % saturation
What is the Bohr effect
it states that when the CO2 pressure increases ( or the H+) the HB will release % satureation of HB by oxygen.
What are the three types of CO2 transport in blood
- DIssolved in the blood (9%)
- as Bicarbonate (64%)
- as carbaminohemoglobin (27%)
what is the function of carbonic anhydrase and where is it locate
it’s located in the blood and it turns CO2 to Bicarbonate and the other carbaminohemoglobin and vice-verse to dissolve it in the blood or allow it to be realeased
what are the three factors in blood that are important in breathing regulation
H+
CO2
Low O2
where in the CNS is breathing controlled
medulla oblongata and pons
what is the hering Bruer reflex
it prevents the over inflation of the lungs
What is the functional unit of the kidney
the nephron
What is a juxtamedullary nephron
they have a long loop of henle,
important in urine concentration
what is a cortical nephron
has a short loop of henle
What are the 4 basic renal processes
Glomerular filtration
tubular reabsorption
tubular secretion
excretion
what happens to fluid filtered by the glomerulus
it passes through
the glomerular capillary wall
the basement membrane
inner layer of bowmans capsule
What is the glomerular capillary wall like
more permiable to water and solutes than anywhere in the body
What is the basement membrane like
gelatinous layer, acellular
what is the inner layer of bowmans capsule like
has podocytes that encircle the glomerular capillaries and form slit pores
what are the four forces that determine glomerular filtration pressure
bowmans capsule hydrostatic pressure
glomerular capillary hydrostatic pressure
and both have osmotic pressure
What are the 3 factors that influence glomerular filtration rate
Glomerular Filtration pressure (GFP)
Renal plasma flow (RPF)
what is renal plasma flow
how many ml of plasma go through the kidney
how do you get the filtration fraction
GFR/RPF, how much is filtered over how much goes through
how is GFR regulated
largely by GFP, most pressures can’t be changed, but glomerular capillary hydrostatic pressure can be
how is the glomerular capillary hydrostatic pressure controlled
intrinsic and extrinsic factors
What are the two types of intrinsic control of GFR
Myogenic regulation
tubeoglomerular feedback
What is myogenic regulation as intrinsic conrtol of GFR
the muscles on the afferent artery squeeze down and don’t let as much blood to the glomerulus
What is tubeoglomerular feedback as intrinsic control of GFR
the macula densa cells detect changes in GFR
high GFR leads the macula dense cells to release adenosine, which leads to constriction of the afferent arterioles = decreased blood flow = decreased GFR
What is extrinsic control of GFR
its most important when MAP gets way off (dehydration, hemorrhage)
MAP increases to decrease urine output, which decreases blood through to the kidneys
What is filtered load
the quantity of a solute that is filtered per unit of time. take concentration of substance in blood and times it by GFR
what is tubular reapsorption
when the water and solutes filtered by the glomerulus enter back into the peritubular capillaries
What are the two types of tubular reapsorption
Active = things are transported against their gradient back into the blood
(glucose, AA’s, NA+ proximal tubules) ( NA+ distal tubules)
Passive = things move down thier gradients back into the blood
(H2O, cl-, Urea proximal)(H20 distal)
What is transport (tubular) maximun
it’s the max amount of a solute that can be reabsorbed, if the filtered load is greater that the transport maximum, some of the solute will be excreted
how does it work when transport maximum is exceeded
all of the transporters are occupied so all of the solute can’t be reabsorbed
What is tubular secretion
its the active transport of substances in the blood into the lumen of the kidney tubules
What can be removed from the blood stream by tubular secretion
H+, K+, and drugs
What is plasma clearance
measure of the rate at which substances are cleared from the plasma
how is plasma clearance expressed
volume of plasma completely cleared of the substance per minute
how is plasma clearance found
rate of urine formation * urine concentration / plasma concentration
how can filtration fraction be determined by inulin and PAH clearance
Inulin clearance / PAH clearance
How does the Renin-angiotensin system work
1) activated by a drop in blood pressure,
2) stimulates the JG cells to release renin.
3) renin turns angiotensinogen to angiotensin I
4) angiotensin converting enzyme turns Angiotensin I to Angiotensin II
What does angiotensin II do
- it causes vasoconstriction = increase in TPR (increases BP)
- it stimulates the adrenal cortex to secrete aldosterone (holds sodium in blood, which because of osmotic pressure holds more water in blood) = increase in BP
2.
How does aldosterone increase Na in blood
it opens up the Na/K channels on the luminal membrane. so more Na is resorbed in the kidney
What are the 4 ways that angiotensin II affects blood pressure
- Vasoconstriction of the systemic arterioles
- increase aldosterone in the adrenal cortex
- increase in ADH secretion from post. pituitary
- increase in thirst stimulation
Why does the body need to modify urine concentration
because if you drank a lot of water and it didn’t modify concentration, then it would throw off plasma volume, blood pressure
what are the steps involved in concentrating urine
- long loops of henle establish osmotic gradient
(greater from cortex to medulla) - Preservation of the gradient by vasa recta
- gradient dependent water absorption through the collecting ducts
How is the osmotic gradient established
by countercurrent multiplication
how does permiability of the loops of henle change
descending limb is permeable to water, not NaCl
Ascending limb is permeable to NaCl, not water
what happens to water and Na concentration through the tubes
descending limb water leaves and the solute becomes more concentrated. then as it goes up the ascending limb the water can’t enter but the Na leaves until it gets low.
What is the affect of ADH on urine concentration
it makes the collecting tubule permiable to water
what happens to ADH during de hydration and too much water
dehydration stimulates ADH to be released, which causes water to leave the collecting tubule and urine to be very concentrated
too much water blocks ADH release so that water can’t leave collecting duct and the urine is very dilute
what is vasopressin
ADH
Where is ADH from
posterior pituitary
What is aquaporin
they are water channels that are opened up by ADH
What is micturition
urination/ emptying the bladder
how is micturition controlled
- too much pee = walls expanding = sets off stretch receptors
- that leads to cause the opening of the internal urethral sphincter
parasympathetic = contraction of detruser
sympathetic = relaxation of internal sphincter - then we control the external urethral sphincter
What digestive processes happen in the mouth
Motility
Saliva Secretion
What is motility in the mouth
chewing on food that breaks it down
what are the functions of the saliva
moisten and lubricate the food salivary amylase starts to break down starch antibacterial action solvent to allow for taste buffers acid
does any absorption take place in the mouth
no, except for some drugs
what is the motility in the stomach
stores food, the contraction of smooth muscle mixes and grinds the food into chyme
what is secreted in the stomach
mucus pepsinogen HCL intrinsic factor gastrin somatosatin histamine
What is the digestion that takes place in the stomache
salivary amylase continues to break down starch
pepsinogen breaks down proteins
What is the absorption that takes place in the stomach
none, except some drugs
how is gastric emptying regulated
- Stretching leads to increased gastric contractivity
- the fluidity of gastric contents become greater
- fat in the duodenum is the most potent inhibitor of gastric emptying
- acid in the duodenum, it has to be neutralized before it can empty more in
- Hypertonicity in the duodenum
- emotion and pain
- distention of duodenum inhibits motility
what is the most potent inhibitor of gastric emptying
fat in the duodenum
what do parietal cells do
Secrete HCL and intrinsic factor
what do Chief cells do
secrete pepsinogen
what is the function of HCL in the stomach
activates pepsinogen
breaks down connective tissue and food particles
denatures proteins
kills microorganisms
what is the function of intrinsic factor
important in vitamin b12 absorption
what is the function of pepsinogen
it is cleaved to pepsin by HCL
pepsin then cleaves more pepsinogen
breaks proteins down into peptide fragments
What is the motility of the small intestine
segmentation = mixes and propels chyme
migrating motility complex = cleans between meals
What is the secretion of the small intestine
juice of the intestine protects and lubricates intestine and water (needed by hydrolysis)
no digestive enzymes
What is the digestion of the small intestine
major site of digestion
accompanied by pancreatic digestive enzymes, secretions, bile and brush border
What is the absorption of the small intestine
the site of food absorption
What does the pancrease secrete
- bicarbonate
- proteolytic enzymes
- pancreatic amylase
- pancreatic lypase
what is the function of bicarbonate
neutralizes acidic chyme because:
acid inhibits pancreatic enzyme activity
protects the small intestine from damage
what is the function of the proteoltic enzymes
they are secreted inactive, then converted to active forms by enterokinase and trypsin (trypsin is a converted proteolytic enzyme that goes and converts the others)
what are the functions of pancreatic amylase
break down polysaccharides into maltose
what is the function of pancreatic lipase
breaks down triglycerides into monoglycerides
What happens when acid is in the duodenum
secretin is released from the duodenum which leads to release of bicarbonate, which neutralizes it
What happens when there is fat in the doudenum
CCK is released from the duodenal mucosa, which causes the release of pancreatic enzymes which digest the fat
what is the function of bile
- excretion of bilirubin
- emulsification of fat (breaks down the fat globs)
where is bile from
continuously made in the liver and stored in the gall bladder
how is the hormonal release of bile controlled
Fat stimulates the secretion of CCK
CCK stimulates bile to be released from the GB
what is the brush border
folds, villi, microvili all increase the surface area for absorption. but the brushborder is specifically made by the microvilli
what does the brush border have in it
enterokinase, maltase, sucrase, lactase, aminopeptidases
how is the digestion of carbs done (whole process)
Starches - polysaccharides in mouth
polysaccharides - disaccharides in doudenum
dissaccharides - monosaccharides on brush border
Monosach absorption
(secondary active transport) into cell, facilitated diffusion into blood
How are proteins digested (whole process)
broken down by pepsin and pancreatic enzymes into small amino acid chains
then broken down into individual amino acids by brush border and absorbed
how are fats absorbed
monoglycerides are paired up with free fatty acids in the brush border cell, then they are exocytosed into the lymph
what is the motility in the large intestine
haustral contractions mix feces, and mass movements propel the feces long distances
what stimulates mass movements
the gastrocolic reflex, food entering the stomach
what are the secretions of the large intestine
alkaline mucus that lubricates and facilitates the passage of feces, sodium bicarbonate neutralizes acid from bacteria
What is the digestion of the large intestine
none
what is the absorption of the large intestine
salt and water
how does the defication reflex go
feces enters rectum and stretches it
that initiates defication reflex
internal anal sphincter relaxes, and muscle of rectum and sigmoid colon contract.
external anal sphincter is voluntarily controlled, when it opens we have defication
what are the 3 main types of chemical messagers
autocrine/paracrine
neurotransmitters
hormones
what is a paracrine/autocrine
messanger to its own cell, or to a neighbor cell
What is a neurotransmitter
released from a neuron
what is a hormone
released from endocrine glands into the blood
long distance signal
carried by blood to target cells where they regulate cell functions
what are the three categories of hormones
- peptide hormone (most common)
- Amino acids, or modified amino acids
- steroids
what are some peptide hormones
pituitary hormones
angiotensin
insulin
glucagon
What are some amino acid hormones
epinephrine, thyroid hormones
what are some steroid hormones
aldosterone, estradiol
how are hormones transported
peptide - usually just in the blood
steroid and thyroid hormones - bound by a carrier protein
how do steroid and thyroid hormones work
they bind nuclear receptors and those bind DNA, this causes altered protein expression which makes the desired response
how do peptide and catecholamines work
they bind to cell surface receptors, these then send signals which activate and deactivate all sorts of things (enzymes, channels)
What hormones are released from the posterior pituitary
vasopressin
oxytocin
tell me about vasopressin
it is synthsized in the hypotalamus
secreted from the posterior pituitary
osmoreceptors stimulate its release
inhibited by blood vessel strech receptors
what are the functions of vasopressin
vasoconstriction
increases water reapsorption
What stimulates oxytocin release
mechanoreceptors at nipple and cervix
infants cry
stress inhibits
what does oxytocin do
stimulates the contraction of the uterus during childbirth
stimulates milk ejection
what hormones come from the hypothalamus
PRH PIH TRH CRH GHRH GHIH GNRH
what do the hormones from the hypothalamus do
they stimulate or inhibit the release of the hormones from the anterior pituitary
What are the hormones of the ANterior pituitary
prolactin TSH ACTH GH LH FSH
Where is growth hormone from
the anterior pituitary
what does GH target and what does it do there
targets most tissues
promotes protein synthesis and growth
promotes lipolysis
promotes increase of blood glucose
how does GH work
it causes cell to differentiate and the liver to secrete IGF1
What is dwarfism
hyposecretion of GH
small weak muscle
increased subcutaneous fat
What is gigantism
hypersecretion of GH before growth plates close
what is acromegaly
hyper secretion of GH after growth plates have closed
What is TSH
its a hormone from the Ant pit
stimulates the secretion of thyroid hormones, and the growth of the thyroid
How is TSH controlled
Stimulated by TRH and inhibited by thyroid hormones
T4 vs t3
most of the thyroid hormone released is T4, but most in then converted to T3 because it’s more active
what do t3/t4 do
increase metabolic rate and heat production
stimulates protein synthesis and growth
t4 participates in negative feed back
yep
what is hypothyroidism
thyroid gland failure due to no TRH or TSH, or iodine deficiency
what is cretinism
hypothyroidism
low metabolic rate = growth and mental retardation, hypothermia
What is Myxedema
hypothyroidism in adults
puffy eyes
low BMR
dry rough skin
what happens with low iodine
endemic goiter because no T4 is made but TSH still tells the thyroid to grow, T4 can’t stop it
What is hyperthyroidism
Excess TSH or TRH
causes a thyroid tumor
what is graves disease
hyperthyroidism TSI bind to TSH sites goiter bulging eyes muscle weakness
