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Bio14 - Harry Bernheim
AAAA
94
Biology
Undergraduate 1
04/15/2013

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Cards

Term
Homeostasis - definition & examples
Definition
Keeping a physiological parameter within a narrow range in the internal environment (blood pressure, blood glucose, cellular/blood CO2, etc.)
Term
Reminder: why do animal cells break/lyse more easily than plant cells?
Definition
Plant cells have rigid cell walls
Term
Negative feedback system - definition & examples
Definition
Limits change in system

Blood glucose
Term
Positive feedback system - definition & examples
Definition
Increases chance in system

Blood clotting, cell signaling cascades, some hormone control systems
Term
Why are most homeostatic systems negative and not positive feedback?
Definition
For most processes, compounding the change will be detrimental (e.g. if body temperature keeps going up, eventually you will die)
Term
Set point

Error signal

Role in physiology
Definition
Ideal level of the variable

(Set point - Actual level)

Negative feedback system decreases error signal & changes controlled physiological variable back towards the set point
Term
Afferent vs. Efferent pathways
Definition
Afferent pathway AFFECTS the change (e.g. neurons going to brain), efferent pathway EFFECTS the change (e.g. signal along nerves from brain to effector organ)
Term
Main function of & role of homeostasis in respiration
Definition

Function: to maintain levels of CO2 and O2 in body tissues via lungs

 

Homeostatic systems help maintain ideal levels of O2 and CO2

Term
Main fucntion of cardiovascular system & role of homeostasis
Definition

Pick up O2 from lungs & deliver it to tissues; pick up CO2 from tissues & deliver it to lungs

 

Maintenance of mean arterial pressure

Maintenance of adequate oxygen delivery to tissues during rest & exercise

Meaintenance of CO2 levels in tissues during rest & exercise

 

Term
Biochemical/internal respiration
Definition
production of ATP by mitochondria from food energy
Term
Physiological/external respiration
Definition
Mechanics of moving O2 from atmosphere to lungs/tissues and moving CO2 from lungs/tissues to atmosphere
Term
Effects of altitude on partial pressure of oxygen & atmospheric pressure
Definition

Lower altitude --> higher atmospheric pressure --> higher partial pressure of oxygen

 

Higher altitude --> lower atmospheric pressure --> lower partial pressuer of oxygen

Term
Henry's Law
Definition

How much gas can dissolve in a solution

 

C = k x P

C: molar concentration of dissolved gas

P: partial pressure of gas

k: solubility constant of gas in solvent

Term

Equilibration

 

Relevance of equilibration to physiology

Definition

Gases move between water & air by going DOWN a partial pressure gradient - over time, partial pressure in water will equal that of air

 

Diffusion of O2 and CO2 from lungs (air) to blood (water)

Term

How much more soluble are O2 and CO2 in water than in air?

 

Why is CO2 20x more soluble than O2 in water?

Definition

O2 is 1.7x more soluble in water than in air

CO2 is 34x more soluble in water than in air

 

CO2: H2O is slightly polar (negative O and positive Hs) --> weak hydrogen bonding between O in CO2 and H in H2O

 

O2: Weak Van der Waals bonding that is weaker than hydrogen bonds

Term
How does heating water affect dissolved CO2 and O2?
Definition
Heat water --> increased kinetic energy --> fragile hydrogen bonds/Van der Waals bonds don't form/remain --> difficult for CO2 or O2 to stay in water (think soda)
Term

Diffusion

  • Energy
  • Distance
  • Movement based on what?
  • Where does it occur (source to sink)? 
Definition
  • Thermal energy (no muscle contraction so no ATP expenditure)
  • Efficient over short distances & much less efficient as distance increases
  • Based on individual partial pressure gradient (mmHg, not molarity when diffusion is occuring between 2 solutions in which the gas has different solubilities) based on how much gas is dissolved in a solution
  • Capillaries - O2 diffuses from lungs into blood & from blood into tissues; CO2 does the opposite
Term
Fick's Law of Diffusion & how this relates area or pressure gradient or distance to diffusion
Definition

For when source & sink concentrations are kept constant (as with blood/lung O2 levels etc.)

 

J = k x A(P2-P1)/D


  • J: rate of diffusion (ml or cm3/sec)
  • k: diffusion constant
  • A: area over which diffusion occurs
  • P2-P1: partial pressure gradient
  • D: distance over which diffusion occurs

 

Term

 

Bulk Flow

  • Energy
  • Distance
  • Movement based on what?
  • Equation

 

Definition
  • Heart's muscle contractions require ATP to generate fluid pressure gradient (highest pressure upon leaving heart, lowest pressure upon entering heart)
  • Efficient over longer distances
  • Based on total pressure gradient
  • Q (rate) = ∆P (change in fluid pressure)/R (resistance esp. frictional based on blood vessel diameter)
Term

In the respiratory system, the pressure gradient for the movement of air is established by the _____________.

 

In the cardiovascular system, the pressure gradient for the movement of blood is established by the ___________.

Definition

Respiratory muscles

 

Heart

Term

Partial pressures to know (sea level & at rest)

  • Atmospheric oxygen
  • Lung oxygen (alveolar)
  • Systemic arterial oxygen
  • Systemic venous oxygen
  • Atmospheric carbon dioxide
  • Lung carbon dioxide (alveolar)
  • Systemic arterial carbon dioxide
  • Systemic venous carbon dioxide
Definition
  • Atmospheric PO2 = 160 mmHg
  • Lung PO2 = 100 mmHg
  • Systemic arterial PO2 = 100 mmHg
  • Systemic venous PO2 = 40 mmHg (lower during exercise)
  • Atmospheric PCO2 = 0.23 mmHg
  • Lung PCO2 = 40 mmHg
  • Systemic arterial PCO2 = 40 mmHg
  • Systemic venous PCO2 = 46 mmHg (higher during exercise)
Term
Respiratory tree
Definition
Trachea --> left and (thicker) right bronchi --> 23 generations of branching into smaller and smaller cartilaginous tubes
Term
"Smoker's cough"
Definition
Paralysis of cilia --> particles enter lungs --> chronis bronchitis
Term

Distance between O2 source (alveoli)

(OR) sink (capillary blood) and between CO2 source (capillary blood) and sink (alveoli)

Definition
0.2 µm
Term
Type I alveolar cells
Definition
Gas exchange with capillaries
Term
Type II alveolar cells
Definition

Secrete pulmonary surfactant (detergent - hydrophobic and -philic portions) to lower alveoli surface tension

 

Hydrophilic part buries itself in water surface - separates & prevents adhesion

Hydrophobic tail sticks up & pulls on surfactant molecule to prevent it from diving into the water column

Term
Mediastinum
Definition
Space between lungs for heart, major blood vessels, lymphatic tissue
Term

Pleural sac

 

& structure

Definition

Surrounds lungs & separates them from chest wall

 

Visceral pleura lies directly on lung

Parietal pleura lies against chest wall

Intrapleural space filled with intrapleural fluid between visceral and parietal pleura

Term
Equation for pulmonary ventilation
Definition

RR (breaths/minute) x IV (volume/breath)

 

RR is respiratory rate, IV is inspiratory volume

Term
Tidal volume
Definition

Quiet inspirations/expirations - inspiratory volume at rest

 

Does not normally change

Term
Inspiratory reserve volume
Definition
Amount you can inhale past tidal volume inhale (usually ≥TV)
Term

Inspiratory volume

 

Relative to tidal volume?

Definition

TV + whatever else you breathe in (up to IRV)

 

Can be <, =, > tidal volume

Term
Expiratory reserve volume
Definition
Amount that can be exhaled after a tidal-volume exhale
Term
Residual volume
Definition
Can't get rid of this
Term
Inspiratory capacity
Definition
TV + IRV
Term
Vital capacity & how it can change
Definition

TV + IRV + ERV

 

Upon reaching adult height, this cannot change much even with exercise. Smoking decreases it.

Term
Functional residual capacity
Definition

ERV + RV

 

Volume of lungs at the end of a tidal-volume expiration, doesn't normally change

Term
Total lung capacity
Definition
RV + ERV + TV + IRV
Term
Equation for minute/pulmonary ventilation:
Definition

Ventilation = RR (breaths/min) x IV (L/breath)

 

 

 

 

Term

Equation for alveolar ventilation

 

What is ADS?

Definition

AV = RR x (IV-ADS)

 

ADS: anatomical dead space - space where air cannot diffuse in conducting zone (increased in smokers)

Term
How to increase ventilation during exercise from 6L/min to 100L/min
Definition

Increase respiratory rate from 12 to 35 breaths/min

 

Increase inspiratory volume from .5 to 3L/breath

Term
Which system limits a person's ability to exercise?
Definition
THE CARDIOVASCULAR SYSTEM, NOT THE RESPIRATORY SYSTEM
Term
Relationship between breathing, lung pressure, and Ideal Gas Law
Definition

Inspiration --> lung pressure < atmospheric pressure

 

Expiration --> lung pressure > atmospheric pressure

Term
Quiet inspiration: diaphragm, external intercostals, chest wall/lungs, sternum
Definition

Diaphragm contracts

External intercostals contract

Chest wall/lungs expand

Sternum moves upward & outward

Term

Quiet expiration: diaphragm, external intercostals, chest wall/lungs, sternum

Definition

Diaphragm relaxes

External intercostals relax

Lungs/chest wall contract

Sternum moves downward & inward

Term
During active expiration (e.g. exercise) only, the ____________ muscles contract.
Definition
Internal intercostal and abdominal
Term

At functional residual capacity, causes of negative intrapleural pressure

 

Negative pressure value to keep lungs at functional residual capacity

Definition

Elastic recoil of lungs (inward) & chest wall (outward) - opposite directions 

 

-4mmHg

Term
Inspiration vs. Expiration (respiratory muscles, intrapleural pressure, alveolar V and P)
Definition

Inspiration: respiratory muscles contract, intrapleural pressure becomes more negative, stronger vacuum pulls on alveoli, increase in alveolar volume, decrease in alveolar pressure (subatmospheric)

 

THEN air flows down the pressure gradient - from atmosphere to lungs

 

Expiration: respiratory muscles relax, intrapleural pressure becomes less negative, weaker vacuum causes alveoli to shrink, decrease in alveolar volume, increase in alveolar pressure (superatmospheric)

 

Term
If not for negative intrapleural pressure, what would happen to lungs?
Definition

Elastic recoil of lungs would lead to their collapse

 

Maintains partial inflation of lungs (FRC) at the end of expiration to make sure oxygen is still reaching blood during expiration

Term
Systemic
Definition

Goes to all parts of body except lungs

Arteries with high oxygen and veins with low oxygen

Term
Pulmonary
Definition

Goes to lungs

Arteries with low oxygen and veins with high oxygen

Term
Two kinds of resistance during breathing
Definition

Frictional

Elastic

  • Minor: Elastic properties of lung tissue
  • Dominant: surface tension (F/L)
Term
Surface tension - why does it exist at air-water interface & how it relates to lungs (interstitial fluid)
Definition

Uneven forces on water surface molecules create strong attraction between water molecules

 

Interstitial fluid: thin layer of water on inside of alveoli/between alveoli and capillaries

Millions of alveoli --> high aggregate surface tension

Term
Hemoglobin - function & structure
Definition

Increases solubility of oxygen in blood (1g hemoglobin holds 1.3 ml oxygen) so that cardiac output does not need to be very high to meet metabolic oxygen consumption

 

4 globins (protein) & 4 ferrous hemes (+2 iron reversibly binds to oxygen - OXYGENATION, NOT OXIDATION)

Term
At rest what happens to oxygen in blood?
Definition
~25% of it used at rest; the rest stored for exercise
Term
P(O2)50
Definition
PO2 at which 50% of hemoglobin are saturated
Term

Higher PO250

 

Lower PO250

 

& situations in which these occur

Definition

Rightward shift - hemoglobin has lower affinity for oxygen

  • Higher temperature
  • Lower pH (exercise --> H+ + HCO3- --> lower pH --> easier to unload oxygen)

 

Leftward shift - hemoglobin has higher affinity for oxygen

  • Lower temperature
  • Higher pH (CO2 removal --> less H2CO3 --> higher pH --> easier to pick up oxygen)
Term
Hemoglobin curve
Definition

Asymptotically approaching 100% saturation

 

Allows us to travel: even if P(O2) is a bit less, if still on plateau, no significant decrease in % oxygen saturation of hemoglobin

 

Allows us to exercise: Steep curve below ~40 mmHg allows us to easily give up oxygen when exercising

Term
Carbonic anhydrase & Law of Mass Action
Definition

Enzyme in RBCs that catalyzes:

  • H2O + CO2 <--> H2CO3 <--> H+ + HCO3-
Term
How the oxygen affinity of hemoglobin changes
Definition
H+ ions bind to hemoglobin, creating bonds between negatively charged side groups on amino acids --> hemoglobin changes configuration & binds to oxygen with lower affinity
Term

Ways to maintain partial pressure gradient/CO2 diffusion:

 

At tissues

 

At lungs

 

 

Definition

TISSUES: CO2 carried as HCO3- or carboamino reduces amount of dissolved CO2 in RBCs and sustains partial pressure gradient

 

Buffering of H+ by amino acids in hemoglobin --> continuation of conversion of CO2 into H2CO3 --> enables further diffusion

 

LUNGS: reverse reaction (production of CO2 and H2O from H+ and HCO3-)

 

Term
Result of lower amounts of oxygen being carried in the blood?
Definition
Higher amounts of CO2 being carried in the blood at the tissues since deoxygenated hemoglobin has a high affinity for CO2
Term
Main functions of cardiovascular system
Definition

Carrying O2 and CO2

Carrying fuel/hormones

Immunity

Heat transfer

Term
Forces involved in cardiovascular system? What energizes?
Definition

DIFFUSION at lungs & tissues due to small distance

 

BULK FLOW - moving blood/contents from heart to tissues and back

Blood pressure potential energy, not blood velocity kinetic energy

Term
Equations for cardiac volume & explanations of any terms
Definition

Q = HR (beats/min) x SV (ml/beat)

 

Q = ∆P (MAP - central venous pressure)/TPR

 

∆P represents potential energy

 

Mean arterial pressure: blood pressure as blood enters aorta, usually 90-100

 

Central venous pressure: blood pressure as blood enters right atrium, usually around 0

 

Total peripheral resistance usually around 20

Term
What kind of circuit is the vascular tree and why?
Definition

Branching/parallel circuit, not series

 

Allows blood to be distributed to many parts of the body as quickly/efficiently as possible

Allows changes in blood distribution to various tissues during various situations (e.g. exercise - skeletal muscle vessels dilate and kidney/GI tract vessels contract)

Term

Difference between velocity and flow rate

 

Relationship between area and velocity

 

What would happen with an increaes in capillary beds?

Definition

Velocity = flow rate/cross-sectional area

 

Inversely proportional (think of capillaries, where diffusion is maximized, and aorta, where rapidity is maximized. Flow rate of all capillaries combined = flow rate of aorta)

 

Decrease in average velocity

Term
Why are the ventricles of uneven thickness?
Definition
Left ventricle has thicker musculature to pump blood into body, whereas right just pumps into lung capillaries
Term
Functional syncitium & components
Definition

Mechanically and electrically interconnected heart cells - allows for greater heart power

 

Pacemaker cells (spontaneously & always electrically active, set rhythm, found in sinoatrial node)

 

Conducting cells - modified muscle cells (conduct electrical activity from SA node with low resistance throughout heart)

 

Contractile cells - cardiac muscle cells (physical contraction as a result of electrical excitement)

Term
Sinoatrial node
Definition

Sends electrical impulses:

To left/right atrii (interatrial pathway)

To AV node (internodal pathway)

Term

Atrioventricular node

 

AV bundle/Bundle fo His

Definition

Resistor - slows down SA node impulse so atrii & ventricles don't contract simultaneously (greater blood flow)

 

Bundle of His - thick fibers & many gap junctions (current travels quickly through septum) --> split into L/R bundle branches and electrical impulse carried quickly to all ventricular cells for almost-simultaneous activation

Term
Systole vs. diastole (definition, length, pressure)
Definition

Diatole - ventricles are filling with blood

Systole - blood being pumped out of heart

 

Diastole twice as long as systole so ventricles will fill (AV node resistor)

Systole half as long as diastole so power (Energy/time) of contraction will be greater

 

Diastolic pressure: pressure as blood enters heart

Systolic pressure: pressure as blood leaves heart

 

 

Term
"Phase 4" & dicrotic notch
Definition

Diastole

Ventricular pressure following

Ventricular volume unchanging

All valves closed

Isovolumetric relaxation & ventricular filling

 


Dicrotic notch - upward blip in aortic pressure because of blood rebound following aortic valve closing

Term
"Phase 1"
Definition

Diastole

Ventricular filling & atrial contraction


Aortic pressure falling


Vent pressure < atrial pressure --> AV valves open, blood flows into ventricle --> increase ventricular volume to end-diastolic volume

 

Halfway through: start of atrial contraction --> active blood flow & increaesd ventricular pressure

Term
"Phase 2"
Definition

Systole

Isovolumetric contraction

All valves closed

Start vent contraction --> rapid increase vent pressure till > atrial pressure --> AV valves close

Term

"Phase 2" to "Phase 3" transition

 

"Phase 3"

Definition

Vent pressure exceeds aortic pressure --> aortic & pulmonary valves open

 

Systole

Ventricular ejection

L ventricular pressure increases & peaks dramatically (R peaks but less dramatically), then decreases

Ejection of blood from ventrical to aorta/pulmonary circuit

Rapid decrease to end-systolic volume

Term
Atrial blood flow
Definition

Blood constantly flowing into atrium (inferior & superior vena cava, pulmonary veins) 

 

Atrial pressure and volume don't change much

Term
Stroke volume equation
Definition
EDV - ESV (how much the heart pumps in a cycle)
Term
Heart sounds
Definition

First sound: right AV valve closing

Second sound: aortic valve closing

Term

Poiseuille's Law: 8ηL/πr^4 = R

Q = ∆P/8ηL/πr^4

 

 

 

Definition

η - viscosity

L - blood vessel length

r - radius


Term
Resistance in circuits & what happens when you add new resistor
Definition

Series - sum each unit's resistance

Add new resistor --> total resistance increases

 

Term
What would happen if capillary beds increased?
Definition
Decrease resistance AND RESULTANT INCREASE IN CARDIAC OUTPUT (if MAP is staying constant)
Term
Blood vessel layers
Definition

Innermost layer: endothelium (1 cell-thick layer) - all blood vessels have this

 

Smooth muscle wall controlled by sympathetic nerves (not consciously controlled, originate in spinal chord)

 

Connective tissue to maintain stucture

 

Term

Arteries

 

Aging

Definition

Thickest walls (high systemic arterial pressure)

 

Highly elastic - stretch under high systolic pressure, rebound during diastole to add force to blood

 

Aging: hardening of the walls --> increase systolic pressure, decrease diastolic pressure (but other factors cause increase diastolic pressure)

Term

Arterioles

 

 

 

What controls smooth muscle contraction?

Definition

Most smooth muscle relative to size - do most changes in blood vessel size (main resistors)

 

Increase resistance by contracting smooth muscles to decrease arteriole radius

 

Decrease resistance by relaxing smooth muscles to increase arteriole radius

 

Sympathetic nerves' basal tone discharge (discharge signal to contract when excited)

Decreased oxygen/high CO2/high pH --> smooth muscles relax (vessels dilate to increase blood flow to tissue)

 

 

 

Term
Pre-capillary sphincter
Definition
Ring of muscle only controlled by local factors, not nerve impulses
Term
Effects of exercise on arterioles
Definition

Low O2/high CO2 --> arterioles in active (skeletal muscle) tissues dilate

Nerves try to constrict but are overridden by local

effects

 

Nerves to inactive tissues (kidney, GI tract) cause arteriole constriction so despite increase in cardiac output no increase in blood flow

Term
Capillaries
Definition

Thin-walled - rapid diffusion

 

Molecules can pass through cell membranes, through pores, or between cells

Term

Hyperventilation

 

Hyperpnea

Definition

Breathing more deeply/often than metabolically necessary - losing CO2 and gaining O2 overall

 

Breathing more deeply/often because metabolic rate has increased (e.g. exercise) -- CO2 and O2 levels match those at rest, but rates of CO2 and O2 disposal/acquisition increase

Term
Muscle physiology definition of "contraction"
Definition
Increasing FORCE - not decreasing length
Term
Veins
Definition

Thin, stretchable walls

COMPLIANT - can be distended without much change in vessel pressure (decreases as smooth muscles contract)

Contain 2/3 of vascular tree blood (capacitous)

Valves to prevent backflow

 

Term
Effects of deviant blood pressure
Definition

Too low --> tissues don't receive enough blood for metabolic functions

 

Too high --> tissues might be damaged by force of blood

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