Exam 4 Respiratory Phys

Physiology 335 with Altschafl/lokuta/strang at University of Wisconsin - Madison

About this deck

By: Nora Thompson
Textbook:

Vander's Human Physiology: The Mechanisms of Body Function with ARIS (HUMAN PHYSIOLOGY (VANDER))
Created: 2011-12-19
Size: 42 flashcards
Views: 96

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Functions of Resp system

-Regulate H+ ion concentration (pH) in coordination w/ kidneys

-Form speech sounds (homeostasis on hold)

-Defends microbes

-Influences arterial conc. of hormones

-Traps/dissolves blood clots arising from systemic veins (from legs...)

Ciliary Elevator

-Microscopic

-Brings particles back up the trachea and out of lungs

-Smoking kills cilia

Bronchioles

-Regulate airflow like arterioles regulate blood flow

Respiratory bronchiole

-exchange

-branch into alveoli

Alveoli

-Main site of gas exchange

-70 sq. Meters of SA

-efficient with gas exchange

protective mechanisms in lungs

-constriction of bronchioles

-macrophages in airways/alveoli [injured by cigarettes]

Type 1 and 2 alveolar cell

-Type 1: flat epithelial cells, line alveoli

-Type 2: interspersed, produce surfactant, immune function

Muscles of Inspiration

-Diaphragm

External intercostals

Scalenus

Muscles of expiration [active]

-Internal intercostals

-abdominals

functional residual capacity (FRC)

-volune in lungs after an exhale when respiratory muscles are relaxed

-lungs LIKE to be smaller when exhaled

-Pressure of IP space is negative compared to atmosphere, keeps lung inflated against chest wall

P atm at sea level

760 mmHg

Inspiration: Palv < Patm (driving force for airflow is negative)

Expiration: Palv > Patm

As chest wall expands

-Pip more negative

-Ptp more positive

-Palv decreased (compared to Patm)

Pneumothorax

-puncture of lung/alveoli, ATM air enters ip space (Pip from - to 0)

-Ptp is eliminated

-Lung collapses, chest wall recoils out

-Often unilateral

-can happen with air from lung OR air from outside

Expiration

-Pip Increases

-Ptp decreases

-elastic recoil

-Palv < Patm

-air out

Boyle's law

-when volume of a space gets larger, pressure in that space gets lower

Compliance

-stretchability

-high compliance = easy inhale

-fibrous tissue (collagen) decreases compliance (Cystic fibrosis)

-Surfactant Increases COmpliance

-Equation: change in lung volume/Ptp (Palv-Pip)

-Less compliance, need more Ptp to breathe

Surfactant

-detergent (hydrophobic and hydrophilic)

-Desrupts H2O binding

-regular water droplet has strong hydrogen bonding forces that pull it together

-If only H2O was in lungs, alveoli would be pulled closed

-Deep breath = strech of type 2 cells = up surfact

2 determinants of Compliance

1) stretchability of lung tissues (elastic CT)

2) surface tension @ air/water interfaces with alveoli

minute ventilation

freq x TV = MV

Alveolar ventilation

freq x (TV-DS) = AV

-Change in TV has more effect than change in frequency in AV

dead space

-airways that do not permit gas exchange with blood

Dalton's law

-Total atmospheric pressure @ sea level: 760 mmHg

-N2 = 79%

-O2 = 21%

-CO2 = ~0%

Henry's law

-Gasses dissolve evenly so their partial pressures are equal in liquid and surrounding air

ex: alveoli and blood

-Dissolved gas = Pgas x Sol coefficient (.03)

-diffusion happens quickly at first

-amount of gas dissolved is proportional to P of gas

Gas exchange between alveoli and blood

-THIN LAYER

-equilibration depends on thin layer

-Diffusion problems:

Cystic Fibrosis

Pneumonia

Congestive heart failure

O2 dissolved vs. bound to hemoglobin

-Systemic Arterial Blood:

197 Bound to Hb

3 Dissolved

=98% saturation

-Systemic venous blood

150 bound to Hb

1.2 dissolved

=75% saturation

O2 bound = Red

No o2 Bound = blue/dark red

O2 is transported in blood in 2 forms

-Dissolved in Plasma & RBC cytosol

-Reversibly combined with hemoglobin in RBCs

Key features of Hb saturation/PO2 curve

1) plateau protects you if alveolar PO2 falls

2) Steep part helps you unload O2 at tissues QUICKLY

3) Sigmoid shape due to cooperative binding of O2

(as more O2 binds, Hb has higher O2 affinity -- explains PO2=0 --> PO2=60)

What Causes dissociation curve to the R

High:

-Blood PCO2

-H+ conc.

-Temp

-DPG conc.

-Hb saturation

-with more of these, Hb has a lower affinity for O2

*DPG important in high altitudes

Transport of CO@ and H+ ions in blood

Begin: 100% CO2 produced in cell

Dissolved CO2 --> Plasma

a) 10% CO2 dissolves in plasma/RBCs

b) 30% Binds to hemoglobin (CO2 + Hb -> HbCO2)

c) 65% --> HCO3-

CO2 + H2O --> H2CO3 --> HCO3 + H+ (Binds to Hb)

-Reaction occurs in nRBCs

Chloride Shift

-HCO3 made in RBCs moves into plasma

-Bicarb OUT chloride IN

-PCO2 in cells = 46

-PCO2 in plasma = 40

Carbonic Anhydrase

-Made from Rxn of CO2 + H2O

-made in RBCs

H+ transport in tissues/lungs

-Small amount of H+ generated in blood remains free

-explains why venous blood is higher in acidity than arterial

CO2 and H+ transport @ the lungs

A) Chloride Shift: HCO3 into RBC, Cl Out

B) HCO3- + H+ --> H3CO3-

C) H2CO3- --> H2O + CO2

D) HbCO2 --> Hb + CO2

*Underlined CO2 are dissolved in plasma

*CA released from reaction C

Hypoventilating

-Increased PCO2

-Increased H+

-Respiratory Acidosis (Increased arterial H+ due to increased PCO2)

Hyperventilating

-decreased PCO2

-Decreased H+ in arteries

Respiratory Alkalosis

Hypoxia

-deficiency of O2 at tissue level

-exposure of decreased PO2 @ high altitude = hypoxic hypoxia

-Emphysema is major cause of hypoxia (less SA for gas exchange)

Acclimitization to high altitudes

1) Peripheral chemoreceptor increase ventilation

2) Erythropoiten (fron kidney) stimulate RBC production

3) DPG increases, shift curve to R, helps O2 unloading at tissues

4) Increased Sk. muscle capillaries

5) Plasma vol. down, increased conc. RBC/Hb

Peripheral Chemoreceptors

-monitor PO2 and H+

-Carotid and Aortic Bodies

-Stimulated by:

down arterial PO2

Up arterial H+

metabolic acidosis

respiratory acidosis

= INCREASED VENTILATION

Effect of O2 level of ventilation

-peripheral chemoreceptors

-only in emergencies (not minute to minute)

Effect of CO2 level on ventilation

-CO2 determines how deeply/quickly you breathe

-Both CENTRAL and peripheral chemoreceoptors

-modulator of non emergency ventilation

-Hyper/hypo ventilation defined by CO2 status

-CO2 less affected by diffusion problems in alveoli

Effect of Plasma H+ level on vent

-Metabolic H+ is under peripheral detection

(metabolic acidosis)

-H+ from CO2 is under peripheral AND central detection

Inputs that affect ventilation during exercise (to respiratory center)

-motor cortex & skeletal muscle (proprioceptic reflex)

-Joints

-Up plasma epi/potassium

-Conditioned response

-Up temperature

-Down PO2, Up PCO2, H+ (MAYBE?) via chemoreceptors

About this deck

By: Nora Thompson
Textbook:

Vander's Human Physiology: The Mechanisms of Body Function with ARIS (HUMAN PHYSIOLOGY (VANDER))
Created: 2011-12-19
Size: 42 flashcards
Views: 96

About StudyBlue

“I have been getting MUCH better grades on all my tests for school. Flash cards, notes, and quizzes are great on here. Thanks!”
Kathy