lung

cutaneous

gills

water enters mouth because bucal pressure is lower

when the pressure increases after the water comes in, it exits through the gills

describe countercurrent flow of blood and water in fish and gills

why is it helpful?

countercurrent flow allows the a maximum amount of Oxygen to be absorbed into the gills

unicameral

vs

multicameral

what are faveoli?

unicameral has one compartment

multi=many

faveoli are the names of those compartments

frog

air is pressurized in pharynx and then pressurized to be forced via posi pressure into the lungs

MEMORIZE SLIDE 12 in pulmonary system functions

list in order from big to small the mammalian lung components

how many lobes in human lung, what sides are they on?

how are they conected to the trachea?

3 on right side

2 on left

the right has 3 broncioles the left has 2 bronchioles

what causes alveolus compliance?

what accounts for more?

parenchymal cells produce elastin and water line the alveolus

water accounts to 75%

chest wall elements

are they compliant?

ribs

sternum

vertebrae

intercostal muscles

ALL NONCOMPLIANT

layout of pluera of lung

prietal, visceral, mediastinum and intrapleural space

intrapeural space contains serous fliud with sub atmospheric pressure

that negative pressure links the lung to chest wall by suction to keep the lung held open

respiratory quotient value

what's a typical value for rest?

what ratio does this represent?

RQ=CO2 production per min/O2 consumption per min

RQ=200mls CO2 per min/ 250mls O2 per min

=.8

4 to 5 ration of CO2 to O2

1. diaphragm contraction

2. air is drawn into system

3. increase in pleural cavity volume

4. decrease in intrapleural pressure

5. increase alveoli volume

6. interalveolar pressure decreases

volume: non overlapping air quantity like tidal volume

capacity: quantity composed of two or more volumes (vital capacity)

respiratory minute volume=tidal volume x respiration rate (in cycles per minute)

alveolar volume=(tidal volume-dead space) * RR

tidal volume

when you exercize you breath deeper not faster

fast in trachea and bronchii

slow and laminar in bronchioles

diffusion slow in alveolus

phospholipids reduce the H bonding between water that would otherwise cause the water to form droplets instead of layers

proteins make a constant concentration gradient that draws water INTO the avleolar space. this replaces water lost do to evaporation and expiration

pressure=2(tension)/radius

p=2t/r

if you had two different sized alveolus, due to LOL and the difference in pressure, they would want to equalize and be the same

small alveoli have more pulmonary surfactant produced by more type 2 cell. this reduces surface tension and pressure so it have the same pressure inside as in the large ones. this maintains alveolus shape to keep the hi surface area for gas exchange

At sea level, how does one calculate the partial pressure of a particular gas? Use O₂ and CO₂ as examples.

Why is there a diference in O2 and Co2 values in the air vs alveolus?

PP= % conc x 760mmHG

air: ppO2= 20.9% X 760mmHG =158.8 mmhg

alveolus: ppO2= 13.2 x 760 mmHG= 100.3

PP CO2 air:0.03%

    alveolus: 5.3 %

Inhale O2 and exhale CO2

driving force= alveolus pressure - air pressure

DF co2 is into the alveolus DF= 6mmHg

DF O2 is into the blood and capillaries DF=60mmHg

roughly equal amounts of CO2 and O2 are exchanged because CO2 has a higher diffusion coefficient

O2 carrying capacity is 20% of your blood volume

.3ml dissolved in plasma (so 98% of the 20 is bound to Hb, only a little is dissolved in plasma)

20ml bound to Hb

What are the four protein elements of Hb and what molecule binds to O₂?

c. In terms of the number of O₂ molecules bound to a heme group, what is oxyhemoglobin and what are the different forms of deoxyhemoglobin?

In 1 hemoglobin there are 2 Beta globin units 2 alpha globin units. Each one of these units has a heme group that binds to the Oxygen

Each heme group has 1 Fe

Oxyhemoglobin has 4 oxygens bound to it, deoxyhemoglobin has less than 4 (3,2,1,or 0)

do the values of pO₂ and pCO₂ unloading and loading (respectively) in the systemic capillaries compare with their values for loading and unloading in the pulmonary capillaries?

In pulmonary capillaries, O2 (40) is being loaded CO2 (46) unloading so it can be expired

In the systemic caplilaries, CO2 (40) is being loaded and O2 (100) is being unloaded (body parts, unloading O2 for cellular respiration)

When venous blood has passed through the systemic capillaries,

 i) what percentage is in the form of oxyhemoglobin?

ii) how many mls of O₂ per 100 mls does the blood contain?

after venous blood has passed through the systemic capillaries, 75% is saturated or in the form of oxyhemoglobin

40ml O2 per 100 mls

In a mechanistic sense, explain the shape of the curve in terms of the effect that O₂ binding has on Hb.

As O2 binding increases, hemoglobin affinity for more O2 increases.

So, when exercising, theres decrease in affinity because your body is trying to unload it quicker; hemoglobin doesn't hold on to the O2 because your body is trying to unload as quickly as possible (get 02 to the rest of your body)

Bohr Effect

Left and Right Shifts significance

Bohr effect: the affinity for O2 decreases as pH decreases and co2 increases

when exercising, you have a decrease in pH which causes the Bohr effect to allow the hemoglobin to unload O2 as quickly as possible

Exercising leads to a right shift

Opposite = left shift

Of the 6 mm Hg of CO2 that loads into the blood as it passes through the systemic capillaries, what percent is transported

 i) dissolved in the plasma,

 ii) bound to Hb,

 iii) dissolved in the plasma in the form of bicarbonate?

8% dissolved in plasma

11% binds to hemoglobin

81% converted to bicarbonate ions

Prepare a diagram of the fate of CO₂ and its derivatives after CO₂ diffuses into an RBC during loading in the systemic capillaries. Include the very important enzyme that facilitates the reactions.

What is the chloride shift and why is it important to the transport of CO₂ in the blood?

CO2 goes into the RBC -> CO2 + H2O + CARBONIC ANHYDRASE-> carbonic acid

later, when the RBC needs to rid itself of the carbonic acid:

carbonic acid + carbonic anhydrase -> H+ + bicarbonate-> H+ attached to hemoglobin, bicarbonate is released out of the cell

The chloride shift is important to the transport of CO2 because when you are releasing the negative bicarbonate it creates an electrical gradient, so the cell needs to take in a negative (chloride) to maintain homeostasis

Where are “central and peripheral chemoreceptors” located and to which chemical stimuli does each respond? 

 Which chemoreceptors monitor cerebrospinal fluid (CSF) chemistry and which directly monitor blood plasma chemistry? 

Central Chemoreceptors (CCs) are located in the medulla oblongata, monitor pH of Cerebral Spinal Fluid

Peripheral Chemoreceptors are in aortic and carotid bodies, monitor blood plasma O2, CO2 and pH

Explain how medullary respiratory centers set the “basic rhythm”. 

What is the efferent pathway and what is the effector?

What is a typical respiration rate for a resting individual?

Medullary centers send bursts of APs to the diaphragm which causes it to contract, blah blah

efferent pathway = Phrenic Nerve

effector = diaphragm

12-14 per minutes

Explain how the activity of the Pontine centers differ fundamentally from the medullary centers. 

Pontine centers alter the # APs in a burst (increase Tidal Volume)

Medullary centers set the rhythm of the bursts of APs (increase respiratory rate)

Define hypercapnia and hypoxemia and describe the ventilatory response to each.

hypercapnia is an increase in CO2 which causes hyperventilation

Hypoxemia is an decrease in arterial 02 which causes hyperventilation

The sympathetic division causes vasocontriction and bronchodilation. 

By what mechanism does it cause smooth muscle to contract in one case and to relax in the other case? 

What functional explanation can you provide for the different effect that the SD has on arterioles vs. bronchioles?

Bronchodilation is a result of a cholinergic response (ACh)

Vasoconstriction is a result of an adrenergic response (Epinephrin/NE)

Sympathetic= fight or flight

so bronchodilation to allow you to breathe in more O2 so you can fight or flight

Vasoconstriction increases BP to move blood around quicker

SO you can haul ass if need be