Cardiovascular/Pulmonary Final

Ventilation

The process of moving air from mouth/nose into alveolar membrane

VA

volume of air entering/leaving the alveoli with each breath, adn available for gas exchange

VD

volume of inspired air in the resipiratory tract that is not involed in gas exchange

Physiological dead space =

oronasal + conducting zone + alveolar dead spaces

Dead space _____ when intubated

increases

External Respiration

between walls of alveoli and pulmonary vessels acoss the respiratory membrane, move by diffusion

External respiratoin requires

air in the alveolus, healthy alveolar membrane, blood flow past alveolus

Internal respiration takes place

in the cells

Three respiratory zones

Oronassal, Conducting, Respiratory

Oronasla Zone contains

Nasal airway, pharynx, larynx

Oronasal Zone function

olfaction, humidify and wamr air, thermoregulate, filter air, slwo air flow (50-70% of resistance)

Functions of pharynx/larynx

phonation/protect air way

Movement of Oronasal Zone during breathing

Soft palate ventral to epiglottis, epiglottis dorsal to soft palate, Arytenoids open

Movemememt of oronasal zone during swallowing

Soft palate rises → arytenoids rotate down to esophagus→ epiglottis rotates up (to cover ariway)

Conducting Zone structures

Trachea, bronchi, nonrespiratory bronchioles

Conducting Zone functions

Filter air, further slow air, no gas exchange

Respiratory Zome structures

Respiratory bronchioles, alveolar dicts, alveolar sacs

Respiratory zone function

Gas exchange

Tidal Volume (tv)

Volume of gas entering or leaving the resilratory tract during one breath

Inspiratoty reserve volume

The amount of extra volume inhaled on deep breath in

Expiratory reserve volume

The amount of extra volume exhaled on a deep breath out

Residual volume

Volume left In lungs after max exhalation, need to stop alveoli from Collapsing

Functional residual capacity

The volume of air remaing in lungs after passive exhalatiom

respiratory forces are generated by

The chest wall, pleurae and pleurae space, lungs (elastin, collagen, surface tension)

At rest what two force are at equilibrium

The lungs generate forces that pull inward (elasticity and surface tension) amd the thoracic wall generates forces that pulls outward

Elastic Force

When the alveolis is distamced during lung expansion elastic fibers are stretched amd want to return to orginal shape

Surface tension force

Created by the surface tension of the fluid that lines each alveolus works to pull each alveolus shut

Pleural fluid is generated by

Hydrostatic and osmotic pressure

Megative pressure

Suctiom pulls visceral and parietal pleura together, since visceral pleura is attached to underlying lung tissue, lungs are pulled with. Therefore lungs/chest wall stay right next to each other

Muscles of inspiration

Diaphragm, External intercostals, accessory muscles (scalenus, sternomastoid)

Contraction of _______ leads to the elevation of the rib cage

External intercostals

Expiration muscles

Internal intercostals, abdominal muscles, diaphragm

Internal intercostals

Actively contracting to lower ribcage

Abdominal muscles

Actievly contract to pull down, compress andominal contents

Boyle’s law

Pressure and volume are inversely proportional

Bulk flow

Describes the process of air moving from

High pressure to low pressure areas

Inspiration pressure

Intrapulmonaru pressure decrease and is less than the atmosphere

Expiration pressure

Intrapulmomaru pressure increase and is more than the atmosphere

3 components of controled breathing

Sensors, intergrator, effector

Brain stem Role in control of breathing

Involuntary and voluntary

Dorsal respiratory group of the medullla

Imitates and maintains inspiration

Ventral respiratory group medulla

During normal quiet breathing (inactive), during exercise activated by foreful inspiration amd signals abdominal muscles to comtract causing active expiration

Basal rhythem is

Generated by the medulla and adjusted by the pons

Baseline breathing is coordinated

By the medulla with inlut from the pons

Chemoreceptor

Perioheral and central chemoreceptor that monitor the chemical composition of arterial blood

Central chemoreceptors

Medulla, detect CO2 (more Sensative) amd H increases

How do central chemoreceptors work

CO2 increases in blkod → imterstitial fluid amd cerebrospinal fluid surrounding

Medulla → central chemoreceptors detect imcreases im H+ amd thus increase respiratory drive

Peripheral chemoreceptors detect

O2 decrease (the only one to detect O2), CO2 and H increases

Glomus Cells

constantly smaple blood and sense increase in CO2, and decreased O2 and pH, and have a fast response to medulla to increase ventilation

The major driver of increased ventilation in mammals is

High CO2, (also decreased O2 but doesn’t kick in until it is very low)

Mechanoreceptors examples

Muscle, joint receptors, Irritant receptors, J recepotr, Stretch receptors

Muscle, joint receptors

role in stimulating the increase in ventilaiton during exercise

Irritant recepotrs

detects rate of lung inflation and faciliates insiprations (coughing, sneezing)

J receptors

respond to edema, chemicals, stretch, causes shallow rapid breahting

Stretch receptors

detech when overstretched and respond accoridingly

Bulk Flow - all gases move ____, staying at ______ concetrations

together, same

Which is faster bulk flow or diffusion

bulk flow

Bulk flow flows down what gradient

pressure

Diffusion moves down what gradient

concentration

Dalton’s law

total pressure exerted by a mixture of gases is the sum of the pressure exerted independently of each gas in the mixture P total = P1 + P2…

Air is ____% oxygen

21

Inspired air vs room air

it is humidified and this lowers the partial pressure of all gasses other than H2O compared to room air

Alveolar air PO2 mmHg

102

Alveolar air PCO2 mmHG

40

Frick’s Principle

rate of gas transfer (V gas) is directly proportional to the difference in partial pressures of the gas across the membrnae AND diffusing capacity of a membrane (DM)

Diffusion Membrane is affected by

Membrane factors (area, thickness), Gas properties (solubuluty and molceular wieght)

CO2 has a much ____ diffusion rate compared to O2

faster

If an animal has a high blood CO2 secondary to lung disease then the lung must be

severly affected and blood O2 will undoubtedly be low

Type 1 Alveolar epithelium

for gas exchange, line the alveolus, >95% of total popultation of epithelial cells

Type 2 alveolar epithelium

secrete surfactnat, can proliferate, differentiate into type 1 cells

Alveolar Membrane Layers

Fluid layer, alveolar epithelium, epithelial basement membrane, narrow intersitial space, capillary basement membrane, capillary endothelium

In bloofd ____ of O2 is on hemoglobin while the rest is

98, dissolved in plasma

Deoxyhemoglobin

O2 is not bound

Oxyhemoglobin

O2 reversibly binds with hemoglobin

Each iron atom binds to

2 oxygen atoms

Hemoglobin strucutre

4 hemoglobin chains with each ahiving a single heme group with a single ferrous iron atom in the middle

Once 1 O atom has bound, the Hgb changes shape and makes

it easier for more O to bind

O2 carrying Capacity

the amount of oxygen that can be transported in the blood of an animal

Hemoglobin dissociated curves shows the relationship between

the fraction of Hgb bound to oxygen adn the partial pressure of oxygen in arterial blood

Left shifted cuver

Hgb is staturated at a lower concentration of oxygen, implying that Hgb now has a high affinity for oxygen

Left shiftd curve is where

lungs, where hemoglobin needs to pick up more oxygen

Right shifted curve

Hgb is saturated at a high concentration of oxygen, implies that Hgb now has a lower affinity for oxygen

Right shifted curve is where

at peripheral tissues, hemoglobin needs to releases more oxygen

Factors that affect Hgb saturation

[CO2}, pH, temp, [2,3 DPG] (metabolite of glycolysis

Three ways CO2 is transported in blood in order

1. Bicarbonate (70%)

2. Carbminohemoglobin (20%)

3. Dissolved CO2 (<10%)

Carbminohemoglobin

carbamino compounds - (CO2 + NH, groups in Hgb)

Birds breath through

Nose (olfaction), open beak breathing is a sign of disease

Causes of block nostrils of a bird include

hyperkeratosis, hypovitaminosis A (high fat, seed diets)

Nasal salt glands in birds

allows sea birds to drink sea water

Birds are missing what upper respiraotry strucutres

epiiglottis and soft palate

Rima glottis

regulates passage of air by dilator.constrictor muscles (prevents aspiration), in avain

Avain trachea is compsed of ____ cartilaginous rings

complete

trachea differences in birds

Greater diamtere to compensate for increased lenght adn resistance, often long and may even be coiled within sternum cavity

Syrinx

avian voice box, commonly located at tracheobronchial junction and is made of modified tracheobrnochila cartilages with tympaniform membranes and common site for foreign body obstruction or granulomas

Avain lung differences

fixed volume, more rigid (20% more area for gas exchange) and no diaphragm

Gas exchange in birds occurs in

tertiary bronchi

Avain teriary bronchi apperance on radiogrpahs

honeycomb apperance

Avian gas exchange differences

Higher O2 demands, unidirectional air flow means continous gas exchange

Avain air capillareis of lung differences

finer and more numerous

Airsacs

in avian species, distensible, transparents, 2 cells thick and extend from body caivty into bones, 80% of respiratory volume, poor blood supply