Physiology Exam 4 Module 12 (Respiratory System)

oxygen, CO2

•The main function of the respiratory system is to ***supply the body tissues with ____*** ***and dispose of*** ***____*** generated by cellular metabolism.

ventilation

•Respiration includes:



1\.Pulmonary ________ (exchange of air between atmosphere and alveoli)

external, internal

2\. Gas exchange

•_______ respiration (movement of O2 from lungs into blood; CO2 from blood to lungs)

•_________respiration (movement of O2 from blood into tissue cells; CO2 from cells into blood) (relates to circulatory)

alveoli

tiniest structure of lungs?

larynx

upper airway:

Air comes in and travels to ______-(where vocal cords are)

alveoli

Airway ends in alveolar sacs

__**_______**__**:** sites of gas exchange with the blood

respiratory

zones:

•________ zone (where the gas exchange happens)

•Conducting zone (everything else)… Particulates (dust, foreign contaminants) stick to mucus in the conducting zone

cilia

•Epithelial surfaces contain ***______*** that secrete mucus and keeps lungs clear of particulate matter

37

•Air is __ degrees (Celsius) in respiratory zone – temperature and moisture is constant

capillaries

•The alveoli are tiny, hollow sacs supplied by ***________***

•Size of the Surface area of alveoli in contact with capillaries is big

•Allows for **quick** diffusion

epithelial

•***Type I alveolar cells***: flat _______ cells forming a continuous layer.

surfactant

•*Type II alveolar*: specialized cells that produce ***________***.

thorax

lungs & diaphragm



•Respiratory system is located in the _______

•Neck to diaphragm

•Wall of thorax includes intercostal (between the ribs) muscles

volume

•Lungs



•Passive, elastic structures whose ________fluctuates

•Volume depends on difference in pressure inside and outside of lungs

boyles

•**______ law:** pressure in alveoli (intrapulmonary) decreases below atmospheric-air will move from atmosphere to alveoli, high to low pressures

atmospheric

4 pressure types

\
•All pressures are relative to ***______pressure*** (760 mmHg at sea level) Patm(the air that surrounds the body)



•Volume of lungs is made to change through Boyle’s Law. An inversely proportional relationship between pressure & volume. (i.e. increasing V, reduces P & vice versa)



•P1V1=P2V2

alveolar

4 pressure types

\
•***Intra-________ pressure (Intrapulmonary aka inside the lungs)*** changes to drive the movement of air.



•Palv is the pressure in the alveoli.

inspiration

•Palv is less than Patm = _______

expiration

•Palv greater than Patm = _________

intrapleural

4 pressure types

**________: pressure in pleural space, Pip**

•It fluctuates with breathing, but it is always less than Palv (or intrapulmonary).

transpulmonary

4 pressure types

\


**_______: holding lungs open  Ptp=Palv- Pip**

•Difference in pressure allows lungs to stick to the chest wall (keeps them in place)

may need to rewatch part of the video on this

motor

inspiration vs expiration

inspiration:



•Movement of air from external environment into alveoli of the lungs



•Initiated by skeletal muscle & ***______ neurons*** firing action potentials to ***intercostal muscles*** (between ribs) and diaphragm (flattens @ base of thoracic cavity)

diaphragm

inspiration vs expiration

Inspiration:



•***__________*** contracts and provides the most important inspiratory muscle

active

inspiration vs expiration



•Enlarging thoracic cavity allows lungs to enlarge and cause increase in size of alveoli (nervous, muscular)

•_____ movement

decrease

inspiration vs expiration

expiration



* Air from alveoli to external environment
* Motor neurons ***_____ action potentials*** to diaphragm and intercostals,  muscles relax

passive

inspiration vs expiration

* Air in alveoli gets compressed as lungs become smaller, air moves out, Palv > Patm
* _______ movement of lungs

respiratory

integration & communication of systems



•Receive information regarding ___________ system

•Nervous system processes information and responds

•Muscles move and respiration occurs

medulla oblongata

neural input

•Respiratory rhythm generated in **_______ _________** Same location for major cardio control centers

•Motor Neurons-Breathing depends on these muscle movements, especially diaphragm

oxygen

receptors

•The carotid bodies are strategically located to ***monitor ______ supply to the brain***



•Called __peripheral chemoreceptor__: responding to changes in H+ concentrations



•Indirectly affects ventilation by affecting chemoreceptor sensitivity to PCO2, PO2 follows changes

H+

receptors



1\.Know ___



2\.Know Co2 and O2 concentrations



3\.go out to lungs to adjust ventilation (rate)

constant

Input from the receptors modifies rate and depth of breathing so these variables remain ________.

inspiration

•When muscles contract in the chest wall the chest expands - _______



•Diaphragm is contracted downward and the thoracic cavity is large

•Opposite occurs for expiration: muscles ______ and the recoil drives passive expiration back out

daltons

partial pressures: proportional to the concentration for that gas

•*_________ Law:* pressure each gas exerts is independent of the pressure of other gases

•The total pressure of the mixture is the sum of the individual, *partial pressures*.

•Written as: Partial pressure of O2 is PO2

pulmonary = lungs

higher

•Alveolar PO2 is ______ than blood, so oxygen diffuses from alveoli into plasma. High to low concentrations

•This induces (simple) diffusion of oxygen to erythrocytes

•Cells obtain more O2 by activity

tissue

\
•During exercise, more O2 is used, decreasing ______ PO2, this increases blood to tissue PO2 gradient.

Oxyhemoglobin: binding oxygen with hemoglobin

Deoxyhemoglobin: produced when oxyhemoglobin releases oxygen

plasma, hemoblobin

Oxygen in blood 2 forms:

•Dissolved in _________ and erythrocyte cytosol (recall no organelles there)

•Combined with _______ molecules in erythrocyte (Majority)

•Recall: O2 binds to iron, on a hemoglobin(protein)

•Heme: iron-containing pigment, our binding sites!

lungs

•Loading (in the _____ ) & Unloading (systemic):



•(tissues) Deoxyhemoglobin + O –> oxyhemoglobin (lungs)

high

•What affects the movement of oxygen to the hemoglobin (loading)?



•____ PO2 and affinity for pulmonary to capillaries (H to L gradient)

concentration,ph

\
•What affects the movement of oxygen on the hemoglobin to the tissues (unloading)?



•______ : Systemic tissues are Low in 02 , 02 in capillaries is high



•Affinity – change that lower ___ or create higher temps decrease affinity of 02 on RBC



•Affinity should be sufficient to hold the bond of oxygen to the iron on the hemoglobin but not so high that it prevents unloading (for example if too highly affinity then only 2 O2 , may unload)

dissolved

Only _________ O2 contributes to PO2 of blood

plasma

•CO2 is a waste product, it produces H+ which gives it a toxicity

•H+ in large amounts changes pH

•Forms of transport:



1\.10% dissolves in _____

hemoglobin

2\.Some react with __________

Carbon dioxide binds on the …. to form **carbaminohemoglobin**

HCO3-

3\.60-65% is converted to ______, where we get the Hydrogen ions that alter pH levels

acid

Carbon Dioxide movement in Tissues and lungs



Carbonic anhydrase catalyzes the reaction to form carbonic ______ at high PCO2

deoxyhemoglobin

•H+ in red blood cell buffered by __________,

bicarbonate

chloride shift:

\
H+ in plasma buffered by _______ moving out



•Bicarbonate builds up in cell, leaves down its gradient

\

cl-

_________ shift cont

•___ is attracted into cell with movement of bicarbonate and trapping of H+

7\.35-7.45

•Range for pH of blood: ______ (Homeostasis)

•Maintained through Lungs-CO2 and Kidneys- Bicarbonate

acidosis

**________:** When plasma H+ concentration increases, pH drops below 7.4

•Arterial H+ concentration increased due to carbon dioxide: ***respiratory acidosis***

alkalosis

**________:** When plasma H+ concentration decreases, pH rises above 7.4

•***respiratory alkalosis*** results from decreased arterial PCO2 and H+ concentration

hypoventilation

• **____________**



•Low pH, cause of respiratory acidosis

•Alveolar ventilation can’t keep up! Too slow

•High CO2

hyperventilation

• **__________**



•High pH, cause of respiratory alkalosis

•Alveolar ventilation too fast

•Low CO2