Respiratory System Study Guide

Define respiration and describe the types.

How organisms make energy

• External Respiration: Also known as breathing, the transportation of gases move through the capillaries, lungs, and air. 

• Internal respiration: This occurs deeper in your body, the gases move to your blood and supply your body's cells.

• Cellular respiration: Occurs in the cell, specifically in the mitochondria. It will create carbon dioxide by using oxygen for its main energy source. The carbon dioxide emitted by the cells will travel to the lungs. 

What are the other functions of the respiratory system?

• Removes particles from air

• Helps control air temperature and water content

• Produces vocal sounds

• Participates in the sense of smell

• Contributes to regulation of blood pH

• Produces a hormone that regulates blood pressure (angiotensin II)

• Platelet production (along with bone marrow)

• Creates pressure gradient for venous and lymph flow

• Filtering blood clots

• Assists in expelling abdominal contents.

Describe the two divisions of the respiratory system. What is the other way we can divide the respiratory system?

• Conducting zone: Passages that serve only for air flow (nostrils through major bronchioles)

• Respiratory zone: Consists of alveoli and other gas exchange regions

Describe the organs of the conducting zone.

• Nose: Warms, cleans, and humidifies inhaled air. Helps detect odors and resonate voice.

• Nasal cavity: Open space behind the nose, includes the nasal chonchae (superior, middle and inferior), air passes over mucous membranes to heat up air because of blood. Air will evaporate and moisten. Mucous will trap dust, viruses, and small particles; cillia will also move the particles towards your lungs.

• Pharynx: Muscular passage in the throat at which the respiratory and digestive tracts cross

  • Oropharynx: Space between posterior margin of the soft palate and the epiglottis

  • Laryngopharynx: Lies mostly posterior to the larynx, the esophagus begins at that point

  • Nasopharynx: Passes only air and is lined by pseudostratified columnar epithelium.

• Larynx: Keeps food and drinks out of the airway, also known as the “voice box”

  • Epiglottis: During swallowing the extrinsic muscles of the larynx pull the larynx upward toward the epiglottis, it closes the airway and directs food and drinks into the esophagus

  • Vocal cords

• Trachea: “Windpipe,” has rings to reinforce the trachea and keep it from collapsing when you inhale and create partial vacuum in the airway.

• Bronchioles: Narrowest airway that lead to terminal bronchiole

Describe the organs of the respiratory zone.

• Alveoli: Made up of simple squamous tissue to easily pass gas, O2 diffuses from the alveoli into blood, carbon dioxide comes from the blood into alveoli

• Alveoli ducts: Connects to respiratory bronchioles and alveolar sacs

• Alveoli sacs: Clusters of alveoli

List the path of airflow through the respiratory system. Distinguish between the two divisions.

In the conducting zone air passes into your nose entering your nasal cavity, it then travels to the pharynx and down to your trachea. It enters the main, lobar, then segmental bronchus into the bronchioles, where it ends at the terminal bronchioles

In the respiratory zone it enters the respiratory bronchiole into the alveolar ducts and finally the alveolus. 

• The bronchioles are housed in the lungs

• Surrounded by pleura

What is the role of the pleurae?

• Reduces friction: Allows lungs to expand and contract with minimal friction

• Creation of pressure gradient

• Compartmentalization: Prevents infections from one organ from spreading to others

Define Boyle’s Law.

The pressure of a given quantity of gas is inversely proprotional to its volume

• Lung pressure changes based on atmospheric pressure

Define Charles’s Law.

Your bodys mechanism of warming up air, meaning that gas entering your body will expand based on your bodys and external temperature.

Describe expiration and inhalation. Explain how they work. Include which muscles are being used and how atmospheric pressure contributes.

Diaphragm is changing the volume of your lungs to oppose the atmospheric pressure

Expiration:

• After inhalation the diaphragm will return to its original spot causing the alveoli to increase in pressure greater than the atmospheric pressure; the air will then leave the respiratory passages down the concentration gradient.

Inspiration:

• Atmospheric pressure creates a pressure gradient that is lower than the external air so that it is able to enter your body. The push of outside air helps your body retain gases.

• The phrenic nerves will activate your diaphragms skeletal muscles to contract, moving the outer pleura downward as the diaphragm moves. Essentially your lungs and chest wall pulls your inner and outer pleura in the opposite direction, one will pull in and the other out.

Define minute respiratory volume

How much air you breath within one minute

Define alveolar ventilation rate

How much oxygen is supplied and able to travel to your tissues. How much gas your alveoli is holding in each breath

Define tidal volume

How much air you breath in and out during one cycle of normal breathing/eupnea. The normal amount is around 500mL

Define inspiratory reserve volume

The amount of air in your lungs after inhaling at your maximum capacity. The normal amount being about 3,000mL

Define expiratory reserve volume

Measures the amount of air your breath out when forcing all the air out of your lungs. The normal range is about 1,100mL

Define residual volume

How much air is left when you try to force all the air out of your lungs. The normal amount being 1,200mL.

Define vital capacity

Maximum volume of air a person can exhale after taking the deepest breath possible

Inspiratory reserve volume + Tidal volume + Expiratory reserve volume

3,000mL + 500mL +1,100mL

Normal value: 4,700mL

Define inspiratory capacity

Breathing in air with as much force as you can then breathing out normally 

Inspiratory capacity= Inspiratory reserve volume + Tidal volume

3,000 mL + 500mL

Normal value: 3,500

Define functional residual capacity

The amount of air left in the lungs after breathing normally 

Functional residual capacity= Expiratory reserve volume + Residual volume

1,100mL + 1,200mL

Normal value: 2,500mL

Define total lung capacity

How much your lungs can hold when inhaling

Total Lung Capacity = Inspiratory reserve volume + Tidal volume + Expiratory reserve volume + Residual Volume

3,000mL + 500mL + 1,100mL + 1,200mL

Total lung capacity = Vital Capacity + Residual Volume

Normal value: 6,000mL

Describe the roles of the three respiratory centers in the brain.

Ventral Respiratory group: Works the hardest to coordinate forced breathing or respiratory patterns. It is located in the medulla and connected with neurons:

• Inspiratory neurons (I): Helps with breathing in, when the I neurons stimulate the integrating centers of the spinal cord in 2 second intervals, which then sends signals phrenic nerve that controls the diaphragm. Your diaphragm will contract when your intercostal nerves are stimulated, causing you to inhale. When I neurons are working the E neurons are resting. 

• Expiratory neurons (E): Helps with breathing out, they are stimulated when the I neurons are tired from working or something prevents them from performing. When E neurons are stimulated they let the I neurons rest, without the I neurons working your external intercostal muscles relax or other part of the inspiratory muscle group. The E neuron pulls back the thoracic cage to release air.

• Both neurons work together to create around 12 breaths within a minute

Dorsal Respiratory Group: Is also located in the medulla oblongata and helps regulate and allow for the basic respiratory rhythm to perform better. 

• It takes in information from the pons, chemoreceptors, medulla oblongata, and part of your brain that regulates breathing based of emotional reactions. It sends this information to the ventral respiratory group so that they can change your breathing pattern. 

Pontine Respiratory Group: Located in the pons; it recieves information from the hypothalamus, limbic system, and cerebral cortex to notify the dorsal and ventral respiratory group.

• It is able to control the duration of breathing, either making it slower or faster. As well as depth, either making it deep or weak.

• It is able to regulate and accustom itself to different physical activity or emotions. 

Describe the other inputs into control of respiration.

Chemoreceptors: They act when pH levels in your cerebrospinal fluid (central chemoreceptors) or blood (peripheral chemoreceptors) changes

• They communicate with the brain through the vagus nerve to send information to the medulla oblongata.

Stretch receptors: Bronchioles contain stretch receptors in their smooth muscle. They communicate using the vagus nerve to notify the dorsal respiratory group

Irritant receptors: In the airways that detect smoke, dust, pollen, chemicals, cold air, mucous. They also communicate with the dorsal respiratory group via the vagus nerve.

Define eupnea

Normal, unlabored breathing that occurs when a person is at rest

Define apnea

Temporary cessation of breathing

Define hypernea

Increased breathing in response to exercise, pain, or other conditions

Define hypoventilation and hyperventilation

• Hypoventilation—Low pulmonary ventilation

• Hyperventilation—High pulmonary ventilation

Explain Dalton’s Law.

An array of gases such as: nitrogen, oxygen and carbon dioxide in the air; less contributed gases such as: argon, neon, helium, methane, and ozone, as well as water vapor all contribute to create the total amount of atmospheric pressure.

Explain Henry’s Law.

At the air-water interface, for a given temperature, the amount of gas that dissolves in the water is determined by its solubility in water and its partial pressure in the air

Why do oxygen and carbon dioxide dissociate in the lungs at the same rate, even though the partial pressure gradient of oxygen is much steeper?

Carbon dioxide is greatly more soluble than oxygen, this big difference allows it to diffuse into the lungs before oxygen without having to use a higher pressure gradient.

Explain ventilation-perfusion coupling.

• Ventilation: Amount of gas reaching alveoli

• Perfusion: Blood flow in pulmonary capillaries

  • Changes to match ventilation

• Po2 (partial pressure of O2) controls perfusion by changing arteriolar diameter

• Pco2 controls ventilation by changing bronchiolar diameter

Increased Airflow:

• Increase O2 in the blood vessels causing vasodilation of pulmonary vessels, increasing blood flow to match the airflow

Decreased Airflow:

• Reduced O2 in the blood constricts the pulmonary vessels, decreasing blood flow to match the airflow.

Describe oxygen transport.

• Hemoglobin plays an important role in oxygen transport, it is made up of four protein chains and a heme group. A heme group can attach to a ferrous ion so that it can carry more oxygen. More than one oxygen adhering onto a hemoglobin turns into a oxyhemoglobin, when hemoglobin lacks oxygen it is called deoxyhemoglobin.

• When there is an abundant amount of oxygen the partial pressure of oxygen also increases

• The partial pressure of oxygen will no longer increase if hemoglobin is carrying too much oxygen on it. 

Describe carbon dioxide transport.

Transportation of gases between the tissues and alveoli. 

1) Most CO2 that can respond to water which turn into carbonic acid, turning into bicarbonate and hydrogen ions

2) Carbamino compounds are created when plasma proteins and hemoglobin adhere to each other. Hemoglobin will be used to take oxygen and carbon dioxide to a targeted area at the same time. 

3) Left over carbon dioxide is then brought into the blood

Explain alveolar gas exchange.

Taking out CO2 into the alveoli and transporting oxygen to the blood. 

1) Most of the oxygen entering the lungs will bind to hemoglobin in the capillaries. The carbon dioxide will be released into the lungs and detach itself from the hemoglobin.

2) The bicarbonate ion will bind to a hydrogen ion to create carbonic acid. The carbon dioxide separates itself from the carbonic acid due to the concentration gradient to make water. 

Explain systemic gas exchange. How does it differ from alveolar gas exchange?

Systemic capillaries take out oxygen and take in carbon dioxide

1) Carbon Dioxide Loading: A small percent (7%) of carbon dioxide dissolved in your blood will travels towards the capillary blood. Carbon dioxide can also travel with hemoglobin to transport O2 and CO2 at the same time, carbaminohemoglobin (23%). Bicarbonate ions are what is mostly transported (70%), it is made when water and CO2 are bound to create carbonic acid. To get rid of the acid a chloride shift releases one hydrogen ion to become a bicarbonate ion, adding another hydrogen ion into your blood increasing pH in your blood. 

2) Oxygen Unloading: Oxygen breakdown the bonds of hemoglobin so these fragments move towards the tissues. More oxygen is released when there is an increase in carbon dioxide levels in the blood, can be caused by exercising. Oxygen will also be released if the blood becomes too acidic or temperature in your body increases. 

Explain the Bohr effect.

How pH affects the unloading of oxygen. When pH in the blood is low hydrogen ions will reduce oxygen and hemoglobin from adhering, causing an increase in oxygen release. 

• What determines oxygen to dissociate from hemoglobin

• Will tell hemoglobin and oxygen to break apart when CO2 levels are too high

Explain the Haldane effect.

Oxygen bound to hemoglobin creates oxyhemoglobin, if there is a decrease in this it stimulates the blood to stimulate more carbon dioxide to leave the blood.