BIOL 2210 Exam 4

muscles that move the ribs during breathing

Intercostal Muscles

muscle sheet between chest and abdominal cavities with a role in breathing

Diaphragm

Components of the Upper Respiratory System

Sinuses, Nasal Cavity, Pharynx, Epiglottis, Larynx

cavities in skull, lightens head, warms and moistens air

Sinuses

produces mucus, olfaction; filters, warms and moistens air

Nasal Cavity

passageway for air and food

Pharynx

covers larynx during swallowing

Epiglottis

air passageway; produces voice; prevents food and drink from entering lower respiratory system

Larynx

Components of the Lower Respiratory System

Lungs, Trachea, Bronchi, Bronchioles, Alveoli

Function of the Lower Respiratory System

Exchanges gases

Function of the Upper Respiratory System

filters, warms, and moistens air

structure that contains alveoli and air passageways; allows exchange of oxygen and carbon dioxide between outside atmosphere and blood

Lungs

connects larynx with bronchi leading to each lung; conducts air to and from bronchi

Trachea

two branches of trachea that conduct air from trachea to each lung

Bronchi

narrow passageways to conduct air from bronchi to alveoli

Bronchioles

microscopic chambers for gas exchange

alveoli

What are the 2 zones of the respiratory system?

Conducting Zone and Respiratory Zone

All of the anatomical structures that air passes through to get into the lungs (conduits to gas exchange sites)

Conducting Zone

Components of the Conducting Zone

Nasal cavity, pharynx, larynx, trachea, bronchi

Zone where gas exchange occurs in the lungs (CO2 out and O2 in)

Respiratory Zone

Components of the Respiratory Zone

Alveolar ducts and sacs, Alveoli, Bronchioles

What gasses are exchanged during respiration?

O2 is brought in and CO2 is released out

Where does the CO2 come from that is breathed out during exhalation?

Byproduct of cellular respiration

Pathway of Air Flow

Nose or Mouth → Trachea → Bronchi → Bronchioles → Alveoli of Lungs → Blood Capillaries

What process occurs between the alveoli and blood capillaries to exchange gases?

Diffusion

Functions of the Nose/Nasal Cavity

• Provides airway for respiration 

• Moistens and warms air 

• Filters inspired air 

• Resonating chamber for speech 

• Olfactory receptors

3 Regions of the Pharynx

• Nasopharynx: in the nasal cavity

• Oropharynx: in the back of the oral cavity

• Laryngopharynx: in the larynx

Functions of the Larynx

• Patent (open) airway

• Voice Production

• Routes air and food into proper channels

What tissue is the larynx composed of?

Elastic Cartilage (allows it to remain open)

Roll of the larynx in routing food and air into proper channels

Air into trachea and Food into esophagus

What is the opening of the trachea referred to as?

Glottis

flap that covers the opening to the trachea, glottis, so food does not enter the trachea

Epiglottis

What tissue is the trachea composed of?

Pseudostratified ciliated columnar epithelial tissue

Why is the trachea composed of PCCE?

allows for debris to be caught in the cilia and propelled back up and outside of the body; prevents debris from entering lungs

cilia from the trachea brings up debris from oral cavity so you can get rid of it

Mucociliary escalator

Why does the trachea contain rings of cartilage around it?

to ensure it remains propped open (do not want the trachea to collapse)

where the trachea branches into the left and right bronchi

Carina

Pathway of air through the Bronchial Tree

R/L Primary Bronchi → R/L Secondary Bronchi (lobar) → R/L Tertiary Bronchi (segmental) → R/L Bronchioles

Lobes of the Right and Left Lungs

• Right Lung: 3 lobes

• Left Lung: 2 lobes

Pathway of Air through the Respiratory Zone

R/L Bronchioles → R/L Terminal Bronchioles → R/L Alveoli

What tissue type are the alveoli composed of?

Simple squamous epithelial tissue

Why are the alveoli composed of simple squamous epithelium?

thin layer of cells, allows for gas exchange

Exchange between alveoli and blood capillary

O2 and nutrients leave alveoli and enter capillaries; CO2 and wastes leave the capillaries and enter alveoli

What is the function of surfactant?

molecule that breaks surface tension of water 

What is produced by Type 2 Alveolar Cells?

Surfactant

What would occur if an individual did not secrete surfactant?

lungs could get waterlogged and the individual could get pneumonia and die

where the alveoli meets the blood vessel

respiratory membrane

Components of the Respiratory Membrane

composed of alveolar wall (simple squamous epithelial tissue) and wall of capillary (simple squamous epithelial tissue); basement membrane between the two walls

mechanical; air moving into and out of the lungs

Pulmonary Ventilation

function of the lungs and blood; exchange of gasses between alveoli and blood capillary

External Respiration

external respiration produces oxygen that is transported; transportation requires circulatory system (blood vessels)

Gas Transport

function between the blood and tissue/organ

Internal Respiration

Relationship between Internal and External Respiration

External respiration provides oxygen that is transported through blood vessels and dropped off to tissue/organ to allow for internal respiration

Difference between internal and external respiration

• Internal: O2 enters tissue; CO2 leaves tissue

• External: O2 enters lungs/capillaries; CO2 leaves lungs/capillaries

Relationship between Pressure and Volume

Volume and pressure are opposites (increase volume, decrease pressure; decrease volume, increase pressure)

How are pressure and volume related to breathing?

• Volume changes lead to pressure changes

• Pressure changes lead to the flow of gases to equalize pressure (gas always flows from high to low pressure)

Air passing from the pharynx to the trachea must pass through _____.

Larynx

This structure prevents food from entering the airway.

Epiglottis

Which of the following delivers air to the lobes of the lungs?

Secondary bronchi

All of the following are part of the conduction zone except the ____. 

• Main bronchi

• Respiratory bronchioles

• Segmental bronchioles

• Terminal bronchioles

• Terminal bronchioles

Which structure delivers oxygen to the alveoli?

Terminal bronchioles

An increase in the volume of a container filled with air would have what effect on the pressure of the container?

Decrease in the pressure

Surfactant decreases the _____ in the alveoli

Surface tension

During inhalation, the chest cavity size _____ and pressure within the lungs _____.

Increases, decreases

During exhalation, the chest cavity size _____ and pressure within the lungs _____.

Decreases, increases

What happens to the diaphragm during inhalation?

• Diaphragm contracts and pulls down

• Lungs expand and air moves in

What happens to the diaphragm during exhalation?

Lungs recoil (diaphragm moves up) and air moves out

Lung Serous Membranes

• Parietal Pleura: surrounds the chest cavity

• Serous fluid located between 

• Visceral Pleura: surrounds the lungs

What are the two muscles involved in inhalation and exhalation?

Diaphragm and External Intercostal muscles

Muscle action during inhalation

• Ribs are elevated as external intercostals contract

• Diaphragm gets pulled down as it contracts

Muscle action during exhalation

• Ribs are depressed as external intercostals relax 

• Diaphragm is pulled up and relaxes

Process of Inhalation

Diaphragm pulled down → Increases the volume of the lungs, which decreases pressure → Air moves into the lungs (moves from higher pressure outside to lower pressure inside)

Process of Exhalation

Diaphragm is pulled back up → Decreases the volume of the lungs, which increases pressure → Air moves out of the lungs (moves from higher pressure inside to lower pressure outside

3 Factors Influence Pulmonary Ventilation

Airway Resistance, Alveolar Surface Tension, Lung Compliance

Relationship between pulmonary ventilation and airway resistance

smaller the airway, less air can get through

Relationship between pulmonary ventilation and alveolar surface tension

• higher surface tension, more airway resistance

• surfactant reduces surface tension which discourages alveolar collapse

Factors that sets up for the best pulmonary ventilation

• low resistance and low surface tension

• high lung compliance (more elastic structures)

Factors that diminish lung compliance

• scar tissue (fibrosis) caused by TB/smoking/emphysema

• reduced surfactant

• decreasing flexibility of thoracic cage

elasticity of lung tissue

lung compliance

volume of air inspired and expired during normal breathing

Tidal Volume

the total amount of air that can be inhaled above tidal volume

Inspiratory Reserve Volume

the total amount of air that can be exhaled above tidal volume

Expiratory Reserve Volume

the total amount of air that can be inhaled and exhaled during a single breath (expiratory reserve + inspiratory reserve + tidal volume)

Vital Capacity

the volume of air that always remains in the lungs; air that the body cannot exhale

Residual Volume

What is the purpose of residual volume?

always some air remaining in the lungs to prevent collapsed lung

the total of all the volumes; total amount of air in the lungs

Total Lung Capacity

AKA pulmonary gas exchange

External Respiration

Where does external respiration occur?

Lungs

Process of External Respiration

• Oxygen moves from alveoli to the pulmonary capillary

• Carbon dioxide moves from the pulmonary capillary to the alveoli

AKA systemic capillary gas exchange

Internal Respiration

Where does internal respiration occur?

in the body tissues

Process of Internal Respiration

• CO2 moves from the tissue cells to the systemic capillary

• O2 moves from the systemic capillary to the tissue cells

What is the relationship between the flow of gas and the pressure gradient?

the steeper the pressure gradient from one area to another, the faster gas will move

How is oxygen transported in the blood?

• on the heme group of hemoglobin in RBCs (attaches to iron)

• can also be carried in the blood plasma

How is carbon dioxide transported in the blood?

• in the blood plasma

• on the globin chains of hemoglobin molecules in RBCs

• can also be carried by bicarbonate ions in the blood

What are the two breathing control centers in the brain?

Pons centers and Medulla centers

What stimulates breathing control centers?

• CO2 and H+ increase in tissue

• nerve impulse from O2 sensor indicating CO2 decrease

Efferent nerve impulses from the medulla trigger:

• contraction of inspiratory muscles and diaphragm

• phrenic nerve and intercostal nerves

Relationship between Pons and Medulla

• Medulla sets the rhythm of breathing 

• Pons can modify the rhythm set by the medulla

Normal respiratory rate set by the medulla

12-15 breaths per minute