Respiratory System

Structures of the Respiratory System

Nose, Pharynx, Larynx, Trachea, Bronchi, Lungs, Alveoli

Functions of the Respiratory System

Oxygen Supplier, Eliminate CO2, Pathway for air, Gas Exchange, Filter, Humidify and warm incoming air, Smell, and Vocal Sounds

Upper Respiratory System

Nose, Pharynx, Larynx, and all of their associated structures

Lower Respiratory System

Trachea, Bronchi, Lungs, and all associated structures

Conducting Zone

Extends from nose to the terminal bronchioles.

No gas exchange

Respiratory Zone

Extends from respiratory bronchioles to alveoli

Gas exchange

Regions of the Nose

1) External Nose

2) Nasal Cavity

3) Paranasal Sinuses

External Nares

aka Nostrils

Opening to the nose from the outside

Nasal Septum

Divides the external nose into 2 areas

Cilia of the Nose

catches fine particles before they can enter the lungs

Vibrissae

longer and thicker nose hairs that stop larger particles from getting into the nose

Bony framework of the nose

Frontal, nasal, and maxilla bones

Cartilaginous framework of nose

Septal, Lateral Nasal and Alar Cartilage

Nasal Cavity

between the external nose and the pharynx

Nasal Conchae

form shelf-like partitions that divide the nose into areas
Superior, Middle and inferior conchae
AKA Turbinates

Nasal Meatus

- pathways formed by the nasal conchae
-Superior, Middle and Inferior meatus.

Paranasal Sinuses

-system of hollow cavities in the skull
- contribute to voice resonance

- Produce mucus that drains into the nasal cavity

Resonance

- Prolonging, amplifying or modifying sound by vibration

List the paranasal sinuses

1) Maxillary Sinus

2) Frontal Sinus

3) Ethmoid Sinus

4) Sphenoid Sinus

Maxillary Sinus

- The largest Sinus
- located in the maxillary bone

Frontal Sinus-

- Found in the lower forehead

Ethmoid Sinus-

- Found between your eyes

Sphenoid Sinus-

-Found behind the nose

Internal Nares-

- the opening between the Nasal Cavity and the nasopharynx

Pharynx-

-13 cm long

-divided into: nasopharynx, oropharynx, laryngopharynx

Nasopharynx

- Passageway from internal nares to soft palate
- Has openings to auditory tube

Oropharynx

- extends from soft palate to hyoid bone
- has opening to the mouth called the Fauces

Fauces

-Opening at the back of the mouth that leads into the oropharynx

Laryngopharynx

- Extends from hyoid bone to the larynx/esophagus

Larynx

- Voicebox
- houses the vocal cords

Glottis

- Opening between the vocal folds in the larynx
- the primary valve between the mouth and lungs

Ventricular Folds-

- aka the false vocal cords
- Allow you to hold your breath
- Do NOT produce any sound

Vocal Folds-

- Produces sound by vibrating the folds (phonation)

The Main Articulators

- Manipulate sound into words
- Tongue, Lips, Teeth, Uvula, Hard and Soft Palate

Phonetics

The study of human speech sounds

Voice Resonating Chambers-

- Give the voice its human and individual quality
- Pharynx, Nasal Cavity, Mouth, and Paranasal Sinuses

How is whispering accomplished-

- by closing all but the posterior portion of the glottis

Epiglottis

- leaf shaped piece of elastic cartilage that moves to cover the glottis (airway) when you swallow food or liquids to keep stuff out of your lungs.

Name the support Cartilages of the Larynx-

1) Thyroid Cartilage

2) Arytenoid Cartilages
3) Cricoid Cartilage

Thyroid Cartilage-

- AKA Adams apple
- Forms the Anterior wall of Larynx

Arytenoid Cartilage-

- Form synovial joints with the cricoid cartilage
- have a wide range of motion for voice production

Cricoid Cartilage-

- Landmark for a tracheotomy
- forms inferior wall of larynx

Trachea-

- Windpipe
- 12 cm long
- extends from Larynx to T5
- composed of 16-20 c-shaped cartilaginous rings
- Divides into the L and R primary bronchi

Trachealis Muscle-

- allows size of trachea to change subtly

Carina-

- projection of the inferior-most tracheal cartilage
- super sensitive
- triggers an immediate cough reflex

Primary Bronchi-

- main airways that lead into each lung
- Right Primary bronchi is more vertical & shorter
- divides into the Secondary Bronchi

Secondary Bronchi-

- AKA Lobar Bronchi
- Each lobe of the lungs gets its own secondary bronchi branch
- Divides into tertiary bronchi

Terminal Bronchioles-

- Mark the end of the conducting zone
- Branch into respiratory bronchioles

Bronchial Tree-

1) Trachea
2) Primary Bronchi
3) Secondary (Lobar) Bronchi
4) Tertiary Bronchi
5) Bronchioles
6) Terminal Bronchioles

Lungs-

- Paired thoracic cavity organs
- Right Lung- has 3 lobes
- Left Lung- has 2 Lobes
- surface area of about 750 square feet for gas exchange

Parenchyma-

lung tissue

Hilum-

- the area where everything enters and leaves the lungs
-Bronchi, Pulmonary vessels, Lymphatic Vessels, Nerves

Cardiac Notch

- indentation on the left lung where the heart sits
-makes the left lung about 10% smaller than the right

Oblique Fissure

- found on both lungs
- runs diagonally

Horizontal fissure-

- only on the right lung
- runs horizontally

Bronchopulmonary segment

- the segment of lung tissue that each tertiary bronchus supplies

Lobules

- Each lobule is wrapped in elastic connective tissue and contains lymphatic vessel, an arteriole, a venule and a branch from a terminal bronchiole

Respiratory Bronchioles-

- First part of the respiratory zone
- Have Alveolar Ducts branching off

Alveolar Sacs-

- Consist of 2 or more cup-shaped alveoli
- surrounded by a pulmonary capillary

Type I Alveolar Cells-

- The main sites of gas exchange
- Composed of simple squamous epithelium

Type II Alveolar Cells-

- AKA Septal Cells
- secrete surfactant to inhibit alveolar collapse

Surfactant-

- Lowers the surface tension of alveolar fluid
- secreted by Type II Alveolar Cells

Alveolar Macrophages-

-Wandering Cells
- remove dust and debris from alveolar spaces

Respiratory Membrane-

- 0.5 micrometers thin
- made of the alveolar and capillary walls combined

Steps in Respiration-

1) Pulmonary Ventilation
2) External Respiration
3) Internal Respiration

Steps in Pulmonary Ventilation-

- the act of breathing (Inhalation / Exhalation)
1) Contraction of Diaphragm and External Intercostal Muscles
2) Expansion of the lungs
3) Air moves down a pressure gradient
4) Contraction of accessory muscles

Diaphragm-

- the most important muscle of respiration
- innervated by the Phrenic Nerve
- Responsible for 75% of the air that enters the lungs

External Intercostal Muscles-

- Pulls ribs up and outward, thus increasing the size of the thoracic cavity.
- Responsible for 25% of the air that enters the lungs 

Alveolar Pressure-

- as the lungs get bigger the pressure inside the lungs drops.

Boyle’s Law-

- Volume of gas varies inversely with its pressure

Inhalation Accessory Muscles

- Help to further increase the size of the thoracic cavity during deep forceful inhalations.
1) Sternocleidomastoids
2) Scalenes
3) Pectoralis Minor

Sternocleidomastoids-

- Elevate the sternum

Scalenes-

- Elevate the first 2 ribs

 

Pectoralis Minor-

- Elevate ribs 3-5

Exhalation-

- is a passive process because no muscles are used
- Occurs through Elastic recoil

Forced Exhalation-

- is an active process
- Abdominals and Internal intercostal are used

External Respiration-

- AKA “Net Pulmonary Gas Exchange”
- Moves O2 from our lungs to our blood
- Moves CO2 from our blood to our lungs

Internal Respiration-

- aka “Net Tissue Gas Exchange”
- Moves O2 from our blood into the tissues
- Moves CO2 from our tissues into our blood

Oxygen Transport-

1) small amount dissolved in plasma
2) Most Oxygen is bound to the Heme portion of hemoglobin.

Hemoglobin-

- Heme portion- contains 4 atoms of iron, each of which can bind to a molecule of O2
- Globin portion- binds to CO2 for transport

Carbon Dioxide Transport-

- a small amount dissolved in plasma
- Some binds to the globin portion of hemoglobin
- Bicarbonate ions carry most of the CO2

Bicarbonate Ions-

- Carry the greatest percentage of CO2 in the blood (70%)

Normal Respiration Rate-

- 12-20 breaths per minute (BPM)

Spirometer

- used to measure the volume of air exchanges during breathing

Tidal Volume-

- (500 ml)
- Volume of air in one breath

Minute Ventilation-

- Breathing Rate x Tidal Volume

Inspiratory Reserve Volume-

- Additional Air during forced inspiration

Expiratory Reserve Volume-

- Additional Air during forced exhalation

Residual Volume-

- about 1200 ml
- Volume of air remaining in the airway after forced exhalation

Anatomic Dead Space-

- Remaining air in Conducting Zone that does NOT undergo gas exchange

Inspiratory Capacity-

- volume of air that can be inspired after a normal, quiet expiration

Functional Residual Capacity-

- Volume of remaining air after a normal breath.

Vital Capacity-

- Maximal amount of air that can be exhaled after maximal inhalation.

Total Lung Capacity-

- the maximum volume of air the lungs can hold.

Cerebral Cortex-

- Voluntarily alters pattern of breathing
- Limited ability to hold your breath
- Emotional Stimuli- Laughing/ Crying

Central Chemoreceptors-

- Associated with the medulla in the CNS
- Respond to changes in the cerebrospinal fluid

Peripheral Chemoreceptors-

- Associated with the aortic and carotid bodies
- Respond to changes in blood

Respiratory Acidosis-

- Decrease in ventilation causes an increase in CO2 concentrations which leads to a decrease in blood pH

Respiratory Alkalosis-

- Increase in Respiration increases the blood pH past the normal range

Restrictive Pulmonary Disease-

- Limits the lungs ability to stretch
- High compliance= stretches easily
- Low compliance= resists stretching
- Ex) Tuberculosis or Emphesema
- All Lung Volumes & Capacities are reduced