Respiratory System

Respiratory Organs

Nose, Pharynx, Larynx, Trachea, Bronchi, Bronchioles, Alveolar Ducts, and Alveoli

Upper Respiratory System

Nose, Pharynx, and Larynx

Lower Respiratory System

Trachea, Bronchi, Bronchioles, Alveolar Ducts, and Alveoli

Pharynx

Throat / Tube located on the back of the Nose, Mouth, and Larynx that is lined with Respiratory Mucosa and is the only shared organ between the Digestive and Respiratory systems

Larynx

Voice box that contains vocal cords that vibrate and make sound

Trachea

Wind pipe located in the mediastinum and is anterior to the esophagus

Bronchi

Smaller airway before the lungs that has two primary branches leading to each lung

Alveoli

Place of gas exchange and has round shape for more surface area

Function of RS

Exchange of gases (O2 and CO2) and adjusting blood pH (7.35-7.45)

Function of Airways

Warm, Clean, and Humidify air

Respiratory Mucosa

Inner lining of the Nose, Pharynx, Larynx, and Bronchi that has short hairs (Cilia) that sends air upwards

Goblet Cells

Cells within the respiratory tract that make mucus

Palate

Structure that separates the Nose and Mouth

Uvula

Covers the back opening of the Nose to prevent food from entering

Nasal Septum

Middle part of the Nose that contains Cartilage, the Vomer Bone, and the Perpendicular Plate of the Ethmoid Bone

Nasal Epithelium

Name of the Respiratory Mucosa within the Nose

Nasal Conchae

Bony shell-like structures containing Superior, Middle, and Inferior parts that are covered by Nasal Epithelium to increase the nasal surface

Paranasal Sinuses

Air filled cavities around the Nose that make the skull lighter, improve voice quality and sound, and aid in sense of smell that consist of the Frontal, Maxillary, Ethmoid, and Sphenoid

Nasopharynx

Upper part of the Pharynx located at the back of the Nose that contains Adenoids and is connected to the middle ear by the Auditory Tube

Oropharynx

Middle part of the Pharynx located at the back of the Mouth that contains Palatine and Lingual Tonsils

Laryngopharynx / Hypopharynx

Lower part of the Pharynx located at the back of the Larynx that does not contain anything

Aspiration

Inhalation of any liquid or solid that enters the Trachea

Glottis

The opening between the vocal cords

Hyoid Bone

Bone of the Glottis that is U shaped and makes no joint

9 Cartilages of Glottis

6 small pairs and 3 large unpaired

Thyroid Cartilage

One of the large cartilages of the Glottis that is the biggest and made of Hyaline cartilage, also known as the Adam’s apple

Epiglottis

One of the large cartilages of the Glottis that is made of elastic cartilage that stops food from entering the trachea

Cricoid Cartilage

One of the large cartilages of the Glottis that makes a complete ring at the opening of the Trachea that stops it from collapsing

15 - 25 C-Shaped Cartilage

Stops the body of the Trachea from collapsing and the opening of the C is closed off by smooth muscle to give the Esophagus space for swallowing

Carina

Largest and last cartilage of the Trachea that bifurcates into two Bronchi

R Primary Bronchi

Bronchi that is straighter, wider, and shorter where aspirated content typically go to

L Primary Bronchi

Bronchi that is angled, narrower, and longer

5 Secondary / Lobar Bronchi

Air comes from the Primary Bronchi into these within the lungs that have 3 in the right lung and 2 in the left lung

18 Tertiary Bronchi

Air comes from the Secondary / Lobar Bronchi into these within the lungs that have 10 in the right lung and 8 in left lung

Bronchioles

Air comes from the Tertiary Bronchi into these very small airways inside of the lungs that only act as passageways

Alveolar Ducts

Air comes from the Bronchioles into these passageways that lead to the Alveoli

Pulmonary Artery

Brings deoxygenated blood from the Heart to the Lungs

Pulmonary Vein

Takes oxygenated blood from the Lungs to the Heart

Surfactant

Fat that helps Alveoli from collapsing that comes form Alveolar Type II Cells

Alveolar Type I Cells

Macrophages that perform phagocytosis

Respiratory Membrane

The wall between the air in the Alveoli and the blood in the Capillaries

Lung Anatomy

Triangle shape with 3 important parts

Apex

Top of the Lungs that contains most of the air

Base

Bottom of the Lungs that are the most prone to collapse

Hilum

Door of the Lungs

R Lung

Shorter and wider lung that has 2 fissures and 3 lobes

2 R Fissures

Horizontal and Oblique

3 R Lobes

Superior, Middle, and Inferior

L Lung

Longer and narrower that has 1 fissure and 2 lobes with a Cardiac Notch

1 L Fissure

Oblique

2 L Lobes

Superior and Inferior

Pleural

Serous membrane covering the Lungs

Pneumothorax

Air in pleural cavity

Hemothorax

Blood in pleural cavity

Pleural Effusion

Fluid in pleural cavity

Parietal Pleura

Attaches the Lungs to the wall of the thoracic cavity

Pulmonary Ventilation

Breathing / Taking air into the lungs (inhalation/inspiration) and removing air of from the lungs (exhalation/expiration)

External Respiration

Exchange of O2 and CO2 between the air in the Alveoli and the blood in the Capillary

Internal Respiration

Exchange of O2 and CO2 between the blood in Capillaries and Tissue Cells to perform metabolism

Inspiration / Inhalation

First step of breathing that involves actively taking air into the lungs

Diaphragm

Dome-shaped muscle that contracts (flattens) to increase thoracic cavity volume during inspiration and relaxes during expiration

External Intercostal Muscles

12 pairs of muscles that contract making the chest wider to increase volume and is required for breathing

Expiration / Exhalation

Second step of breathing that involves passively taking air out of the lungs that does not require muscle contraction unless done forcefully

Inter Intercostal Muscles

Muscles that contract to decrease the volume of the chest cavity during forced expiration

Atmospheric Pressure

760 mmHg at sea level

Intra-pleural / Negative Pressure

Should be less than atmospheric and intra-pulmonary pressures to prevent Lung collapse

Intra-Pulmonary / Intra-Alveolar Pressure

< 760 mmHg during Inhalation, = 760 mmHg in between, and > 760 mmHg during Exhalation

Tidal Volume

Amount of gas in one breath, Normally 500 mL

Inspiratory Reserve Volume

Maximum amount of air that can be inhaled after a normal tidal inhalation, typically around 3100 mL above the normal 500 mL

Expiratory Reserve Volume

Maximum amount of air that can be exhaled after a normal tidal exhalation, typically around 1200 mL less than the normal 500 mL

Vital Capacity

Maximum amount of air that can be forcefully removed from the Lungs after a forceful inspiration (IRV + TV + ERV), that is normally 4800 mL

Residual Volume

Air that stays in the lungs to prevent collapse, that is normally 1200 mL

Total Lung Capacity

RV + VC that is normally 6000 mL

Pons

Controls respiratory rate and depth

Medulla Oblongata

Inspiratory and Expiratory Center

Vagus Nerve X (10)

Parasympathetic nerve that branches into the Phrenic Nerve and Intercostal Nerve

Phrenic Nerve

Controls the Diaphragm

Physical Factors Influencing Breathing

Talking, laughing, and coughing

Emotional State Influencing Breathing

Emotional situation triggers Sympathetic NS and release of Adrenaline that can increase RR and depth

Higher Brain Center Influencing Breathing

Cerebrum gives ability to hold breath for short periods

Chemical Factors Influencing Breathing

O2, CO2 and H+ in the blood

Chemoreceptors

Checks chemical levels in the blood

Central Chemoreceptors

Located in the Brainstem (Pons and Medulla Oblangata), that is more important and is sensitive to CO2 and H+

Peripheral Chemoreceptors

Located in the arch of the Aorta and the body of the Carotid Artery, that is less important and is sensitive to O2

How does most of the O2 get transported in the blood?

As Oxyhemoglobin

How does most of the CO2 get transported in the blood?

As Bicarbonate