A&P II Ch. 6 - The Respiratory System

Nose/Nasal Cavity

What do airways begin with?

1. Warm and moisten incoming air (nasal conchae)

2. Trap & filter foreign particles (ciliated pseudostratified epithelium)

3. Olfaction (olfactory epithelium)

4. Voice resonation

What are the 4 main functions of the Nose/Nasal Cavity?

the exchange of gases between the body and the external environment

What is External Respiration?

1. Upper respiratory tract - nose to pharynx

2. Lower respiratory tract - larynx to lungs

What are the 2 main structural areas of the respiratory tract?

1. Conducting zone - warms/humidifies/conducts air as it enters body (pulmonary ventilation)

2. Respiratory zone - performs gas exchange at the respiratory epithelia (alveolar ventilation)

What are the 2 main functional zones of the respiratory tract?

the respiratory system is used to supply oxygen TO body tissues & remove carbon dioxide FROM body tissues

What is Internal Respiration?

- Occurs within cells

- Involves production of ATP from glucose oxidation via glycolysis, Krebs cycle, and oxidative phosphorylation

Define Cellular Respiration.

Internal respiration is!

Out of the 9 Respiratory Functions, which is PRIMARY function?

It's the exchange of gases w/ the external environment

- Pulmonary ventilation — bulk flow air (conducting zone). "act of breathing"

- Alveolar ventilation — diffusion of gases across respiratory epithelium (respiratory zone)

External Respiration is one of the 9 respiratory system functions. Define/describe it.

moving oxygen to and carbon dioxide from the cells by blood capillaries

Transporting is one of the 9 respiratory system functions. Define/describe it.

exchange of gases with the internal environment

Internal respiration is one of the 9 respiratory system functions AND is the primary one. Define/describe it.

sound production is done using vocal cords (phonation)

Sound production is one of the 9 respiratory system functions. Define/describe it.

Bring odorants in the air into the nose for smell

Olfactory assistance is one of the 9 respiratory system functions. Define/describe it.

Uses mucus, cilia, and coughing to keep dust and microbes out of body

Protection is one of the 9 respiratory system functions. Define/describe it.

A. To match body temperature

B. To create humidity levels for diffusion

Warming & Moistening is one of the 9 respiratory system functions. Define/describe it.

ok cool

Acid-base balance is one of the 9 respiratory system functions. No need to define or describe it, it is what it is.

1. Surfactant — reduces surface tension of alveoli

2. ACE — angiotensin converting enzyme

Producing Chemical Mediators is one of the 9 respiratory system functions. Define/describe it.

involves the bulk flow (pulmonary ventilation) of air moves prior to diffusion of gases. Ends at terminal bronchioles.

The Conducting Zone is part of External Respiration. Define/describe it.

Begins at respiratory bronchioles where diffusion (alveolar ventilation) of O2 and CO2 occurs and continues down to the alveoli

The Respiratory Zone is part of External Respiration. Define/describe it.

is alveolar ventilation (diffusion) through the Respiratory Zone

The reason for pulmonary ventilation (bulk flow) through the Conducting Zone is what?

Conducting zone & Generation 0

What's the zone (conducting or respiratory) and generation number for Trachea?

Conducting zone & Generation 1

What's the zone (conducting or respiratory) and generation number for Primary Bronchi?

Conducting zone & Generations 2-10

What's the zone (conducting or respiratory) and generation number for Smaller Bronchi?

Conducting zone & Generations 11-16

What's the zone (conducting or respiratory) and generation number for Bronchioles?

Respiratory Zone & Generations 17-19

What's the zone (conducting or respiratory) and generation number for Respiratory Bronchioles?

Respiratory Zone & Generations 20-22

What's the zone (conducting or respiratory) and generation number for Alveolar Ducts?

Respiratory Zone & Generation 23

What's the zone (conducting or respiratory) and generation number for Alveolar Sacs?

1. Pulmonary Ventilation

2. Alveolar Ventilation (diffusion)

3. Gas Transport via blood circulation

4. Internal (systemic) Respiration

5. Cellular Respiration

What are the 5 Steps in the Process of Respiration?

1. Pulmonary Ventilation

2. Alveolar Ventilation (diffusion)

Which steps in the process of respiration involve external respiration?

- Air from environment enters conducting zone

- Bulk flow

Describe Step 1. Pulmonary Ventilation.

- Respiratory zone

- Carbon dioxide from blood is released

- Oxygen from air is absorbed

Describe Step 2. Alveolar Ventilation (diffusion).

none needed, it is what it is LOL

Describe Step 3. Gas Transport via blood circulation.

- Exchange of gases between blood & body tissues

- Oxygen from red blood cells is released

- Carbon dioxide from tissues is absorbed in the blood

Describe Step 4. Internal (systemic) Respiration.

- The metabolic process of oxygen for aerobic respiration

- Aerobic glycolysis produces ATP

Describe Step 5. Cellular Respiration.

equals gas exchange

Alveolar Ventilation equals what?

nope it can't

While pulmonary ventilation can bring air into lungs via bulk flow (or release it from lungs), can it bring oxygen into the bloodstream?

- Alveolar ventilation gas exchange is the process of getting oxygen into bloodstream via diffusion (beginning w/ respiratory bronchioles)

- Systemic gas exchange is the process of getting oxygen into body's tissues (cells) from bloodstream

- Gas exchange occurs through the process of diffusion at the capillary lvl (both pulmonary & systemic)

Describe Gas Exchange.

1. Pressure gradients — how do gas lvls compare in blood versus alveoli/tissues?

2. Solubility — which gases can travel through plasma w/o "assistance"

3. Perfusion — how much blood is present at the alveoli?

What are the factors that influence gas exchange?

1. Frontal

2. Ethmoid

3. Maxillary

4. Sphenoid

What are the 4 Paranasal Sinuses?

Mnemonic: FEMS

1. Secrete mucus for filtering pathogens & particles

2. Warms & moistens the air

3. Lightens the skull

4. Assists w/ voice resonance

What are the functions of the 4 Paranasal Sinuses?

Upper Respiratory Tract & Conducting Zone

Are the Paranasal Sinuses part of the Upper Respiratory Tract or Lower? Conducting Zone or Respiratory Zone?

Upper Respiratory Tract and Conducting Zone

Is the Nasal Cavity part of the Upper or Low Respiratory Tract? Conducting or Respiratory Zone?

capture odorants for the sense of smell aka olfaction

The olfactory epithelium does what?

increase the air turbulance

What does the Nasal Conchae (turbinates) do?

Superior and Middle are part of the ethmoid bone. Inferior is its own separate bone.

The Superior and Middle Nasal Conchae are part of which bone? What about the inferior?

warms & moistens incoming air AND the mucus traps foreign particles

What does the Ciliated Pseudostratified Columnar epithelium lining the nasal conchae do?

Upper Tract & Conducting Zone

Is the Pharynx in the Upper or Lower Respiratory tract? Conducting or Respiratory zone?

1. Nasopharynx

2. Oropharynx

3. Laryngopharynx

What are the 3 sections that the Pharynx is made up of?

- Directly behind the nasal cavity

- Only transports air

- Uvula blocks this structure during swallowing

Describe the Nasopharynx.

- Directly behind the oral cavity

- Transports air & food

- Palatine tonsils are found here

Describe the Oropharynx.

- Splits into the larynx & esophagus

- Transports (larynx) air and food (esophagus)

- Epiglottis covers the glottis (lumen) of the larynx during swallowing

Describe the Laryngopharynx.

- Air is sent forward to the trachea

- Food is sent backwards to the esophagus

The larynx splits the contents of the pharynx. Describe/elaborate.

1. Large Thyroid Cartilage (location of adam's apple)

2. Smaller Cricoid Cartilage...the attachment site for vocal cord muscles and to only one that completely encircles the larynx

The larynx is made of 9 cartilages. The two largest are...

- Sounds are made

- Length & tension in the cords determines vocal pitch

What happens when air vibrates through the vocal cords?

during breathing to allow air passage

When do vocal cords open?

when speaking for air to vibrate them to produce sound

When do vocal cords open AND close?

Lower respiratory tract & Conducting zone

Is the Trachea in the Upper/Lower respiratory tract? Conducting or Respiratory zone?

it branches within the mediastinum and transports air from the neck into the chest

Where's the Trachea and what does it do?

1. Mucosa

2. Submucosa

3. Adventita

Identify the 3 tissue layers of the Trachea.

innermost layer with ciliated pseudostratified columnar epithelium with goblet (mucus) cells

What's the Trachea's Mucosa layer?

Middle layer with:

- dense connective tissue

- glandular epithelium

- hyaline cartilage c-rings

- glands

- smooth muscle

- vessels & nerves

- elastic & collagen fibers

What's the Trachea's Submucosa layer?

outermost layer with loose connective tissue, collagen, nerve endings, and vasa vasorum

What's the Trachea's Adventitia layer?

- left and right primary bronchus

- primary bronchi enter each lung

- left primary bronchi is more horizontal due to the heart

The trachea branches into 2 primary bronchi. Describe them.

- Secondary bronchi enter each lobe of the lungs

- Bc the left lung has only 2 lobes, it only has 2 secondary bronchi

The primary bronchi branch into secondary bronchi. Describe them.

- Terminal bronchioles are the end of pulmonary ventilation (bulk flow)

- Respiratory bronchioles are the beginning of alveolar ventilation (diffusion)

- Bronchi become bronchioles when the cartilage disappears

The bronchi continue to branch until they become bronchioles. Describe them.

less cartilage and more smooth muscle

What does more branching lead to in terms of amount of cartilage and smooth muscle?

Lower respiratory tract & Respiratory zone

Is Alveoli part of the Upper/Lower respiratory tract? Conducting or Respiratory zone?

the thin epithelial tissue sacs used for the process of gas exchange

What are Alveoli?

- Since they're thin, gases can quickly diffuse through them

- Since they have a large surface area, more gases can be exchanged

Describe Alveoli.

1. Type I cells

2. Type II cells

3. Alveolar macrophages

What are the cells of an Alveolus?

simple squamous epithelium, allowing gas exchange

What are Type I cells of an alveolus?

simple cuboidal epithelium, secreting surfactant

What are the Type II cells of an alveolus?

"big eaters" (dust cells) keep the alveolus free of infection & capture particulate matter

What are the Alveolar macrophages of an alveolus?

~1400 sq ft (half a tennis court)

What's the surface area of an alveoli?

made of alveolar & capillary tissues

The respiratory membrane is made of what?

- Type I alveolar cells (simple squamous epithelium)

- The basement membrane (of the Type I alveolar cells)

Describe the Alveolar contributions to gas exchange.

- The basement membrane (of the endothelial cells)

- Endothelial cells (simple squamous epithelium)

Describe the Capillary contributions to gas exchange.

they're fused!

What's special about the basement membranes underlying the alveolar epithelium and capillary endothelium?

the process of moving air in & out the lungs (bulk flow) via the conduction zone

Give the actual definition of Pulmonary Ventiliation.

the process of bringing air IN

What is Inspiration?

the process of pushing air OUT

What is Expiration?

from HIGH pressure to LOW pressure

Air always moves from what?

pressure OUTSIDE > pressure INSIDE

Describe the pressure during Inspiration.

pressure INSIDE > pressure OUTSIDE

Describe the pressure during Expiration

1. Atmospheric Pressure

2. Intrapulmonary Pressure (alveolar pressure)

3. Intrapleural Pressure

What are the 3 Pressures of Ventilation?

- This is the pressure of air outside of the body

- This pressure changes with things like elevation or temperature

- Increase this --> pushes air IN

Describe Atmospheric Pressure.

- This is the pressure of the air inside the lungs

- Increase this --> pushes air OUT

Describe Intrapulmonary Pressure (alveolar pressure).

- This is the pressure of the pleural cavity

- Increase this --> (indirectly) pushes air OUT

Describe Intrapleural Pressure.

volume & pressure are inversely proportional in a closed system

What is Boyle's Law?

- Occurs when the diaphragm & the external intercostal muscles contract

- Diaphragm makes the thoracic cavity longer

- The external intercostals make the thoracic cavity wider

Identify and explain when Inspiration (inhalation) occurs.

- Intrapulmonary pressure (in lungs) and Intrapleural pressure (in pleural cavity) decrease

- This is bc of Boyle's law --> more space = less pressure

What happens pressure wise when the thoracic cavity enlarges?

- Occurs when the diaphragm & external intercostal muscles relax

- Diaphragm = thoracic cavity shorter

- Internal intercostals = thoracic cavity narrow

Identify and explain when Expiration (exhalation) occurs.

Intrapulmonary pressure (in lungs) & Intrapleural pressure (in pleural cavity) increase

- Boyle's law --> less space = more pressure

What happens pressure wise when the thoracic cavity shrinks?

- Occurs when internal intercostal & abdominal muscles contract

- Internal intercostals = narrow thoracic cavity

- Abdominal muscles = increase pressure, pushes the diaphragm up

Identify and explain when/how Forced Expiration occurs.

- Diaphragm

- External intercostals

- Sternocleidomastoid

- Scalenes

- Pectoralis minor

What are the Muscles of Inspiration?

- Diaphragm

- Internal intercostals

- Abdominals

- Quadratus lumborum

What are the Muscles of Expiration?

the size of the airway's lumen

Airway resistance is primarily impacted by what?

decreased resistance --> faster airflow

Wider airways lead to what?

increased resistance --> slower airflow

Narrower airways lead to what?

Bronchioles!

- have relatively little cartilage --> cartilage keeps airway open

- have relatively more smooth muscle --> contraction decreases airway size

What part of the respiratory tract has the most resistance? Why?