HN220- Respiratory + Renal

What does the respiratory tract include?

nose, throat, larynx, trachea, bronchi, and lungs

The bronchi are also known as the __________________

conducting zone

Bronchi branch into _________________

secondary bronchi

How many secondary bronchi are in the left lung

two

- one per lobe

How many secondary bronchi are in the right lung?

three

- one per lobe

true or false: both lungs have an equal amount of secondary bronchi

false

Which lobe has more secondary bronchi?

right

Secondary bronchi branch into ____________________

tertiary bronchi

Tertiary bronchi have ________________ orders of branching

20-23

Tertiary bronchi branch into _______________

bronchioles

True or false: bronchioles are 1 mm in diameter

false: less than 1 mm

Bronchioles branch into __________________

terminal bronchioles

Terminal bronchioles lead to the __________________

alveoli

the alevoli are also known as the _____________________

respiratory zone

What are the functions of the conducting zone?

1) Passage of air

2) Matches air temperature to body temperature

3) Humidifies air

How much volume does the conducting zone contain?

150 mL

What is dead space?

passageways that transport air but are not available for gaseous exchange

- air is not used for gas exchange here

Why does the air need to be humid?

humid air is needed in order for efficient gas exchange to occur at the alveoli

What does the epithelium of the conducting zone contain?

1) goblet cells

2) Ciliated cells

3) Mucus escalator

What is the purpose of the goblet cells?

secrete mucus to trap pathogens and foreign particles

What is the purpose of ciliated cells?

The cilia moves the mucus containing the pathogens towards the mouth

What is the mucus escalator?

group of cells with cilia that sweep mucus and particles out of airways

What prevents the trachea from collapsing?

cartilage rings

What allows for bronchioles to change their resistance?

contraction of smooth muscle

What is the function of the respiratory zone

exchange of gases between air and blood

Gas exchange between air and blood occurs through ___________________

diffusion

What are the structures of the respiratory zone?

1. respiratory bronchioles

2. alveolar ducts

3. alveolar sacs

4. alveoli

Where does gas exchange occur?

alveoli

How many alveoli are there in the lungs?

300 million

How does the alveoli get its blood?

the alveoli have a sheet of capillaries over them

What do type 1 alveolar cells do?

make up the wall of alveoli and perform gas exchange

Type 1 alveolar cells are a single layer of __________________________

epithelial cells

What do type 2 alveolar cells do?

secrete surfactant

Surfactant reduces _____________________

surface tension

What is the purpose of the surfactant?

prevents alveoli from sticking to each other

What do alveolar macrophages do?

removes foreign substances

The respiratory membrane is made of the _________________ of the respiratory zone

epithelium

The respiratory membrane is made of the ________________ cell layer of type 1 alveoli and _______________ cell layer of the capillaries

epithelial , endothelial

What feature do alveoli have that allow for quick gas exchange?

large surface area

What are the parts of the thoracic cavity?

- chest wall

- rib cage

- sternum

- thoracic vertebrae

- internal and external intercostal muscles

- diaphragm

- pleura

What is the purpose of the chest wall?

airtight wall that protects lungs

What is the pleura?

membrane lining of lungs and chest wall

What surrounds each lung?

pleural sac

What is the intrapleural space?

space between lungs and chest wall

The intrapleural space is filled with __________________

intrapleural fluid

What is the purpose of the intrapleural fluid?

creates surface tension between lungs and pleural sac to keep lungs open

the surface tension creates _____________ pressure which results in suction

negative

Air moves in and out of lungs by __________

bulk flow

What drives the flow for pulmonary ventilation?

pressure gradient

Air moves from ____________ pressure to _______________ pressure

high , low

Describe the pressure in the lungs and atmosphere during inspiration

Pressure in the lungs is less than the pressure in the atmosphere

Describe the pressure in the lungs and atmosphere during expiration

pressure in the lungs is greater than atmospheric pressure

What is the atmospheric pressure at sea level?

760 mm hg

What is the relationship between atmospheric pressure and altitude

inversely proportional

As altitude increases, atmospheric pressure _________________

decreases

True or false: atmospheric pressure decreases under water

false: it increases

What is intra-alveolar pressure?

pressure within the alveoli

Intra alveolar pressure is given relative to ________________

atmospheric pressure

Intra alveolar pressure varies with the __________________

phase of respiration

During inspiration, intra alveolar pressure is ______________

negative

- less than atmospheric pressure

During expiration, intra alveolar pressure is __________________

positive

- more than atmospheric pressure

The difference between Palv and Patm drives _________________

ventilation

True or False

There is pressure inside the pleural sac

True

The pressure inside the pleural sac is always _______ under normal conditions

Always negative

Negative pressure is analogous to ________

suction

True or False

Intrapleural pressure is always more than the pressure in the alveoli

LESS

What is intrapleural pressure

Pressure inside the pleural sac

Intrapleural pressure is ____ mm Hg at rest

-4 mm Hg

Why is intrapleural pressure always negative?

To help maintain proper inflation of the lungs and to help prevent a pneumothorax

_________ ________ of intrapleural fluid prevents wall and lungs from pulling apart

Surface tension

What is the formula for Transpulmonary pressure

Alveolar pressure - Intrapleural pressure

Describe the effects of an increase in transpulmonary pressure

-Increases distending pressure across lungs

-Causes the alveoli in the lungs to expand, increasing their volume

What would happen if we lost the negative pressure in the intrapleural space (Ex. got stabbed in the chest)

Atmospheric air will rush in to equilibrate the pleural space

This cause the lung to collapse (pneumothroax)

Movement of air in and out of the lungs occurs due to __________ _________

Pressure gradients

Mechanics of breathing describes mechanisms for creating ___________ _______

Pressure gradients

During the breathing cycle atmospheric pressure remains ________

constant

If atmospheric pressure remains constant, changes to which pressure affects gradients?

Changes in alveolar pressure affect gradients

What is Boyle's Law?

Pressure is inversely related to volume

How do we change alveolar pressure to form a gradient

Change volume in the alveoli

What are the factors determining the intra-alveolar pressure

-Quantity of air in alveoli

-Volume of alveoli

Describe changes in alveolar volume/pressure during inspiration

-Lungs expand, causes alveolar volume to increase

-Alveolar volume increases causes alveolar pressure to decrease

-Pressure gradient will drive air into the lungs

Describe changes in alveolar volume/pressure during expiration

-Lungs recoil, causes alveolar volume to decrease

-Alveolar volume decreases causes alveolar pressure to increase

-Pressure gradient will drive air out of the lungs

Inspiratory muscles __________ volume of thoracic cavity

Increase volume

What are the muscles associated with inspiration

- Diaphragm

- External intercostals

Expiratory muscles ________ volume of thoracic cavity

Decrease

What are the muscles associated with expiration

-Internal intercostals

-Abdominal muscles

Describe how the muscles, chest wall and lungs work together for inspiration

-External intercostals contract

-Diaphragm contracts

-Chest wall and lungs expand

-Expansion of ribs moves sternum up and out

Describe how the muscles, chest wall and lungs work together for expiration

-External intercostals relax

-Diaphragm relaxes

-Internal intercostals and abdominals contact for active expiration only

- Chest cavity and lungs contract

-Ribs and sternum depress

Inspiratory muscles are _______ stimulated

Neural stimulated

During inspiration the volume of the thoracic cavity _______

increases

The contraction of the diaphragm causes it to _______ and move _______

FLATTEN AND MOVE DOWNWARD

During inspiration, the outward pull on the pleura decreases _________ ________, which results in an increase in ___________ _________

Outward pull on the pleura decreases Intrapleural pressure, which results in an increase in transpulmonary pressure

During inspiration, alveoli ________, causing a __________ in alveolar pressure

Alveoli expand, decreasing alveolar pressure

During inspiration, air flows into the alveoli by ______ _____

BULK FLOW

Expiration is normally a ________________ process

passive

What muscles are relaxing during expiration?

External intercostals and diaphragm

What happens when the inspiratory muscles stop contracting?

the lungs and chest wall return to their original positions and the recoil causes the volume of the thoracic cavity to decreases

Active expiration requires ________________ muscles

expiratory

Why does active expiration require expiratory muscles?

Contraction of expiratory muscles creates a greater and faster decrease in the volume of the thoracic cavity

What are the 2 factors affecting pulmonary ventilation?

1) lung compliance

2) airway resistance