Respiratory System Respiratory System

Which lung is bigger? Why is it Which lung is bigger? Why is it bigger?bigger?

Why does breathing in cold air hurt?Why does breathing in cold air hurt?

Can you get sick from breathing in Can you get sick from breathing in cold air?cold air?

FunctionFunction

Gas exchange for the Gas exchange for the bodybody

–Supply OSupply O2 2

–Remove CORemove CO22

StructureStructure

Two major divisions:Two major divisions:

–Upper Respiratory TractUpper Respiratory Tract

–Lower Respiratory TractLower Respiratory Tract

Upper Respiratory TractUpper Respiratory Tract

Think Think holes holes and tubesand tubes

Nasal/oral Nasal/oral cavitiescavities

PharynxPharynx LarynxLarynx TracheaTrachea

Upper Respiratory TractUpper Respiratory Tract

Air is Air is –FilteredFiltered

–MoistenedMoistened

–WarmedWarmed

Lower Respiratory TractLower Respiratory Tract

Think Think upside upside down treedown tree

BronchiBronchi

BronchioleBronchiole

AlveoliAlveoli

Bronchus vs. BronchioleBronchus vs. Bronchiole

Bronchus – lots of cartilage – won’t Bronchus – lots of cartilage – won’t collapsecollapse

Bronchiole – more muscle – so can Bronchiole – more muscle – so can dilate and constrictdilate and constrict

AlveoliAlveoli

300 million alveoli in each lung300 million alveoli in each lung Wall is single cell layer thickWall is single cell layer thick

Where does Respiration Where does Respiration Occur?Occur?

Respiration:Respiration:

Gas exchange Gas exchange across a across a membranemembrane

Ventilation:Ventilation:

Conducting Conducting air in/outair in/out

Which lung is bigger? Why is it Which lung is bigger? Why is it bigger?bigger?

Why does breathing in cold air hurt?Why does breathing in cold air hurt?

Can you get sick from breathing in Can you get sick from breathing in cold air?cold air?

As Nate would say, “I don’t As Nate would say, “I don’t want to breathe anymore…”want to breathe anymore…”

Ciliated Ciliated epithelial epithelial cellscells in trachea in trachea (250 cilia/cell)(250 cilia/cell)

Goblet cellsGoblet cells located located between these between these cells produce ½ cells produce ½ cup of cup of mucus/daymucus/day

Coughing and SneezingCoughing and Sneezing

the cilia beat about 1,000 the cilia beat about 1,000 1,500/minute, moving mucus up 1,500/minute, moving mucus up about 10-20 mm/min (1 mile/week) about 10-20 mm/min (1 mile/week)

You cough when nerve endings in the You cough when nerve endings in the larynx, trachea, or larger bronchi are larynx, trachea, or larger bronchi are irritated. irritated.

You sneeze when nerve endings at You sneeze when nerve endings at the back of the nasal cavity are the back of the nasal cavity are irritated. irritated.

HOW do we breathe?HOW do we breathe?

What keeps your lungs from collapsing?What keeps your lungs from collapsing?

How MUCH do we breathe?How MUCH do we breathe?

How do we TRANSPORT what we How do we TRANSPORT what we breathe?breathe?

What makes us take the next breath?What makes us take the next breath?

HOW do we breathe?HOW do we breathe?

What is the relationship between What is the relationship between pressure and volume?pressure and volume?

HOW do we breathe? HOW do we breathe? Inhaling:Inhaling:

1.1. Diaphram and intercostal muscles Diaphram and intercostal muscles contract – thoracic cavity expandscontract – thoracic cavity expands

2.2. Lungs expand (adhered to walls) Lungs expand (adhered to walls)

3.3. Since Since intrapulmonary volumeintrapulmonary volume has increased, pressure has increased, pressure ____________.____________.

4.4. Air is sucked inAir is sucked in  http://http://www.smm.org/heart/lungs/breathing.htmwww.smm.org/heart/lungs/breathing.htm

How do we breathe? How do we breathe? ExhalingExhaling

1.1. Diaphram and intercostals relaxDiaphram and intercostals relax

2.2. Thoracic/intrapulmonary volume Thoracic/intrapulmonary volume decreasesdecreases

3.3. Intrapulmonary pressure is now Intrapulmonary pressure is now ____________

4.4. Gases flow outGases flow out

So what keeps your lungs from So what keeps your lungs from collapsing?collapsing?

Intrapleural pressure is always negativeIntrapleural pressure is always negative

If it equalizes with atmospheric pressure (as in If it equalizes with atmospheric pressure (as in a chest wound), lungs immediately collapsea chest wound), lungs immediately collapse

Air in intrapleural Air in intrapleural space = space = pneumothoraxpneumothorax

How MUCH do we breathe?How MUCH do we breathe?

Tidal volume – normal exhaled breathTidal volume – normal exhaled breath

Vital Capacity – largest exhaled breathVital Capacity – largest exhaled breath

Residual Volume - left over amt after Residual Volume - left over amt after VCVC

Total Lung Capacity – RV + VCTotal Lung Capacity – RV + VC

How MUCH do we breathe?How MUCH do we breathe?

How MUCH do we breathe?How MUCH do we breathe?

Tidal volume – 500 mlTidal volume – 500 ml

Vital Capacity – 4800 mlVital Capacity – 4800 ml

Residual Volume - 1200 mlResidual Volume - 1200 ml

Total Lung Capacity – 6000 mlTotal Lung Capacity – 6000 ml

How do we TRANSPORT what How do we TRANSPORT what we breathe?we breathe?

OXYGEN: Transported by hemoglobin (Hb) OXYGEN: Transported by hemoglobin (Hb) as oxyhemoglobin (HbOas oxyhemoglobin (HbO22))

Each OEach O22 attaches to attaches to one Hemeone Heme

Each RBC has 250 Each RBC has 250 million hemoglobinsmillion hemoglobins

How do we TRANSPORT what How do we TRANSPORT what we breathe?we breathe?

Carbon Dioxide: two Carbon Dioxide: two methodsmethods

1.1. On the globin of HbOn the globin of Hb

2.2. As bicarbonate:As bicarbonate:

COCO22 + H + H220 0 HH22COCO33 H H++ + HCO3 + HCO3- -

This occurs inside the RBC – but then the HCO3This occurs inside the RBC – but then the HCO3- -

goes back into the blood plasma. goes back into the blood plasma. WHY?WHY?

Carbonic anhydraseCarbonic anhydrase

Oxyhemoglobin - Oxyhemoglobin - HbOHbO22

Carbaminohemoglobin - Carbaminohemoglobin - HbCOHbCO22

Bicarbonate - HCO3Bicarbonate - HCO3--

What makes us take the next What makes us take the next breath?breath?

Too dangerous to wait for OToo dangerous to wait for O2 2 levels to droplevels to drop

The major stimulus for inspiration is a The major stimulus for inspiration is a slight increase in blood acidity:slight increase in blood acidity:

HH++ + HCO + HCO33-- normoventilationnormoventilation

respiratory control respiratory control

center in braincenter in brain

What happens when you What happens when you hypoventilate?hypoventilate?

What happens when you What happens when you hyperventilate? hyperventilate?

What Is Asthma?What Is Asthma?

Spasmodic contraction of bronchi Spasmodic contraction of bronchi

Bronchial swellingBronchial swelling

Increased production of mucusIncreased production of mucus

What is bronchitis?What is bronchitis?

bronchi are inflamed and swollenbronchi are inflamed and swollen

mucus is hypersecretedmucus is hypersecreted

Why?Why?

What is emphysema?What is emphysema?

Airways are permanently damagedAirways are permanently damaged

Alveoli are permanently damagedAlveoli are permanently damaged

Reduced ability to exchange gasesReduced ability to exchange gases

DiphtheriaDiphtheria