respiratory system - napa valley college...

Respiratory System

Biol 105

Lecture 18

Chapter 14

Copyright © 2009 Pearson Education, Inc.

Outline - Respiratory System

I. Function of the respiratory system

II. Parts of the respiratory system

III. Mechanics of breathing

IV. Regulation of breathing

V. Disorders of the respiratory system


Respiratory system Function

The function of the respiratory system is to

bring in oxygen to the body and remove

carbon dioxide.


The Respiratory System

Figure 14.1

Breathing moves airin and out of the lungs.

External respiration

is the exchange ofoxygen and carbondioxide between thelungs and the blood.

Internal respiration isthe exchange of oxygenand carbon dioxidebetween blood and thebody tissues.

Gas transport

moves oxygen andcarbon dioxidebetween the lungsand the body tissues.

TissueGas diffusion Gas diffusion

Oxygen

transport

Carbon

dioxide

transportLungs


This type of tissue covers and lines body parts

1. Connective

2. Epithelial

3. Muscle

4. Nervous


Lined by pseudostratified ciliated columnar epithelial cells. The cilia sweeps mucus, germs and debris toward the throat.

Mucas produced by goblet cells.

Smoking damages the ciliated cells

8-4

Cells lining respiratory tract



Figure 14.4a


Ciliated cells in respiratory tract



Figure 14.3



Figure 14.2 (1 of 2)

Nasal cavity

• Produces mucus

• Filters, warms, and

moistens air

• Olfaction

Pharynx

• Passageway for

air and food

Sinuses

• Cavities in skull

• Lighten head

• Warm and moisten

air

Intercostal

muscles Diaphragm

• Muscle sheet between

chest and abdominal

cavities with a role in

breathing

UPPER RESPIRATORY

SYSTEM

RESPIRATORY

MUSCLES

• Cause breathing

• Filters, warms, andmoistens air

• Move ribs during

breathing



Figure 14.2 (2 of 2)

Epiglottis

• Covers larynx during

swallowing

Bronchi

• Two branches of

trachea that conduct

air from trachea to

each lung

Bronchioles

• Narrow passageways

to conduct air from

bronchi to alveoli

Lungs

• Structures that contain

alveoli and air

passageways

• Allow exchange of

oxygen and carbon

dioxide between

atmosphere and blood

Alveoli

• Microscopic chambers

for gas exchange

Trachea

• Connects larynx with

bronchi leading to

each lung

• Conducts air to and

from bronchi

Larynx

• Air passageway

• Prevents food and drink

from entering lower

respiratory system

• Produces voice

LOWER RESPIRATORY

SYSTEM

• Exchanges gases


Functions:

1. filter

2. warm

3. moisten the air entering the lungs

4. smell

8-3

1. Nasal cavity


Parts of the nasal cavity:

Mucus membranes - secrete sticky mucus

to trap germs & debris.

Contains olfactory receptor cells for the

sense of smell

Sinuses – air filled cavities, warm and

moisten air

8-3

1. Nasal cavity


Functions - is a passageway for air, liquids, and food. (swallowing begins here). Connects the nasal cavity to the esophagus and the larynx

Tonsils are found here – lymphatic tissue that protects against infection

8-4

2. Pharynx


Functions1. Connects the pharynx to the

trachea

2. Contains vocal cords used to generate sound

3. Prevents food from entering lower respiratory tract

8-4

3. Larynx


Structure made from cartilage

Epiglottis closes the trachea when swallowing

8-4

3. Larynx


Windpipe held open by concentric rings of cartilage

Function – Connects the larynx to the bronchi.

8-4

4. Trachea


Trachea leads to the bronchial tree: Bronchi (bronchus)

Bronchioles

Alveoli (alveolus).

8-4

Bronchial Tree



Figure 14.7


Sacs at the end of the bronchioles, they are

surrounded by blood capillaries .

Function: It is here that the oxygen diffuses

across the membrane into the capillaries, and

carbon dioxide goes from the capillaries to the

inside of the lungs.

8-6

7. Alveoli


Alveoli

Lungs - have about 300 million alveoli

The structure of the alveoli increases

surface area of lung

For alveoli to function properly they are

coated with phospholipid molecules called

surfactant that keep them open


Alveoli

Figure 14.8



Table 14.1 (1 of 2)



Table 14.1 (2 of 2)


What cells secrete mucus

1. Cilliated columnar epi

2. goblet

3. Squamous epi

4. osteocytes


The tube connecting the larynx to the primary

bronchi is

1. pharynx

2. trachea

3. bronchioles

4. alveoli


Common passageway for air, food and drink

1. pharynx

2. trachea

3. bronchioles

4. alveoli


Conduct air from the trachea to the bronchioles

1. pharynx

2. trachea

3. bronchi

4. alveoli


Gas exchange takes place here

1. pharynx

2. trachea

3. bronchioles

4. alveoli


Which cavity is the lung located in?

1. Abdominal

2. Pericardial

3. Pleural

4. Dorsal


Inhalation

Figure 14.9a

The lungs expand, and

air moves in.

The chest cavity increases

in size, and pressure within

the lungs decreases.

Diaphragm

contracts

and flattens Diaphragm

contracts

Intercostal

muscles

contract

Rib cage

moves up

and out

Air flow

Inhalation

(a)


Inhalation

When the diaphragm and intercostal muscles

contract, the volume of the thoracic cavity

increases, causing the pressure in the lungs to

decrease

Inhalation is also called inspiration


Exhalation

Figure 14.9b

The lungs recoil,

and air moves out.

The chest cavity decreases

in size, and pressure

within the lungs increases.

Diaphragm

relaxes and

moves upward Diaphragm

relaxes

Intercostal

muscles relax

Rib cage

moves down

and inward

Air flow

Exhalation

(b)


Exhalation

Exhalation = Expiration

When the same muscles relax, volume of

the thoracic cavity decreases, pressure in

the lungs increase


Air Volumes

The volume of air inhaled or exhaled

during a normal breath is called the tidal

volume

Tidal volume is usually around 500 ml

The volume of air moved into and out of

the lungs is an indication of health


Air Volumes

Inspiratory reserve volume = forced inhalation

volume

Expiratory reserve volume = forced exhalation

volume

Residual volume is the amount of air left in the

lungs after forced exhalation

Vital capacity is the amount of air brought in

and out of the lungs during forced breathing


Air Volumes

Figure 14.10 (1 of 2)

6000

5000

4000

3000

2000

1000

0

Inspiratory

reserve

(forced

inhalation)

volumeVital

capacity

Expiratory reserve

(forced exhalation)

volume

Residual

volume

Tidal volume

Total

lung

capacity

Lung V

olu

me (m

l)


Remember that O2 enters and CO2 leaves the

lungs = External respiration

Then O2 and CO2 is exchanged between the

blood vessels and tissues = Internal Respiration

This gas exchange is due to diffusion

8-14

Gas Exchanges in the Body


Oxygen is transported on Hemoglobin.

When Oxygen is bound to hemoglobin, then it is

called Oxyhemoglobin

8-15

Oxygen Transport


1. CO2 is transported dissolved in the plasma (10%)

2. CO2 is bound to hemoglobin (20%)

3. CO2 is converted to bicarbonate ions (70%)

8-14

Carbon Dioxide Transport


CO2 + H2O H2CO3 H+ + HCO3-

8-14

Bicarbonate ions

Carbonic

anhydrase


Diffusion of Gasses: Alveoli and Capillaries

Figure 14.11 (2 of 2)


Diffusion of Gasses: Capillaries and Tissues

Figure 14.11 (1 of 2)


Normally we breath 12 - 15 ventilations per

minute.

This rate is controlled by the medulla oblongata

region of the brain. Nerves transmit signal to the

diaphragm and muscles.

Chemoreceptors in the medulla oblongata and

arteries detect levels of CO2 and O2 in the blood,

controlling the rate and depth of breathing.

8-12

Regulation of Breathing


Common cold

Flu

Pneumonia

Strep Throat

Tuberculosis

Bronchitis

Asthma

Emphysema

Lung Cancer

8-16

Respiratory Disorders


Respiratory Disorders – Common Cold

The common cold - Caused by several types

of viruses.

Symptoms: runny nose, sore throat, sneezing,

nasal discharge

Treatment: rest and plenty of fluids

Prevention: wash your hands


Respiratory Disorders - Flu

The flu is caused by the Influenza viruses but there are many variants of these viruses

Symptoms: Similar to colds but appear suddenly and more severe. Usually have fever and chills, may have muscle aches, headache, and weakness.

Treatment and prevention – same as cold

Can take drugs to ease symptoms and antiviral medications may ease symptoms


Respiratory Disorders - Pneumonia

Pneumonia is an inflammation of the lungs that

causes fluid to accumulate in the alveoli,

reducing gas exchange

Usually caused by a viral or bacterial infection

Symptoms: fever, chills, chest pain, cough,

shortness of breath.

Treatment depends on cause – bacteria can be

treated with antibiotics.


Respiratory Disorders Strep throat

Strep throat is caused by Streptococcus

bacteria

Can lead to rheumatic fever which can

damage heart and kidney disease

Symptoms: Sore throat accompanied by

swollen glands and fever

Treatment: antibiotics


Respiratory Disorders - Tuberculosis

Tuberculosis is caused by a bacteria =

mycobacterium tuberculosis.

Bacteria spread through airborne transmission

Our body encapsulates the bacteria with a

fibrous capsule made of connective tissue to

try to protect itself, capsule is called tubercles


Respiratory Disorders - Tuberculosis

Symptoms: similar to flu, weight loss, tired, dry

cough.

Treatment: Antibiotics must be taken for 6

months to 2 years – some people to stop early

– leads to antibiotic resistant strains of bacteria


Respiratory Disorders - Bronchitis

Bronchitis is an inflammation of the mucous

membrane of the bronchi

Caused by viruses, bacteria, or chemical

irritation

Symptoms: Inflammation results in the

production of excess mucus, which triggers a

deep cough

Treatment: Depends on cause


Respiratory Disorders - Asthma

The smooth muscles surrounding the

bronchi spasm – causing the bronchi to

constrict, making it hard to breathe

Causes and triggers: allergies, colds,

exercise, stress


Respiratory Disorders - Emphysema

Emphysema is caused by the destruction of

alveoli, usually by smoking

Reduction in the surface area available for

gas exchange and the increased dead air

space results in shortness of breath

Treatment - no cure, can supplement with

oxygen and drugs can dilate airways.


Respiratory Disorders - Emphysema

Figure 14.14


Lung Cancer

Lung Cancer is the result of uncontrolled cell

division forms a tumor

The smoke irritates the lining of the bronchi.

The cilia that normally function to clear dust

and particles from the lungs are destroyed.

Often caused by inhaled carcinogens,

including those found in tobacco smoke.

Between 85 – 90% of lung cancer is from

smoking.


Lung cancer is more common in men, but as

more women are smoking, the rate of lung

cancer in women is rising. Women are more at

risk

Many compounds in the smoke are cancer

promoters, they trigger the progression of cancer

in cells.

8-16

Lung Cancer


The 5-year survival rate is 13%. Smoking can

cause cancers of other parts of the respiratory

system.

8-16

Effects of Smoking


Cigarette smoke contains CO, the fetal blood has

a higher affinity for CO than the mothers blood,

so CO builds up in the fetuses body.

Nicotine is also passed into the fetus, stimulating

the developing nervous system.

Men smoking can damage the DNA in their

sperm and pass genetic mutations to their

offspring.

8-16

Effects of Smoking on Pregnancy


Lung Cancer

Figure 14.15


What is the smoking policy on campus?

1. You can smoke

anywhere

2. You can smoke

anywhere outside

3. You can smoke at

designated spots

4. No smoking on campus


Do you think smoking should be allowed on

campus?

1. Yes

2. No


Do you smoke?

1. Never

2. Used to, but quit

3. Smoke, but trying to quit

4. Smoke


Important Concepts

Read Ch 15

What is the function of the respiratory system?

What is the location and function of the all the

parts of the respiratory system?

What are the parts of the nasal cavity and their

functions?

What are the parts of the larynx and their

functions?


Important Concepts

What cell types lines the trachea, what are

their functions, be able to discus how

smoking effects this tissue?

Where does the exchange of gases occur in

the lungs?

What cavity contains the lungs?

What controls the rate of breathing?

Be able to discuss the mechanics of

breathing?


Important Concepts

How is oxygen carried in the blood?

How is carbon dioxide carried in the blood,

know all the ways, and the which is the

predominate mode? (You don’t need to know

the chemical equation of bicarbonate

formation)

What is the diaphragm and what is its

function?


Important Concepts

Be able to discuss the disorders of the

respiratory system including the description,

symptoms, cause, and treatments.

How does smoking effect pregnancy?


Definitions

Goblet cells, sinuses, epiglottis, surfactant,

diaphragm, intercostal muscles,

Inhalation/inspiration, exhalation/expiration

tidal volume, inspiratory reserve volume,

expiratory reserve volume, residual volume,

vital capacity, hemoglobin, oxyhemoglobin,

chemoreceptors, tubercles, antibiotic

resistant

respiratory system - napa valley college...

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