bio 105: respiratory system - napa valley college … 17... · 5/5/2016 2 the respiratory system...

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Bio 105: Respiratory System

Lecture 17

Chapter 14

Copyright © 2009 Pearson Education Inc.1

Outline

• Function of the Respiratory System

• Parts of the Respiratory System

• Mechanics of breathing

• Regulation of breathing


Respiratory System

• Function

–Bring in oxygen to the body

–Remove carbon dioxide from the body


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


Review Question

• What type of tissue covers and lines body parts?

–Connective

– Epithelial

–Muscle

–Nervous


Respiratory Tract

• Lined by pseudostratified ciliated columnar epithelial cells

–Cilia “sweeps”

–Mucous

• Produced by goblet cells

– Smoking damages ciliated cells


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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, and

moistens 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


Nasal Cavity

• Functions

– Filters the air

–Warms the air

–Moistens the air entering the lungs

– Smell

• Taste


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Nasal Cavity

• Parts

–Mucus membranes

• Secrete sticky mucus

–Olfactory receptor cells

• Sense of smell

– Sinuses

• Air filled cavities

• Warm and moisten air


Pharynx

• Functions

–Passageway for air, liquids and food

–Connects the nasal cavity to the esophagus and larynx

• Tonsils

– Lymphatic tissue that protects against infection


Larynx

• Functions–Connects the pharynx to the trachea

–Contains the vocal cords

–Prevents food from entering the lower respiratory tract

• Made from cartilage

• Epiglottis–Closes the trachea when swallowing

Copyright © 2009 Pearson Education Inc.15 Copyright © 2009 Pearson Education Inc.16


Trachea

• Windpipe

• Held open by concentric rings of cartilage

• Function

–Connects the larynx to the bronchi


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Bronchial Tree

• Trachea leads to the bronchial tree

–Bronchi (bronchus)

–Bronchioles

–Alveoli (alveolus)



Figure 14.7


Alveoli

• Sacs at the end of the bronchioles

• Surrounded by blood capillaries

• Function

–Oxygen diffuses across the membrane into the capillaries

–Carbon dioxide goes from the capillaries to the inside of the lungs


Alveoli

• About 300 million alveoli

• Structure of alveoli increases surface are of the lung

• Coated with phospholipid molecules called surfactant to keep them open


Alveoli

Figure 14.8



Table 14.1 (1 of 2)


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Table 14.1 (2 of 2)


Review Questions

• What cells secrete mucus?• What tube connects the larynx to the

primary bronchi?• What is the common passageway for air,

food and drink?• What conducts air from the trachea to the

bronchioles?• Where does gas exchange take place?• What cavity is the lung located in?


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)Copyright © 2009 Pearson Education Inc.27

Inhalation

• Inhalation

• Diaphragm and Intercostal muscles contract

–Volume of thoracic cavity increases

–Causes pressure in the lungs to decrease


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)Copyright © 2009 Pearson Education Inc.29

Exhalation

• Expiration

• Diaphragm and intercostal muscles relax

–Volume of the thoracic cavity decreases

–Causes pressure in the lungs to increase


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Air Volumes

• Tidal Volume

–Volume of air inhaled or exhaled during a normal breath

–Usually around 500 ml

– Indication of health


Air Volumes

• Inspiratory Reserve Volume– Forced inhalation volume

• Expiratory Reserve Volume– Forced exhalation volume

• Residual volume – The amount of air left in the lungs after forced

exhalation

• Vital capacity – 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

Lu

ng

V

olu

me

(m

l)


Gas Exchanges in the Body

• External respiration

–O2 enters and CO2 leaves the lungs

• Internal respiration

–O2 and CO2 is exchanged between the blood vessels and tissues

• Gas exchange is due to diffusion


Oxygen Transport

• Transported on hemoglobin

–When oxygen is bound = Oxyhemoglobin


Carbon Dioxide Transport

• 3 ways

–Dissolved in plasma (10%)

–Bound to hemoglobin (20%)

–Converted to bicarbonate ions (70%)

Carbonic Anhydrase

CO2 + H2O H2CO3 H- + HCO3-


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Diffusion of Gases: Alveoli and Capillaries

Figure 14.11 (2 of 2)


Diffusion of Gasses: Capillaries and Tissues

Figure 14.11 (1 of 2)


Regulation of Breathing

• Respiratory Rate– 12 to 15 ventilations (breaths) per minute

• Controlled by the medulla oblongata– Nerves transmit signal to the diaphragm and

muscles

• Chemoreceptors in medulla oblongata and arteries– Detect levels of CO2 and O2 in the blood– Controlling the rate and depth of breathing


Important Concepts

• Chapter 15

• What is the function of the respiratory system?

• What is the location and function of all of 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 type lines the trachea?

–What are their functions?

–How does smoking effect this tissue?

• Where does the exchange of gases occur in the lungs?

• What cavity contains the lungs?

• What controls the rate of breathing?

• Discuss the mechanics of breathingCopyright © 2009 Pearson Education Inc.41

Important Concepts

• How is oxygen carried in the blood?

• How is carbon dioxide carried in the blood?

– Know the 3 ways and how much is carried in each way

– It is not necessary to know the chemical equation of bicarbonate formation

• What is the diaphragm?

– What is its function?


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Definitions

• Goblet cells• Sinuses• Epiglottis• Surfactant• Diaphragm• Intercostal muscles• Inhalation or Inspiration• Exhalation or Expiration• Tidal volume• Inspiratory reserve

volume

• Expiratory reserve volume

• Residual volume• Vital capacity• Hemoglobin• Oxyhemoglobin• Chemoreceptors


The End


bio 105: respiratory system - napa valley college … 17... · 5/5/2016 2 the respiratory system...

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