Chapter 11 - Respiratory System and Gas Exchange

What does metabolism require?

ATP

What does ATP synthesis require?

O2 and generates CO2

Respiratory system delivers air to lungs by?

O2 diffuses into blood, CO2 diffuses out.

What are the four processes for gas exchange?

- pulmonary ventilation

- pulmonary gas exchange

- gas transport

- tissue gas exchange

gas exchange is known as?

external respiration

external respiration

bringing air into the lungs (inhalation) and releasing air into atmosphere (exhalation); gas exchange between lungs and blood

internal respiration

exchange of gases (o2 & co2) between blood and body cells

Pulmonary Ventilation

breathing

Pulmonary Gas Exchange

gas diffusion across alveoli; oxygen moves from alveolar air to blood, while CO2 moves from blood to alveolar air

Gas Transport

gas travels in blood

Tissue Gas Exchange

gas exchange at the tissues; O2 from blood to cells and CO2 from cells to blood

Functions of the respiratory system

gas exchange, regulation of blood pH, voice production, olfaction, protection

Regulation of blood pH

altered by changing blood carbon dioxide levels

voice production

movement of air past vocal folds makes sound and speech

Olfaction

smell occurs when airborne molecules are drawn in nasal cavity

Protection

against microorganisms prevents entry and removing them from respiratory surfaces

Seven principle organs

1. nose

2. pharynx

3. larynx

4. trachea

5. bronchi

6. lungs

7. diaphragm

Upper respiratory tract location

airway from nose to larynx

Upper Respiratory Tract consists of what?

respiratory organs in head and neck

Lower Respiratory Tract location

airway from trachea to lungs

What does the lower respiratory tract consist of?

respiratory organs of thorax

Conducting Zone

passages for airflow

Airflow starts and goes where?

from nostrils to bronchioles

Airflow is too thick for what?

for O2 diffusion into blood

Respiratory Zone

gas exchange

Alveoli

air sacs in the lungs

Conducting Zone vs Respiratory Zone (image)

Nose does what?

warm, cleanses, humidifies, inhaled air detects odor, amplifies voice

Olfactory Epithelium

sensory cells, detects odors; in nasal cavity

Respiratory Epithelium

contains goblet cells; in respiratory tract

What does the respiratory epithelium secrete?

mucus

Where is mucus moved too?

ciliated cells move mucus to pharynx

What gets swallowed by respiratory epithelium?

inhaled dust, pollen, bacteria, and foreign matter

What is the pharynx made of?

nasopharynx, oropharynx, and laryngopharynx

Nasopharynx

inhaled air makes 90 degree pass, large particles get caught in mucus

Oropharynx

posterior of soft palate and epiglottis, where air arrives if breathing through mouth

Laryngopharynx

posterior to larynx, esophagus begin at this point

Pharynx (image)

What is the primary function of the larynx?

keep food and drink out of ariway

What is another role of the larynx?

sound production "voice box"

Vocal Cords

produces sounds when air pass through

Epiglottis

in larynx is the opening guarded by flap

Larynx (image)

Epiglottis (image)

Functions of Epiglottis?

stands vertical at rest to allow airflow

What does the epiglottis do while eating?

closes airway

What is another function of the epiglottis?

directs food and drink into esophagus

Trachea is aka?

windpipe

What is the trachea supported by?

C-shaped rings of cartilage

Bronchii?

reinforce trachea, prevent collapsing

What is the inner lining of the trachea and bronchi composed of?

columnar epithelium (mucus secreting goblet cells and cilia)

mucociliary escalator

mucus traps particles and move debris up to pharynx to be swallowed (inner lining of trachea)

What is inferior to the lungs and diaphragm?

liver, spleen, and stomach

Position of right and left lungs?

right lung is shorter than left lung.

Why is the right lung shorter?

the liver rises higher on the right

Why is the left lung taller?

narrow and heart tilts to left

How many lobes does the right lung have?

3

3 Lobes of Right Lung

superior, middle, inferior

Horizontal Fissure

deep groove, separates superior and middle lobes

Oblique Fissure

separate middle and inferior lobe

Fissures of Right Lung

Left Lung consists of how many lobes?

2

Lobes of left lung

superior and inferior

What is the single fissure in the left lung?

oblique fissure

Source of blood to lungs:

pulmonary artery brings deoxygenated blood to lungs from right side of heart to be oxygenated in capillary beds that surround alveoli. Blood leaves via pulmonary veins and returns to left side of heart

Two lymphatic supplies?

superficial and deep lymphatic vessels

Superficial lymphatic supplies?

drain superficial lung tissue and visceral pleura

Deep Lymphatic Vessels supplies?

drain bronchi and associated C.T.

Do any lymphatics drain alveoli?

no

Diaphragm

dome shaped, muscular, separates thoracic and abdominal cavities

Principle of respiration for diaphragm

provides 2/3 of pulmonary airflow

What does the diaphragm do when we breathe?

contracts when we breathe in and relaxes we we exhale

Diaphragm inhalation and exhalation

Bronchial Tree

branching system extends from main bronchus

How many bronchioles are in the bronchial tree?

~65,000 terminal bronchioles

Bronchial Tree (image)

Main (Primary) Bronchi

Lobar (secondary) bronchi

Segmental (tertiary) bronchi

Bronchioles

Terminal Bronchioles

Alveoli

Tracheobronchial Tree

Trachea and network of air tubes in lungs

Four Classes of Tracheobronchial Tree

Lobar (secondary) bronchi, segmental (tertiary) bronchi, bronchioles, and terminal bronchioles

Lobar Bronchi

(secondary), arise from main bronchi, each seres as lobe of lungs

What does the lobar bronchi contain?

cartilage plates and lined with pseudo stratified ciliated columnar epithelium

Amount of Lobar Bronchi

three of right and two on left

Segmental Bronchi

(tertiary) supply bronchopulmonary segments

Bronchioles size

less than 1 mm in diameter

What are larger bronchioles lined with?

ciliated simple columnar epithelium

Terminal Bronchioles have?

no cartilage in walls, but prominent in smooth muscle, lined with ciliated simple cuboidal epithelium

Alveoli

small, spongy sacs in lungs, where exchange of oxygen and carbon dioxide occurs

Squamous Alveolar Cells

cover 90-95% surface

Cuboidal Great Cells

~5% , repair epithelium, secrete pulmonary surfactant

Pulmonary Surfactant

phospholipids and protein coat

Alveolar Macrophages

dust cells, phagocytize dust particles

Pleura

lines thoracic wall, forms surface of lungs

What is pleural fluid for?

lubrication

What are the two layers of the pleura?

visceral (inner) and parietal (outer)

Visceral Pleura

(inner) surface of lung and extends to fissure between lobes