Ch.24 - The Respiratory System

Alveoli

Site of gas EXCHANGE

Upper Respiratory system (1)

CONDITIONS the air as it enters the body

• Filters air before it reaches inside the LUNGS

• Temp & Humidity reach acceptable levels

Lower Respiratory System

Passages and air exchange surfaces

Main Functions of the Respiratory System

• Provides area of GAS exchange

• Moves air to/from EXCHANGE surfaces of lungs

• Protect respiratory surfaces from DEHYDRATION & temp changes

• DEFEND against pathogens

• Productions of sound (SPEAKING)

• Helps regulate blood volume, pressure, and pH

Pseudostratified Ciliated, Columnar Epithelium w/Numerous Mucous cells

_____ Cells that line entire respiratory tract EXCEPT in

• Inferior portion of the PHARYNX

• Smallest conducting passages

• Alveoli

Respiratory DEFENSE System

Mucous glands/cells produce a sticky substance that bathes exposed surfaces

• Collect Debris/Microorganisms that are inhaled

  • moved to PHARYNX to be EXPECTORATED (swallowed)

Nares

Paired nostrils

• Open into the Nasal VESTIBULE & CAVITY

Nasal Septum

Divides the R/L portions of the Nasal Cavity

Allows for CONDITIONING & contact with the sensory epithelium

Air bounces off the CONCHAE causing turbulence which allows for ______

3 divisions of the Pharynx

1. NASOpharynx

2. OROpharynx

3. LARYNGOpharynx

NASOpharynx

Most superior portion, connects to posterior nasal cavity

• Separated from oral cavity by SOFT PALATE

OROpharynx

Extends from soft palate to base of TONGUE at the hyoid bone

• Posterior part of soft palate the uvula divides oral and respiratory passage

LARYNGOpharynx

From the level of the hyoid to the entrance of the esophagus

The GLOTTIS and into the → pharynx

Inhaled air passes from the pharynx through ______

3 Types of Cartilages of the LARYNX

1. Thyroid Cartilage

2. Cricoid Cartilage

3. Epiglottis

(Also contains 3 Pairs of SMALLER cartilages: Arytenoid, Corniculate, & Cuneiform)

Thyroid Cartilage

• Largest in the Larynx

• Forms the Anterior & Lateral walls

Cricoid Cartilage

• Forms a complete CIRCLE

• Protects Glottis & entrance to Trachea

Epiglottis

• Shoe-horn shaped

• During swallowing, it folds over the GLOTTIS to ensure food/liquids enter Esophagus

Laryngeal Ligaments

A series of intrinsic ligaments bond all 9 cartilages together

• Forms the Larynx

TRUE Vocal Cords

Vocal folds that produce SOUND

FALSE Vocal Cords

Vestibular folds that DO NOT produce sound

Trachea Characteristics

• Tough FLEXIBLE Tube

• Begins C6 & attaches to Cricoid cartilage

• Lining→ Pseudostratified & Ciliated

• Branches into L/R main Bronchi

Main Bronchi Characteristics

• T5 trachea branches to FORM the Bronchi

• Travels thru the HELIUM of the lung before further branching occurs

RT Bronchi

• Shorter

• Larger diameter

• More acute angle

The Lungs

• In the L/R Plural Cavities

• Apex is pointing superiorly

• Broad inferior portion (Base) rests on DIAPHRAGM

Left Lung

• Has 2 Lobes (separated by deep fissures)

  • Superior & Inferior

Right Lung

• Has 3 Lobes (separated by deep fissures)

  • Superior, Middle, Inferior

Bronchial Tree

Each main bronchi DIVIDES after entering the lung

• LOBAR Bronchi

• Segmental Bronchi

LOBAR Bronchi

First split in the main bronchi forms 2ndary ______

SEGMENTAL Bronchi

Lobar Bronchi split to form TERTIARY _____

Bronchioles

• Branch to form TERMINAL Bronchioles

  • Insert onto the alveolar clusters

Alveolar Ducts

Connect individual/multi alveoli to a single Bronchiole

• End at alveolar SAC, have multi alveoli

Each lung has around 150 Million

Blood- Air Barrier

• Gas Exchange occurs here

• Diffusion is rapid

• Short distance

• O2 & CO2 are small molecules

Eupnea

PASSIVE Respiratory movement

• Expansion of lung stretches ELASTIC Fibers

Hypernea

ACTIVE Respiratory Movement

• Accessory muscles assist with respiration

• Expiration involves activation of the thoracic and intercostal muscles