Chapter 24 : respiratory system

functions of the respiratory system

• supply O2 and eliminates CO2

• receptors for the sense of smell ( upper part )

• filters inspired air

• produced sound

• eliminate waste

respiration

Overall exchange of gases among the atmosphere, blood, and cells (different for cellular respiration, the goal is to produce energy)

respiratory epithelium

Respiration must occur on a ____

Respiratory epithelium

consists of :

pseudostratified ciliated columnar cells

• except for the pharyngeal, smaller bronchI and alveoli

Mucous-producing cells

• nasal cavity - sneezing

• respiratory epithelium - coughing

Pharynx

This passage way contain stratified squamous cells because it’s a common passageway

respiration

overall exchange of gases among the atmosphere, blood & cells

3 process:

• pulmonary ventilation

• external ( pulmonary ) respiration

• internal ( tissue ) respiration

Pulmonary ventilation

inspiration and expiration ( breathing)

External ( pulmonary ) respiration

lungs and blood

Internal ( tissue ) respiration

blood and cells

the nose

includes:

• external nares

• internal nares ( posterior nasal apertures)

• internal nose is made of several nasal and cranial bones

Nasal cavity

• external and internal nose

• nasal septum - vertical partition

3 regions

• vestibule

• respiratory area

• olfactory area

Vestibule

most anterior portions of the nasal cavity

• just inside the nostrils

• cartilage- lined by stratified squamous epithelium

• coarse hair - filters dust particles

Respiratory area

• the rest of the nasal cavity

• pseudostratified columnar epithelium with goblet cells

• Mucus warms air and traps dust

• Cilia move dust to the pharynx

Olfactory area

• root of the nasal cavity

• pseudostratified columnar epithelium with reduced cilia

• No goblet cell (Bowman’s capsule)

• contain olfactory cells

the nose and nasal cavity functions

• incoming air is warmed, moistened, and filtered

  • Cilia move particles to the throat

• Stimuli are received

• large hollow chamber for speech

• nose is important for speech

the pharynx

• after the nose of the pharynx

• passage that connects the nose to the mouth to the throat

• shared by the respiratory and digestive systems

• not covered with pseudostratified ciliate epithelium

• Instead, it is covered with stratified squamous epithelium

  • bc food goes through that area

3 regions

• nasopharynx

• oropharynx

• laryngopharynx

nasopharynx

• back of the nose area

• 4 openings

  • 2 internal nares

  • 2 Eustachian tubes

• contains the pharyngeal tonsil

• pseudostratified ciliated epithelium - moves mucus down the pharynx

• exchange a small amount of air with the eustachian tubes to equalize pressure in the middle ear with atmospheric pressure

Oropharynx

• Opening from the mouth

• stratified squamous epithelium

• respiration and digestion functions

• palatine and lingual tonsils

Laryngopharynx

• continues with the esophagus and larynx

• stratified squamous epithelium

• respiratory and digestive pathway

the larynx

• a cylinder whose cartilaginous wall is stabilized by the ligament of skeletal muscles of both

Major structures of note

• epiglottis- covers the glottis

  • arytenoid cartilage

• thyroid cartilage

• cricoid cartilage - encircles the trachea

  • cricothyroid ligament

• vestibule ligament

• vocal ligament

Vestibular ligament

false vocal chords

Vocal ligament

true vocal cords

the trachea

Characteristics

• 2.5 cm diameter

• contain 15 - 20 tracheal cartilages

  • incomplete rings of hyaline cartilage ( which allow the expansion of the esophagus)

  • Annular ligament connects rings

the main bronchi

• trachea branches at the carina

  • forms the left & right main ( primary) bronchi

• enters the lungs at the hilum

• left main bronchus - left lung

• right main bronchus - right lung

  • contain incomplete rings of cartilage also

  • more vertical, shorter, wider than left

    • easier to aspirate foreign objects

the lungs

• the thoracic cavity

• 2 layers of pleural membrane

  • parietal pleural

  • visceral pleura

• Pleural cavity

Parietal pleura

attached t thoracic wall

Viceral pleura

cover lungs ( inner)

Pleural cavity

small potential space with pleural fluid

• prevent friction

Apex

narrow, superior portion of the lungs

Base

interior, next to the diaphragm ( lungs)

Costal surface

next to the ribs ( lungs)

Mediastinal surface

hilum

• bronchi, blood and lymph vessels, nerves enter and exit

right lung

This structure has

• three lobes - superior, middle, and inferior

• two fissures - horizontal and oblique fissures

the main bronchi

this structure

• Divides into secondary bronchi, one for each lobe

• The right main divides into three, and the left one divides into two

• Further dividing into the tertiary bronchi

the right lung

This lobe has 10 tertiary bronchi

the left lung

This lobe has 9 tertiary bronchi

Bronchioles

• branches of the tertiary bronchi

• bronchiole branch into terminal bronchioles

  • They are very small

  • have a wall of smooth muscles

    • no cartilage, self-supporting

    • asthma

• Branches into the respiratory bronchial within a pulmonary lobule

Asthma attack

muscle spasms and excessive muscles in the lungs

alveolar ducts

Respiratory bronchioles leads to ____ within a pulmonary lobule

Alveolar ducts

This structure is connected to :

• individual alveolus

• alveolar sacs

Alveoli

• Lungs have about 150 million of these structures

• a network of capillaries surrounds each one

The alveolus and the blood-air barrier

Individual alveoli

Out- of pocket that are sites of gas exchange

Alveolar sacs

chambers connecting multiple alveolus

Type 1 Alveolar cells

• simple squamous cells ( pulmonary epithelium )

• line alveoli

Type 2 Alveolar cells

• scattered among the type 1 alveolar cells

• secretes a surfactant ( which prevents alveolar collapse )

Alveolar macrophages

remove dust particles and other debris

Blood air barrier

Gas exchange occurs at the ___

the alveolus

This structure includes three layers

• alveolar cell layer

• capillary endothelium

• Fused basement membrane

Alveolar cell layer

type 1 and 2 alveolar cells, macrophages

Fused basement membrane

located between alveolar cells and capillary endothelium

Alveoli

CO2 goes from the capillaries to the ___

Capillaries

O2 goes the alveoli to the ___