The Respiratory The Respiratory SystemSystem

Respiration begins in the Respiration begins in the nosenose

Psuedostratified Columnar Ciliated epithelial tissue lines the nose to warm and mositen the inhaled air.

Mucous cells are found within the lining to allow moistening of the air.

3 Areas of the Oral Cavity3 Areas of the Oral Cavity

1.1. OROPHARYNX OROPHARYNX -soft palate to epiglottis-soft palate to epiglottis -two sets of TONSILS-two sets of TONSILS a. Palatinea. Palatine b. Lingualb. Lingual -the tonsils remove pathogens that -the tonsils remove pathogens that

enter the pharynx. They contain enter the pharynx. They contain lymphocyteslymphocytes

►2. NASOPHARYNX2. NASOPHARYNX

-located superior and posterior to -located superior and posterior to the soft palate.the soft palate.

-contains the PHARYNGEAL -contains the PHARYNGEAL TONSILS and TUBAL TONSILSTONSILS and TUBAL TONSILS

The soft palate is a muscular structure that separates the nasal cavity from the oral cavity.

The soft palate moves superiorly to seal the nasal cavity during swallowing.

An 11-month-old girl's mother noted this asymptomatic cyst on her daughters soft palate.

►3. LARYNGOPHARYNX3. LARYNGOPHARYNX

-inferior to the epiglottis and -inferior to the epiglottis and posterior to the larynx.posterior to the larynx.

- this division opens into the - this division opens into the esophagus and larynx.esophagus and larynx.

The Lower Respiratory TractThe Lower Respiratory Tract

► The TRACHEA begins at the level of C6 The TRACHEA begins at the level of C6 superiorly.superiorly.

► Directly superior to the beginning of the Directly superior to the beginning of the trachea is the LARYNX (vocal cords).trachea is the LARYNX (vocal cords).

► The trachea bifurcates into the BRONCHI at The trachea bifurcates into the BRONCHI at the sternal angle (T4 or T5) when supine the sternal angle (T4 or T5) when supine (laying on the back) or T7 when standing.(laying on the back) or T7 when standing.

►The trachea is composed of 16-20 The trachea is composed of 16-20 cartilagenous rings (hyaline cartilage).cartilagenous rings (hyaline cartilage).

►These rings are flexible but keep the These rings are flexible but keep the trachea open.trachea open.

►Each ring is open in the back (allows Each ring is open in the back (allows flexibility)flexibility)

►The rings are approximately 1.5 inches The rings are approximately 1.5 inches in diameter and held together by in diameter and held together by connective tissue.connective tissue.

►The connective tissue is dense CT.The connective tissue is dense CT.►Air can pass through the tube without Air can pass through the tube without

resistance.resistance.

►The trachea must be able to filter The trachea must be able to filter debris (dust or dirt). Coughing occurs debris (dust or dirt). Coughing occurs when such debris enters the trachea.when such debris enters the trachea.

Principles of Animal Principles of Animal PhysiologyPhysiologyRespiratory System

►Mammalian respiratory pathwayMammalian respiratory pathwayAir Respirers

Nasal cavity and trachea.Nasal cavity and trachea.

►Psuedostratified columnar ciliated Psuedostratified columnar ciliated epithelium.epithelium.

►Mucous cells (goblet cells)Mucous cells (goblet cells)►Sub-mucosal tubuloacinar seromucous glandSub-mucosal tubuloacinar seromucous gland►Intraepithelial gland in chicken.Intraepithelial gland in chicken.

Principles of Animal Principles of Animal PhysiologyPhysiologyRespiratory System

►Ciliated respiratory epithelium cellsCiliated respiratory epithelium cellsAir Respirers

Histology of the tracheaHistology of the trachea

cartilage

Ciliated epithelium

Principles of Animal Principles of Animal PhysiologyPhysiologyRespiratory System

►Diagram representing the human Diagram representing the human airwaysairways

Air Respirers

Principles of Animal Principles of Animal PhysiologyPhysiologyRespiratory System

►Respiratory zone structuresRespiratory zone structuresAir Respirers

BronchiBronchi

►Psuedostratified columnar to columnar Psuedostratified columnar to columnar to cuboidal epithelium with mucous to cuboidal epithelium with mucous cells and mixed bronchial glands in all cells and mixed bronchial glands in all species except goat.species except goat.

BronchiolesBronchioles

►Simple columnar to cuboidal Simple columnar to cuboidal epitheliumepithelium Ciliated cells Ciliated cells Bronchiolar exocrine glands.Bronchiolar exocrine glands.

Both secretory and metabolizing xenobiotic Both secretory and metabolizing xenobiotic compounds.compounds.

Adundant in horses and sheep.Adundant in horses and sheep. Min in carnivores, cattle and pigs.Min in carnivores, cattle and pigs.

Principles of Animal Principles of Animal PhysiologyPhysiologyRespiratory System

►Alveolus and associated pulmonary Alveolus and associated pulmonary capillariescapillaries

►Alveolar epithelial cellsAlveolar epithelial cellsType I: flattened processes which cover Type I: flattened processes which cover

most of the inner surfacemost of the inner surfaceType II: produce and store surfactantType II: produce and store surfactantMacropharges: phagocytic cellsMacropharges: phagocytic cellspores of Kohn - permit airflow between pores of Kohn - permit airflow between

adjacent alveoli, a process known as collateral adjacent alveoli, a process known as collateral ventilationventilation

Air Respirers

The LarynxThe Larynx

►The LARYNX (voice box) is a modified The LARYNX (voice box) is a modified portion of the trachea.portion of the trachea.

► It is superior to the trachea.It is superior to the trachea.►There are cartilaginous rings that are There are cartilaginous rings that are

connected by dense connective tissue connected by dense connective tissue forming a tube.forming a tube.

► The TYROID CARTILAGE is shaped like a The TYROID CARTILAGE is shaped like a shield when viewed from the anterior shield when viewed from the anterior surface. This is the ADAM’S APPLE. This is surface. This is the ADAM’S APPLE. This is not a complete ring.not a complete ring.

► On the posterior side of the thyroid On the posterior side of the thyroid cartilage, the CRICOID CARTILAGE extends cartilage, the CRICOID CARTILAGE extends superiorly to where the thyroid cartilage superiorly to where the thyroid cartilage would be. This cartilage is sometimes called would be. This cartilage is sometimes called the SIGNET RING CARTILAGE.the SIGNET RING CARTILAGE.

► It has a narrow band across the It has a narrow band across the anterior side.anterior side.

► It is superficial to the thyroid cartilage It is superficial to the thyroid cartilage posteriorly where it is connected by posteriorly where it is connected by the CRICOTHYROID LIGAMENT (dense the CRICOTHYROID LIGAMENT (dense connective tissue).connective tissue).

► Inferiorly, the cricoid is attached to the Inferiorly, the cricoid is attached to the first ring to the trachea by dense CT.first ring to the trachea by dense CT.

► The EPIGLOTTIS is a spade shade cartilage The EPIGLOTTIS is a spade shade cartilage that is important during swallowing.that is important during swallowing.

► It tips inferiorly to seal off the glottis and It tips inferiorly to seal off the glottis and prevents food from entering the trachea.prevents food from entering the trachea.

► The ARYTENOID CARTILAGE is below the The ARYTENOID CARTILAGE is below the epiglottis at the entrance to the GLOTTIS.epiglottis at the entrance to the GLOTTIS.

► The GLOTTIS is a passageway into the The GLOTTIS is a passageway into the trachea. The thyroid cartilage forms the trachea. The thyroid cartilage forms the walls of the glottis. The arytenoid cartilage walls of the glottis. The arytenoid cartilage extends inferiorly into the glottis.extends inferiorly into the glottis.

► The arytenoid cartilages anchor the vocal cords.The arytenoid cartilages anchor the vocal cords.► The true vocal cords are located inferiorly inside the The true vocal cords are located inferiorly inside the

glottis.glottis.► As air passes over the vocal cords they flutter, As air passes over the vocal cords they flutter,

producing sound from the vibration.producing sound from the vibration.► Pitch can be changed by tightening or loosening the Pitch can be changed by tightening or loosening the

cords.cords.► In humans, the tongue is used to make sense of the In humans, the tongue is used to make sense of the

sounds (make words). You cannot talk if your sounds (make words). You cannot talk if your tongue is not functioning.tongue is not functioning.

► There are folds covering part of the epiglottis called There are folds covering part of the epiglottis called FALSE VOCAL CORDS.FALSE VOCAL CORDS.

Cricoid cartilage

Aryetnoid cartilage

Thyroid Cartilage

Hyoid Bone

Epiglottis

Tracheal rings

tracheaANTERIOR

POSTERIOR

Thyrohyoid Ligament

Tracheostomy – Step 1

The skin incision is made with a Colorado Needle mounted on an electric knife (Bovie).  A steel blade scalpel is as good and is preferred by many surgeons.

Step 2

After incising the subcutaneous tissue and platysma, the strap muscles are separated in the midline.

The strap muscles is a name given to the four infrahyoid muscles that lie in front of the larynx. They are the sternohyoid, sternothyroid, thyrohyoid and the omohyoid.

Step 3

The isthmus of the thyroid gland is either retracted or divided in the midline. (In this picture, the isthmus has been divided and retracted laterally, along with the strap muscles.)  The anterior tracheal wall is divided between the third and fourth tracheal rings.  A clamp is used to widen the tracheal opening.  The endotracheal tube is seen inside the tracheal lumen

Step 4

Normal vocal cords as they appear through a 90 degree telescope. The cords are partially opened and the opening into the trachea can be seen between them.

One may compare this person at a high and a low pitch, demonstrating the elongation of the vocal cords that takes place to raise pitch by contracting the Cricothyroid muscles

Acute LaryngitisAcute Laryngitis

Chronic LaryngitisChronic Laryngitis

68 year old non-smoker with history of gastroesophageal reflux. She complained of daily belching and burning in her throat due to the stomach acids.

trachea

Left primary bronchus

Right Primary Bronchus

Wider, shorter, and more vertical than the left

Both primary bronchi have the same anatomic structure as the trachea.

► The primary bronchi divide to form The primary bronchi divide to form SECONDARY BRONCHI (lobar bronchi).SECONDARY BRONCHI (lobar bronchi).

► There is one secondary bronchus for each There is one secondary bronchus for each lobe of the lungs.lobe of the lungs.

► There are 2 lobes on the left lung.There are 2 lobes on the left lung.► There are 3 lobes on the right lung.There are 3 lobes on the right lung.► These also have the same anatomy as the These also have the same anatomy as the

trachea.trachea.

► The secondary bronchi branch to form The secondary bronchi branch to form TERTIARY BRONCHI.TERTIARY BRONCHI.

► They continue to branch.They continue to branch.► As they get smaller, they lose their As they get smaller, they lose their

cartilage.cartilage.► When they lose their cartilage, they are When they lose their cartilage, they are

called BRONCHIOLES which are microscopic.called BRONCHIOLES which are microscopic.

Histology of the Bronchus

►The bronchioles terminate in the The bronchioles terminate in the ALVEOLI through an ALVEOLAR DUCT.ALVEOLI through an ALVEOLAR DUCT.

►The walls of the alveoli are one-cell The walls of the alveoli are one-cell thick and is covered in capillaries.thick and is covered in capillaries.

►The alveoli are the functional unit of The alveoli are the functional unit of the lungs.the lungs.

Bronchiole and Alveolar Duct

► There are air sacs, where gas exchange There are air sacs, where gas exchange occurs.occurs.

► Walls of the alveoli are highly vascularized.Walls of the alveoli are highly vascularized.► The alveoli are the terminal branches of the The alveoli are the terminal branches of the

BRONCHIAL TREE. This arrangement allows BRONCHIAL TREE. This arrangement allows for a drastic increase in surface area.for a drastic increase in surface area.

The LungsThe Lungs

►The right lung starts 1” above rib 1 The right lung starts 1” above rib 1 and crosses the clavicle at about the and crosses the clavicle at about the medial 1/3 of it. It progresses medial 1/3 of it. It progresses inferiorly to costal cartilage 6 inferiorly to costal cartilage 6 (midsternally). At the midaxillary (midsternally). At the midaxillary region, it is at rib 8 and rib 10 at the region, it is at rib 8 and rib 10 at the vertebral border.vertebral border.

► The right lung has 3 lobes (4 in the cat).The right lung has 3 lobes (4 in the cat).► The left lung starts about 1” above rib 1 and The left lung starts about 1” above rib 1 and

crosses deep to the manubrioclavicular crosses deep to the manubrioclavicular joint. There it goes to the left and continues joint. There it goes to the left and continues inferiorly to rib 6.inferiorly to rib 6.

► The left lung has an indentation called the The left lung has an indentation called the CARDIAC NOTCH. This area provides room CARDIAC NOTCH. This area provides room for the HEART.for the HEART.

►Lung size varies from individual to Lung size varies from individual to individual.individual.

►The left lung has 2 lobes (3 in the cat).The left lung has 2 lobes (3 in the cat).►The lobes are anatomically and The lobes are anatomically and

functionally separate. Thus, they are functionally separate. Thus, they are independent of each other.independent of each other.

► There is a deep fissure between the lobes. There is a deep fissure between the lobes. The lobes overlap each other like shingles.The lobes overlap each other like shingles.

► The OBLIQUE FISSURE on each lobe begins The OBLIQUE FISSURE on each lobe begins posteriorly across from the root of the spine posteriorly across from the root of the spine of the scapula at T3. They come around of the scapula at T3. They come around laterally and inferiorly in an oblique path laterally and inferiorly in an oblique path and eventually reach rib 6 on both sides.and eventually reach rib 6 on both sides.

► On the right side, there is also a On the right side, there is also a TRANSVERSE FISSURE which follows rib 4 TRANSVERSE FISSURE which follows rib 4 anteriorly. It joins the oblique fissure anteriorly. It joins the oblique fissure midaxillary.midaxillary.

► On the posterior surface, one can see only 2 On the posterior surface, one can see only 2 lobes on each lung. On the anterior surface, lobes on each lung. On the anterior surface, you can see the third lobe on the right lung.you can see the third lobe on the right lung.

► The lobes are further divided into LOBULES. The lobes are further divided into LOBULES. These cannot be separated as easily as the These cannot be separated as easily as the lobes can.lobes can.

► They are functionally separate.They are functionally separate.► They are also anatomically partitioned to They are also anatomically partitioned to

allow removal of a lobule while keeping the allow removal of a lobule while keeping the functionality of the rest of the lung.functionality of the rest of the lung.

The The Pleural Pleural CavityCavity

Slide Slide of of

AlveoliAlveoli

Gaseous exchange relies on simple diffusion. In order to provide sufficient oxygen and to get rid of sufficient carbon dioxide there must be

•a large surface area for gaseous exchange •a very short diffusion path between alveolar air and blood •concentration gradients for oxygen and carbon dioxide between alveolar air and blood.

Intercostal MusclesIntercostal Muscles

► External IntercostalsExternal Intercostals O: Inferior border of rib aboveO: Inferior border of rib above I: Superior border of rib belowI: Superior border of rib below Fibers run OBLIQUE (down and forward)Fibers run OBLIQUE (down and forward) Aid in Inspiration (lift ribcage, increase dimensions)Aid in Inspiration (lift ribcage, increase dimensions)

► Internal IntercostalsInternal Intercostals O: Superior border of rib above O: Superior border of rib above I: Inferior border of rib belowI: Inferior border of rib below Fibers run at RIGHT ANGLES to external intercostalsFibers run at RIGHT ANGLES to external intercostals Aid in expiration (depress ribcage, decrease dimensions)Aid in expiration (depress ribcage, decrease dimensions)

► Innermost IntercostalsInnermost Intercostals Attachments similar to Internal Intercostals, Attach ribsAttachments similar to Internal Intercostals, Attach ribs Fibers run Anterior/PosteriorFibers run Anterior/Posterior

Neurovascular Bundle of Neurovascular Bundle of IntercostalsIntercostals

► VVAANN (vein, artery, (vein, artery, nerve)nerve) Intercostal veinIntercostal vein Intercostal arteryIntercostal artery Intercostal nerveIntercostal nerve

► Sit in Subcostal Sit in Subcostal GrooveGroove

► Between Internal Between Internal Intercostal and Intercostal and Innermost Innermost intercostal musclesintercostal muscles

During inspiration the diaphragm moves downward allowing air to enter the respiratory tract. The external intercostals contract along with the pectoral muscles.

During Expiration, the diaphragm moves upward forcing air out the lungs. The internal intercostals contract.