Respiratory AnatomyRespiratory Anatomy

May 5, 2010May 5, 2010

Notes from Lab and Notes from Lab and DissectionDissection

General Functions of the General Functions of the SystemSystem• Ventilation (breathing) – the entrance and Ventilation (breathing) – the entrance and

exit of air into and out of the lungsexit of air into and out of the lungs• External respiration – the exchange of External respiration – the exchange of

gases (carbon dioxide and oxygen) gases (carbon dioxide and oxygen) between the air and bloodbetween the air and blood

• Internal respiration – the exchange of Internal respiration – the exchange of gases between the blood and tissue fluidgases between the blood and tissue fluid

• Transport – of gases to and from the lungs Transport – of gases to and from the lungs and the tissuesand the tissues

Anatomy and the flow of air:Anatomy and the flow of air:

• The Nose / Nasal passages begin to cleanse the The Nose / Nasal passages begin to cleanse the air with course hairs inside the nostrils and air with course hairs inside the nostrils and continue to do so with cilia and mucus in the continue to do so with cilia and mucus in the nasal cavities.nasal cavities.

• Air warmed by the blood vessels lying close to the Air warmed by the blood vessels lying close to the surface of the lining of the airways.surface of the lining of the airways.

• Air is moistened by the mucus epithelium that Air is moistened by the mucus epithelium that lines most of the air passages.lines most of the air passages.

• Conversely, as air leaves the body it deposits its Conversely, as air leaves the body it deposits its moisture along the way. This can cause the nose moisture along the way. This can cause the nose to drip and is what is responsible for you being to drip and is what is responsible for you being able to see your breathe on a cold day.able to see your breathe on a cold day.

Nose and Nasal CavityNose and Nasal Cavity

• 2 Nostrils2 Nostrils• 2 Nasal cavities separated by a septum 2 Nasal cavities separated by a septum

composed of bone and cartilage.composed of bone and cartilage.• Conchae are bony ridges that project out Conchae are bony ridges that project out

laterally trapping air and increasing laterally trapping air and increasing surface area for moistening and warming.surface area for moistening and warming.

• Lacrimal glands (tear) drain into the nasal Lacrimal glands (tear) drain into the nasal cavity which is why your nose runs when cavity which is why your nose runs when you cry.you cry.

• Nasal cavity is separated from the oral Nasal cavity is separated from the oral cavity by the hard and soft palate.cavity by the hard and soft palate.

PharynxPharynx

• Broken into three parts: nasopharynx, Broken into three parts: nasopharynx, oropharynx, and laryngopharynx.oropharynx, and laryngopharynx.

• The tonsils form a protective ring around The tonsils form a protective ring around the pharynx – this is lymphatic tissue that the pharynx – this is lymphatic tissue that protects against the invasion of inhaled protects against the invasion of inhaled pathogens.pathogens.

• It is the junction of air and food passage. It is the junction of air and food passage. The esophagus remains closed by the The esophagus remains closed by the epiglottis unless a person is swallowing.epiglottis unless a person is swallowing.

LarynxLarynx

• A cartilaginous structureA cartilaginous structure• Contains the Adam’s AppleContains the Adam’s Apple• Called the voice box because it contains Called the voice box because it contains

the vocal cords.the vocal cords.• The vocal cords are mucosal folds The vocal cords are mucosal folds

supported by elastic ligaments, and the supported by elastic ligaments, and the opening between them is the glottis. opening between them is the glottis.

• When air is expelled past the vocal cords When air is expelled past the vocal cords through the glottis the cords vibrate through the glottis the cords vibrate producing sound. The greater the tension producing sound. The greater the tension on the cords and the narrower the glottis, on the cords and the narrower the glottis, the higher the pitch.the higher the pitch.

TracheaTrachea

• Tube with c-rings of cartilage. The open Tube with c-rings of cartilage. The open part of the c is facing the esophagus – why part of the c is facing the esophagus – why do you think this is?do you think this is?

• Lined with pseudostratified ciliated Lined with pseudostratified ciliated columnar epithelium. Cilia beat upward columnar epithelium. Cilia beat upward moving the particles out of the system. moving the particles out of the system. Goblet cells produce mucus to trap debris.Goblet cells produce mucus to trap debris.

• Smoking destroys the cilia causing soot Smoking destroys the cilia causing soot from smoking to get caught in the lungs.from smoking to get caught in the lungs.

Bronchial TreeBronchial Tree

• Contains the same histology as the trachea. Contains the same histology as the trachea. Divides trachea into right and left primary Divides trachea into right and left primary bronchi.bronchi.

• Branches into a large number of secondary Branches into a large number of secondary bronchi that eventually lead to bronchioles – bronchi that eventually lead to bronchioles – rings of cartilage are no longer present.rings of cartilage are no longer present.

• During an asthma attack, the smooth muscle During an asthma attack, the smooth muscle of the bronchioles contracts, causing of the bronchioles contracts, causing constriction and wheezing.constriction and wheezing.

• Each bronchiole leads to an elongated space Each bronchiole leads to an elongated space enclosed by a bunch of air pockets called enclosed by a bunch of air pockets called alveoli.alveoli.

LungsLungs

• Paired, cone-shaped structures.Paired, cone-shaped structures.• The right lung has 3 lobes and the left, The right lung has 3 lobes and the left,

2. The lobes are divided further into 2. The lobes are divided further into lobules which each have a bronchiole lobules which each have a bronchiole serving many alveolar sacs.serving many alveolar sacs.

• Diaphragm sits inferiorly to the lungs.Diaphragm sits inferiorly to the lungs.• Each lung is enclosed by a pleural sac Each lung is enclosed by a pleural sac

(serous membrane).(serous membrane).

AlveoliAlveoli

• Composed of simple squamous epithelium Composed of simple squamous epithelium and is surrounded by capillaries which are and is surrounded by capillaries which are also composed of simple squamous. What also composed of simple squamous. What major function does the structure of major function does the structure of simple squamous allow?simple squamous allow?

• Alveoli are covered in surfactant, a Alveoli are covered in surfactant, a lipoprotein that allows them not to lipoprotein that allows them not to collapse under the pressure of water collapse under the pressure of water surface tension.surface tension.