Name and explain the four stages of respiration
1. Pulmonary Ventilation (breathing): movement of air in and out of the lungs
2. External Respiration: O2 and CO2 exchange between the lungs and blood.
3. Transport: of O2 and CO2 using the blood
4. Internal Respiration: O2 and CO2 exchange between the tissues and the blood.
Define the respiratory zone and what is it includes.
Site of gas exchange
Respiratory bronchioles, alveolar ducts, and alveoli
Define conducting zones and what it includes
Conduits of air
- Nose, nasal cavity, and paranasal sinuses
- Bronchi and their branches
Name the functions of the Nose
- 1. provides and airway for respiration
- 2. moistens and warms the entering air
- 3. filters and cleans inspired air
- 4. Serves as a resoning chamber for speech
- 5. Houses olafactory receptors
Describe the regions of the nose
Describe the anatomy of the nasal cavity
What filters course particles from inspired air through the nose?
Describe the respiratory mucosa
Pseudostratified ciliate columnar with goblet cells
Mucous and serous secretions contain lysozyme and defensins as a natural antibiotic
Cilia move contaminated mucus posteriorly to throact
Inspired air is warmed by plexuses of capillaries and veins
sensory nerve endings trigger sneezing
What are the functions of the Nasal Mucosa and Conchae?
during inhilation: filter, heat, and moisten air
during exhalation: reclaim heat and moisture
Describe the Nasopharynx
Air passage posterior to nasal cavity
lined with pseudostratified columnar epithelium
soft palate and uvula close the nasopharynx during swallowing
Pharyngeal tonsils (Adenoids when swollen) on posterior wall
Pharyngotympanic (auditoty) tubes open in lateral walls with tubal tonsils
Describe the Oropharynx
passage for food and air
lined with stratified squamous epithelium
isthmus of tha fauces: opening to the oral cavity
palantine tonsils on the lateral walls of fauces
Lingual tonsils at base of tongue
Describe the laryngopharynx
passage for both air and food
extends to the larynx where it is continuous with esophogus
What kind of cartilage is the larynx?
- 8 hyaline cartilages:
- thyroid, cricoid, paired artynoid, paired cuniform, paired corniculate
- 1 elastic cartilage:
- tracheal cartilage is also hyaline
Whats the difference between the vestibular folds and the vocal folds?
- Vestibular folds are superior and are called false vocal cords
- -no part in sound production
- -help close glottis during swallowing
are true vocal cords that vibrate to produce sound
the vocal ligaments are attached to the thyroid cartilage by the arytnoid cartilages and contain elastic fibers
How is the sound of your voice produced?
Speech: intermittent release of expired air while opening and closing the glottis
Pitch: determined by the length and tension of vocal cords
Loudness: force of air
chambers of the pharynnx, oral, nasal, and sinus cavities amplify and resonate sound
sound is shaped into language by muscles of the pharynx, tongue, soft palate, and lips
How does the larynx act as a sphincter?
Prevents air passage
- Example: Valsalva's Maneuver
- -glottis closes to prevent exhalation
- -abdominal muscles contract
- -intra-abdominal pressure rises
- -helps to empty the rectym or stabilize trunk during heavy lifting
Describe the 3 layers of the Trachea (windpipe)
1. Mucosa: ciliated pseudostratified epithelium with goblet cells
2. Submucosa: connective tissue with seromucous glands that secrete mucus sheets
3. Adventitia: outtermost layer composed of connective tisse that encloses the C shaped rings of hyaline cartilage
What is the respiratory tree?
The branching of the Bronchi
23 orders of branching, beginning with the primary bronchi at the carina
Lobal (Secondary) bronchi into segmental (tertiary) bronchi
What is the difference between bronchi and bronchioles other than their diameter?
Cartilage rings give way to plates as they get loser to bronchioles
Bronchioles do not have cartilage, but have smooth muscle
Epithelium turns from pseudostratified columnar into cuboidal in bronchioles. Goblet cells and cilia disappear
What makes up the bulk of the lungs volume?
about 300 million alveoli
main site of gas exchange
What is the respiratory membrane?
The blood air barrier
alveolar and capillar walls and their basement membrane
What is the makeup of alveoli?
Simple squamous epithelium (Type I cells)
Scattered Cuiboidal cells (Type II cells): secretre surfectant and antimicrobioal protetins
surrounded by fine elastic fibers
contain pores: connecting alveoli, allow pressure to be equalized, provide alternative air routes for collapsed or damaged tissue
house alveolar macrophages that keep surfaces sterile
Describe the lungs
- Right: 3 lobes separated by oblique and horizontal fissure. 10 bronchopulmonary segments
- Left: 2 lobes separated by oblique fissue-has cardiac notch. 8-9 bronchopulmonary segments
outside surface covered by hexagonal lobules that are served by bronchioles and their branches
What are the two circulations of blood supply to the lungs?
- Pulmonary circulation: (low pressure, high volume)
- *remember it is opposite of the rest of the body
- -pulmonary arteries deliver systemic venous blood
- -lie anterior to main bronchi
- -pulmonary veins carry 02 blood back to heart
- Systemic Circulation (high pressure low volume)
- -bronchial arteries supply blood to lung tissue (run along branching bronchi)
- -arise from the aorta and enter lung at hilum
- -supply all lung tissue EXCEPT alveoli (they get it from the pulmonary circulation)
bronchial veins anastome with pulmonary veins
most venous blood is carried back to the heart by pumonary veins
Describe the pleura
Double layered serosa
Parietal pleura on thoracic wall and superior face of diaphram
visceral pleura on the external lung surface
pleural fluid fills slitlike pleaural cavity
provides lubrication and surface tension
Why is alveolar surface tension important?
Because of elastic recoil, the lungs always assume the smallest size possible.Surface tension on the alveoli also reduce its size (draws water molecules close together where it meets gas)
this promotes atelectasis! (collapse!)
- Surfectant (Secreted by Type II cells) Saves the day!
- -detergent like lipid protein complex
- -reduces surface tension and discourages alveolar collapse
- -insufficient quantity in premature infants causes infant respiratory distress syndrome (IRDS)
What is Lung Compliance?
- A meaure of the change in lung volume that occurs with a given change in traqnspulmonary pressure
- Normally high due to:
- distensibility of lung tissue
- alveolar surface tesnion
*the higher the CL
the easier it is to expand the lungs
What diminishes Lung Compliance?
- Nonelastic scar tissue (fibrosis)
- reduced production of surfectant
- decreased flexibility in the thoracic cavity
- *homeostatic imbalances
- -deformities of the thorax
- -ossification of the costal cartilages (common in elderly)
- -paralysis of intercostal muscles
What is COPD?
Chronic obstructive pulmonary disease
Exemplified by chronic bronchitis (chronic excessive mucus) and emphysema
irreversible decrease in the ability to force air out of the lungs (reduced FEV)
- 80% of patients have a history of smoking
- dyspnea: labored breathing
- coughing and frequent pulmonary infections
- most victims develop respiratory failure (hypoventiliation) accompanies by respiratory acidosis
What are the two types of emphysema?
Emphysema is a permanent enlargement of the alveolar and destruction of alveolar walls
Pink Puffer: works hard to maintain ventilation and is often red in the face
Blue Bloater: right side heart failure has reduced oxygen. Air trapping frequently cuases bloated chest
characterized by coughing, dyspnea, wheezing, and chest tightness
active inflammation is an immune response caused by release of interleukins, productions of IgE, and recruitment of inflammatory cells
airways thickened with inflammatory exudate magnify the effect of bronchospasms
Infectious disease caused by teh bacterium mycobacterium tuberculosis
symptoms include fever, night sweats, weight loss, a racking cough, and spittig up blood
treatment entails a 12 month course of antibiotics
Describe lung cancer and the 3 most common types
leading cause of cancer deaths in North America for both men and women
90% of all cases result of smoking
- 3 Most common types
- 1. Squamous cell carcinoma (20-40%) in bronchial epithelium
- 2. Adenocarcinoma (~40%) originates in the peripheal lung areas
- 3. Small cell carcinoma (~20%) contains lymphocyte-like cells that originate in the primary bronchi and subsequently metastasizes
Describe the development aspects of the Respiratory system before birth
Olfactory placodes invaginate into olfactory pits by 4th week
laryngotracheal buds are present by 5th week
mucosae of the bronchi and lung alveoli are present by the 8th week
by the 28th week, a premature baby can breathe on its own
during fetal life, the lungs are filled with fluid and blood bypasses the lungs
gas exchange takes place via the placenta
Describe the development aspects of the Respiratory system AFTER birth
At birth, respiratory centers are activated, alveoli inflate, and lungs begin to function
respiratory rate is highest in newborns and slows until adulthood
lungs continue to mature and more alveoli are formed until young adulthood (any addtl alveoli are lost if start smoking young)
respiratory efficiency decreases in old age