Human Anatomy - Chapter 23

What are the three processes to respiration?

1. ventilation (breathing)
2. external (pulmonary) respiration
3. internal (tissue) respiration

What is pulmonary ventilation?

air flows between the atmosphere and alveoli of the lungs

What is external (pulmonary) respiration?

1. exchange of gases between alveoli and blood in pulmonary capillaries
2. pulmonary capillary blood gains o2 and loses co2

What is internal (tissue) respiration?

1. exchange of gas between blood in the capillaries and tissue cells
2. consume o2 and give off co2

What are the two parts of the respiratory system?

1. upper respiratory
2. lower respiratory

What makes up the upper respiratory system?

1. nose
2. pharynx
3. associated structures

What makes up the lower respiratory system?

1. larynx
2. trachea
3. bronchi
4. lungs

What divides the upper and lower respiratory system?

larynx

What are the two zones of the respiratory system?

1. conducting zone
2. respiratory zone

What is the conducting zone?

1. interconnecting cavities and tubes both outside and within the lungs
2. filter, warm, and moisten air and conduct it into the lungs

What structures make up the conducting zone?

1. nose
2. pharynx
3. larynx
4. trachea
5. bronchi
6. bronchioles
7. terminal bronchioles

What is the respiratory zone?

tubes and tissues within the lungs and where gas exchange occurs

What structures make up the respiatory zone?

1. respiratory bronchioles
2. alveolar ducts
3. alveolar sacs
4. alveoli

What is the external portion of the nose made of?

1. cartilage
2. skin
3. lined with mucous membrane

What are the four parts of the surface anatomy of the nose?

1. root
2. apex
3. bridge
4. nostril

Where is the root located?

superior attachment fo the nose to the frontal bone

Where is the apex located?

tip of nose

Where is the bridge located?

bony framework of nose formed by nasal bones

Where is the nostril located?

external opening into nasal cavity

What are the functions of the nose?

1. warming, moistening, and filtering incoming air
2. detecting olfactory stimuli
3. modifying speech vibrations as they pass through nasal chambers

What is the bony framework of the internal anatomy of the nose formed by?

1. frontal bone
2. nasal bone
3. maxillary bone

What does the internal portion of the nose do?

communicates with the paranasal sinuses and nasopharynx through the internal nares

What is the nasal cavity?

1. inside of both the external and internal nose
2. divided into right and left side by nasal septum
3. anterior portion called vestibule

What secretes mucus?

goblet cells

What does nasolacrimal ducts do?

drainage moisten’s air

What is the pharynx?

muscular tube lined by a mucous membrane

What is the function of the pharynx?

1. passageway for air and food
2. provides resonating chamber for speech sounds
3. houses tonsils

What do the tonsils do?

participate in immunological reactions against foreign invaders

What are the anatomic regions os the pharynx?

1. nasopharynx
2. oropharynx
3. laryngopharynx

What is the function of the nasopharynx?

respiration

What is the function of the oropharynx and laryngopharynx?

digestion and respiration

What is the larynx?

1. voice box
2. passageway that connects the pharynx and trachea

What does the larynx contain structurally?

1. thyroid cartilage
2. epiglottis
3. cricoid cartilage
4. vocal folds
5. paired arytenoid
6. corniculate
7. cuneiform cartilages

What is the thyroid cartilage?

adam’s apple

What is the epiglottis?

prevents food from entering the larynx

What is the cricoid cartilage?

1. connects the larynx and trachea
2. ring of hyaline cartilage (landmark for tracheotomy)

What are vocal folds?

folds which produce sound when they vibrate

What are the two types of vocal folds?

1. taunt (high pitched)
2. relaxed (low pitched)

What does the glottis consist of?

1. vocal folds
2. rima glottidis
3. vestibular folds

Where is the trachea located?

anterior to the esophagus and extends from the larynx to the main bronchi

What is the trachea made of?

1. smooth muscle
2. c-shaped rings of cartilage
3. pseudostratified ciliated columnar epithelium

How many c-shaped rings are there?

16-20

What are two methods to bypass obstructions from the respiratory passageways?

1. tracheostomy
2. intubation

What is the order of branching of the bronchial tree?

1. trachea
2. main bronchi
3. lobar (secondary) bronchi
4. segmental (tertiary) bronchi
5. bronchioles
6. terminal bronchioles

What do terminal bronchioles contain?

exocrine bronchiolar (clara) cells (columnar and noncilitared) among epithelial cells

What does clara cells do?

protect against toxins and produce surfactant

How does the mucous membrane change as it goes down the bronchial tree?

ciliated pseudostratifed epithelium with many goblet cells → non-ciliated cuboidal epithelium

How does the cartilage change as it goes down the bronchial tree?

plates of cartilage → no cartilage, more smooth muscle

How does epithelium of the respiratory membrane remove inhaled particles?

1. mucous produced by goblet cells traps the particles
2. cilia move the mucous and trapped particles toward the pharynx for removal
3. macrophages in places with no cilia

What encloses and protects the lungs?

double-layered serous membrane called the pleural membrane

What are the two parts of the pleural membrane?

1. parietal pleura
2. visceral pleura

What is the parietal pleura?

1. outer layer
2. attached to the wall of the thoracic cavity

What is the visceral pleura?

1. inner layer
2. covering the lungs themselves

What is the pleural cavity?

1. small space between pleurae
2. contains serous lubricating fluid to reduce friction between membranes

What is pleural effusion?

accumulation of excess fluid in pleural space

What is a thoracentesis?

1. removal of excessive fluid in the pleural cavity
2. inserting a needle into the pleural space

What is the structure of the right lung?

1. three lobes
2. two fissures

What is the structure of the left lung?

1. two lobes
2. one fissure
3. cardiac notch

What do the segmental bronchi do?

supply segments of lung tissue called bronchopulmonary segments

What are the structures of bronchopulmonary segments?

lobules that contain:


1. lymphatics
2. arterioles
3. venules
4. terminal bronchioles
5. respiratory bronchioles
6. alveolar ducts
7. alveolar sacs
8. alveoli

What is the order of the microscopic airways?

1. respiratory bronchioles
2. alveolar ducts
3. alveolar sacs
4. alveoli

What does the alveolar wall consist of?

1. pneumocyte type I
2. pneumocyte type II
3. alveolar macrophages

What is the most numerous in the alveolar wall?

pneumocyte type I

What are pneumocyte type I?

1. simple squamous epithelial cells
2. form nearly continuous lining
3. main site of gas exchange

What are pneumocyte type II?

secrete alveolar fluid containing surfactant

What is surfactant?

1. lowers surface tension of alveolar fluid
2. prevents collapse of alveoli with each expiration

Where does gas exchange occur?

across the alveolar capillary membrane

What is the respiratory membrane composed of?

1. a layer of pneumocyte type I, type II, and alveolar macrophages
2. epithelial basement membrane underlying the alveolar wall
3. capillary basement membrane fused to epithelial basement membrane
4. capillary endothelium

How does blood enter the lungs?

1. pulmonary arteries (pulmonary circulation)
2. bronchial arteries (systemic circulation)

How does blood leave the lungs?

1. pulmonary veins
2. bronchial veins

What is ventilation-perfusion coupling?

vasoconstriction in response to hypoxia diverts pulmonary blood from poorly ventilated areas to well ventilated areas

What structures have non-keratinized stratified squamous epithelium?

1. nasal vestibule
2. oropharynx
3. laryngopharynx
4. larynx above vocal folds

What structures have pseudostratified cilitated columnar epithelium?

1. respiratory region of nose
2. nasopharynx
3. larynx below vocal folds
4. trachea
5. main bronchi
6. lobar bronchi
7. segmental bronchi

What structure has ciliated simple columnar epithelium?

bronchioles

What structure has non-ciliated simple columnar epithelium?

terminal bronchioles

What structures have simple squamous epithelium?

1. respiratory bronchioles
2. alveolar ducts
3. pulmonary alveoli

Why does the air flow between the atmosphere and alveoli?

because of alternating pressure differencese created by contraction and relaxation of respiratory muscles

What influences rate of airflow and effort needed to breath?

1. alveolar surface tension
2. compliance of the lungs
3. airway resistance

What is boyle’s law?

the volume of a gas varies inversely with pressure, assuming that temperature is constant

When does inhalation occur?

when alveolar (intrapulmonic) pressure falls below atmospheric pressure

How does inhalation occur?

1. contraction of the diaphragm and external intercostal muscle
2. size of thorax increases
3. intrapleural (intrathoracic) pressure decreasees

When does exhalation occur?

when alveolar pressure is higher than atmospheric pressure

How does exhalation occur?

1. relaxation of the diaphragm and external intercostal muscles
2. decreases thoraic size
3. intrapleural pressure increases

What muscles are used during normal, quiet inhalation?

1. diaphragm contraction
2. external intercostals contraction

What muscles are used during forced inhalation?

1. sternocleidomastoid
2. scalene (ribs 1-2)
3. pectoralis minor (ribs 3-5)

What muscles are used during normal, quiet exhalation?

1. diaphragm relaxation
2. external intercostals relaxation

What muscles are used in forced exhalation?

1. abdominal
2. internal intercostals

How does surface tension affect pulmonary ventilation?

1. inwardly directed force in the alveoli which must be overcome to expand the lungs during each inspiration
2. produces an inwardly directed force

What does surfactant do for surface tension?

allows alteration of the surface tension of the alveoli and prevents their collapse following expiration

How does elastic recoil affect pulmonary ventilation?

1. decreases the size of the alveoli during expiration
2. recoil of elastic fibres stretched furing inhalation
3. inward pull of surface tension

How does compliance affect pulmonary ventilation?

1. ease with which the lungs and thoracic wall can be expanded
2. high compliance = expand easily
3. conditions that destroy lung tissue cause it to become fluid filled, produce a deficiency in surfactant, or in any way impedes lung expansion or contraction, decreases compliance

How does airway resistance affect pulmonary ventilation?

1. walls of respiratory passageways, especially the bronchi and bronchioles, offer some resistance to the normal air flow into the lungs
2. impacted by bronchoconstriction, bronchodilaiton, and conditions the obstruct airways

What is eupnea?

normal breathing rate and depth

What is apnea?

breathing temporaily stops

What is dyspnea?

painful or difficulty breathing (SOB)

What is tachypnea?

rapid breathing rate

What are kussmaul respirations?

increased rate and depth, usually indicates an acidotic state

What are cheyne stokes?

a repeated cycle of irregular breathing that begins with shallow breaths that increase in depth and rapidity and then decrease and cease altogether for 15-20 seconds

What is coughing?

complete closure of the rima glottidis after inhalation which causes strong exhalation to push open rima glottidis

What is sneezing?

spasmodic contraction of muscles of exhalation that forcefully expel air through nose and mouth