chapter 22 - respiration Flashcards
primary functions of respiratory system
- external respiration
- pulmonary ventilation
- protect respiratory surfaces from dehydration, temp, changes, pathogens
- internal respiration
- provide sound + olfactory sensation
pneumatic bones and sinuses
found in nasal cavity; The paranasal sinuses develop and enlarge after birth; ethmoid and sphenoid sinuses may not be of significant size until age 3-7 years. The frontal sinuses are the last to develop and may not be of significant size until adolescence. sinuses produce muscous to moisturize + protect inside of nose
what structures are involved in sound production?
glottis and vocal folds
phonation
sound production at the larynx
articulation
modification of sound by other structures – tongue, lips, teeth, cheeks
resonance + amplification by pharynx, oral + nasal cavities, sinuses
how are pitch of phonation altered?
position of arytenoid cartilage relative to thryoid cartilage changes pitch
- -> distance increases, causes tense vocal folds and increase in pitch
- -> distance decreases, relaxed vocal folds and decrease in pitch
right lung
3 lobes –> superior, middle, inferior that are separated by horizontal + oblique fissures
wider and larger than left
displaced by liver
left lung
2 lobes –> inferior and superior
separated by oblique fissure
longer than right
displaced leftward by heart, forming cardiac notch
bronchial tree
Supportive connective tissues change: C-shaped rings are replaced by cartilage plates
Epithelium changes: Pseudostratified ciliated columnar 🡪 simple columnar 🡪 simple cuboidal epithelium
Smooth muscle gains importance:
Sympathetic direction 🡪 airways widen
Parasympathetic direction 🡪 airways constrict
which portions of respiratory system are conducting?
from nasal cavity to terminal bronchioles
filter, humidify, warm air
where is gas exchange possible?
respiratory portion –> respiratory bronchioles and alveoli
types of cells that make up alveolar epitheloium + functions
Pneumocytes type I (type I alveolar cell) – simple squamous Alveolar macrophages (dust cells) – phagocytize particles Pneumocytes type II (septal cells) – produce surfactant (oily secretion containing phospholipids and proteins) --> Responsible for reducing surface tension, which keeps the passageways to alveoli open
external respiration
Includes all processes involved in exchanging O2 and CO2 with the environment including:
- Pulmonary ventilation (breathing in and out)
- Gas diffusion across membranes and capillaries
- Transport of O2 and CO2 between alveolar capillaries and capillary beds in other tissues
internal/cellular respiration
Involves the use of O2 as the terminal electron acceptor of the respiratory chain with the formation of H2O.
muscles used in eupnea (quiet breathing)
diaphragm
external intercostals
muscles used in hyperpnea inhalation
Diaphragm: Contraction draws air into lungs; 75% of normal air movement
External intercostal muscles: Assist inhalation; 25% normal
Accessory muscles assist in elevating ribs: Sternocleidomastoid, serratus anterior, pectoralis minor and scalene muscles
muscles used in hyperpnea exhalation
Internal intercostal and transversus thoracis–>Depress the ribs
Abdominal muscles–>Compress the abdomen and force diaphragm upward
changes with age + smoking
Arthritic changes – restrict chest movements and limit respiratory minute volume
Restrictive lung disease –pulmonary fibrosis, sarcoidosis, etc.
Lowered lung compliance, difficulty breathing in
Obstructive lung disease –emphysema, chronic obstructive pulmonary disease (COPD) etc, lowered lung elastance–>#3 cause of death –leading cause is cigarette smoking–>Atelectasis, increased lung compliance, difficulty breathing out due to loss of elastin components
