Chapter 22- The respiratory system Flashcards
Gas exchange
Body tissues must be supplied with oxygen, carbon dioxide waste must be disposed of. Gasses only move in one direction during gas exchange (might not be in the same direction for every gas)
4 processes involved with gas exchange
- Pulmonary ventilation
- External respiration
- Transport of respiratory gasses to/from tissues- does not occur in the respiratory system
- Internal respiration- does not occur in the respiratory system
External respiration
Gas exchange occurring in the lungs (alveoli)
Internal respiration
Gas exchange occurring in the tissues (does not occur in the respiratory system). If PCO2 in tissues is greater than PCO2 in blood- carbon dioxide leaves tissues and enters blood. If PO2 in blood is greater than PO2 in tissues- oxygen leaves blood and enters tissue. Partial pressure and diffusion gradients are opposite to external respiration
2 zones of the respiratory system
- Conducting zone
2. Respiratory zone
Conducting zone
Respiratory passages leading from the nose to the respiratory bronchioles. Transports air to/from the lungs- no gas exchange, just movement of air
Respiratory zone
Actual site of gas exchange. Found in respiratory bronchioles, alveolar ducts, and alveoli
Upper conducting zone (2 parts)
- Nasal cavity
2. Pharynx
Nasal cavity function
Air is warmed and humidified as it passes through this cavity. Inhaling cool/dry air slows down respiration overall- warming and humidifying ensures a normal respiratory rate
Mucous membranes of the nasal cavity
Consists of the respiratory mucosa- contains 2 different types of cells. Nerve endings in membrane- invading debris triggers a sneezing reflex
2 cell types of the respiratory mucosa
- Goblet cells
2. Seromucous nasal glands
Goblet cells
Mucus producing cells. We usually only notice mucus during a cold
Seromucous nasal glands
“Mucus” portion traps particles and debris- immune function- clears pathogens. “Serous” portion secretes watery fluid containing lysozyme
Vascularization of the mucous membranes of the nasal cavity
Capillaries and veins located superficially to help warm air as it passes through- they sit very close to the surface of the membrane. This is why damage to these vessels can cause severe nosebleeds
3 regions of the pharynx
- Nasopharynx
- Oropharynx
- Laryngopharynx
Nasopharynx
Contains pharyngeal tonsils and tubal tonsil. Closes during swallowing by soft palate and uvula (dangling thing at back of throat)- stops food/liquid from getting in
Oropharynx
Meets oral cavity at the isthmus of the fauces. Contains palatine tonsils and lingual tonsils
Laryngopharynx
Where respiratory and digestive passages split. The lower conducting zone divides the laryngopharynx from the respiratory passages
Parts of the lower conducting zone (4)
- Epiglottis
- Larynx
- Trachea
- Bronchi
Epiglottis
Cartilage flap that closes off lower conducting zone. Function- separates food and air passageways
Larynx composition
Composed of cartilage- provides an open airway. Consists of thyroid cartilage and cricoid cartilage- XY individuals tend to have an Adam’s apple (testosterone makes thyroid cartilage larger and thicker). The larynx contains vocal cords for sound production
Glottis
Open passageway surrounded by vocal cords. Vocal cords are ligaments composed of elastic fibers, the fibers vibrate as we exhale to produce sound
Sound pitch vs sound loudness of vocal cords
If chords are tense, they vibrate more quickly- higher pitch. Increased testosterone usually causes the chords to be longer and looser, causing a deeper voice. Loudness increases as air is passed across the cords with greater force. Many sound properties are created by other structures- tongue, lips, etc.
Trachea composition
Windpipe. Composed of elastic fibers and cartilage rings. Elastic fibers provide flexibility- trachea can stretch/relax while breathing cartilage rings prevent the trachea from collapsing. Without the cartilage rings, the trachea and larynx would collapse between breaths. It would take a large amount of work to breathe