APPP 18: Respiratory Systems Flashcards
What are the functions of the respiratory system? (6)
- gas exchange – intake O2 to convert nutrients to energy, eliminate toxic CO2
- helps regulate blood pH
- filters inspired air
- contains receptors for sense of smell
- produces vocal sounds
- excretes small amounts of water/heat in exhaled air
What are the structures of the upper respiratory system? (3)
- nose
- pharynx (throat)
- larynx (voice box)
What are the structures of the lower respiratory system? (3)
- trachea (windpipe)
- bronchi
- lungs
What is the conducting zone and what structures are a part of it?
cavities and tubes that filter, warm, and moisten air to ‘conduct’ air to the lungs
- nose
- pharynx
- larynx
- trachea
- bronchi
- bronchioles
- terminal bronchioles
What is the respiratory zone and what structures are a part of it?
tissues within lungs where gas exchange between air and blood occurs
- respiratory bronchioles
- alvelolar ducts
- alveolar sacs
- alveoli
Describe the structure of the external nose.
- 2 external nares (nostrils)
- made up of bone and hyaline cartilage that is covered with skin/muscle and lined by mucous membrane
Describe the structure of the internal nose.
- large cavity that extends from external nose to pharynx
- lined with muscle and mucous membranes
What are the functions of the nose? (3)
- warm, moisten, and filter air
- detect smells through olfactory receptors,
- modify sound
Describe the structure of the pharynx.
- funnel-shaped tube made out of skeletal muscle and mucous membrane
- around 13 cm (5 in) long
- located between nasal cavity and larynx
What are the 3 anatomical structures of the pharynx?
- nasopharynx
- oropharynx
- laryngopharynx
What is the nasopharynx?
- receives air from nasal cavity that contains dust-laden mucus
- lined with cilia that moves mucus (produced by goblet cells) down
- helps to equalize air pressure between ear and pharynx by exchanging small amounts of air through auditory tubes
What is the oropharynx?
- opens to the mouth
- has both digestive and respiratory function
What is the laryngopharynx?
- opens into the esophagus (food) and larynx (air)
- has both digestive and respiratory function
What are the functions of the pharynx? (3)
- passageway for food and air (respiratory and digestive functions)
- resonating chamber for sound (voice production)
- houses tonsils (involved in immune response)
Describe the structure of the larynx.
- connects laryngopharynx to trachea
- composed of 9 pieces of cartilage, including thyroid cartilage (Adam’s apple) and muscles that connect the cartilage to each other or other structures in the throat
- contains epiglottis – covers larynx to prevent food/liquids from travelling into trachea and airways
- contains vocal cords – create sound
What are the functions of the larynx? (2)
- connects upper and lower respiratory tracts
- voice production
What is laryngitis?
inflammation of the larynx most often caused by respiratory infections or environmental irritants (smoking)
- inflammation of vocal cords causes swelling, leading to a hoarse voice
Describe the structure of the trachea.
- tubular passageway for air that extends from larynx to 5th thoracic vertebra, where it divides into left and right primary bronchi
- composed of 16-20 incomplete ‘C-shaped’ horizontal rings of hyaline cartilage that provide a semi-rigid support
- open part of the ‘C shape’ faces the esophagus (is anterior to it) to allow for expansion of esophagus into trachea when swallowing
What procedure may be performed when airflow is blocked by obstruction of the trachea? (2)
- tracheotomy: insertion of a metal/plastic tracheal tube
- intubation: insertion of a tube into mouth/nose and down larynx into the trachea
What is the structure of the bronchial tree?
- trachea
- primary bronchi
- secondary bronchi
- tertiary bronchi
- bronchioles
- terminal bronchioles
Describe the structure of the bronchi.
- left and right primary bronchi are also made of incomplete rings of cartilage
- right primary bronchus is more vertical, shorter, and wider than the left – more likely for things to aspirate into the right
- once entering the lungs, primary bronchi become secondary bronchi – one for each lobe of the lung (right lung has 3 lobes, left lung has 2 lobes)
- secondary bronchi become tertiary bronchi
- tertiary bronchi become bronchioles
- bronchioles become terminal bronchioles
What are the 2 structural changes that occur during the branching of the bronchial tree (from trachea to terminal bronchioles)?
- mucous membrane goes from ciliated to non-ciliated
- incomplete C rings of cartilage become plates of cartilage, then no cartilage (instead, smooth muscle surrounds the lumen and muscle spasms (like in asthma) can close off airways
What are the pleural membranes?
two layers of serous membrane that enclose/surround and protect the lung
- parietal pleura: lines wall of thoracic cavity
- visceral pleura: covers lungs
What is the pleural cavity and what is its function?
- located between pleural membranes
- contains a small amount of fluid that is secreted by the membranes
- function is to reduce friction and allow membranes to slide easily over each other when breathing
Describe the differences between the left and right lungs. (4)
- left is 10% smaller due to location of heart
- right is slightly shorter due to diaphragm being higher on right side to accommodate the liver
- right has 3 lobes and left has 2 lobes
- fissures divide the lung into lobes – both lungs have an oblique fissure, but right lung also has horizontal fissue
What do terminal bronchioles divide into?
- respiratory bronchioles that penetrate into the lungs
- alveolar ducts
- alveolar sacs
- 2+ alveoli per sac that share a common opening
What are alveoli?
- sites of gas exchange
- walls contain two types of epithelial cells – type I alveolar cell and type II alveolar cell
- walls also contain alveolar macrophages
What are type I alveolar cells?
- more numerous
- form a nearly continuous lining
- main site of gas exchange
What are type II alveolar cells?
- fewer
- found in between type I alveolar cells
- have microvilli
- secrete alveolar fluid to keep the surface between cells and air moist
- alveolar fluid has surfactant, which lowers surface tension and reduces likelihood of alveoli collapse
What are alveolar macrophages?
- found in alveolar wall
- remove fine duct/debris from alveolar space