Respiratory System Flashcards
What is external respiration?
exchange of gases between blood and lungs
What is internal respiration?
exchange of gases between cells and blood
What is in the upper respiratory tract?
nose, pharynx, larynx
What is in the lower respiratory tract?
Trachea and lungs
What is the conductive zone?
it includes all airways
What is the respiratory zone?
alveoli, where gas exchange occurs
What is the structure of the nasal cavity?
Includes 2 equal passages, the lining is ciliated columnar epithelium. Paranasal sinuses are cavities in the face and cranium bones.
What is the function of the nasal cavity?
Passageway for air Warming Filtering and cleaning (hair and mucus) Humidification (air travelling through moist mucus) Smell
What is the structure of the pharynx?
Nasopharynx, oropharynx and laryngopharynx
What is the function of the pharynx?
Passageway for air and food
Warming
Humidifying
Hearing (connection to the middle ear)
Protection (lymphatic tissue; tonsils)
Speech: acting as a resonating chamber for sound ascending from larynx
Facilitating swallowing via palate and uvula
What happens to the uvula and soft palate when swallowing?
they are pushed upwards close to the nose
What is the larynx?
Composed of several cartilages including thyroid and cricoid cartilage. Includes 2 pale folds of vocal cords stretched across laryngeal opening. Epiglottis: a leaf shaped fibroelastic cartilage attached on a flexible stalk. The lid of the voice box and will close the box during swallowing.
What is the function of the larynx?
sound (pitch, volume, tone) Speech Protection of lower respiratory tract when swallowing Passageway for air Warming Humidifying Filtering
What is the trachea?
10-11cm long Composed of 16-18 C-shaped cartilages: incomplete at posterior to allow expansion of oesophagus during swallowing Position: Lateral: lungs, Posterior: oesophagus Anterior: aorta, sternum Inferior: RT and LT Bronchi
What is the function of Trachea?
Air of passageway
Warming, humidifying and filtering
Mucociliary escalator: regular beating of the cilia membrane upwards towards larynx where it is swallowed or coughed u
Cough reflex
What is the structure of the lungs?
Composed of the bronchi and smaller air passages, alveoli, connective tissue, blood and lymph vessels and nerves embedded in an elastic connective tissue. Contains 300 million alveoli in each lung. Includes 5 lobes.
What is the name for the cells lining the alveoli?
Pneumocytes
what are the two types of cells in the alveoli?
PneumocyteType 1
PneumocyteType 2
What is the function of PneumocyteType 1?
oxygen in — carbon dioxide out
what is the function of PneumocyteType 2?
Surfactant
What is the function of the lungs?
External respiration via diffusion
What is a Pleura?
A closed sac of serous membrane for each lung. It includes the visceral pleural. the parietal pleural. A cavity inside the sac: pleural cavity a few millilitre of plural fluid allowing the two layers to glide over each other
What are the breathing muscles?
Intercostal muscles
Diaphragm
Describe the Intercostal muscles.
11 pairs between 12 pairs of ribs. Arranged in 2 layers: internal and external. The first pair of ribs are fixed, when these muscles contract rib cage would move upwards allowing lungs to expand.
Describe the diaphragm.
It is a dome- shaped muscular structure. Separating thoracic and abdominal cavities. During respiration it contracts and moves towards abdomen allowing lungs to expand.
Describe the transport of gases in blood stream.
Oxygen is combined with Haemoglobin (98.5%). Solution is plasma water (1.5%).
Carbon dioxide appears as HCO3 in the plasma (70%). Combined with Haemoglobin (23%). Dissolved in plasma (7%)
What is the pH of blood?
between 7.35 and 7.45
How is respiration controlled?
The nervous system is the respiratory centre. Chemoreceptors are located both centrally in the the medulla of the brain and peripherally in the arch of the aorta and carotid bodies.
What are chemoreceptors?
They are sensitive to the increase of arterial PCO2.
Sensitive to small reduction of PO2. Substantial PO2 depresses breathing.
what are the changes in pregnancy?
Chest shape alters during pregnancy
The ribs flare out, prior to mechanical pressure exerted by the growing uterus. the diaphragm rises by approx 4cm. the diameter of the chest )anterior- posterior and transverse diameters) both increase by 2 cm, leading to overall increased chest circumference of 5-7 sm. These effects are due to progesterone and relaxing on the the ribcage and associated ligaments.
what happens to blood during pregnancy?
Expanded blood volume and vasodilation can produce oedema (swelling) and hyperaemia (Increase blood flow) in the upper respiratory tract. Pregnant women can often experience nasal congestion, epistaxis (nosebleeds) and sometimes even changes in voice
What effect does progesterone have during pregnancy?
Progesterone is a respiratory stimulant; it increases the sensitivity of the peripheral and central chemoreceptors for carbon dioxide. Therefore respiratory drive is stimulated at lower carbon dioxide so pregnant women breathe more deeply.
Oxygen consumption increases but arterial oxygen pressure does not change.
