Respiratory System Flashcards
How are the right and left nasal cavities seperated?
By the nasal septum
What is the function of the respiratory system?
Extracts oxygen from the atmosphere and allows excretion of carbon dioxide. Provides a surface area for gaseous exchange, moves air along the respiratory tract, acts as a protective function, used for communication, assists in a sense of smell
What does the upper respiratory tract consist of?
nasal cavity, nose, pharynx,
what does the lower respiratory tract consist of ?
Larynx, lungs, bronchial tree and trachea
What are the anterior nares of the nasal cavity?
The openings from the exterior into the nasal cavity
What are the posterior nares in the nasal cavity?
The openings from the nasal cavity into the pharynx
What does the nasal cavity do to the air once it has been breathed in?
Air is warmed, moistened and filtered
How does the nasal cavity warm the air?
The nasal mucosa is very muscular and rapiudly warms the air.
How does the nasal cavity perform filteration of the air?
The hais at the anterior nares trap the larger particles. The smaller particles such as dust settle and adhere to the mucus. Synchronous beating of the cilia walls wafts the mucus towards the throat where it is swallowed or coughed up.
How does the air moisten?
The air travels over the moist mucosa where it becomes saturated with water vapor.
What organ is responsible for sense of smell
The nose
What is the nasal cavity lined with?
The nasal caivty is lined with very vascular and very ciliated columnar epithelium which contain goblet cells. These goblet cells secret the mucus. The epithelium also have coarse hairs which are covered in sticky mucus
What other body system is the pharynx involved in?
The digestive system
Where does air flow in the pharynx?
Air passes through the oral sections into the larynx
What are the three sections that make up the pharynx?
Nasopharynx, Oropharynx, Larynpharynx
Where does the nasopharynx lie?
Posterior to the nasal cavity, inferior to the sphenoid bone but superior to the soft palates level.
How long is the pharynx in cm?
12-14cm
What tonsils are loacted very high up on the posterior wall of the nasopharynx?
Pharyngeal tonsils (adenoids) - this tonsil traps pathogens
What is the second part of the pharynx
oropharynx
What passes through the oropharynx?
Both air and food as it extends inferiorly from the level of the soft palate to the epiglottis.
What is the last section of the pharynx
laryngopharynx
What is the laryngopharynx lined with?
stratified squamous epithelium
Where does the laryngopharynx lie?
directly posterior to the epiglottis
What does the laryngopharynx do?
Allows food and air to pass through
rings
What is the larynx composed of?
Nine irregualrly shaped cartliage which is attached to eachother by ligaments and membranes
What are the main cartilage of the larynx?
The epiglottis, the thyroid cartliage, the cricoid cartliage and two arytenoid carliage.
What epithelial tissue does the epiglottis have?
stratified squamous epithelial
What does the epiglottis do?
Acts as a lid, closes off the larynx during swallowing, protecting the lungs from accidental inhalation of foreign objects.
How does the epiglottis rise?
It rises obliquely upwards behind the tongue and the body of the hyoid bone.
How many lobes does the right lung have ?
3
What are the lobs called in the right lung?
Superior (upper), medial (middle) and inferior (lower)
What is each lung divided into?
individual subunits called lobes whihch are seperated by fissures
How many lobes does the left lung have?
2
What are the left lung lobes called
The superior and inferior
How many fissures does the right lung have?
2
What is the base of the lung?
This is the inferior surface of the lung. It is concave and semilunar in shape.
What is the role of chemoreceptors?
Respond to changes in P02 (partial pressure of oxygen - reflects the amount of oxygen being diffused in the blood) and PC02 (Partial pressure of Carbon Dioxide - reflects the amount of c02 in the arterial or venous blood).
Where are the central chemoreceptors in the body?
Located on the surface of the medulla oblongata and are bathed in the CSF (Cerebrospinal fluid).
What do the central chemoreceptors do?
When arterial PCO2 rises (hypercapnia occurs), it also rises in the CSF (cerebrospinal fluid). The central chemoreceptors respond by stimulating the respiratory centre increasing the rate and depth of breathing to reduce the arterial PCO2. A reduction in PO2 (hypoxaemia) has the same affect.
Why are central chemoreceptors important?
important for Controlling normal gas levels
What are goblet cells?
Type of intestinal mucosal epithelial cell. Function is to secrete mucous and to trap the particular matter. They are underneath the cilia to move the mucous along.
02 dissociation curve - What does it show?
Initially oxygen fidns it hard to bind to the haemoglobin but as more oxygen binds the easier it becomes. This is because the haemoblobin has cooperative bonding. When haemoglobin has higher affinity more oxygen will bind to it.
What does having higher affinity mean?
Means that oxygen can bind more tightly to the haemoglobin.
