Respiratory system Flashcards
What happens in inspiration?
Diaphragm contracts and moves down, increasing the volume of the cavity meaning that the pressure decreases so air is drawn in
What happens in exhalation
Diaphragm relaxes and the chest moves up. There is a smaller volume and increased pressure so air moves out
What is the name of the serous membrane lining the lungs
Pleural sacs
The are the names of the 2 membranes which make up the serous membrane
Outer membrane is the parietal serosa and the inner membrane is the visceral serosa
What is found in between the serous membranes
A lubricating fluid which creates surface tension and reduces friction.
What is the advantage of surface tension in the serous membrane
Prevents the lungs collapsing due the the many elastic fibres trying to recoil and shrink
What can the pleural cavity fill with?
Air (pneumothorax), blood (haemothorax), pus (empyema) or water (pleural effusion)
What is Boyles law?
When the volume of a contains increases the pressure will decrease
What is LaPlaces law?
Air will move from an area of lower pressure than higher pressure e.g air moves from a smaller lung into a larger lung as there is a smaller pressure in the larger lung
Why is the pressure in the intrapleural space negative
The recoiling of the lungs separates the membranes so that there is a large volume and so lower pressure
How do you drain fluid in the pleural cavity
Inserting a needle into an intercostal space
What is a pancoast tumour?
Tumour in the apex of the lung
What an pancoast tumour impinge on?
Brachialis plexus causing wasting of the lower arm
What is horners syndrome?
Syndrome caused by an pancoast tumour impinging in the sympathetic trunk.
What are the symptoms of horners syndrome?
Constricted pupil, droopy upper eyelid
Where is pseudostratified Epithelium found in the respiratory system?
Nasal cavity, pharynx, larynx, trachea, primary bronchi and secondary bronchi
Where is simple columnar epithelium found in the digestive system
Bronchiole and terminal bronchioles
Where are simple cuboidal epithelial found in the respiratory system?
Respiratory bronchioles and alveolar ducts
Where is simple squamous epithelium found int he respiratory system
Alveoli
What 2 regions are found in the nasal cavity?
Non olfactory and olfactory regions
What is found in the olfactory regions of the nasal cavity
Pseudostratified columnar epithelium, with no goblet cells and non-motile cilia
What is the role of the olfactory region?
Detect odours
What is the role of the vocal cords in the larynx
Stop foreign objects reaching the lungs and contribute to the resonance of the voice
Which is anterior the oesophagus of the trachea?
Trachea
What is the structure of the trachea?
Pseudostratified ciliates columnar epithelium, mucus membrane, submucosa, C shaped hyaline cartilage, adventita
What happens to the hyaline cartilage with age
It ossifies
What is secreted by the epithelium in the trachea and bronchi
Mucins, water, proteins and lysozymes
What disease results from hyperproliferation of goblet cells and less cilia
COPD
How does cystic fibrosis affect the mucus?
The CFTR in not present in apical membranes and so chloride transport is compromised. As less chloride ions move out so does less water, making the mucus more viscous which often results in infections
How does the cartilage of secondary and tertiary bronchi differ to the trachea
Irregular cartilage
What is the cartilage like in primary bronchi
Continuous ring
Why do bronchioles not need cartilage
Surrounding alveoli keep the lumen open
What potential issue can arise due tot the lack of cartilage in bronchioles
Excessive smooth muscle contraction (bronchoconstriction) causes difficulty in expiration. This is asthma
What are Clara cells
Cells which secrete a surfactant lipoprotein which prevents walls sticking together during expiration. Also secrete a Clara cell protein
Where are Clara cells found
Bronchioles
What are supporting the alveoli walls
Elastic and reticular fibres
What 2 types of cell compose the alveoli
Type I and II pneumocytes
What is the function of type I pneumocytes
The simple squamous cells permit gas exchange
What is the function of type II pneumocytes
These cuboidal cells produce surfactant
What third type of cell are also found in the alveoli
Macrophages
What is pneumonia
Inflammation of the lungs caused by the presence of bacteria
What is emphysema
The destruction of the alveoli walls creating permanent air spaces
