Respiratory Flashcards
(197 cards)
What is the primary function of the respiratory system?
To supply the blood with oxygen in order for the delivery of oxygen to tissues in all parts of the body - via breathing
Purpose of upper respiratory tract:
Where air is taken into the body and warmed, moistened, and filtered before passing into the lower respiratory tract
Why is the air warmed, moistened, and filtered?
To enable maximum gaseous exchange and larger molecules of impurities do not penetrate as far as the lungs
Purpose of lower respiratory tract:
Air comes into close contact with capillary system of the pulmonary circulation and gaseous exchange occurs. Oxygen moves from air into blood and CO2 moves from blood into lungs.
What makes up the upper respiratory tract?
Nose, pharynx (throat), larynx (voice box), and trachea
How is the air moistened and warmed?
Nasal cavity of nose has a large surface area lined with a mucous membrane
The mucous membrane in the nasal cavity is continued into the pharynx, continuing the filtering
process. What does the pharynx provide a common passage to? (2)
Oesophagus & trachea with a mechanism, the epiglottis, to prevent food going down into the lungs
Where is lymph tissue found (2) and its role?
Lymph tissue present in the tonsils & lymph glands of the neck. Provides moist environment and defence against bacteria.
What protects the larynx?
Protrusion of cartilage known as the Adam’s apple. The larynx is the channel between the pharynx & trachea
Function of larynx:
Helps to facilitate speaking. As air flows from the lungs, the vocal cords open and close together and vibrate, creating sounds.
What makes up the trachea? (2)
Incomplete rings of cartilage & smooth muscle for support
Why are the rings of cartilage incomplete?
To allow food to be swallowed easily in the oesophagus without squashing the trachea
What lines the trachea (2) & why?
The trachea is lined with mucus-secreting goblet cells and ciliated epithelium. The mucus traps dust, dirt and pathogens from the air while the cilia beat and move the mucus (including dust and pathogens) away from the lungs.
What comes after the trachea?
Passes down the neck into the chest until it divides to form the right & left bronchus
Structural differences (2) between bronchi and bronchioles & one similarity:
Bronchioles are much smaller
They do not have cartilage rings around them
They do contain smooth muscle
Why do bronchioles have smooth muscle and what do bronchioles then divide repeatedly into?
They do contain smooth muscle which means they can dilate and constrict in response to environmental factors such as the temperature of the air.
Terminal bronchioles (tiny tubule network)
Where do the bronchioles end in?
Alveoli
Alveoli structure: (2)
Each alveolus is a tiny air sac with thin walls of flattened epithelial cells.
They have a big surface area
What surrounds the alveoli & why?
Network of blood capillaries so the distance for gaseous exchange is as short as possible - maintaining a steep concentration gradient
What are the anatomical features of the lungs in terms of lobes & pleural membranes?
Right lung - upper, middle, lower lobes
Left lung - upper & lower lobe
Pleural membranes - 2 of them. One stuck to lung surface and the other lines inside of the chest wall. There is pleural fluid to reduce friction between the membranes (in thorax (chest cavity)) & make breathing more efficient.
5 functions of the respiratory system:
- Creating sounds involved in speaking
- Assisting the detection of smell by olfactory receptors in the nasal cavity
- Moving air to and from the lungs, along the respiratory passages
- Providing a broad surface area for gaseous exchange between air & circulating blood
- Protecting respiratory surfaces from dehydration and temperature changes; protecting the respiratory
system and other body tissues by invasion by pathogens
The amount of oxygen in the blood depends on…(2)
Volume of blood & haemoglobin concentration
Which part of the respiratory system do bacterial & viral infections predominate?
Viral = upper airways
Bacterial = further down
Microorganisms can enter the lungs either by …
Inhalation or aspiration