Breathing and Exchange of Gases Flashcards
Ribs 1-7
True ribs
They are called so because there are directly connected to the sternum
Ribs 8, 9, 10
False ribs
Called so because they are not connected directly to the sternum. Instead these ribs are connected to the 7th rib.
Ribs 11 and 12
Floating ribs
Not connected to the sternum at all
Nostrils
Nostrils are the openings of the nasal cavity at the lower end of the nose just above the mouth
Nasal cavity- location
A pair of chambers present above the palate
Three regions of the nasal cavity
- Vestibular region
- Respiratory region
- Olfactory region
Vestibular region
> Anterior region of the cavity
> Contains hairs and sebaceous glands which secrete an oily secretion called sebum
Respiratory region
> Vascular middle part of the nasal cavity.
Lined by pseudo-stratified ciliated columnar epithelium
Rich is mucous cells (viscid fluid- mucus) and serous cells (watery fluid)
Olfactory region
> Upper posterior region of the cavity
> Lined by highly sensory olfactory epithelium cells which help in detecting the odour of the inspired air.
Nasopharynx- location
> Situated at the base of the skull behind the nasal cavities.
Nasopharynx extends to the oral pharynx which leads to two openings- the Trachea in the front and the Oesophagus at the back.
The nasopharnyx bears the openings of the eustachian tubes in its lateral walls by which it is connected to the middle ear.
Location of the larynx
Situated in the neck region parallel to the 4th-6th cervical vertebrae.
Largest cartilage seen in the larynx
Thyroid cartilage
Adam’s Apple
Protrusion of the larynx visible externally in the neck is called the Adam’s Apple.
Glottis
The larynx opens into the oral pharynx by a slit like aperture called the glottis.
What cells provide a mucous covering to the epithelium of the trachea?
Goblet cells and subepithelial mucous glands
How is meaningful sound or speech made in human beings?
> The meaningful sound or speech in human beings is made by the combined action of the tongue, vocal cords, larynx, and lips
In the normal condition, the vocal cords lie apart and the glottis is open, allowing the passage of air.
For sound production, vocal cords come close together, vibrate when air passes through the glottis and produce sound.
Trachea- location
> The trachea extends downward from the larynx.
> It bifurcates in the thoracic cavity along the level of the 4th-5th thoracic vertebrae into primary bronchi.
Why are the rings supporting the trachea and primary bronchi C-shaped?
The trachea and primary bronchi are supported by 16-20 C-shaped cartilaginous rings which provide flexibility and prevent them from collapsing.
Name the cells that line the trachea
Pseudo-stratified ciliated mucous epithelium
How do the bronchi divide until they become alveoli?
- Bronchi
- Bronchioles
- Alveolar ducts
- Atria
- Alveolar sacs
- Alveoli
Lungs- location
Situated in the thoracic cavity on either side of the heart
What encloses the lungs?
The lungs are enclosed in double walled sacs called pleura with pleural fluid between them.
Main site of respiration in the lungs
Alveoli
How does exchange of respiratory gases take place?
Respiratory gases are exchanged between the walls of the alveoli and blood through the process of diffusion.