respiratory system Flashcards
(31 cards)
1
Q
describe the thorax
A
- Between the neck (above) and the abdomen (below)
Thoracic wall:
Protect the heart & lungs
Make the movements of breathing
Breast tissue – lactation
Thoracic cavity:
Within the chest walls
Contains vital organs (also known as viscera)
Also contains major vessels and nerves
Consists of the mediastinum & the right & left pleural cavities
2
Q
describe the skeleton of the thoracic wall
A
- 12 pairs of ribs:
- true ribs: 1-7 (attach via their costal cartilage to the sternum)
- false ribs: 8-10 (attach via their costal - cartilage above to the sternum)
- floating ribs: 11 & 12 (no attachment to sternum)
- Intercostal spaces
- Costal margin
- 12 thoracic vertebrae
- Clavicle and scapula
- Sternum
- Manubrium, body, xiphoid, sternal angle
3
Q
describe the posterior view of the thoracic wall
A
4
Q
describe the intercostal spaces
A
- Space between ribs is called the intercostal space (numbered according to the rib superior to it)
- Each intercostal space contains intercostal muscles which help to move the ribs during breathing/ changing the volume within the thoracic cavity during respiration.
5
Q
describe the 3 types of intercostal muscles
A
external intercostal:
* The most superficial layer of intercostal muscle
* Function ribs to elevate in inhalation
internal intercostal:
* The middle layer of intercostal muscle
* Only function in forced exhalation
innermost intercostal:
* The deepest layer of intercostal muscle
* Separated from the other 2 layers of muscle by the neurovascular bundle
6
Q
describe the neurovascular supply to intercostal muscles
A
- Each intercostal space has a separate blood and nervous supply (neurovascular bundle)
- This neurovascular bundle runs along the inferior aspect of the rib in the costal groove
- These run anteriorly from the spinal column to the sternum
Always in the arrangement (superior -> inferior) - VAN
Intercostal Vein
Intercostal Artery
Intercostal Nerve
7
Q
describe the diaphragm
A
- Forms the floor of the chest cavity and forms the roof of the abdominal cavity
- Has “openings” to permit structures to pass between the 2 cavities
- It is a skeletal muscle with an unusual central tendon
- Anatomically arranged as right & left “domes”
- the right dome is normally the more superior (due to the presence of the liver inferiorly)
The muscular part attaches peripherally to:
* The sternum
* The lower 6 ribs & costal cartilages
* L1-L3 vertebral bodies
- The muscular part is supplied by the phrenic nerve (C3,4 & 5 anterior rami)
8
Q
describe the openings in the diaphragm
A
- IVC passes through at T8 level ( Inferior vena cava has 8 letters and so passed through at T8)
- Oesophagus passes through at T10 level ( oesophagus has 10 letters so passes through at T10)
- Aorta and thoracic duct ( which collects lymphatic fluid) passes though at T12 level
9
Q
describe how thoracic volume is increased in 3 planes during inspiration
A
- Anteroposterior increase is illustrated with pump handle movement
- Transverse increase is illustrated using bucket with two handles. Lifting handles is like raising right and left ribs at the costovertebral and costosternal joints.
- Vertical dimension is increased by downward pull of diaphragm.
10
Q
describe relaxed inhalation and exhalation
A
Relaxed inhalation:
Diaphragm contracts and external intercostals elevate thoracic cavity
Relaxed exhalation:
The muscles above relax, this allows the lungs to recoil and push air out
11
Q
describe the respiratory tract
A
Upper: Nose, nasal passages, paranasal sinuses, pharynx and portion of the larynx above the vocal cords
Lower: Larynx below vocal cords, trachea, bronchi, bronchioles and lungs
12
Q
describe the nasal cavity
A
- Air enters via the nasal cavity.
- The nasal cavity is entered anteriorly through the anterior nares (nostrils).
- It opens posteriorly into thenasopharynx through thechoanae ( posteriornares)
- Mucosa lines the nasal cavity, except for thenasal vestibule, which is lined with skin.
13
Q
describe the epithelial lining in the nasal cavity
A
- The majority of the nasal cavity is linedby ‘respiratory epithelium’
- A small part of the nasal cavity is lined bystratified squamous epithelium (nasal vestibule)
- Respiratory epithelium ispseudostratified columnar ciliatedepithelium (with goblet cells)
14
Q
describe the paranasal sinuses
A
- Cavities within the skull filled with air
- Lined by ciliated pseudostratified columnar epithelial cells
- Connected to the lateral walls of the nasal cavity
- Lighten the skull
- Increase resonance of voice
- Humidify inspired air
- Innervated by trigeminal nerve (CN V )
- Blood supply : Branch of external carotid artery
15
Q
describe the oral cavity
A
- Anteriorly - oral fissure
- Posteriorly - oropharynx
- Laterally - cheeks
- Superiorly - palate (hard and soft)
- Inferiorly- muscular floor and (Tongue)
16
Q
describe the pharynx
A
- The pharynx can be divided into 3 parts:
Nasopharynx, oropharynx and laryngopharynx - Nasopharynx= posterior to nasal cavities and above soft palate
- Oropharynx= posterior to oral cavity, inferior to the level of the soft palate, and superior to the upper margin of the epiglottis
- Laryngopharynx= extends from the superior margin of the epiglottis to the top of the oesophagus
17
Q
describe the tonsillar region
A
- Waldeyer’s tonsillar ring/pharyngeal lymphoid ring is a group of lymphoid tissues in the pharynx
- Pharyngeal tonsil (Adenoids)
- Tubal tonsils (x2)
- Palatine tonsils (x2)
- Lingual tonsil
- The first line of defence against pathogens entering through the nasopharynx or oropharynx
18
Q
describe the larynx
A
- Vocal cords. Sound is created by forcing air through the vocal folds of the larynx which vibrate to make noise. This is how we talk/sing!
- So air travels through the larynx in to the trachea. There are a few cartilage structures surrounding the larynx keeping it patent and protected.
19
Q
describe the trachea
A
- Through the larynx, air then travels through the trachea which is the tube through which air is transported to the lungs. It runs from the level of the lower border of the cricoid cartilage C6/C7 to T4/T5 vertebral level.
- Here it bifurcates into the left & right primary (main) bronchi
- The trachea is formed of ‘horse shoe’ or ‘C shaped’ rings of hyaline cartilage, held together by dense connective tissue
- Posteriorly, at the junction where the trachea is in contact with the oesophagus, the trachea has a membrane void of cartilage and covered in smooth muscle, the trachealis muscle
20
Q
describe the carina
A
- At the bifurcation of the trachea lies the carina; a ridge that can be seen on a bronchoscopy (little camera)
- The carina is a key landmark in determining pathologies. Widening/ distortion of the carina can often indicate cancer in the lymph nodes that lie just inferior to the carina.
- The name of these lymph nodes is Inferior tracheobronchial lymph nodes
21
Q
what is a bronchoscopy ?
A
- Bronchoscope travels down thetrachea to enter a main bronchus
- The bronchoscope must move aroundthe carina to get to the bronchus
- Theinferior tracheobronchial lymphnodescanblunt the carinawhenenlarged → indicating pathology
22
Q
describe the bronchi
A
- The trachea bifurcates into the left & right primary (main) bronchi
The bronchi have characteristic hyaline cartilage rings, supporting them, the same as in the trachea. - The position each bronchi sits at is different; the right is wider, shorter and lies at a steep vertical angle, whereas the left is narrower and more horizontal.
*Inhaled foreign objects are more likely to get lodged in the right side bronchus
23
Q
describe the secondary bronchi
A
- The left & right primary (main) bronchi divide further into secondary (lobar) bronchi; 2 on the left and 3 on the right. We will see shortly that these divisions correspond to the number of lobes in each lung!
- The secondary bronchi then further divide to give tertiary (segmental) bronchi; usually 10 for each lung
24
Q
describe the terminal bronchioles
A
- Each tertiary bronchi gives rise to many terminal bronchioles – these now differ in structure as they no longer have hyaline cartilage in their walls
- Respiratory bronchioles branch from these terminal bronchioles
- Each respiratory bronchiole ends in an acinus of clustered alveoli
25
describe the lungs
* The lungs are the functional organs of respiration.
* 2 lungs- either side of the mediastinum and are protected by the ribcage.
* The diaphragm lies inferior to lungs which separates the thoracic cavity from the abdominal cavity.
* The function of the lungs is to oxygenate blood. They achieve this by bringing inhaled air into close contact with oxygen-poor blood in the pulmonary capillaries
* They can expand down to the lower border of the ribs; the costal margin and extend as far up as the root of the neck. Above the 1st rib
26
describe the pleura
* Each lung (right and left) is contained within a serous membrane called a pleural sac. The pleural sacs flank both sides of the heart and occupy most of the thoracic cavity. Each pleural sac is composed of two serous layers called: the parietal pleura and visceral pleura.
* The thin space between these two layers is called the pleural cavity. This thin pleural cavity contains a thin layer of liquid called pleural fluid which provides lubrication between the two layers of pleura as the lungs expand which helps prevent friction.
27
describe the types of pleura
* The parietal pleura lines internal surface of thoracic cavity. Parietal Pleura is named differently depending on the area it is lining:
8 Diaphragmatic parietal pleura- lines superior surface of diaphragm
* Mediastinal parietal pleura- lines lateral surface of mediastinum (which contains the heart).
* Costal parietal pleura- lines internal surface of ribs
* Cervical parietal pleura- extends above rib 1 to the root of the neck
* The visceral pleura surrounds and is intimately attached to each lung; Following the contour of the lobes. The visceral pleura is contiguous with the parietal pleura at the hilum of each lung
28
describe the lobes of the lung
The lungs are divided into lobes
2 lobes on left: Superior & inferior divided by oblique fissure
3 lobes on right: Superior, middle & inferior divided by oblique fissure and horizontal fissure.
29
label the lobes
30
describe the hilum of the lungs
The hilum= located on the medial aspect of each lung. It is the site where the bronchi, arteries, veins & nerves enter/ exit the lung.
Like the doorway into the lung!
31
label the hila
