202 1 what is the key content of respiratory anatomy and physiology in nursing examination center?

Anatomical structure of respiratory system:

It consists of respiratory tract, lung and pleura. It is divided into upper and lower respiratory tract by cricoid cartilage.

Upper respiratory tract: nose, pharynx and larynx.

Lower respiratory tract: trachea and bronchus.

Respiratory tract:

1. Upper respiratory tract

The nose can filter, moisturize and warm the inhaled gas.

The pharynx is the same pathway of respiratory system and digestive system.

The larynx is the main organ of pronunciation and plays an important role in cough. When swallowing, epiglottis covers the larynx to prevent food from entering the respiratory tract.

2. Lower respiratory tract

The trachea divides into two main bronchi at carina (located in sternal angle).

The right bronchus is thicker, shorter and steeper than the left bronchus, and the left bronchus is relatively slender and tends to be horizontal. Therefore, foreign body inhalation is easier to enter the right lung. The diameter of the airway is getting smaller and smaller, which makes the airflow speed slow down gradually during surgery. The bronchioles with a diameter less than 2mm are called small airways. Because the small airway wall has no cartilage support, the gas flow rate is slow, and it is easy to block. It is a common part of respiratory diseases, and it is difficult to find and diagnose early.

Lung:

An organ for gas exchange. The left lung is divided into upper and lower lobes. The right lung has upper, middle and lower lobes. In the lobe, according to the branches of bronchi and blood vessels, the lobar bronchi are subdivided into lung segments.

Alveola is a place for gas exchange. There is a rich capillary network around alveoli, which is very conducive to gas exchange.

Pleura:

Divided into dirty layer and wall layer.

The visceral layer is close to the lung surface, the wall layer is lined with the inner surface of the chest wall, and the two pleuras migrate with each other at the root of the lung to form a potential closed cavity, which is called pleural cavity.

Respiratory function of lung:

Pulmonary ventilation: the exchange of gas between the external environment and the lungs, through the change of chest volume caused by the movement of respiratory muscles, makes the gas effectively enter or exit the alveoli.

Pulmonary ventilation: it is the exchange of gas partial pressure difference between alveoli and pulmonary capillary blood, mainly through the respiratory membrane in alveoli, in the form of gas dispersion.

Defense and immune function of respiratory system;

① Upper respiratory tract heating, humidification and filtration.

② Respiratory mucosa and mucociliary carrier system.

③ Reflex defense functions such as cough reflex, sneezing and bronchoconstriction.

④ Defensive power, mainly alveolar macrophages, has the function of swallowing or neutralizing and detoxifying various inhaled dust particles and microorganisms.

⑤ Immunoglobulin secreted by respiratory tract (IgA and IgM secreted by B cells, etc. ) and lysozyme play an important role in resisting respiratory tract infection.

Anatomical and physiological characteristics of children's respiratory system;

The nasal cavity is short, with no nose hair, soft mucosa and rich blood vessels, which is easy to be infected. Inflammation is prone to congestion, swelling and nasal congestion, leading to difficulty breathing. Nasal mucosa and sinus mucosa are continuous, and the ostium of sinus is relatively large, so acute rhinitis is easy to cause sinusitis. The eustachian tube is wide, short, straight and horizontal, so nasopharyngitis is easy to invade the middle ear and cause otitis media. The throat is long and narrow, the mucosa is delicate, the blood vessels are rich, and it is easy to be inflamed and swollen, so laryngitis is prone to obstruction and suffocation. The trachea and bronchial cavity are relatively narrow, lack of elastic tissue, and cilia are not moving smoothly, which is prone to inflammation and obstruction. Lung tissue is poorly developed, elastic tissue is poorly developed, blood vessels are abundant, interstitial development is vigorous, and the number of alveoli is small, which makes it relatively rich in blood and less in gas, easy to be infected, and easy to cause interstitial pneumonia, atelectasis and emphysema. The nonspecific and specific immune function of children's respiratory tract is poor. Infants and young children are prone to respiratory tract infection due to low immunoglobulin content, especially secretory IgA(SIgA) content and insufficient function of alveolar macrophages.