RESPIRATORY SYSTEM

what are organs of respiratory system?

nose, nasal cavity, mouth, larynx, pharynx, lungs, and diaphragm

what organs are in the upper respiratory tract?

nasal cavity, pharynx, and larynx

what organs are in the lower respiratory tract?

trachea, bronchus, and lungs

what is a defense mechanism if we breathe through our noses?

tiny nose hairs and mucus produced by the epithelial mucosa cells in the nose help prevent particles in the air from entering the lungs.

pharynx

is behind the nasal cavity.

larynx

Just below the pharynx, voice box

epiglottis

covers the trachea during swallowing to prevent food from entering the lungs. Once food passes the epiglottis, it moves toward the esophagus

trachea

windpipes, long tube

process of breathing

Behind the nasal cavity is the pharynx. Both food and air pass through this long tube. Just below the pharynx is the larynx, or voice box.

It channels air to the trachea and pushes food past the epiglottis, which covers the trachea during swallowing to prevent food from entering the lungs.

Once food passes the epiglottis, it moves toward the esophagus.

When air reaches the trachea, or windpipe, it travels down a long tube that branches into bronchi.

The bronchi enter the lungs. As shown in the image, the bronchi branch into bronchioles before reaching tiny air sacs in the lung called alveoli. Gas exchange occurs in the alveolar region.

diaphragm

is a muscle that plays a large role in breathing. It is found at the base of the lungs and spreads across the bottom of the rib cage, forming the chest cavity

surfactant

consists of chemical compounds that lines the alveolar surfaces of the lungs. are lipopolysaccharides which have both a hydrophobic and hydrophilic layer to help keep the lungs inflated or prevent them from collapsing

pleura

serous membranes that cover each lung. They form a two-layered membrane that cushions the lungs while reducing friction between the lungs and chest cavity or rib cage

how does the diaphragm work for inspiration?

this dome-shaped structure flattens when it contracts. The rib cage moves outward, allowing outside air to be drawn into the lungs. During relaxation, the diaphragm returns to its dome shape and the rib cage moves back to its natural position.

air conducting portion

Air is delivered to the lungs. This region consists of the upper and lower respiratory tract—specifically, the larynx, trachea, bronchi, and bronchioles.

gas exchange portion

Gas exchange takes place between the air and the blood. This portion includes the lungs, alveoli, and capillaries.

what does too much acid in blood mean ?

too much carbon dioxide in the blood (pH value is too low)

what does alkaline in blood mean ?

not enough carbon dioxide in the blood (pH value will be too high)

what is the process of gas exchange between the outside air and the body called

respiration

external respiration

occurs between the lungs and blood. When a person inhales, alveoli fill with oxygen through diffusion. Oxygen content is much higher than carbon dioxide levels. While in the alveoli region, blood becomes oxygen-rich. Once oxygenated, the blood leaves the lungs and travels through the left side of the heart, where it is pumped into circulation.

internal respiration

occurs between the blood and tissues. Once blood enters circulation, it reaches the capillaries. Oxygen diffuses through the capillaries into the cells. Carbon dioxide diffuses from the cells into the capillaries. Because carbon dioxide content is higher than oxygen content in blood at this point, it is called oxygen-poor blood. This oxygen-poor blood travels to the right side of the heart. It moves through the pulmonary circuit, where external respiration begins.

steps of respiration summarized:

1. Air moves in and out of the lungs, which is called pulmonary ventilation.

2. Gases are exchanged between air and blood in the lungs by diffusion.

3. Gases are transported by circulation of the blood, with help from the heart.

4. Gases are exchanged by diffusion between blood and tissues throughout the body.