Respiration and Lungs

Study Notes

Respiration is the process of exchanging oxygen and carbon dioxide between the environment and the body's cells.
It involves three stages: ventilation, exchange of gases, and transport of gases.

Ventilation is the movement of air into and out of the lungs.
It involves the contraction and relaxation of the diaphragm and intercostal muscles.
Inspiration (inhalation) occurs when the diaphragm contracts and the rib cage expands, increasing the volume of the chest cavity.
Expiration (exhalation) occurs when the diaphragm relaxes and the rib cage descends, decreasing the volume of the chest cavity.

Gas exchange occurs in the alveoli, tiny air sacs located at the end of the bronchioles.
Oxygen from the inhaled air diffuses into the bloodstream and binds to hemoglobin in red blood cells.
Carbon dioxide, a waste product, diffuses out of the bloodstream and into the alveoli to be exhaled.

Oxygen-rich blood is transported from the lungs to the body's tissues through the pulmonary veins.
Oxygen is released from hemoglobin and diffuses into the tissues.
Carbon dioxide, a waste product, is transported from the tissues to the lungs through the pulmonary arteries.
The carbon dioxide is then exhaled out of the body.

The respiratory center in the brainstem regulates breathing rate and depth.
The respiratory center responds to changes in CO2 levels, pH, and oxygen levels in the blood.
The respiratory center sends signals to the diaphragm and intercostal muscles to adjust ventilation accordingly.

Respiration involves three stages: ventilation, exchange of gases, and transport of gases.
The process exchanges oxygen and carbon dioxide between the environment and the body's cells.

Ventilation is the movement of air into and out of the lungs.
It involves the contraction and relaxation of the diaphragm and intercostal muscles.
Inspiration occurs when the diaphragm contracts and the rib cage expands, increasing the chest cavity volume.
Expiration occurs when the diaphragm relaxes and the rib cage descends, decreasing the chest cavity volume.

Gas exchange occurs in the alveoli, tiny air sacs located at the end of the bronchioles.
Oxygen diffuses into the bloodstream and binds to hemoglobin in red blood cells.
Carbon dioxide, a waste product, diffuses out of the bloodstream and into the alveoli to be exhaled.

Oxygen-rich blood is transported from the lungs to the body's tissues through the pulmonary veins.
Oxygen is released from hemoglobin and diffuses into the tissues.
Carbon dioxide, a waste product, is transported from the tissues to the lungs through the pulmonary arteries.
Carbon dioxide is then exhaled out of the body.

The respiratory center in the brainstem regulates breathing rate and depth.
The respiratory center responds to changes in CO2 levels, pH, and oxygen levels in the blood.
The respiratory center sends signals to the diaphragm and intercostal muscles to adjust ventilation accordingly.

Glomerular filtration: Blood pressure forces water, ions, and small molecules out of the blood and into the Bowman's capsule
Tubular reabsorption: Useful substances like water, glucose, and amino acids are reabsorbed into the bloodstream
Tubular secretion: Waste products like urea, creatinine, and excess ions are secreted into the filtrate
Urine composition: 95% water, 2% urea, 1% other waste products, and electrolytes like sodium, potassium, and calcium

Muscular tubes that transport urine from the kidneys to the bladder
Composed of mucous membrane, smooth muscle, and fibrous connective tissue
Inner lining is mucous membrane
Middle layer is smooth muscle
Outer layer is fibrous connective tissue
Peristalsis: rhythmic contractions of the smooth muscle to propel urine down the ureter
Ureters are narrow to prevent backflow and infection