Tag: respiration in organisms

The most significant limiting factor in high mountain regions is the lower air pressure, which makes it more difficult for oxygen to enter our vascular systems resulting into hypoxia. When we travel to high mountain areas, our bodies initially develop inefficient physiological responses. Then there is an increase in breathing and heart rate to as much as double, even while resting. Pulse rate and blood pressure go up sharply as our hearts pump harder to get more oxygen to the cells. These are stressful changes, especially for people with weak heart. Later, a more efficient response normally develops as acclimatization takes place. Additional red blood cells and capillaries are produced to carry more oxygen. The lungs increase in size to facilitate the osmosis of oxygen and carbon dioxide. There is also an increase in the vascular network of muscles which enhances the transfer of gases.

Babies and children normally breathe faster than older children and adults. Newborn to 6 months: 30-60 breaths/min

• The respiratory system represents the organs that are involved in the exchange of oxygen and carbon dioxide between the organism and the environment.
• In animals, a primary layer of cells is formed during embryogenesis, three in number and are differentiated as ectoderm, mesoderm, and endoderm. The tissues produced by these layers give rise to the organs of the body. 
• The respiratory tract with tracheae, bronchi, alveoli of the lungs is developed from the endoderm. The mesoderm forms the mesothelium from which lines the thoracic cavity and external intercostal muscles.
  Hence, the correct answer is D.

The blood pumped by the right ventricle enters the pulmonary artery, whereas the left ventricle pumps blood into the aorta.The deoxygenated blood pumped into the pulmonary artery is passed onto the lungs from where the oxygenated blood is carried by the pulmonary veins into the left atrium. This pathway constitutes the pulmonary circulation. 

Altitude sickness is also known as acute mountain sickness (AMS), altitude illness, hypobaropathy, "the altitude bends" or soroche is a pathological effect of high altitude on humans, caused by acute exposure to low partial pressure of oxygen at high altitude. It commonly occurs above 2,400 metres (8,000 feet). 

The breathing centre in the brain responds to changes in the carbon dioxide concentration of the blood.

Respiration is a process based on chemical reaction and takes place  in all living cells. In this process, energy is released from glucose, for the functioning of our cells. Sugars used as a substrate for respiration comes from the hydrolysis of starch which results in loss of dry matter. 

Bacteria perform respiration via the cytoplasmic membrane, while cyanobacteria use specialized extensions of the plasma membrane called mesosomes. Eukaryotic cells utilize mitochondria for cellular respiration.

The main respiratory surface in humans is the alveoli, which are small air sacs branching off from the bronchioles in the lungs. They are one cell thick and provide a moist and extremely large surface area for gas exchange to occur. Capillaries carrying deoxygenated blood from the pulmonary artery run across the alveoli. Due to the enormous number of alveoli (approximately 300 million in each human lung), the surface area of the lung is very large (75 m2). Having such a large surface area increases the amount of gas that can diffuse into and out of the lungs.

Not all cells use oxygen to produce energy. Aerobic cells use oxygen to produce energy. Anaerobic organisms do not require oxygen to produce energy. They obtain energy from metabolism in absence of oxygen. For example, yeasts in absence of oxygen convert sugar into alcohol and produces energy. This energy is then utilized for their survival.