The alveoli of lungs are lined by
Simple squamous epithelium
The respiratory or gas-exchange surface consists of millions of small sacs, or alveoli, lined by a simple squamous epithelium. This epithelium is exceedingly thin to facilitate diffusion of oxygen and CO2. The alveolar walls also contain cuboidal surfactant-secreting cells.
Which one of the following mammalian cells is not capable of metabolising glucose to carbon dioxide aerobically?
Cell organelles and nucleus are absent in mature red blood cells, therefore, aerobic respiration do not take place.
The pharynx opens into the larynx by a slit-like aperture called
Nasopharynx lined by ciliated pseudostratified epithelia, oropharynx and laryngopharynx lined by non keratinized epithelium.
Mouth serves as an alternate route for air when nasal chambers are blocked. Foramen by which pharynx opens into larynx called glottis. In general it remains open. During swallowing, it is closed. It provides passage for air.
Pharyns leads into the oesophagus through an aperture called gullet. In general condition it remains closed and opens at the time of swallowing. During swallowing epiglottis closes the glottis.
Book lungs are respiratory organs of
A book lung is a type of respiration organ used for atmospheric gas exchange that is found in many arachnids, such as scorpions and spiders
Regarding the functions of our respiratory system, mark the right entry.
Respiration involves the following steps:
(i) Breathing or pulmonary ventilation by which atmospheric air is drawn in and CO2 rich alveolar air is released
(ii) Diffusion of gases (O2 and CO2) across alveolar membrane.
(iii) Transport of gases by the blood.
(iv) Diffusion of O2 and CO2 between blood and tissues.
The two organisms which breathe only through their moist skin are
Earthworms respire only through moist skin which is permeable to gases. Leeches breathes through the skin.
• Frogs doesn't respire always through the skin.
• Fishes respire through gills.
The total number of alveoli in both lungs are
Alveoli are small, thin-walled, very fragile air sacs located in clusters at the end of the bronchial tubes deep inside the lungs.
There are about 300 million alveoli in normal lungs.
As you breathe in air, the alveoli stretch, drawing oxygen in and transporting it to the blood. When you exhale, the alveoli shrink, forcing carbon dioxide out of the body.
Lungs have a large number of narrow tubes called
► The narrow tubes found inside lungs are called bronchioles.
When we breathe, air travels from the nose or mouth, and goes down the trachea and reaches the part called carina. From here the tube branches into two, creating two bronchi that lead to left and right lung each. From there onwards, the bronchi split into smaller and smaller bronchioles until it terminates in the alveoli where gas exchange occurs.
The lungs are enclosed in a covering called
► The pleural membranes are two layers of the serous membrane which enclose and protect the lung.
► The superficial layer is called the parietal pleura and lines the wall of the thoracic cavity.
► The deep layer is called the visceral pleura and covers the lungs themselves.
The term ‘Glycolysis’ has originated from the Greek words
The word glycolysis is of Greek origin, where 'glycos' means sweet, and 'lysis' means splitting. Hence, Glycolysis literally means "sugar splitting" or "sugar breaking"; this accurately describes the process of glycolysis, in which a 6-carbon sugar molecule is broken down into two 3-carbon molecules.
There are three stages in glycolysis which are Investment stage, Splitting stage and Energy Yielding stage.
Glycolysis consists of ten separate reactions, each catalyzed by a different enzyme.