Class 10 Science notes

  The basic definitions and working of heart are covered in other page  BLOOD   CLOTTING When a tissue is wounded or a blood vessel is ruptured due to some injury the blood flows through it.  If not checked it may cause an excessive loss of blood. Sometimes this immense loss of blood even leads to death.  However the body has its own natural device of preventing the loss of blood by forming a blood clot which heals blood cell injury and stops flow of blood and also checks the entry of pathogenic microorganisms.  This complex process is initiated by PLATELETS which circulates within blood around the body.   Mechanism of blood clotting  In the region of injury, the platelets get ruptured and release a substance called thromboplastin .  It converts protein prothrombin into thrombin.   Vitamin K is essential for formation of thrombin in liver. THROMBIN then changes soluble fibrinogen protein into fibrin(insoluble). This latter goes Rapid polymerisation to form long fibres the fibres

WORKING OF HEART ❤ The muscular organ which is located near the chest slightly towards the left in the thoracic region.The heart is the main pumping organ of the body. It makes the sound of LUB-DUB due to the closing and opening of valves present in the heart. It is made up of cardiac tissue. The human heart is divided into four chambers which are involved in the transportation of oxygenated and deoxygenated blood. The upper two chambers are called atria whereas the lower two chambers are called ventricles. It is surrounded by a tough two layered sac called pericardium .  The pericardial fluid is secreted in pericardial cavity between pericardium and heart which reduces the friction between heart wall and surrounding tissues when heart is beating. Height is divided by Septa into two halves:  right and left.   Each have consists of two communicating chamber. The upper auricle or Atrium and the lower larger ventricle. VALVES There are walls between left Atrium and left ventricle and betw

  (THIS PAGE CONTAINS DEFINITIONS AND FUNCTIONS OF CIRCULATORY SYSTEM ONLY FOR WORKING OF HEART REFER- https://yournotesparadise.blogspot.com/2021/08/transportation-in-animals-working-of.html ) For the food to be absorbed by each part of the body the digested food need to be transported to every location within the body !! TRANSPORTATION is a life process In which a substance synthesized observed in one part of the organism is carried to other parts of the body. TRANSPORTATION IN ANIMALS Before learning the mechanism involved in transportation, let us look at some basic terms to be used in transportation… Circulatory System : The circulatory system is responsible for transport of various substances  in human beings. It is composed of the heart, arteries, veins and blood capillaries. Blood plays the role of the carrier of substances. Heart: is a muscular organ; which is composed of cardiac muscles. It is so small that it can fit  inside and adult’s fist. The heart is a pumping organ wh

  After digestion the food needs to be absorbed.before that the digested food needs to be transported to each and every part of the body. ABSORPTION and ASSIMILATION IN HUMANS After digestion food is converted into soluble form i.e (carbs into glucose/ fats into glycerol/ proteins into amino acids).so these soluble molecules are absorbed by cells of body to assimilate(PRODUCE ENERGY) Absorption occurs in small and large intestine.mainly nutrients are absorbed by small intestine and water by large intestine. Being soluble, these products are easily absorbed by capillaries.The internal regions of the small intestine are folded into numerous finger-like projections called VILLI.  They increase the absorptive surface area for absorption. Villi are richly supplied with blood capillaries and also contained lymph vessels. Each villus has its cell membrane of the lumen side again folded into microscopic processes, called microvilli. Large intestine is present after and  does not have villi.

DIGESTION IN HUMANS (BY YASH) Humans are heterotrophic organisms , going deep into that they are omnivores ( feed on both plants and animals). Being Multicellular and having greater complexity They have a complex digestive system.  Their digestive system is made up of an alimentary canal and many digestive glands. There are five stages in human nutrition; Ingestion, Digestion, Absorption, Assimilation and Egestion. STRUCTURE AND FUNCTIONS OF ALIMENTRY CANAL AND RELATED DIGESTIVE GLANDS Alimentary canal has a long tube with muscular walls And extends to mouth to anal opening (anus).  It is about 9 Metre long tube in which several digestive glands open to secrete their respective digestive enzymes. The elementary Canal consists of following… MOUTH BUCCAL CAVITY PHARYNX OESOPHAGUS STOMACH SMALL INTESTINE LARGE INTESTINE 1.MOUTH It forms the uppermost opening of human digesti