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Summary
Biology Class 03

EXCRETORY SYSTEM:

  • Waste removal and regulation of water.
  • Urine (urea 2.5%, other waste 2.5%, water 95%).
  • Kidney stone- calcium oxalate.

CIRCULATORY SYSTEM (05:10 PM)

  • System of transportation in the body (heart, blood, blood vessels).
  • Heart:
  • 4 chambers of the heart.
  • Upper chamber- auricles/atrium (right auricles and left auricles).
  • Lower chamber- ventricle (right ventricle and left ventricle).
  • Blood vessels:
  • Arteries are those blood vessels that take blood away from the heart.
  • Veins are those blood vessels that take blood towards the heart.
  • Veeins are thin-walled and arteries are thick walls.
  • Veins are superficial and bluish-green.
  • Arteries are deep-seated and reddish.
  • Double circulation in the Heart:
  • Right ventricle-lungs-left auricle- left ventricle- body except for lung-right auricle-right ventricle.
  • * Please refer to the diagram of Double circulation in the Heart, as shown on the whiteboard.
  • Arteries always carry oxygenated blood except for the pulmonary artery.
  • Veins carry deoxygenated blood except for pulmonary veins.

GLANDS (05:27 PM)

  • Exocrine gland and endocrine gland.
  • Exocrine glands have ducts/tubes to connect the body organ, for example, the liver.
  • Endocrine glands do not have ducts/tubes and these gland release chemicals called hormones directly into the blood.
  • Endocrine system:
  • It is meant for internal communication and regulation of the Human body.
  • Hormones are secretions of endocrine glands that do not have ducts and secret directly into the blood to be transported to distantly located target organs.
  • Hypothalamus (05:41 PM)
  • Releasing hormone- it stimulates the pituitary gland to release its secretion.
  • Inhibiting hormone- It inhibits the pituitary glands from releasing its secretion.
  • Pituitary Gland:
  • Anterior pituitary- 
  • Thyroid-stimulating Hormone (TSH) stimulates the thyroid gland to release its secretion.
  • Prolactin- this is for the formation of milk.
  • Adrenocorticotropic Hormone (ACTH) stimulates the adrenal gland to release its secretions.
  • Follicle Stimulating Hormone (FSH) helps in the maturation of eggs and the formation of sperm.
  • Growth Hormone- is for the growth and development of the body.
  • Luteinizing Hormone (LH) stimulates the gonads or sex organs to produce the sex hormones.
  • Posterior Pitituary (05:53 PM)
  • Anti Diuretic Hormone (ADH or Vasopressin)- reabsorption of water and mineral from the kidney.
  • Oxytocin is released during childhood.
  • Thyroid  Gland and Parathyroid Gland (05:59 PM)
  • Thyroxine/Thyroid Hormone helps in the metabolism of carbohydrates, proteins, and fats.
  • Parathyroid Hormone is involved in the metabolism of calcium and phosphate in the body.
  • High amount of parathyroid hormone  (high calcium and low phosphorous).
  • Low amount of parathyroid hormone  (low calcium and high phosphorous).

ADRENAL GLAND (06:04 PM)

  • Adrenal Medulla:
  • Adrenaline and nor-adrenaline are the emergency hormone of the body, which are released in situations of fear, being frightened, anxious, or extreme excitement.
  • Adrenal cortex:
  • Mineralocorticoid regulates the balance of water and minerals in the body.
  • It helps to maintain blood pressure in the body.
  • Glucocorticoids are involved in carbohydrate metabolism.

PANCREAS (06:11 PM)

  • Insulin reduces blood glucose levels.
  • Glucagon increases blood glucose levels.
  • Nephrons- the basic unit of the kidney.

HEALTH (06:44 PM)

  • Health is the complete physical, mental, and social well-being of a person and not merely the absence of diseases.
  • Disease (congenital disease and acquired disease).
  • Acquired diseases- communicable diseases/ infectious diseases and noncommunicable/ non-infectious diseases.
  • Congenital disease is any abnormality in the structure or function of a person which is present right from the time of birth.
  • For example genetic diseases like Down syndrome, and congenital heart disease.
  • Acquired disease is any disease that is not present at the time of birth but develops at a later stage of the life of an organism.
  • Communicable/ infectious disease occurs because of the disease-causing organism called pathogens.
  • For example- malaria, dengue, covid, etc.
  • Non-communicable/ non-infectious diseases are not caused by a pathogen but by lifestyle or environmental factors.
  • For example- cardiovascular disease, respiratory disease (asthma), deficiency disease (vitamins and minerals- rickets), mental disorder(depression, bipolar), environmental disease (Minamata disease- mercury), occupational disease (silicosis), cancer. 

COMMUNICABLE DISEASES (07:15 PM)

  • Modes of transmission:
  • Air- covid, TB.
  • Water- cholera.
  • Food- typhoid, amoebiasis.
  • Soil- hookworm.
  • Blood and body fluid- AIDS.
  • Direct contact- covid-19, common cold.
  • Fomite- non-living things- chicken pox.
  • Zoonotic- animal- swine flu, rabies.
  • Vector- mechanical vector versus biological vector.
  • Vectors are organisms that do not cause the disease itself but spread the infection by taking pathogens from one organism to another.
  • Mechanical vectors carry the pathogen on the surface of their body and biological vectors carry the pathogen within their body.

HELMINTHIC DISEASE (07:33 PM)

  • Worm infection (roundworms, flatworms).
  • Ascariasis by ascaris, a roundworm.
  • Taeniasis by taenia solium, a flatworm.
  • Lymphatic filariasis- elephantiasis.
  • Hookworm infection, a roundworm.

PROTOZOAN DISEASES (07:41 PM)

  • Example- Amoebiasis, Giardiasis, and Malaria.
  • Malaria- Plasmodium( Vivax, and Falciparum).
  • Vector- female Anopheles mosquitos.
  • Malaria Transmission Cycle:
  • First infected mosquito (Plasmodium in female Anopheles mosquitos).
  • First infected person (Plasmodium in the blood). 
  • Infected liver cells (growth of plasmodium in the liver).
  • Infected Red blood cells (increase in number in Plasmodium- RBCs burst).
  • Second infected mosquito (Plasmodium in the blood).
  • Second infected person.
  • Reproduction-Asexual (one parent) and sexual (male and female).

FUNGAL DISEASES (07:56 PM)

  • Ringworm.
  • Athletes' foot.
  • Candidiasis- Candida Albicans.
  • Please refer to Ncert:
  • Class 7- Chapter 7.
  • Class 8- Chapters 2, and Chapter 7.
  • Class 11- chapter 19.

NEXT CLASS TOPIC:  Health and Immunity.