Human Excretion and Kidney Physiology

The cardiovascular system transports nutrients, oxygen and hormones to the cells of the body. At the same time, it removes the wastes produced by bodily functions. These include gases such as carbon dioxide and nitrogen as well as heat that is emitted by the functions of the body.

Urinary system is also known as excretory system of human body. It is the system of production, storage and elimination of urine. Formation and elimination of urine is important for human body because urine contains nitrogenous wastes of the body that must be eliminated to maintain homeostasis.

Kidneys are the major organs of urinary system. Formation of urine takes place in kidneys which are two bean shaped organs lying close to the lumbar spine, one on each side of the body.

Nephron is the basic structural and functional unit of the kidney. Its chief function is to regulate the concentration of water and soluble substances like sodium salts by filtering the blood, reabsorbing what is needed and excreting the rest as urine.

The urinary bladder is a temporary storage reservoir for urine. It is located in the pelvic cavity, posterior to the symphysis pubis, and below the parietal peritoneum. The size and shape of the urinary bladder varies with the amount of urine it contains and with the pressure it receives from surrounding organs

The renal pyramids are conical segments within the internal medulla of the kidney. The pyramids contain the secreting apparatus and tubules and are also known as the malphighian pyramids.

This statement is incorrect. It is the left kidney that is placed a little higher than the right kidney. Yes, apart from removing the poisonous substances such as urea and other wastes from blood, this is another function of the kidney.

Glycosuria is the medical term for the presence of glucose (sugar) in the urine, which can indicate diabetes mellitus or other metabolic conditions. The term derives from 'glyco' (sugar) and 'uria' (urine). Gonadotropism relates to hormonal effects, asphyxia is lack of oxygen, and albuminuria refers to albumin protein in urine.

Nephrostome is the funnel-shaped inner opening of a nephridium that is lined with cilia and allows water and waste to enter from the body cavity. It is the upper part of nephridia.

Spleen is a lymphatic tissue and stores blood. It plays no role in excretion.

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Metanephric kidney is the functional kidney of adult reptiles, birds and mammals.

Liver excretes vitamins, bile pigments, drugs and cholesterol.

Kidney is involved in the excretion of urea, extra salts and excess water.

The urinary bladder is a muscular sac that stores urine produced by the kidneys before it is expelled from the body. It can hold approximately 400-600ml of urine in adults. The bladder expands as it fills and contracts during urination.