Human Excretory SystemLife of every organism depends on certain basic processes. Excretion is one among them. Different organisms follow different modes of excretion. In complex organisms including humans, there is a specialized system for excretion called human excretory system.We all obtain our nutrients from different sources which are later digested and metabolized in our body.
Q.1: The kidneys in human beings are a part of the system for – (a) nutrition (b) respiration (c) excretion (d) transpiration. Oct 04, 2010 Kidneys are any of the two bean-shaped organs situated just below the rib cages. As you must know, these are excretory organs that filter wastes from the blood and release them from the body. A pain in the kidney region typically arises when there is some ailment or interference in normal activity in the region. Location of kidney painPage Contents1 Location of kidney pain2 Kidney Pain. The body system that helps rid the body of wastes, toxins, and excess water or nutrients; major organs include kidneys, ureters, bladder, urethra, skin, and lungs Nervous system the body system of specialized cells that carry messages throughout the body; directs behavior, movement, and processes of the body; major organs include brain, spinal cord, peripheral nerves.
After metabolic reactions, the body starts to sort out useful and toxic substances in an individual. As we all know, the accumulation of the toxins may be harmful, the body removes all the metabolic wastes by the process called excretion.Different organisms follow different modes of excretion such as kidney, lungs, skin, eyes, etc., depending on their habitat and food habit.
For example, aquatic animals excrete waste in the form of ammonia while birds and insects excrete mainly uric acid. Humans produce urea as the major excretory product.Let us have a detailed look at the excretory system in human beings, different organs of excretory system and the mechanism of excretion in humans.Also Read: Excretory System OrgansThe human excretory system organs include:. A pair of kidneys. A pair of ureters. A urinary bladder. A urethraKidneysKidneys are bean-shaped structures located on either side of the backbone and protected by the last two ribs. Each human adult kidney has a length of 10-12 cm, a width of 5-7 cm and weighs around 120-170g.The kidneys have an inner concave structure.
At the centre of which there is a notch called hilum through which the Human Excretory System enters the kidney. Towards the inner surface of the hilum, there is a broad funnel-shaped space called renal pelvis with projections called calyces. Structure of KidneyThe structure of the kidney is explained below: CapsuleThe outer layer is called the capsule. Inside the kidney, there are two zones- the outer zone is cortex and the inner zone is medulla. The cortex extends in between the medullary pyramids as renal columns called columns of Bertin. NephronsNephrons are the functional units of the kidney. Each nephron has two parts- glomerulus and renal tubule.Glomerulus consists of a bunch of capillaries formed by afferent arterioles.
Blood from glomerulus is carried away by efferent arterioles.The renal tubule starts with a cup-like structure called Bowman’s capsule and this encloses the glomerulus. Malpighian body consists of glomerulus and Bowman’s capsule. The highly coiled structure in the tubule next to the Bowman’s capsule is the proximal convoluted tubule. Henle’s loopThe next part of the tubule is Henle’s loop which has an ascending and a descending limb. The ascending loop continues as a distal convoluted tubule. The distal convoluted tubules of many nephrons open into the collecting duct.The cortical region of the kidney comprises of malpighian corpuscle, proximal convoluted tubule and distal convoluted tubule whereas the medullary region contains a loop of Henle.There are two types of nephrons – cortical and juxtamedullary.
In case of cortical, the loop of Henle is very short and extends only a little into the medulla. In juxtamedullary, the loop of Henle is very long and runs deep into the medulla.
UreterA thin muscular tube called the ureter comes out of each kidney extending from the renal pelvis. It carries urine from the kidney to the urinary bladder. Urinary BladderIt is a sac-like structure that stores urine until micturition. Is the expulsion of urine from the body. The urine is carried to the bladder through the ureters. UrethraThis tube arises from the urinary bladder and helps to expel urine out of the body.
In males, it acts as the common route for sperms and urine. Its opening is guarded by a sphincter.Also Read: Human Excretory System DiagramThe diagram below represents the different parts of the human excretory system. Human Excretory System Diagram Excretion in HumansExcretion is the process where all the metabolic wastes are removed from the body. Excretion in humans is carried through different parts in a series of processes.Most of the unicellular organisms eliminate waste from their body through diffusion. A human body is an exceptional machine where a lot of processes (respiration, circulation, digestion, etc.) take place simultaneously. As a result, a lot of waste products produced in our body are in different forms that include carbon dioxide, water, and nitrogenous products like urea, ammonia, and uric acid.In addition to these, the chemicals and other toxic compounds from medications and hormonal products are also produced.
A simple diffusion or evaporation will not be sufficient to eliminate the waste from our body. Therefore it is eliminated through different parts in a series of processes.contains both useful and harmful substances. Hence, we have kidneys which separate useful substances by reabsorption and toxic substances by producing urine.Kidney has a structural filtration unit called nephron where the blood is filtered. Each kidney contains a million nephrons.Capillaries of kidneys filter the blood and the essential substances like glucose, amino acids, salts, and the required amount of water are reabsorbed. Meanwhile, the pure blood circulates back to other parts.Excess water and nitrogenous waste in humans are converted to urine.
Urine thus produced is passed to the urinary bladder via the ureters. The urinary bladder is under the control of the Central Nervous System. The brain signals the urinary bladder to contract and through the urinary opening called urethra, we excrete the urine. Mechanism of Excretion in HumansThe process of excretion in humans takes place in the following steps: Urine FormationThe urine is formed in the nephrons and involves the following steps:.Glomerular Filtration.Tubular Reabsorption.SecretionGlomerular FiltrationIt is the primary step in urine formation. In this process, the excess fluid and waste products from the kidney are filtered out of the blood into the urine collection tubules of the kidney and eliminated out of the body.The amount of filtrate produced by the kidneys every minute is known as Glomerular Filtration Rate. Tubular ReabsorptionIt is the absorption of ions and molecules such as sodium ions, glucose, amino acids, water etc.
Water involves passive absorption, while glucose and sodium ions are absorbed by an active process.
The muscular system parts refer to the types, locations and the number of muscular organs in the human body, as you can see in the muscular system diagram. According to the most recent research findings related to the human anatomy, there are more than 700 types of contractile organs in the body that have been identified and given particular names by the scientists. However, to make the study more comprehensive and understandable, all of these contractile organs have been grouped in three major categories, namely, skeletal muscles, smooth muscles and cardiac muscles. A brief description of these three major groups of human muscular system is being given as under: Skeletal MusclesThese are considered as a form of striated muscles that are set into operation and controlled by the somatic nervous system. In other words, these are subjected to movement or resisted against a move with an individual's own will and, that is why, you can call them voluntary contractile organs. Concerning their location, as the very name suggests, these muscles are associated with the bony skeleton and are firmly attached with the bones through collagen fibers or tendons.The individual components that combine to form these larger structures are known with three different names, viz. Muscle fibers, muscle cells or, simply, myocytes.
These unitary structures are formed in the process of myogenesis during which the developmental myoblasts undergo fusion to form larger multinucleated cells. These longer, cylindrical, larger and multinucleated structures are, in fact, termed as myocytes or myofibers. Concerning 'What is a myoblast'; this is a kind of embryonic progenitor cell that develops to form a muscle cell.
The myofibers are, in turn, made up of myofibrils which contain actin and myosin filaments. The repetition of these actin and myosin fibers results in a structure, called sarcomere. Sarcomere is not only considered as the basic functional unit of the muscle fiber, but it also accounts for the striated appearance of the contractile organ. In other words, it forms the basic machinery that is needed for the mechanism of muscle contraction.
Cardiac MusclesLike skeletal muscles, the cardiac or heart muscles are also striated, but unlike the former, the latter are involuntary and do not come under the voluntary control of an individual. Unlike the skeletal muscles, here you will find only one unique nucleus in each cell but the process of their formation is the same, i.e. These contractile organs contribute to the synthesis and development of the walls and histological components of the heart, including the myocardium. The cardiac muscle cells contract in coordination with the nearby cells and as a result, the blood is propelled out of the atria and ventricles.
These vital heart muscles are ensured ample supply of blood through the coronary arteries. By means of this circulatory fluid, the muscle cells not only get replenished with oxygen, but are also able to remove the waste products, such as carbon dioxide (CO2). Smooth MusclesAs opposed to the other two major types of muscles, these are not only involuntary in action but also non-striated in appearance. These contractile tissues are divided into two types, i.e.
Single unit or unitary smooth muscle tissues and multiunit smooth muscle tissues. Talking about their location, the smooth muscle tissues are scattered across many parts of the body, such as blood vessels (including arteries and veins), lymphatic vessels, uterus, urinary bladder, respiratory tract, male and female reproductive tracts, gastrointestinal tract, the ciliary muscles, iris of the eye and arrector pili of the skin. The smooth muscle cells located in different organs of the body show structural and functional similarities, but there is a substantial difference in the nature of inducing stimuli.
Kidneys In Human Beings Are Part Of The System For Sale
This significant difference in the inducing stimuli is very necessary, so that individual desired effects are performed in the body at individual times. The contraction of a smooth muscle is caused by its excitation which is, in turn, induced by external stimuli. When the filaments of actin and myosin slide across each other, the result is the contraction of smooth muscles. Contraction is followed by the relaxation, thus initiating a rhythmic impulse across the length of the vessel or tract.