Learn About Human Excretory System | iKen | iKen Edu | iKen App

Summary

The human excretory system plays a crucial role in maintaining homeostasis by removing excess or toxic materials from the body. It involves the skin, kidneys, and other organs to filter waste products such as salts, toxins, and excess nutrients. The kidneys, the main excretory organs, filter blood through nephrons, reabsorbing essential substances and secreting waste into urine. This waste is transported to the bladder and eventually excreted through the urethra. The system's primary function is to regulate chemical balances in the body, ensuring good health by eliminating harmful substances.

Takeaways

• 😀 The excretory system helps maintain homeostasis by removing excess, unnecessary, or dangerous materials from the body.
• 😀 The skin plays a minimal role in the human excretory system, secreting sweat that carries a small amount of metabolic waste.
• 😀 Digestion and absorption release nutrients into the bloodstream, but excess salts, minerals, water, drugs, and toxins can enter through the digestive system.
• 😀 The liver converts toxic ammonia into less toxic urea, which is released into the bloodstream for excretion.
• 😀 Toxic buildup in the bloodstream can disrupt chemical balances, threatening an individual’s health.
• 😀 The kidneys are the body’s primary excretory organs, filtering metabolic waste products and maintaining proper chemical balance.
• 😀 Each kidney contains up to 1 million functional units called nephrons, which consist of a glomerulus and a system of tubules.
• 😀 The glomerulus filters blood through a specialized filtration membrane, producing a primary urine called filtrate.
• 😀 Tubular reabsorption in nephrons returns electrolytes and nutrients from the filtrate back into the bloodstream.
• 😀 Tubular secretion moves substances from the peritubular capillaries into the urine, which is then passed through the ureter to the bladder.
• 😀 Urine is stored in the bladder until it is released through the urethra, regulated by sphincter muscles under voluntary and involuntary control.

Q & A

What is the primary function of the human excretory system?

The primary function of the human excretory system is to remove excess, unnecessary, or harmful substances from the body, helping to maintain homeostasis and prevent damage to the body.

How does the skin contribute to the excretory system?

The skin plays a minimal role in the excretory system by secreting sweat through sweat glands. Sweat carries small amounts of metabolic waste, helping to remove excess substances from the body.

What happens to excess nutrients, salts, and toxins in the bloodstream?

Excess nutrients, salts, minerals, water, drugs, and toxins can enter the bloodstream through the digestive system. If allowed to accumulate, these substances could threaten health by disturbing the chemical balance of the body.

What role does the liver play in the excretory system?

The liver helps detoxify the body by converting toxic ammonia into less harmful urea, which is then released into the bloodstream and eventually excreted by the kidneys.

How do the kidneys maintain chemical balance in the body?

The kidneys help regulate the chemical balance by filtering blood to remove metabolic waste, reabsorbing essential nutrients and electrolytes, and secreting waste products into urine. This process helps maintain the proper concentration of salts, water, and other substances in the body.

What is a nephron, and what is its function?

A nephron is the functional unit of the kidney, consisting of a glomerulus and a system of tubules. Nephrons filter blood to produce urine, reabsorb necessary substances, and secrete waste products into the urine.

What is the role of the glomerulus in the filtration process?

The glomerulus is a cluster of capillaries that filters the blood by allowing plasma-like fluid to pass through its walls. The filtered fluid, called filtrate, enters the Bowman’s capsule and eventually becomes urine.

What are the functions of the renal pelvis and tubules in the kidney?

The renal pelvis is a hollow chamber that collects urine from the nephrons and funnels it into the ureter. The tubules reabsorb water, nutrients, and electrolytes back into the bloodstream while secreting waste products into the filtrate to form urine.

How does urine travel from the kidneys to the bladder?

Urine travels from the kidneys through narrow muscular tubes called ureters. Peristaltic contractions help move urine from the kidneys to the bladder for storage.

What is the function of the bladder in the excretory system?

The bladder is a muscular organ that stores urine until it is ready to be excreted. It can expand to hold urine and has sphincter muscles that control the retention and release of urine.