Excretion and homeostasis l.3 U.1 Sec.1

What is the various functions that the metabolism enable the body to perform

Obtaining energy from the food 2. Building essential biological molecules 3. Resisting infections 4. Replacing damaged cells

What is metabolism?

A group of biochemical reactions that occurs continuously inside the body cells and helps in the continuation of human life

What is anabolism?

It's a process in which new substances needed by the body are formed

What is catabolism?

It's the breaking down of complex molecules to get energy

What are the metabolic wastes ?

1 . Carbon dioxide 2. Ammonia 3. Urea 4. Excess water and mineral salts

How is the carbon dioxide gas produced to be from the metabolic wastes

It's produced from the cellular respiration process

How is the Ammonia produced to be from the metabolic wastes

It's produced from the breaking down of excess amino acids in liver

What about urea ?

It's produced from the conversion of toxic ammonia into a less harmful form

Excess water and mineral salts

Excerted in various methods

What would happen if the metabolic wastes stays in the human body ?

A disruption in the chemical balance of fluids in the body 2. The effect on the efficiency of cell function

What is the Excretion process ?

It's a biological process in which metabolic wastes are removed from the body and the the balance of homeostasis is maintained

What are the excretory organs in the human body ?

Kidney , liver, lungs , skin

Where is the kidney located ?

It's located on either side of vertebral column in the lower part of the back

The size of the kidney

The size of fist

The function of kidney

Maintaining the balance of ions and water in the body , filtration of the blood from liquid wastes

Why ions are essential?

For the function of nerves and muscles , maintaining the osmosis pressure inside and outside the cell, maintaining the blood pressure at normal level

When the ions increase

The kidney reabsorps water to dulite it's concentration

When ions decrease

The kidney excrets larger amount of water

The things that the nephrons filter the blood from

Water , wastes , ions , glucose

The elements that don't be filtered

Blood cells and proteins as they are big

Reabsorption process

It's a process of re gaining the useful substances filtered in the nephrons to the blood again

Substances reabsorped

Most of glucose to get energy for the cells A large portion of water to maintain the blood volume and fluids balance in the body Important ions for the muscles and nerves function and maintain the blood pressure

Substances that are not needed by the blood

They are transported through the two ureters to the urinary bladder where they are expelled from the urethra in the form of urine

What is the urine

It's a liquid expelled from the urethra which consists of urea , excess salts and water and some ions and other dissolved wastes

Important reabsorbtion

Enables the body to control what it retains and what it eliminates

What is the kidney doesn't do the reabsorption

Severe dehydration , Electrolyte imbalance , low blood pressure, possible ot failureof the body vital organs. What does the skin represent

What does the epiderms represent?

It represent the outer layer of the skin

What is the demis consist of ?

Sweet gland , hair follicles, blood vessels

Hypothesis

Rich in fats

Importance of skin

It plays a role in protecting the body

The Excretion of some metabolic wastes

It regulates the body temperature

It acts as a thermal insulator

How the skin protects our body

Due to the presence of epidermis which protects the body from microbes and water loss

Give reason

Why the skin excretes metabolic wastes

Due to what it secrets of sweat which consists of water , mineral salts and small amount of urea helping thebody maintain the balance of fluids

How does the skin regulates our body temperature

The skin secrets sweat from the sweat glands and as it evaporates from the skin it absorbs some of excess heat

Why the skin act as a thermal insulator

Due to the presence of hypodermis rich in fats

Why is liver considered a detoxification center ?

As it acts on :

1. Purifying the blood from harmful substances and accumulated waste products resulting from biochemical reactions

2. converting toxic substances into safe compounds to make it easier for the body to get rid of them

Where is the ammonia be converted into urea ?

In the liver

How is the ammonia converted to urea in liver

Proteins are broken down to ammonia

ammonia be converted into urea by liver

Urea is transferred to kidneys to excreted out in the form of urine

What happens to old red blood cells ?

The liver break the hemoglobin which provides bilirubin

The steps :

Red blood cells contains hemoglobin it's breakdown results in bilirubin is secreted in bile juice and excerted with feces

What are the nitrogenous wastes ?

Ammonia and urea

What does the body cells use to produce energy

Oxygen gas and glucose

What is produced after the cells produce energy ( the wastes ) ?

Carbon dioxide and water

How is carbon dioxide expelled from the body in the form of gas ?

It's expelled out through the lungs with the exhaled air

Why is the regular respiration essential ?

It's essential for maintaining the balance of gas levels in blood so it keeps the body internal balance

What happens if the carbon dioxide stays in the blood ?

The blood acidity increases which disrupts the function of enzymes and threatens biological processes in the body