Human Body

The human body is a single unit made up of billions of smaller structures: cells, tissues, organs, and systems. An organ is a group of different tissues working together for a specific function.

Systems in the Body:

Different organs work together to perform important functions in the body. If even one organ doesn’t work properly, the process (like respiration) won’t be completed. A system is a group of organs that work together to do a specific job.

• The body has ten major systems, including skeletal, muscular, nervous, endocrine, cardiovascular, lymphatic, respiratory, digestive, urinary, and reproductive.
• For example, the respiratory system includes the nose, trachea, lungs, and diaphragm, all working together to help us breathe.

Respiration helps oxygen enter the blood and spread throughout the body. Digestion breaks down food, and some substances from digestion mix with the blood and act like fuel for the body. When oxygen reaches different parts of the body, it helps burn this fuel slowly, which gives the body energy. The body uses this energy to perform all its activities.

• Homeostasis is the body's way of maintaining a stable internal environment, essential for survival.
• Human life processes include organisation, metabolism, responsiveness, movement, reproduction, growth, differentiation, respiration, digestion, and excretion. These processes work together to keep the body balanced and functioning well.
• Life relies on environmental factors like water, oxygen, nutrients, heat, and pressure.