What is Human Body Systems?

The human body performs various functions with the coordination of several systems. Our heart and lungs are working all the time, even when we are at rest. There is an assortment of different functions that happen inside our bodies. With the advancement of development, life forms started to display progressed attributes and highlights that empowered them to be more productive and flourish in their differentiated climate.

The human body is bipedal and has a body covered with hairs. It has mammary glands and a bunch of well-developed and advanced receptors. While talking about human body structures, we have a varied appearance and functions of each physiological system. Along with these features, we also have a specific circulatory framework that behaves as the proficient vehicle of materials and supplements inside the human body.

Categories of Human Body Systems

A brief idea of their capacities is as per the following:

The Muscular System

The muscular system consists of muscle tissues that form the solid framework of vertebrates.  Except for the cardiovascular muscles found in the heart, muscles are under the voluntary control of an individual.

Muscles cover almost every area of the human body. Each muscle has a particular name based on its location or capacity. Every muscle works and renders the human body to work regularly. For instance, when you need to play a musical instrument named woodwind, you need to pucker your lips with the assistance of facial muscles such as Orbicularis Oris (a muscle surrounding the lips).

The Digestive System

The digestive system is one of the most important systems in the human body. It helps in the breakdown of the food and edibles and obtains essential nutrients from them. 

The food we eat serves as the fuel of the body. The nutrients present in food provide essential energy for the different cells present to perform various tasks.  Before deriving nutrients from the food, it has to be broken into simpler substances.

The proteins present in our food are broken down as amino acids, starches into sugars, and fats into fatty acids and glycerol. The digestion process is carried out by various enzymes and digestive juices present in different organs of the alimentary canal and controlled by our brain.

The Integumentary System

Our skin is the largest sense organ of the body.  It ensures the protection of the internal organs of the body from the external environment. This system also controls the internal temperature level and regulates the excretion of waste materials from the body, such as sweat.

The epidermis, the outermost layer, is made up of dead keratin that helps to withstand the wear and tear of the outer environment. It also prevents direct entry of pathogens.

Furthermore, the layer that lies underneath the epidermis, i.e., the dermis, performs significant activities and also supports the epidermis. It contains various constructions, including veins, nerves, hair follicles, smooth muscle, organs, and lymphatic tissue. It plays a significant job in thermoregulation.

The hypodermis is equally important for the skin, which lies underneath the dermis. Its work is to attach the upper layers with bones and muscles and provide them with veins and nerves.

Hairs on the skin can trap a layer of heat close to the skin and thus help regulate the body's temperature. Skin also absorbs sunlight which is responsible for obtaining vitamin D.

The Skeletal System

The skeletal system upholds the body and ensures the protection of internal organs such as the heart, brain, and lungs).

The solid framework of the skeletal system gives a definite shape to the body of an individual. Also, the skeletal framework gives an appropriate appearance and development to our bodies. Without this framework, the human body could never be so particularly coordinated.

Our skeleton comprises our bones, teeth, cartilage, and joints. Humans have around 300 bones at birth, and as we grow, the small bones fused, and there are 206 bones in adults.

These bones are two major divisions: the axial skeleton that runs along the body's midline axis and 80 bones in the regions such as skull, hyoid, auditory ossicles, ribs, sternum, vertebral column. These bones protect the major internal organs of the body.

The appendicular skeleton consists of 126 bones and is part of the upper limbs, lower limbs, pelvic girdle, pectoral (shoulder) girdle. These bones help in movement.

The Circulatory System

The circulatory system consists of the heart and blood vessels. The blood carries chemicals, oxygen, and different other gases to and from all the cells in the body. The circulatory system framework is critical in supporting life. It also behaves as the main system responsible for the elimination of carbon dioxide from the body. The circulatory system supports the ideal pH of different materials, and maintenance of temperature, etc.

The four-chambered heart pumps the blood through all parts of the body.

• Veins: Veins carry the deoxygenated blood from various parts of the heart except for the pulmonary vein, which carries oxygenated blood from the lungs to the heart.
• Arteries: Arteries carry oxygenated blood from the heart to different organs except for the pulmonary artery that carries deoxygenated blood from the heart to the lungs. The strong framework of capillaries is additionally engaged with this flow of blood. 

The Respiratory System

The respiratory system consists of a network of air passages such as nostrils, bronchi, and lungs. The whole process involves the exchange of oxygen and carbon dioxide between the body and the atmosphere.

During inhalation, we breathe in oxygen, and during exhalation, we give out carbon dioxide. Moreover, the respiratory framework likewise regulates the pH of the blood and internal body temperature.

The Nervous System 

The nervous system helps to coordinate the behavior of different body parts and transmits signals between them. The sensory system is associated with nervous coordination. The nervous system is divided into two categories -

• Central nervous system (CNS) and peripheral nervous system (PNS).
• CNS includes the brain and the spinal cord. It integrates and is the control center of the entire body.
• The peripheral nervous system (PNS) consists of nerves with elongated fibers to connect CNS with other body parts.
• The peripheral nervous system consists of sensory and motor nerves.
• The autonomic nervous system is the component of PNS that controls involuntary physiological processes such as heart rate, respiration, digestion, etc.

The Lymphatic System

It consists of a network of tissue, vessels, and different organs that helps to move colorless lymph back to the circulatory system. It maintains the fluid level in the body, absorbs fat from the digestive tract, and protects the body against unfamiliar invaders.

The Endocrine System

The endocrine system consists of various glands that secrete chemical substances called hormones to maintain coordination among different body parts and functions.

The secreted hormones are directly poured into the blood vessels and reach the target tissues to carry out the specific work. For instance: When the sugar level in the blood drops, the endocrine portion of the pancreas discharges glucagon that attempts to build glucose in the blood.

Endocrine and sensory systems cooperate and help other organ systems to perform efficiently.

The Excretory System

The excretory system consists of a pair of kidneys and urinary bladder, and urethra. It helps in the discharge and removal of the waste product from the body.

Kidneys control the amount of water removed from the body and also regulate the number of electrolytes present in the body. It also helps maintain the blood's normal pH and a stable inner climate (homeostasis) for ideal cell and tissue performance. 

The Reproductive System

The reproductive system is responsible for the continuation of species. This system is responsible for producing eggs or sperm cells, transportation of sperm cells, nurturing offspring in the uterus, and producing reproductive hormones. The reproductive organs are different in males and females.

 Female Reproductive System

The organs of a female reproductive system are the uterus, ovaries, oviducts, or fallopian tubes. Ovaries produce female gametes. The baby develops in the uterus. The cervix is the entry canal to the uterus. The vagina is the opening of the uterus.

 Male Reproductive System

The male reproductive framework comprises paired testes and the penis. Testes are responsible for producing and storage facilities for sperms, the male gamete. These oval-shaped organs are pocketed in the scrotum.

Context and Application

This topic is significant in the professional exams for both undergraduate and graduate courses, especially for

• Bachelors in human anatomy and physiology.
• Masters in human anatomy and physiology.
• Medical courses (Masters and Bachelors)

Related Concepts

• The digestive system
• The respiratory system
• The skeletal system
• The cardiovascular system