Anatomy of the human body is the study of the structure of the human body. The anatomy of the human body is composed of cells, tissues, organs and organ systems. Organ systems are the parts that make up the human body. This system consists of various types of organs, which have specific structures and functions. Organ systems have distinct structures and functions. Each organ system is interdependent, either directly or indirectly.
1. Sceleton System
The human body is supported by the skeletal system, which is made up of 206 bones connected by tendons, ligaments and cartilage. This bone is composed by the axial skeleton and the appendicular skeleton. The axial skeleton consists of 80 bones which are located along the axis of the human body. The axial skeleton includes the skull, middle ear bones, hyoid bone, ribs, and vertebrae.
The appendicular skeleton consists of 126 bones which are appendages that connect the axial skeleton. The appendicular skeleton is located in the upper leg, lower leg, hip and shoulder area. The function of the skeletal system is to move, support and shape the body, protect internal organs, and act as a place for muscles to attach.
The human skeletal system is a collection of bones that are interconnected with each other to form a locomotion system. In the locomotion system, the skeleton cannot move on its own, but instead works together with the muscles. The cooperation between the two is known as the musculoskeletal system. Muscles with the help of joints and other supporting structures (ligaments, tendons, fascia and bursae) allow the bones of the skeleton to move.
The human skeleton is made up of single or composite bones (such as the skull) that are supported by other structures such as ligaments, tendons, muscles, and other organs. The average adult human has 206 bones, although this number can vary between individuals. The 206 bones have different structures and functions.
The human skeleton has many functions, including:
- Gives body shape;
- Protects organs and soft body parts/tissues;
- Upright body;
- Place of attachment of skeletal muscles;
- passive motion apparatus;
- Place of production of red blood cells (hematopoiesis); And
- Reserves for calcium and phosphate.
2. Muscular System
The muscular system consists of about 650 muscles that help with movement, blood flow, and other bodily functions. There are three types of muscles namely skeletal muscles which are connected to bones, smooth muscles which are found within the digestive organs, and cardiac muscles which are found in the heart and help pump blood.
a. Skeletal/Striated Muscles
Skeletal muscles are muscles attached to the skeleton. The fleshy parts of our body are the skeletal muscles. This muscle is also called striated muscle, because when viewed from the side, these muscle fibers show a transverse or striped fiber pattern.
Cross section of this muscle shows thousands of muscle fibers. The fibers are arranged in parallel bundles, and are held together by connective tissue through which blood vessels and nerves pass. The diameter of this muscle is 50 microns with a length of 2.5 cm.
Skeletal muscle contractions are fast, forceful and conscious. Each muscle fiber is covered by an endomysium, a collection of fiber bundles is wrapped by the fascia propia/perimisium, while the muscles (flesh) are covered by the superficial fascia/epimisium. The endomysium, perimysium, and epimysium join to form the tendons that attach muscles to bones.
b. Smooth muscle
Smooth muscle cells have an elongated shape with both ends pointed and the nucleus is located in the center of the muscle cell. Myofibril fibers in smooth muscle are homogeneous and smaller than striated muscle fibers. Smooth muscle is found in the walls of blood vessels, walls of the digestive tract, lungs and ovaries. This muscle is slow to react in receiving stimulation, but is resistant to fatigue, and works under the influence of unconscious nerves.
c. Cardiac muscle
Cardiac muscle is found only in the walls of the heart. The structure of cardiac muscle resembles that of striated muscle, but the nucleus is located in the center of the cell and is branched. Each branch of the cardiac muscle has a connective tissue called the intercalated disc. Cardiac muscle works under the influence of unconscious nerves, reacts quickly to stimuli, and is resistant to fatigue.
3. Circulatory System
The circulatory system consists of the heart, blood vessels, and about 5 liters of blood carried by the blood vessels. The circulatory system is supported by the heart, which is only the size of a closed fist. Even at rest, the average heart easily pumps more than 5 liters of blood around the body every minute.
The circulatory system has three main functions:
- Circulates blood throughout the body. Blood provides essential nutrients and oxygen and removes waste and carbon dioxide to be removed from the body. Hormones are transported throughout the body via blood plasma fluids.
- Protects the body through white blood cells by fighting pathogens (germs) that have entered the body. Platelets function to stop bleeding during wounds and prevent pathogens from entering the body. Blood also carries antibodies that provide specific immunity to pathogens that the body has previously been exposed to or been vaccinated against.
- Maintaining homeostasis (balance of body conditions) in several internal conditions. Blood vessels help maintain a stable body temperature by controlling blood flow to the surface of the skin.
There are two types of circulatory systems: open circulatory systems, and closed circulatory systems. the circulatory system, which is also part of the performance of the heart and blood vessel network (cardiovascular system) is formed. This system ensures the survival of organisms, is supported by the metabolism of every cell in the body and maintains the chemical and physiological properties of body fluids.
First, blood carries oxygen from the lungs to the cells and carbon dioxide in the opposite direction. Second, what is transported are nutrients derived from digestion such as fat, sugar and protein from the digestive tract in the respective tissues to consume, according to their needs, processed or stored.
The resulting metabolites or waste products such as urea or uric acid are then transported to other tissues or excretory organs of the kidney and colon. It also distributes blood like hormones, immune cells and parts of the clotting system in the body.
4. Digestive System
The digestive system is a group of organs that work to receive food, convert and process food into energy, absorb nutrients contained in food into the bloodstream, and dispose of food scraps that are left or cannot be digested by the body.
Food passes through the digestive tract which consists of the oral cavity, pharynx (throat), larynx (oesophagus), stomach, small intestine, large intestine, and ends at the anus. Apart from the digestive tract, there are several important accessory organs in the anatomy of the human body that help digest food. The accessory organs of the digestive system include the teeth, tongue, salivary glands, liver, gallbladder, and pancreas.
5. Endocrine System
The endocrine system consists of several glands that secrete hormones into the blood. These glands include the hypothalamus, pituitary gland, pineal gland, thyroid gland, parathyroid glands, adrenal glands, pancreas, and gonads. The glands are controlled directly by stimuli from the nervous system as well as by chemical receptors in the blood and hormones produced by other glands.
By regulating the function of organs in the body, these glands help maintain the body’s homeostasis. Cellular metabolism, reproduction, sexual development, sugar and mineral homeostasis, heart rate, and digestion are among the many processes regulated by hormones.
6. Nervous System
The nervous system consists of the brain, spinal cord, sensory organs, and all the nerves that connect these organs to the rest of the body. These organs are responsible for the control of the body and the communication between its parts.
The brain and spinal cord form a control center known as the central nervous system. The sensory nerves and sense organs of the peripheral nervous system monitor conditions inside and outside the body and transmit information to the central nervous system. Efferent nerves in the peripheral nervous system carry signals from control centers to muscles, glands, and organs to regulate their function.
7. Respiratory System
The cells of the human body need oxygen flow to stay alive. The respiratory system provides oxygen to the body’s cells while expelling carbon dioxide and waste products that can be lethal if allowed to accumulate. There are three main parts of the respiratory system: the airways, the lungs, and the muscles of respiration.
The airways include the nose, mouth, pharynx, larynx, trachea, bronchi and bronchioles. This tube carries air through the nose to the lungs. The lungs function as the main organs of the respiratory system by exchanging oxygen into the body and carbon dioxide out of the body. Respiratory muscles, including the diaphragm and intercostal muscles, work together to pump, pushing air in and out of the lungs during breathing.
8. Immune System
The immune system is the body’s defense against bacteria, viruses, and other potentially harmful pathogens, by defending against and attacking these pathogens. These include lymph nodes, spleen, bone marrow, lymphocytes (including B cells and T cells), thymus, and leukocytes, which are white blood cells.
9. Lymphatic System
In human anatomy, the lymphatic system includes lymph nodes, lymph ducts, and lymph vessels, and also plays a role in the body’s defense. Its main job is to make and move lymph, a clear fluid that contains white blood cells, which help the body fight infection. The lymphatic system also removes excess lymph fluid from body tissues, and returns it to the blood.
10. Excretion and Urinary System
The excretory system removes residual substances that are no longer needed by humans. In the anatomy of the human body, the excretory organs consist of the kidneys, liver, skin, and lungs. The urinary or urinary system is included in the excretory system which consists of the kidneys, ureters, bladder and urethra.
Kidneys filter blood to remove waste and produce urine. The ureters, bladder, and urethra together form the urinary tract, which functions as a system for carrying urine from the kidneys, storing it, and then releasing it during urination.
In addition to filtering and eliminating waste from the body, the urinary system also maintains homeostasis of water, ions, pH, blood pressure, calcium, and red blood cells. The liver functions to secrete bile, the skin functions to secrete sweat, while the lungs function to remove water vapor and carbon dioxide.
11. Reproductive System
The reproductive system allows humans to reproduce. The male reproductive system includes the penis and testicles, which produce sperm. The female reproductive system consists of the vagina, uterus and ovaries, which produce ova (egg cells).
During fertilization, the sperm cell meets the egg in the fallopian tube. The two cells then carry out fertilization which is implanted and grows in the uterine wall. If not fertilized, the lining of the uterus which has thickened to prepare for pregnancy will shed into menstruation.
12. Integumentary System
The skin or integumentary system is the largest organ in the anatomy of the human body. This system protects against the outside world, and is the body’s first line of defense against bacteria, viruses and other pathogens. The skin also helps regulate body temperature and removes waste products through sweat. In addition to skin, the integumentary system includes hair and nails.