لینک دانلود و خرید پایین توضیحات
فرمت فایل word و قابل ویرایش و پرینت
تعداد صفحات: 5
Human body
This article is about the human body as a whole. For components within the human body, see human anatomy.
Human body features displayed on bodies on which body hair and male facial hair has been removed
The human body is the entire structure of a human organism, and consists of a head, neck, torso, two arms and two legs. By the time the human reaches adulthood, the body consists of close to 100 trillion cells,[1] the basic unit of life. These cells are organised biologically to eventually form the whole body.
Size, type and proportion
The average height of an adult male human (in developed countries) is about 1.7–1.8 m (5'7" to 5'11") tall and the adult female about 1.6–1.7 m (5'2" to 5'7") tall.[3] This size is firstly determined by genes and secondly by diet. Body type and body composition are influenced by postnatal factors such as diet and exercise[
Constituents of the human bodyIn a normal man weighing 60 kg
Constituent
Weight [2]
Percent of atoms[2]
Oxygen
38.8 kg
25.5 %
Carbon
10.9 kg
9.5 %
Hydrogen
6.0 kg
63 %
Nitrogen
1.9 kg
1.4 %
Calcium
1.2 kg
0.3 %
Phosphorus
0.6 kg
0.2 %
Potassium
0.2 kg
0.06 %
Systems
Main article: Organ systems
The organ systems of the body include the musculoskeletal system, cardiovascular system, digestive system, endocrine system, integumentary system, urinary system, lymphatic system, immune system, respiratory system, nervous system and reproductive system.
/
Anterior (frontal) view of the opened heart. White arrows indicate normal blood flow.
Cardiovascular system
Main articles: Cardiovascular system and Human heart
The cardiovascular system comprises the heart, veins, arteries and capillaries. The primary function of the heart is to circulate the blood, and through the blood, oxygen and vital minerals are transferred to the tissues and organs that comprise the body. The left side of the main organ (left ventricle and left atrium) is responsible for pumping blood to all parts of the body, while the right side (right ventricle and right atrium) pumps only to the lungs for re-oxygenation of the blood.[4][5] The heart itself is divided into three layers called the endocardium, myocardium and epicardium, which vary in thickness and function.[6]
Digestive system
Main articles: Digestive system and Human gastrointestinal tract
The digestive system provides the body's means of processing food and transforming nutrients into energy. The digestive system consists of the - buccal cavity, esophagus, stomach, small intestine, large intestine ending in the rectum and anus. These parts together are called the alimentary canal (digestive tract).
Integumentary system
Main article: Integumentary system
The integumentary system is the largest organ system in the human body, and is responsible for protecting the body from most physical and environmental factors. The largest organ in the body, is the skin. The integument also includes appendages, primarily the sweat and sebaceous glands, hair, nails and arrectores pili (tiny muscles at the root of each hair that cause goose bumps).
Lymphatic system
Main articles: Lymphatic system and Immune system
The main function of the lymphatic system is to extract, transport and metabolise lymph, the fluid found in between cells. The lymphatic system is very similar to the circulatory system in terms of both its structure and its most basic function (to carry a body fluid).
Musculoskeletal system
Main article: Musculoskeletal system
The human musculoskeletal system consists of the human skeleton, made by bones attached to other bones with joints, and skeletal muscle attached to the skeleton by tendons.
Bones
Main articles: Human skeleton and List of bones of the human skeleton
An adult human has approximately 206 distinct bones:
Spine and vertebral column (26)
Cranium (8)
Face (14)
Hyoid bone, sternum and ribs (26)
Upper extremities (70)
Lower extremities (62)
Nervous system
Main articles: Nervous system and Human brain
The nervous system consists of cells that communicate information about an organism's surroundings and itself.
Reproductive system
Main article: Reproductive system
Human reproduction takes place as internal fertilization by sexual intercourse. During this process, the erect penis of the male is inserted into the female's vagina until the male ejaculates semen, which contains sperm, into the female's vagina.
تحقیق درمورد Human body
