Forensic Science: Everything You Need to Know

The human body system consists of many different organs, body parts, and systems. The organs are the kidneys, liver, heart, lungs, large and small intestines, esophagus, stomach, rectum and anus, vagina and vulva, penis, urethra, and skin. The body parts are the bones, legs, arms, hands, feet, fingers, toes, head, eyes, pelvis, lips, and nose. The systems are circulatory, respiratory, digestive, reproductive, excretory, endocrine, nervous, muscular, and skeletal.

The kidneys remove waste and excess fluid, as well as acid from cells in order to maintain water, salt, and minerals. Those minerals are sodium, calcium, phosphorus, and potassium.

The liver breaks down nutrients and metabolizes drugs into forms that are easier t use for the rest of the body and are nontoxic.

The heart pumps blood throughout the body and exchanges oxygen and carbon dioxide.

The lungs take in oxygen and release carbon dioxide through respiration. The oxygen-carbon dioxide exchange.

The large intestine converts food waste into feces and passes it through to the anus for excretion as poop.

The small intestine digests food from the stomach, and absorbs nutrients such as, vitamins, minerals, carbohydrates, fats and proteins. It absorbs water from food to be used by the body.

The esophagus allows air and food to travel their separate ways through the body. There is a flap called the epiglottis that flips one way for air, and another way for food.

The stomach acidifies and breaks down food, and pases it along to the small intestine.

The rectum (internal) and anus (external) expel the poop from the body as solid waste.

The vagina (internal) and vulva (external) are used for the penis to enter during vaginal sex and as a passageway for the fetus to pass through when being born.

The penis is a male sex organ used for sexual intercourse, expulsion of semen and sperm, and expulsion of pee as liquid waste.

The urethra expels pee from the body as liquid waste.

The skin protects the body from damage and is the largest organ of the body. It can also be damage from things such as sun damage from too much UV exposure.

The circulatory system involves the heart, lungs, arteries, and veins. This system delivers oxygen and takes away wastes. The upper right chamber is the atrium and it takes in deoxygenated blood and travels to the lower right chamber, called the vertical. The blood then travels through the arteries to the lungs. The lungs exchange the carbon dioxide for oxygen, and the carbon dioxide is expelled. The oxygenated blood travels back through to the left upper chamber of the heart, called the atrium, and pumped to the lower left chamber, the ventricle, and into a artery called the aorta. After this, the blood travels all around the body.

The respiratory system involves the nose, mouth, pharynx (throat), larynx (voice box), trachea (windpipe), bronchi (large airway), bronchioles (small airway), and lungs. Air is brought in through the nose and mouth, travels through the pharynx, larynx, trachea, bronchi, bronchioles, and lungs as oxygen, and pushed out through the same path in reverse as carbon dioxide in the oxygen-carbon dioxide exchange known as respiration, or breathing.

The digestive system involves the mouth, esophagus, stomach, small intestine, large intestine, rectum, and anus. The food enters the mouth, travels down the esophagus, and to the stomach. The food is acidified and broken down. The food then travels to the small intestine for further decomposing, and to the large intestine to be turned to solid waste, otherwise known as poop. The waste travels to the rectum for a pit stop until the person goes to the bathroom, and excretes the poop through their anus.

The reproductive system involves the ovaries, fallopian tubes, uterus, cervix, and vagina for females. The male reproductive system involves the prostate, testes, and penis.

The ovaries release an egg, also know as an ovum, to the fallopian tube. Sometimes there can be an egg in both tubes, or one in one tube, and then later have another in the other tube after fertilization. The sperm is ejaculated from the penis, along with semen. The sperm race to the egg, and one sperm fertilizes the egg. The egg then travels down the fallopian tube while dividing and growing and settles in the uterus.

During this travel, the cervix seals itself with a mucus plug. The vagina allows for the fetus to pass through and be born as a male or female baby.

The prostate supply fluid for nourishment and transport of the sperm. The testes produce sperm and testosterone. The penis expels urine and semen. The semen has sperm, which is needed for the fertilization of the egg.

The excretory system involves the kidneys, ureters, unrinary bladder, and urethra. The kidney take waste and excess fluid, and send them to the ureters. The ureters acts as a transport station for the waste and fluid to arrive at the bladder. This is the holding station until a person goes to the bathroom to excrete the liquid waste as pee through the urethra.

The endocrine system involves the pituitary gland, pineal gland, hypothalamus, thymus, pancreas, thyroid, adrenal glands, ovaries in females, and testes in males. This system regulates functions in the body, such as growth and development of the brain, and nervous system, as well as growth and function of the reproductive system. This system is also responsible for metabolism and blood sugar levels.

The nervous system involves the central nervous system and the peripheral nervous system. The central nervous system involves the brain and spinal cord. The peripheral nervous system involves the nerves from the spinal cord and body, which make up the autonomic nervous system and the somatic nervous system.

The autonomic system involves processes such as the beating of our heart, and the processing of information in our brain. The somatic system involves processes such as moving our limbs and head, and the breathing process. The autonomic nervous system branches out to the sympathetic and parasympathetic nervous systems.

The sympathetic system involves arousing, or exciting things, such as running from an escaped tiger coming into a room, and the parasympathetic system involves calming, or relaxing things, such as meditating.

The somatic nervous system branches out to the sensory input and motor output nervous systems. The sensory input system takes in sensory processes such as touching a hot stove. This information is sent to the brain, processed as heat, and therefore something to be stopped, and sends a signal to the motor output system to remove the hand from the hand stove, because the stove is burning the hand. This causes the person realize they touched something hot and burned themselves, which causes them to yank their hand away from the stove.

The muscular system involves the skeletal, smooth, and cardiac muscles that allow movement, retraction, and contraction of the body and its parts, this allowing mobility, heart pumping, excretion, and even movement of the fetus when being born.

The skeletal system involves 206 bones. The main bones that are learned are the cranium, vertebral column, or vertebrae, scapula, clavicle, sternum, ribs, humerus, radius, ulna, carpals, metacarpals, phalanges, for fingers and toes, pelvis, femur, patella, tibia, fibula, tarsals, and metatarsals. The vertebral column consists of seven cervical bones, twelve thoracic bones, five lumbar bones, 5 sacral bones, and 5 fused coccygeal bones.