Human body system

Cardio vascular system consists of the heart and blood vessels in the blood vessels 5 litres of blood is transported. The cardiovascular system is responsible for transporting oxygen, nutrients, hormones and cellular waste products throughout the body. The heart is the hardest working organ in the cardiovascular system. The heart

The heart is muscular pumping organ located medial to the lungs, at the bottom tip of the heart is known as the apex this turns to the left so that about 2/3 of the heart is located on the body’s left side with 1/3 on the right. The top of the heart is known as the heart base is connected to many blood vessels in the body such as the aorta, vena cava, pulmonary trunk, and pulmonary veins. Circulatory loops

There are two main circulatory loops in the human body: the pulmonary circulation loop and the systemic circulation loop. The pulmonary circulation loop- in this loop deoxygenated blood is transported from the right side of the heart to the lungs, where the blood picks up oxygen and returns to the left side of the heart. In the pulmonary circulation loop there is a pumping chamber of the heart that supports the right atrium and right ventricle. Systemic circulation loop- this is where oxygenated blood is carried from the left side of the heart to all the other tissues of the body. The job of the systemic circulation loop is to remove waste from the body tissues and return deoxygenated blood to the right side of the heart. The left atrium and left ventricle of the heart are the pumping chambers for the systemic circulation loop. Blood vessels

This is where blood flows quickly and efficiently from the heart to every other region of the body and back again. The amount of blood flowing depends on the size of the blood vessel. Inside the blood vessels contain a hollow area called lumen which helps blood flow quickly. Around the lumen is a wall of vessels, which may be thin in case of capillaries or very thick in case of arteries. All blood vessels are lined with a thin layer of simple
squamous epithelium which is also known as endothelium, this keeps the blood cells inside of the blood vessels and prevents clot from forming the endothelium lines the circulatory system, all the way from interior of the heart, where it is called the endocardium. There are 3 major types of blood vessels: arteries, capillaries, and veins. Arteries and arterioles- arteries are blood vessels that carry blood away from the heart this type of that is carried is usually highly oxygenated. In the arteries the blood that is carried is pushed from the heart under great force, here we see high levels of blood pressure. To stop the pressure from building up walls of the arteries are thick and more elastic and more muscular than those of other vessels.

Respiratory system

The respiratory system is divided into two parts the upper and lower respiratory tracts. Respiratory system shows the way we breathe; breathing is the process that brings oxygen in the air into your lungs and moves oxygen and through your body. Our lungs remove the oxygen and pass it through our bloodstream, where it’s carried off to the tissues and organs that allow us to walk, talk, and move. Our lungs also take carbon dioxide from our blood and release it into the air when we breathe out. The parts of the upper respiratory tract

Mouth, nose and nasal cavity: The function of this part of the system is to warm, filter and moistens the incoming air. The sinuses are hollow spaces in the bones of your head. Small openings connect them to the nasal cavity. The sinuses help to regulate the temperature and humidity of air your breathe in, as well as to lighten the bone structure of the head and to give tone to your voice. We also have the nasal cavity (nose) is the best entrance for outside air into your respiratory system. The hairs that line the inside wall are part of the air-cleansing system. Air can also enter through your oral cavity (mouth), especially if you have a mouth-breathing habit or your nasal passages may be temporarily blocked. Pharynx: this is where the throat divides into the trachea (wind pipe) and oesophagus (food pipe). There is also a small flap of cartilage called the epiglottis which prevents
food from entering the trachea Larynx: This is also known as the voice box as it is where sound is generated. It also helps protect the trachea by producing a strong cough reflex if any solid objects pass the epiglottis. Trachea: also known as the windpipe this is where air gets carried out from a tube to the throat to the lungs. It ranges from 20-25mm in diameter and 10-16cm in length. The inner membrane of the trachea is covered in tiny hairs called cilia, which catch particles of dust which we can then remove through coughing. The trachea is surrounded by 15-20 C-shaped rings of cartilage at the front and side which help protect the trachea and keep it open. They are not complete circles due to the position of the oesophagus immediately behind the trachea and the need for the trachea to partially collapse to allow the expansion of the oesophagus when swallowing large pieces of food. Bronchi: The trachea divides into two tubes called bronchi, one entering the left and one entering the right lung. The left bronchus is narrower, longer and more horizontal than the right. Irregular rings of cartilage surround the bronchi, where the walls also consist of smooth muscles. Once inside the lung the bronchi split several ways, forming tertiary bronchi.

Bronchioles: Tertiary bronchi continues to divide and become bronchioles, very narrow tubes, less than 1 millimetre in diameter. There is no cartilage within the bronchioles and they lead to alveolar sacs. Alveoli: Individual hollow cavities contained within alveolar sacs (or ducts). Alveoli have very thin walls which permit the exchange of gases Oxygen and Carbon Dioxide. They are surrounded by a network of capillaries, into which the inspired gases pass. There are approximately 3 million alveoli within an average adult lung. Diaphragm: The diaphragm is a broad band of muscle which sits underneath the lungs, attaching to the lower ribs. Reference

http://www.brianmac.co.uk/physiolr.htm
Digestive system
Why digestion is important?
Digestion is important in order for nutrients to break down food in our body; it uses energy for growth and cell repair. Food and drinks must be broken down into smaller molecules of nutrients before the blood can absorb them
and carry them into the cells throughout the body. The body breaks down the food and drinks into carbohydrates, protein, fats, and vitamins. Carbohydrates- sugar, starch, and fibre are found in our food. Carbohydrates are called simple or complex depending on their chemical structure. Simple carbohydrates include sugars found naturally in foods such as fruits, vegetables, milk, and milk product, as well as sugars added during food processing. Complex carbohydrates are things such as cereal, starchy vegetables and legumes; they contain starch and fibre found in whole- grain bread. Protein- proteins are digested in the stomach and small intestine. Protease enzymes break down protein into amino acids, the stomach helps protein digest by having stomach acids which kill harmful micro-organisms that may be in the food. Fats – lipase enzymes breaks down fat into fatty acids and glycerol. Bile is made in the liver and digestion of fat in small intestine is helped by bile. Bile breaks the fat into small droplets that are easier for the lipase enzymes to work on. Things that don’t digest are things such as minerals, vitamins, and water. They are already too small to be absorbed by the body without being broken down, so they cannot be digested. Digestive system cannot break down fibre, which is why it cannot be absorbed by the body. Digestion begins in the mouth with chewing and ends up in the small intestine. As food passes down the esophagus this is a muscular tube that carries food and liquid from the mouth to the stomach. Saliva is mixed with the food in the salivary gland this is where the food is moisten so its moves more easily through the esophagus into the stomach. The saliva also contains enzymes that begin to break down the starch from our food. When the food reaches the stomach it mixes with digestive juices. The body also uses saliva to lubricate food as it passes through the mouth, pharynx, and esophagus. The pharynx is a funnel – shaped tube that is connected to the posterior end of the mouth to the esophagus . The role of the pharynx is to play an important part in the respiratory system as the air from the nasal cavity passes through the pharynx. Because the pharynx serves two different functions, it contains a flap of tissue known as the epiglottis that act as a switch to route the food, where the esophagus and air to the larynx. As the food gets swallowed it becomes involuntary and proceeds under the control of the esophagus and brain. The lower esophageal is a type of muscle at the espohagus and stomach, which
controls the passage of food and liquid between the esophagus and stomach. Saliva is mixed with the food in the salivary gland this is where the food is moisten so its moves more easily through the esophagus into the stomach. The saliva also contains enzymes that begin to break down the starch from our food. When the food reaches the stomach it mixes with digestive juices. The stomach contains muscles the role of the stomach is to churn and mix the food into smaller pieces, the digestive glands in the stomach lining produces stomach acids and enzymes which mix with the food to form a murky semi fluid or a paste called chime. The food normally stays in the stomach for 2 hours. After leaving the stomach the food gets taken into the small intestine. The small intestine is 20-25 foot tube that breaks down enzymes released by the pancreas and bile in the liver. In the small intestine in the liver. In the small intestine the duodenum is largely responsible for breaking down continuously with the jejunum and ileum; these are mainly there for absorbing nutrients into the bloodstream. Liver and gall bladder

The liver has a very rough surface it’s a triangular organ of the digestive system located to the right of the stomach. The liver weighs about 3 pounds and it is the second largest organ in the body. The liver performs many functions in the body, but the main function of the liver is the digestion of the production of bile and its secretion into the small intestine. The gall bladder is a small pear shaped organ located just posterior to the liver. The gall bladder is used to recycle and store excess bile from the small intestine. Pancreas

The pancreas is a large gland that is located near the stomach. Its 6 inches long – the pancreas secretes digestive enzymes into the small intestine to complete the chemical digestion of foods. Large intestine

The large intestine is very thick and long, its 2 ½ inches in diameter and about 5 feet long. The job of the large intestine is to absorb lots of water and contain many symbiotic bacteria that help break down wastes to extract small amount of nutrients. After the food goes sin the large intestine, the food turns into faces where it’s taken out of our body through the anal canal. References

http://www.hsamuel.co.uk/webstore/watches/ladiesWatches.cdo
http://www.livescience.com/22367-digestive-system.html
Nervous system
The nervous system of the body is made up of many different organs, such as the brain, spinal cord and etc. This highly complex system is responsible for several different activities, such as communicating, coordinating, and controlling and regulating. Nervous system is spilt up into two major parts: the central nervous system (CNS) and the peripheral nervous system (PNS). The role of the (CNS) central nervous system is the primary control centre for the body and is composed of the brain and spinal cord. The (PNS) peripheral nervous system contains a network of nerves that connects the rest of the body to the CNS.

Peripheral nervous system is under a voluntary control, this is where the nerves that carry instructions from your brain to your limbs. As well as controlling your muscles and joints, it sends all the information from your senses back to your brain. Other parts of the PNS are responsible for controlling the brain automatically. This is called the autonomic nervous system; this is when it manages some things in the body such as digestion and temperature control. The two systems both work in collecting information from inside the body and from the environment outside it. Parts of the nervous system

Neurons are cells that make up the nervous system, they are also known as nerves cells. Their job is to communicate within the body by transmitting electro chemical signals. Neurons are very different to other parts of the nervous system; this is due to many long cellular processes that extend from the central cell body. The cell body is a rough round part of the neuron that contains the nucleus, mitochondria, and most of all the cellular organelles. The dendrites extend from the cell to pick up any stimuli from the environment. Long transmitting processes called the axons extend from the cell body to send signals onward to other neurons or effectors cells in the body. There are 3 basic classes of neurons: afferent neuron, efferent neuron, and interneuron’s 1. Afferent neuron: