Areola tissue in the stomach is also found between the linings of the muscular coat binding them together. It gives these layers elasticity and tensile strength.
Another type of connective tissue called Adipose is also found in the skin which consists of lipid filled cells that are called adipocytes there are two types of adipose tissue, white and brown. The skin consists of whit adipose tissue. The tissue varies in thickness due to the size and amount of these cells present, so there would be more in the sole of feet and palms of the hand and less in thinner layers of the skin such as eyelids. Its helps with the skin insulation due to its lipid filled cells and stores energy.
Epithelial has four types. Compound, which is two or more layers and protects deeper structures, cuboidal which is cube shaped which material can pass through and responsible for secretion and absorption, columnar which is associated with cilia and simple which are flat, consists of one layer of cells and also allows materials to pass through it by diffusion and osmosis.
In the skin keratinised stratified epithelium is found which stems from the epidermis layer of the skin. The outer surface has dead epithelial cells which contains protein keratin. This is how the skin gets it tough; dry basically water proof surface layer which also protects the cell from lower layer drying up and rejuvenates using these layers witch is called desquamation of the keratinised cells. Columnar epithelium is also found in the sweat glands of the skin. These help with the secretion of sweat release onto the skins surface to regulate the body’s temperature. Also epithelial cells help with the healing of the skin as they proliferate across the wound through to the clot.
Columnar epithelium in the stomach secrets goblet cells which produces a thick mucus that protects the lining from the acid erosion that take place in the stomach.
Muscle tissue has three main types which are striated, which is voluntary under conscious as it forms muscle that moves bones, non- striated (smooth) which has no conscious control and cardiac which is only found in the heart wall. They all provide movement within the body as each contains muscle fibres that are able to contract and relax. It does this by receiving blood supplies which consists of adequate oxygen, calcium and nutrients.
Non-striated muscle in the skin is formed as little bundles that are attached to the hair follicles called erector muscles. With the help of this muscle contractions erects the hair and raises the skin around the hair which is also know as ‘goose bumps’. This is assisted with sympathetic nerve fibres. It also insulates and warms the skin when contractions take place as it traps more air.
Non-striated muscle is also found in the stomach and consists of three layers in its walls. These are an outer layer of longitudinal fibres, an inner layer of oblique fibres and in-between these, a middle layer of circular fibres. All three layers give the stomach a strong structure and are responsible for the churning motion of the food and releases secretions from the gastric glands.
Nerve tissue consists of cells called neurons which transmit nervous impulses around the body. In the skins dermis consists of sensory receptors that contain nerve endings which are sensitive to touch, pressure, temperature or pain. This helps the body to be aware and cope with the environmental changes as it sends nervous impulses to the brain. Some parts of the skin have more of these sensory receptors such as the lips and finger tips causing them to be more sensitive.
Gross structures of the body
The Cardio Vascular System
The cardio vascular system has several functions:-
To transport a supply of oxygen to the body, continuous blood supply and nutrient to the cells.
To export waste gasses of carbon dioxide.
The focal point of the cardio vascular system is the heart witch pumps the blood into two separate systems of blood vessels, the pulmonary circulation and the systemic circulation. These are separated by the septum. The pulmonary circulation witch is on the right side and carries deoxinated blood, is the purpose of the transport of carbon dioxide from the blood to the lungs and then exhaled out. The left side witch is the systemic circulation witch carries oxinated blood supplies the rest of the body
Respiratory System
The respiratory system has three main functions which are:-
Ventilation- Inhaling oxygen and exhaling carbon dioxide
External respiration- The exchange of gases between the lung and blood
Internal respiration- Breaking down food using oxygen and producing carbon dioxide
The lungs are the two main breathing organs which is were the gas exchange takes place. They contain bronchioles which air sacs are attached to them called alveoli. Alveoli is surrounded by capillaries which blood contains carbon dioxide that passes out through the capillary wall into the alveoli to be exhaled out.
Digestive system
The digestive system is were food pass through and gradually breaks down into simple soluble substances through digestion. They are the absorbed into the blood vessels around the digestive system and transported to the body cells for them to be used as energy and create new tissue. The main parts of the digestive system form the alimentary tract which is a long tube that stems from the mouth to the anus. Food travels down the oesophagus to the stomach which the early stages of digestion occur as it the passes through to the small intestine were the main sit of digestion takes place. Small intestine contains capillaries which most the food is absorbed. The remaining semi liquid fluid is then passed into the large intestine. This breaks down any remaining food and leaves faeces which is excreted by the body at the anus.
Renal System `
The renal system is closely linked to the urinary system and is based from the two kidneys and tubes called the ureters that run down posterior abdominal wall to the bladder. The kidney have short renal arteries and renal veins transports the blood from the kidneys into the vena cava
The renal system has many functions including renal blood flow with carries waste products It involves filtering fluids out the body by renal corpuscles consisting of glomerulus (a ball of capillaries) and a bowman’s capsule (outer layer of each renal corpuscle)..
Nervous system
The nervous system consists of the brain, spinal cord and peripheral nerves. It detects and responds the environmental changes in the body internally and external giving an immediate response. Response to Internal changes regulates involuntary aspects such as digestive activity and response to external changes maintain composure and other voluntary activities.
Parts of the nervous system
Central nervous system includes brain and spinal cord
Peripheral nervous system includes nerves out side the brain and spinal cord
Sensory division
Motor division (voluntary and involuntary)
Endocrine system
The endocrine system consists of several glands scattered throughout the body with no direct links to each other. They send chemical messages known as hormones around the body through the blood stream. These hormones influence growth and metabolism in tissues and organs concerned with slow and precise adjustments in the internal environment. Body cells exist in these environments which are water based.
The endocrine glands from top to bottom are:
Pineal body
Pituitary gland
Thyroid gland
Parathyroid glands
Thymus gland
Adrenal glands
Pancreatic glands
Ovaries (in females)
Testes (in males)
The Reproductive System
The reproductive system consists of the male and the female and produce new life by sexual reproduction. Organs associated with reproduction are called genital organs. Primary reproductive organs in women are two ovaries an in men two testes these are called gonads. Cells in the gonads secret many important hormones.
After puberty in males the seminiferous tubules in the testicles produce sperm.
During sexual intercourse the sinuses and blood vessels fill with blood and this makes the makes the penis erect and then spermatozoa is released through the penis.
After puberty in females the female sex cells (gametes) are produced regularly in the ovaries over during the premenstrual cycle
Female reproductive functions
Forming of the ova
Receiving spermatozoa
Fertilisation and development of the foetus
Child birth
Breasts development of special glands that produce milk
Male reproductive functions
Produces spermatozoa
transports spermatozoa to the female
Lymphatic system
The lymphatic system is a system of tube and lymphoid organs that take part in the recycling of body fluids and fight against disease these organs are made up of the same type of tissue call lymphatic tissue and produce lymphocytes. Lymph vessels carry the liquid lymph around the body and empty it back into the veins and the organ carry the disease fighting cells.
Lymphoid organs
Lymph nodes is organs witch is strategically places throughout the body which contain a filter system that traps bacteria and foreign bodies that have been inhaled or comes from damaged tissue. By time lymph enter the blood it has usually been cleared of foreign matter and cell debris.
The spleen is the largest lymphoid organs which store a back up supply of red and whit blood cells.
The thymus gland is found in the upper part of the chest and reaches its maximum size at puberty and the wastes away.
Tonsils are four of the lymphoid organs, pharyngeal tonsil, lingual tonsil, and two palatine tonsils.
Musculo-Skeletal System
Bones
Provides structure to the framework of the body
Gives movement to the body at joints powered by muscle attached to the
Protects vita organs in the body
Contains re blood cells in the red bon marrow
Contain minerals such as calcium and phosphate which are essential for blood calcium levels
Skeletal Muscle function
Attached to connective tissue
Creates movement with contractions
Contain elastic tissue
The muscular skeletal system is muscles and bones working together to create movement of the skeleton. The muscle is attached to the bone by tendons using series connective tissues which contain protein fibres that can b tough or even elastic (flexible). Ligaments holds together the bones of joints.
Immune system
The immune system helps protect the human body from harmful micro-organisms and rejects foreign materials. Immunity has two categories non- specific mechanisms which prevent entry and specific mechanisms which includes long term immunity against certain infection. White blood cells involved in immunity are called lymphocytes granulocytes and monocytes, witch fight against disease and infection.