- Just as it takes many specialized cels to create a tissue and several different tissues to build an organ, it takes the inter gration of several organs into organ systems to carry out the major body functions.

- there are 12 major organ systems in our body
1. Digestive system
2. Respiratory system
3. Circulatory system
4. Immune system
5. Lymphatic system
6. Excretory system
7. Endocrine system
8. Nervous system
9. Integumentary system
10. Skeletal system
11. Muscular system
12. Reproductive system


1. Digestive system- Ingests and breaks down food into smaller chemical units to be used as fuel for cellular respiration; eliminates undigested material.

-Digestive system consist mouth, esophagus, liver, stomach, small and large intestines, and anus.

Mouth- a cavity in the head containing the teeth for mastication, and the tongue, palate etc.
Esophagus- the tube through which food passes from the mouth to the stomach.
Liver- a large, vascular, glandular organ of vertebrates that plays an importants role in
digestion, that converts carbohydrates to glycogen, which it then stores, and elaborates
many important substances.
stomach- an enlarged portion of the alimentary canal of a vertebrates between the
rhythymically, thoroughly grinding and mixing food.
small intestine- the narrow upper partof the intestines lined with a glandular mucos
menbrane which secretes enzymes responsible for the digestion of food and through
which digested nutrients pass into the blood and lymph.
large intestine- the posterior division of the vertebrate intestine, divided into the cecum,
colon, and rectum, serving esp. to extract moisture from the undigested remnants
of food and to store them until they may be expelled as feces.
anus- the opening at the lower end of the alimentary canal, through which the solid refuse of
digestion is excreted.


2. Respiratory system- Exchanges gases with the environment; supplies the blood with oxygen (O2) and disposes carbon dioxide (CO2).

-Respiratory system consist of nasal cavity, larynx,trachea, bronchus and lungs

nasal cavity- either of the two cavities lying between the floor of the cranium and the roof of
the mouth and extending from the face to the pharynx.
larynx- an organ of the respiratory tract of air-breathing vertebrates situated above the wind
pipe.
trachea- a tube through which air passes to and from the lungs, extending from the larynx to
the lungs.
bronchus- either of the two main divisions of the trachea leading directly into the lungs, where
they ramify.
lung- one of the pair of spongy saclike organs that oxygenate the blood in air-breathing
vertebrates and remove carbon dioxide from it.



3. Circulatory system- delivers nutrients and O2 to body cells, carries CO2 to the lungs and metabollic wastes to the extretory organs, the kidneys.

-Circulatory system consist of heart, blood vessels

heart- the hollow muscular organ which, by rhythmical contraction and expansion, forces the
blood through the circulatory system of vertebrates.
blood vessel- a tube or canal in an animal through which blood circulates, e.g. an artery, vein
capillary.


4.Immune system- Defends the body against infections and cancer
5. Lymphatic system- Returs fluid that leaks from blood vessels to circulatory system; functions
as a part of the immune system.

-Lymphatic system consist of bone marrow, thymus, spleen, lymph nodes, lymph vessels


bone marrow- a soft tissue filling up the cavities in most bones, where many cells of the blood
are manufactured.
thymus- a ductless glandular structure of undetermined function behind the breastbone,
which degenerates with the onset of puberty.
spleen- a soft fleshy organ in the upper left abdomen, chiefly concerned with the formation
and purification of blood.
lymph nodes- a lymph gland
lymph vessel- a container for fluids.
- a tube or canal through which a fluid can pass
- a continuous tube formed by the superposition of numerous specially adapted
tracheids, that serves in water conduction.




6. Excretory system- Removes nitrogen containing waste products from the blood; regulates the chemicals make up and water balance of the blood.

-excretory system consist of kidney, ureter, urinary bladder, urethra

kidney- one of a pair of abdominal organs in all vertebrates
- they filter impurities from the blood and excrete them as urine.
- they also help to maintain the acidity and other important chemical characteristics
of the blood at a constant level.
ureter- one of the paired ducts which convey urine from the kidneys tothe bladder in man
or other mammals or from the cloaca in lower vertebrates.
urinary bladder- a membranous sac filled with fluid or air, esp. the musculo membranous
receptacle for urine.
- any hollow bag that can be inflated.
urethra- the canal which in most mammals discharges urine from the bladder, and in the male
serves also as the genital duct.


7. Endocrine system- secrets chemicals called hormones, that regulate body activities such as digestion, metabolism, growth, reproduction, heart rate, and water balance.

- Endocrine system consist of pituitary gland, thyroid gland, thymus, adrenal gland, pancrease,
testis (male) ovary (female).

pituitary gland- a small vascular endocrine gland located at the base of the brain and found in
most vertebrates.
- it consist of an anterior and posterior lobe.
- the posterior lobe secretes hormones affecting renal functions, contraction of
smooth muscle and reproduction.
- the anterior lobe secretes hormones which control and regulate most of the other
endocrine glands.
thyroid gland- an endocrine gland of many vertebrates in the pharyngeal area secreting
thyroxine, which principally increases the rate of oxidative reactions in metabolism,
thus greatly enfluencing growth and development.
thymus- a ductless glandular structure of undetermined function behind the breastbone,which
degenerates with the onset of puberty.
adrenal glands- either of a pair of endocrine glands situated near the kidney and consisting of
an inner fatty cortex and an outer vascular portion (the medulla).
pancrease- a large gland that in man lies behind the stomach.
- it consists of two portions, one secreting digestive juices which pass into the
duodenum, the othe secreting insulin which passes into the blood stream.
testis- a testicle (male)
ovary- one of a pair of female reproductive organs that produce eggs and female sex hormones
(estrogen).


8. Nervous system- Coordinates body activities by detecting stimuli, integrating information and directing the body's responses.

- Nervous system consist of brain, sense organ, spinal cord and nerves.

brain- that part of the central nervous system within cranium that is the organ of thought,
memory and emotion.
- it contains all the higher centers for various sensory impulses, and it initiates, controls and coordinates muscular movements.
sense organ- an organ, e.g. the eye, ear, etc., adapted to recieve stimuli.
spinal cord- the dorsal cord of neutral tissue continuous with the medulla oblongata that lies
within the spinal canal in vertebrates.
nerves- any of the cordlike fibers or bundles of fibers of neural tissue that connect the nervous system with other organs of the body for the purpose of conducting nervous impulses to or away from these organs.



9. Integumentary system- Protect against mechanical injury, infection, excessive heat or cold,
and drying out.

-Integumentary system consist of hair, skin, nails.

hair- a threadlike tube of horny, fibrous substance with a core cotaining pidment cells, rooted in the skin and growing freely outwards, kept pliable by oil from glands in the skin, tending to lose its pigmentation with age or(where protective coloring of animals is concerned) in regions of ice or snow, or because of disease.
skin- the membrane,of complex stucture, which forms the outer covering of a human or animal body, or one of the layers of which it is composed epidermis, dermis.
nails- the hard thin covering of the upper surface of the ends of the fingers or toes of men and animals.


10. Skeletal system- Supports the body; protects certain internal organs, such as the bain and lungs; provides the frame work for muscles to produce movement.

-Skeletal system consist of cartilage and bones

cartilage- a very tough,translucent,bluish-white elastic tissue, found in connection with bones in vertebrates.
bones- is a hard parts of the skeleton of a vertebrate animal.
- bone is a hard living tissue which forms the frame work of the body.
- it is also serves to protect such orhans as the brain, heart, and lungs.


11. Muscular system- Skeletal muscles produce movement, maintain posture, and produces heat.

-Muscular system consist of skeletal muscles.

skeletal muscle- a muscle attached to the skeleton.


12. Reproductive system- Produce gametes and sex hormones, female system provides organs to support a developing embryo and gland for producing milk.

-Male Reproductive system consist of prostate gland, vas deferens, urethra, penis and testis.

prostate gland- the partially muscular gland at the neck of the bladder sorrounding the beginning of the urethra in male mammals.
vas deferens- the duct that carries sperm from the testicle to the ejaculatory duct of the penis.
urethra- the canal which in most mammals discharges urine from the bladder, and in the male serves also as the genital duct.
penis- the male organ of copulation in mammals.
testis- a testicle.
- Female Reproductive system consist of oviduct, ovary, uterus, vagina.

oviduct-a tube carrying egg (ova) from the ovary to the exterior and often processing modefied regions. e.g. the uterus or a region where a shell is produced by specialized secreations.
ovary- one of a pair of female reproductive organs that produce eggs and female sex hormones
(estrogen).
uterus- the organ in female mammals in which the embryo (fetus) develops and nourished before birth.
vagina- a sheath or sheatlike tube, esp. the canal leading from the uterus to the vulva in female mammals.