Chapter 4 : Organs and Organ System
Organs are the next level of organization in the body.
An organ is a structure that contains at least two different types of tissue functioning together for a common purpose.
There are many different organs in the body: the liver, kidneys, heart, even your skin is an organ.
In fact, the skin is the largest organ in the human body and provides us with an excellent example for explanation purposes.
Organ systems are composed of two or more different organs that work together to provide a common function.
There are 10 major organ systems in the human body, they are:
Topics covered in this snack-sized chapter:
The integumentary system is the organ system that protects the body from various kinds of damage, such as loss of water or abrasion from outside.
This function protects underlying tissues from injury
Prevents excessive loss or absorption of water and the consequent effect on tissues
Aid excretion and absorption of specific metabolites and ions
Almost all sense organs are derived in part from the integument
The skeletal system provides the framework and support for our bodies' muscles, tissues, nerves and skin. It also protects vital organs, allows movement, stores minerals and, through marrow, produces blood cells.
Provide a framework for all body systems
Provide attachments for muscles, tendons, and fascia
Enclose and protect vital organs
Serve as a reserve storehouse for minerals
The muscular system is an organ system consisting of skeletal, smooth and cardiac muscles.
Movement of body and parts
Maintenance of posture
Internal transport and expulsion (movement of food through digestive tract, blood through vessels, germ cells through reproductive tract, bile from gallbladder, urine from kidneys, feces from alimentary canal)
Homeostatic adjustments such as size of opening of the pupil of the eye, the pylorus, the anus, and blood vessels; heat production in some vertebrates
The Digestive system is a series of connected organs whose purpose is to digest food.
The process of breaking down larger food molecules into smaller molecules is called digestion.
The digestive tract begins at the mouth and ends at the anus.
Teeth are used for grinding food, and the tongue mixes food with saliva.
All of these organs and glands contribute to the physical and chemical breaking down of ingested food.
The circulatory system is composed of the heart, arteries, capillaries and veins.
Transport, formation, and storage of blood cells for oxygen transport, defense, and immunogenic functions
Drains fluids from between cells and return it to the regular circulatory system from which it leaked
A system of organs functioning in respiration and in humans consisting especially of the nose, nasal passages, pharynx, larynx, trachea, bronchi, and lungs.
Exchange of gases (primarily intake of oxygen and discharge of carbon dioxide) between the organism and its environment (water or air)
The systems that excrete wastes from the body.
For example, the system of organs that regulates the amount of water in the body and filters and eliminates from the blood the wastes produced by metabolism.
Get rid of waste.
Eradicate harmful chemical build-ups.
Maintain a steady, balanced chemical concentration.
The organs and glands in the body that aid in the production of new individuals (reproduction).
Formation of zygotes by the union of two gametes to produce new individuals of the same biological species
Regulation and correlation/integration of body activities through chemical substances (hormones) carried by the blood.
As opposed to the method of action of the nervous system, the endocrine system is slower acting, being limited by the rate of blood flow, but it is capable of long, continuous action.
Regulation and correlation/integration of body activities through conduction within and between individual cells or neurons, which eventually cause a response in some other system (especially muscular contractions)
The nervous system is fast acting; conduction may be faster than 90 meters per second.
Human body has five sense organs.
We call them sense organs because whatever body feels is due to these organs.
Such as electroreception and detection of polarized light.
Five senses are:
Eyes are the sense organ used for seeing.
Seeing is common for the entire organism living on earth.
This organ is in human as well as animals.
Ears are used for hearing.
Animals have high sense of hearing than human.
Some creatures have ability to listen voice in very low pitch.
The tongue is used for taste.
This sense is very highly developed in human only.
Many taste buds are there on our tongue that is used for taste.
Nose is used for smelling.
Smelling sense is highest in every animal.
Animals can smell their prey when they are far away from them.
Skin is the sense organ responding for touch.
We have skin all over our body.
If anything touches us we can sense it.
It is because of sense of touch.
Humans have a good sense of touch.