In Ayurveda, Human Anatomy in known as Sharira Rachna. Human Anatomy is an important subject of all medical sciences. For proper clinical diagnosis, knowledge of human anatomy us vital. For better but brief understanding of human body make up, principle organ systems are narrated below:
Skin or integument
The skin is the chief seat of the touch sensation. It acts as a covering for the protection of the deep-seated tissues. Skin has to play important role in the regulation of the body-temperature.
Fig 1: Basic structure of skin
Skin is divided into two parts:
- Epidermis (cuticle),
- Dermis or true skin.
- Epidermis (as shown in the diagram) is the outer layer which provides protection to the inner layers. On the surface of the skin are the sensitive papillae and within, are sweat glands, hair follicles, and sebaceous glands. Sebaceous glands (see diagram) are found in the moist parts of the skin but are abundant in scalp (head region) and face. These glands manufacture sebum which lubricates the skin. Sweat glands (see diagram) are situated in small pits on the under surface of the true skin. Hairs and nails are outgrowth of the epidermis.
- Dermis is tough, flexible, and highly elastic. Dermis is very thick in the soles of the feet as well as palms of the hands. The colour of the skin is due to pigment known as melanin.
The eyeball lies in the cavity of the orbit. The eye is acted upon by muscles, blood vessels and nerves. The structure of the eye ball has been depicted in the following diagram.
Fig 2: Structure of human eye
Conjunctiva. It is a mucous membrane (see diagram) which covers the under surface of the eye lids and is reflected form the eyelids to cover the anterior part of the eyeball up to the margin of the cornea.
The three layers (see the diagram for better understanding) of the eye are:
- Sclera and cornea. Sclera is a firm, fibrous membrane and serves to maintain the shape of the eyeball. Cornea is a transparent part and is circular in shape.
- Choroid, ciliary body and iris. Choroid is the vascular and pigmentary layer of the eyeball. The ciliary body connects the choroid to the iris. Iris is a thin, circular-shaped part, suspended in the aqueous humour behind the cornea.
- Retina: It is a delicate and thin membrane and forms the inner part of the eyeball. On the surface of the retina images of the external objects are received. A small area of the retina lying opposite to cornea is known as yellow spot. The point of the retina from where the optic nerve emerges is known as blind spot.
Lens lies just behind the iris and held in place by the suspensory ligament. These two structures divide the eyeball into two chambers aqueous chamber and vitreous chamber. The chambers contain fluid known as aqueous and vitreous humour. The humour helps to maintain the form of the eyeball.
The working of the eye resembles with that to photographic camera. The human eye has good power of accommodation. It beautifully adjusts itself to see objects at distant places and vice versa. Rods and cones are the cells responsible for our vision. Vitamin A is necessary for proper eyesight.
Digestive system is also known as gastro-intestinal system. It chiefly consists of the alimentary canal and of certain accessory organs. Following diagram shows parts of the digestive system.
Fig 3: Anatomy of digestive system
The alimentary canal is about thirty feet long extending from the mouth to the anus. It is lined by mucus membrane throughout its length. Every organ (as shown in the diagram) has definite role to play in digestion. In fact the process of digestion starts from the mouth and continues throughout the intestine.
The essential components of the digestive system are
Accessory organs of digestion include digestive glands, liver and pancreas..
Fig 4: Anatomy of the liver
The chief function of the respiratory system is to supply oxygen to the human-body and simultaneous removal of carbon dioxide. As far as anatomy is concerned, the respiratory tract is brodally divided into two parts
- Upper (it represents the respiratory tract) and
- Lower (it represents the respiratory organs).
Pharynx, larynx, trachea, bronchi and bronchioles are included in the respiratory tract
Fig 5: Anatomy of the respiratory system
The cardiovascular system is composed of the heart and blood-vessels (arteries and veins). Arteries and veins carry the blood. The heart is basically a muscular organ pumping blood to all parts of the body by the process of contraction. Oxygenated blood is carried by the arteries and deoxygenated blood by the veins. Another group of blood vessels, known as capillaries which carry lymph. Diagram explaining the structure of heart is given below.
Fig 6: Anatomy of the Heart (Aorta is mother of all arteries; Superior vena cava collects impure blood from upper parts of body; pulmonary artery carries impure blood to lungs).
Living organisms respond to changes in the environment. The information from the outside word is received in the form of stimulus. Stimulus is a change in the environment which evokes a response from the human being). The nervous system plays vital role in coordinating the information received. The nervous system in addition, ensures the coherence of the functioning of internal organs.
Nervous system is perfectly organized as far as anatomy (structure) and physiology (function) is concerned. Nervous system is divided in two main divisions as illustrated below:
The excretory system includes a pair of kidney, ureter, urinary bladder and the urethra. The parts of the excretory system have been shown in following diagram.
Fig 7: Anatomy of human excretory system
Female reproductive system
The anatomy of the female reproductive system has been shown in following diagram.
Male reproductive system
The glands present in the human- body are classified in two types:
- Exocrine glands. These glands release secretions via ducts. Sweat glands are typical examples of exocrine glands.
- Endocrine glands. These glands pour secretions (which are basically hormones) directly into the bloodstream as they lack ducts. That is the reason, endocrine glands are also known as the ductless glands.
Major endocrine glands of the human body are depicted in following diagram.