Biomedical Engineering Theory And Practice/Introduction

The biomedical engineer works with the medical doctors, the nurses,the manufacturers and so on. In order to design new device for healthcare, basical understanding human body is prior. In order to find out the requirement of the special medical devices, therapy and so on, when we read the patents,journals, articles and so on and communicate with medical field people, it would be very helpful. In this chapter, fundamental anatomical terms and medical glossary would be introduced.

Anatomical Terms

 * The body is composed of the head, trunk and limbs.


 * The trunk consists of the neck, thorax(chest) and abdomen (belly). The lowest part of the trunk is the perineum. The central axis of the trunk is the vertebral column, and the upper part of it(cervical part) supports the head.


 * The main parts of the upper limb are the arm, forearm and hand. Arm in anatomical form means the part between the shoulder and elbow. But, generally the arm means from the shoulder to before the hand.


 * The main parts of the lower limb are the thigh, leg and foot. Here also leg in anatomical term point out the part from knee to foot.But, generally the leg means from thigh to before the foot.

Anatomical Planes

 * For the positions of structure in human anatomy, the whole body should stand upright with the feet together and the head and eyes looking to the front with the arms straight by the side and the palms of the hands facing forwards.
 * The ‘Median plane’ is an virtual vertical longitudinal line through the middle of the body from front to back, dividing the body into right and left halves.
 * The ‘Coronal planes’ are imaginary planes at right angles to the median plane.
 * The 'Transverse plane' divides the body into head and tail portions.

Anatomical Movement
'See also Wikipedia,Anatomical terms of motion.




 * 1) 'Flexion' means a bending movement that decreases the angle between two parts like bending elbow, sitting down and so on.
 * 2) 'Extension' is the opposite of flexion. It is a straightening movement that increases the angle between body parts.
 * 3) 'Abduction' is a motion that pulls a structure or part away from the midline of the body.
 * 4) 'Adduction' is a motion that pulls a structure or part toward the midline of the body, or towards the midline of a limb.
 * 5) 'Elevation' is the movement in a superior direction like raising the arm upwards.
 * 6) 'Depression' is the movement in an inferior direction, the opposite of elevation.
 * 7) 'Internal rotation' (or medial rotation) means rotation towards the axis of the body like the arms against the chest.
 * 8) 'External rotation' (or lateral rotation) means rotation away from the center of the body. For instance, the leg can rotate.

Medical Terminology
'See also Wikipedia,List of medical roots, suffixes and prefixes

Medical Glossary
'See also Wikipedia, Medical Dictionary

Histology
Histology is the study of the microscopic anatomy of cells and tissues. All organs of the body are formed of tissues. A tissue is a collection of similar type cells associated with some intercellular matrix (ground substance) controlled by some laws of growth and development. These cells perform the same functions. Tissues are usually divided into four categories:muscle tissue, nervous tissue, connective tissue, and epithelial tissue.

Muscle tissue
Muscle tissue is composed of "excitable" cells which can contract. Muscle tissue include a lot of microfilaments composed of actin and myosin, which are contractile proteins. There are three major types of muscle tissue:


 * Skeletal Muscle:It is attached to bones by tendons and associated with the body's voluntary movements. Skeletal muscle is striated muscle. Unlike cardiac muscle, the cells are not branched.
 * Visceral (Smooth) Muscle:It is found in many parts of the body such as the arteries, the bladder, the digestive tract and so on. Visceral muscle is also called smooth muscle as it doesn't have cross striations. Visceral muscle contracts slower than skeletal muscle, but the contraction can be continued for a longer period.
 * Cardiac muscle:It is so named because it is found in the heart. Cells are joined to one another by intercalated discs which allow the synchronization of the heart beat. Cardiac muscle is branched, striated muscle.

Nervous tissue
Nervous tissue is specialized to sense stimuli and transmit signals to and from different parts of an organism. The nervous system is split into two parts. One is the central nervous system which includes the brain and spinal cord while the peripheral nervous system contains the cranial and spinal nervous and provides the communication between the CNS and the rest of the body. Two main cell types are neurons and neuroglia. The neurons are the basic structural units of the nervous system. The neuroglia assist the propagation of the nerve impulse and provide nutrients to the neuron. Neurons transmit electricity through their plasma membrane and lose their ability to split once they commit to their roles (after birth). They last a life time and store memory. However, if they are destroyed they cannot be replaced. However with that said, you cannot avoid other parts of the brain to take over functions. Neurons also needs lots of oxygen and glucose and will die within 5 minutes without oxygen. Nervous tissue is composed of various types of nerve cells, all of which having an axon, the long stem-like part of the cell that sends action potential signals to the next cell. Nervous tissue is discussed more in Chapter 3.

Connective tissue
Connective tissue (CT) supports, connects, or separates various tissues and organs of the body. It is one of the four major type tissues—the others of which are epithelial, muscle, and nervous tissues. Connective tissue can be found everywhere in the body except the central nervous system.

Epithelial tissue
It is one of the four major types tissues. It is related to secretion, selective absorption, protection, transcellular transport and detection of sensation. In Greek ἐπί (epi) means "on" or "upon", and θηλή (thēlē) means "nipple".

Fill up the gaps

 * 1) The body consists of the head, ______and limbs. ((a) arms (b) trunks)
 * 2) Sagittal plane is parallel to _______ plane.((a)lateral (b) median)
 * 3) Nose is _______ to the ears. ((a) anterior (b) posterior)
 * 4) Rotation is the movement of a part of the body around its _______axis. ((a) central (b) long)
 * 5) All organs of the body are formed of ______.((a) flesh (b) tissue)
 * 6) Epithelium is ______ tissue. ((a) covering (b) connecting)