Fundamentals of Biomedical Engineering

2.The main parts of the upper limb are the arm, forearm and hand. Arm in strict anatomical term means the upper arm (the part between the shoulder and elbow) however, this word is commonly used for the whole of the upper limb.

3.The main parts of the lower limb are the thigh, leg and foot. Here also leg in strict anatomical form means the lower leg (the part between the knee and foot) but the word is commonly used for whole of the lower limb.

4.In order to describe the positions of structure in human anatomy, the body is assumed to be standing 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. This is the anatomical position and structures are always described relative to one another using this as the standard position. This is also applicable even when the body is lying on the back to bed or when lying on a dissecting table.

M edian plane

Coronal

plane

5.The ‘Median plane’ is an imaginary vertical longitudinal line through the middle of the body from front to back, dividing the body into right and left halves. The ‘sagittal plane’ is any plane that is parallel to the median plane. The adjective ‘medial’ means nearer to the median plane, and ‘lateral’ means farther from it. Thus we can say in anatomical position, the little finger is on the medial side of the hand and the thumb is on the lateral side, similarly the great toe is on the medial side of the foot and the little toe on the lateral side. If we consider forearm which has two bones with radius bone on the lateral side and ulna bone on the medial side, then the adjective ‘radial’ and ‘ulnar’ can be used instead of lateral & medial. Similarly in the lower leg where there are two bones, the fibula on the lateral side and the tibia on the medial side, the alternative adjectives ‘fibular’ and ‘tibial’ can be used.

6.‘Coronal planes’ are imaginary planes at right angles to the median plane. Horizontal or transverse planes are at right angles to both the median and coronal planes.

Horizontal

or

Transverse

plane

7.The terms ‘anterior’ and ‘posterior’ are used to indicate the front or back of the body respectively. Therefore we have anterior and posterior view of the body or any part of body or organ. It is also used to describe the relationship of two parts. One is said to be anterior or posterior to the other if it is closer to anterior or posterior to the body surface. Hence on the face, the nose is anterior to the ears and the ears are posterior to the nose. Sometimes ‘ventral’ is used instead of posterior.

8.In describing the hand, the term ‘palmar’ and ‘dorsal’ surfaces are used instead of anterior and posterior. Similarly in describing the foot, the ‘plantar’ and ‘dorsal’ surfaces, are used instead of lower and upper surfaces.

9.The terms ‘proximal’ and ‘distal’ describe the relative distances from the roots of the limbs. The arm is proximal to the forearm and the hand is distal to the forearm.

10.The terms ‘superior’ and ‘inferior’ means nearer the upper or lower end of the body respectively. Hence the nose is superior to the mouth and, inferior to the forehead. ‘Superficial’ means near the skin surface and ‘deep’ means farther away from the surface. The terms ‘internal’ and ‘external’ are used to describe the relative distance of a structure from the centre of an organ or cavity. ‘Ipsilateral’ and ‘contra-lateral’ are used for parts on the same side or not of the body. Hence, left hand and left foot are

ipsilateral while the left biceps branchii muscle and the right rectusfemoris muscle, are contralateral. The ‘supine’ position of the body is lying on the back and the ‘prone’ position is lying face downward.

TERMS RELATED TO MOVEMENTS

1.Wherever two or more bones meet, it is known as a joint. The degree of mobility varies from joint to joint. Some joints have no movement (as in bones of skull), some have only slight movement (as in vertebrae) and some are freely morable. These movements are made in any of three planes as explained above. Different terms are used to describe the movements as explained below.

2.‘Flexion’ is a movement that takes place in a sagittal plane. It is infact folding of the bones so as they may come nearer. For example, flexion of the elbow joint bring the anterior surface of the forearm to the anterior of the arm. It is usually an anterior movement but it can be posterior movement also as in the case of the knee joint. ‘Extension’ means unfolding or straightening the joint. The movement usually takes place in a posterior direction. However, flexion and extension of trunk takes place in the coronal plane (lateral).

3.‘Abduction’ of a limb is the movement away from the midline of the body in the coronal plane. ‘Adduction’ of a limb is the movement towards the body in the coronal plane. In

Abduction

Abduction

Adduction

Adduction

the fingers and toes abduction signifies the spreading of these parts and adduction indicates the drawing together of these parts.

Adduction

Abduction

4.‘Rotation’ is a term applied to the movement of a part of the body around its long axis. It can be.

(a) ‘Medial rotation’, which is the movement that takes place in the

anterior surface of the part when facing medially.

(b) ‘Lateral rotation’ is the movement that takes in the anterior surface of the part facing laterally.

INTRODUCTION

(c) ‘Pronation of the forearm’ is medial rotation of the forearm in such a manner that the palm faces posteriorly.

5

(d) ‘Supination of the forearm’, is a lateral rotation of forearm from the pronated position so that palm of the hand comes to face anteriorly.

Pronation of Forearm

5.‘Circumduction’, is the combination of four movements which is in sequence of the movements of flexion, extension, abduction and adduction.

Supination of Forearm

6.Inversion is the movement of the foot so that the sole faces in a medial direction while eversion is the opposite movement of the foot so that the sole faces in a lateral direction.

MEDICAL TERMINOLOGY

1.Engineers and technicians working in medical field have to learn enough physiology, anatomy and medical terminology to be able to discuss problems intelligently with members of medical profession. They face great difficulty in

PREFIXES

learning medical terminology. However with a few simple rules, medical terminology, can be understood more easily. Most medical words have been derived from latin and Greek. Most words consist of a root or base which is modified by a prefix or suffix or both. The root is often abbreviated when the prefix or suffix is added.

(o) Arteries = Aeir (air) + tercm (to keep). It is a greek word. After death the arteries (blood vessels to take blood to organs) are usually empty of blood whereas the veins (blood vessels to take blood to heart) are full of clotted blood. The ancient concluded from this, that the arteries carried air. Hence the name given to these vessels as arteries.

(p) Robotic = Robota (Slave) + ic (Like). In 1921, Czech dramatist, KAREL CAPEK published ROSSUM’s UNIVERSAL ROBOTS. Based on this, the word “robot” has been coined for something working as slave. A Robot is any mechanical device operated automatically to perform in seemingly human way. Current research efforts focus on creating a smart robot that can hear, touch, taste & consequently make decision. Robots do not have to

look like humans and it is functions, not form which matters. Robots have capability to interact with humans via synthesised speech. They have vision sensors to identify obstructions, road blocks and detect motion in the environment. They can navigate and make documentation. They can be programmed to make decisions. Robotic intensive care cart is being used in intensive care unit. Robots can be used as device to provide technical aids to the handicapped.

MEDICAL GLOSSARY

1.In this book many medical words have been used which are unfamiliar to the readers. The glossary of medical words which will be used in this book is presented in alphabetical order.

Collagen – Literally meaning is glue producing. The major portion of the white fibers of

connective tissue and bone.

Computerised

Axial tomography (CAT) : A technique combining X-ray and computer technology for visualisation of internal organs and body structure.

D

K

Korotkoff sounds – Sounds produced by sudden pulsation of blood being forced through a partially occupied artery and heard during ausculatory blood pressure determination.

M

Membrane – A thin layer of tissue that covers a surface or divides a space or organ

Metabolism – The sum of all the physical and chemical processes by which the living organised substance is produced and maintained.

Mitral valve – Valve between the left atrium and ventricle of the heart.

O

Orthosis – Making straight, the correction of maladjustment.

Oxyhaemoglobin – A compound of oxygen and haemoglobin which is formed in lungs whereby oxygen is carried through the arteries to the body tissue.