BASIC ANATOMY

HISTORY Hippocrates: He is the founder of the

science of anatomy.(370 ---460 BC) Herophilus: He is the father of

Anatomy.

HUMAN ANATOMY“It is concerned with the consideration of various structures which

make up the human body.”Branches:i. Systematic Anatomyii. Regional Anatomy /Topographical Anatomyiii. Surface Anatomyiv. Radiological Anatomyv. Morphologyvi. Comparative Anatomyvii. Embryologyviii. Teratologyix. Statistical Anatomyx. Anthropologyxi. Cross-section Anatomyxii. Cytology

xiii. Applied Anatomy/ Clinical Anatomyxiv. Histology

ANATOMICAL NOMENCLATURE Anatomical position

In order to avoid confusion when describing the body, it is always described in the anatomical position.

In the anatomical position, a person stands erect, legs together and arms by their sides, with their head, eyes, toes and palms of the hands facing forward. It is important to remember that the palms face forward as their relaxed position is generally facing inwards.

Importance: The anatomical position allows us to describe

the position of structures in relation to their surroundings, e.g. ˜the heart lies above the diaphragm. The anatomical position avoids confusion as to whether the body is lying down or standing up.

You should also bear in mind that when looking at a person in the anatomical position, their right side will be on your left. The structures will always be described as they are to the subject rather than as they appear to you.

ANATOMICAL PLANES & DIRECTIONS

PlanesThere are three major anatomical planes; 1) Axial 2) Coronal 3) Sagittal

Axial (also know as the transverse plane): This plane cuts the body horizontally, into superior (upper) and inferior (lower) portions

Coronal (also known as the frontal plane): This plane cuts the body vertically, into anterior (front) and posterior (back) portions.

Sagittal: This plane cuts the body vertically, into left and right portions.

DIRECTION Direction is used, when the body is in the anatomical position to explain the location of a structure relative to the structures surrounding it.

Anterior (or ventral): Towards the front of the body (in front of) e.g. The sternum lies anterior to the heart.

Posterior (or dorsal): Towards the back of the body (behind). The heart lies posterior the sternum.

Superior (or cranial): Above (on top of). The heart lies superior to the diaphragm.

Inferior (or caudal): Below (underneath). The diaphragm lies inferior to the heart.

Lateral: Away from the mid line of the body (towards the sides). The lungs lie lateral to the heart.

Medial: Towards the mid line of the body (towards the middle). The heart lies medial to the lungs.

Deep Away from the body surface (towards the inner body). The heart is deep to the sternum.

Superficial Towards the external surface of the body. The sternum is superficial to the heart.

Proximal Nearer to the trunk of the body. The shoulder is proximal to the elbow.

Distal Furthest from the trunk of the body. The elbow is distal to the shoulder.

REGIONS

The body is split up into two main areas, the axial and appendicular regions.

The axial region refers to the head, vertebral column and trunk, and the appendicular region refers to the pelvic girdles and the upper and lower limbs. Each area is further divided into descriptive regions.

Axial regions Description

Cephalic Head Frontal Forehead Facial Face Occipital Back of the head Orbital Eye cavity Buccal Cheek Thoracic Chest Sternal Sternum Umbilical Navel (belly button) Inguinal Groin Pubic Mons pubis (pubic bone) Genital Reproductive organs Perineal Perineum Dorsum Back

Vertebral Spinal column Cervical Neck Thoracic Middle of the back Lumbar Lower back Sacral SacrumAppendicular / Upper Limb Pectoral Chest Clavicular Clavicles Acromial Acromion of the shoulder Scapular Scapula Interscapular Between the two scapulae Axillary Armpit Brachial Arm Antebrachial Forearm Cubital Elbow

Carpal Wrist Digits Fingers Pollicis Thumb Palmar Palm of the handLower Limb Gluteal Buttocks Coxal Hip Femoral Thigh Patellar Front of the knee Popliteal Back of the knee Crural Leg Tarsal Ankle Calcaneal Heel Pedal Foot Plantar Sole of the foot

BODY CAVITIES There are two main cavities within the body, 1. Ventral 2. Dorsal

The dorsal body cavity is at the back of the body and is the smaller of the two cavities. It can be further divided into the upper and lower portions, the cranial cavity and the vertebral canal respectively.

The ventral body cavity is at the front of the body and is the larger of the two cavities. It can be further divided into three cavities, the thoracic cavity, abdominal cavity and pelvic cavity. The thoracic and abdominal cavities are divided by the diaphragm and the abdominal and pelvic cavities are continuous with each other

DORSAL CAVITYSmall cavity at the back of the body.1) Cranial cavity Upper portion , bounded by the skull . Contain brain and

meninges. 2) Vertebral canal Lower portion. Bounded by the vertebral column, intervertebral

discs and surrounding ligaments. Contain spinal cord and spinal nerve roots.VENTRAL CAVITY

Large cavity at the front of the body.  Thoracic cavity:

Large cavity above the diaphragm. It is bound laterally by the ribs (covered by costal pleura) and the diaphragm inferiorly (covered by diaphragmatic pleura) Contain Heart, lungs, trachea, oesophagus, large blood vessels and nerves.

Abdominal cavity Large cavity below the diaphragm. It is bound

superiorly by the diaphragm, laterally by the body wall, and inferiorly by the pelvic cavity. Contain gastrointestinal tract, spleen, kidneys and adrenal glands.

Pelvic cavity Small cavity below the brim of the pelvis. It is bounded

superiorly by the abdominal cavity, posteriorly by the sacrum, and laterally by the pelvis . Contains urinary bladder, genitals, sigmoid colon and rectum.

QUADRANTS AND REGIONS OF THE ABDOMEN

The abdomen can be divided by two lines into 4 quadrants or by 4 lines into 9 regions.

The two lines that divide the abdomen into quadrants form a cross, the centre of which is positioned over the umbilicus (belly button). These quadrants are often used to indicate the location of pain.

Right upper quadrant Left upper quadrant Right lower quadrant Left lower quadrant

LINES There are two vertical lines and two

horizontal lines that divide the abdomen into a grid. The vertical lines also known as lateral lines are positioned using the middle of each clavicle as a reference.

The upper horizontal line (also known as the transpyloric or subcostal line) is positioned at the level of the pylorus of the stomach close to the subcostal margin of the ribs.

The lower horizontal line (also known as transtubercular line) is positioned at the level of the anterior superior iliac spines of the coxal (hip) bone

REGIONS

Regions Name Right hypochondriac region Left hypochondriac region Epigastric region Right lateral region Left lateral region Umbilical region Right inguinal region Hypogastric (pubic) region Left inguinal region

LIFE SPAN OF HUMAN BEING1) PRE-NATAL LIFE: ( Life before birth)a) OVUM: Fertilization to end of 1st week.b) EMBRYO: Second to Eighth week.c) FOETUS: Third to Tenth month.

2) POST-NATAL LIFE (Life after birth till death)d) NEW BORN: Neonatal period. Birth to end of 2nd weeke) INFANCY: Third week to the end of 1st year.3) CHILDHOOD:i. Earlyii. Middle iii. Later

i. Early Childhood: Milk tooth period ( 2nd to 6th year inclusive)

ii. Middle Childhood: Permanent tooth period (7th to 9th or 10th year inclusive)

iii. Later Childhood: Pre-Pubertal period. From 9-10 years to 12-15 years in female.From 9-10 years to 13-16 years in males.

4) Adolescence:The six years following puberty.5) Adult :iv. Prime & Transition: Between 20 years to 60

years.v. Old Age & Senescence: From 60 years to death.

BASIC ORGANIZATION OF THE BODY

ORGANS

An association of different tissues is called an Organ which perform certain functions. E.g. heart , stomach & urinary bladder.

TISSUEA collection of cells of similar morphology performing a special

function is called tissue. Epithelium, connective tissue , nervous tissue and muscle tissue are its types.

CELLCELL THEORY: The human body can be organized on the basis of

cell theory that the cell is the structural unit of the whole human body.

ORGAN SYSTEMA group of organs working harmoniously to discharge a specific function forms a system e.g.Skeletal SystemMuscular System Cardiovascular SystemNervous SystemUrogenital SystemEndocrine SystemLymphatic System

GYRI & SULCI Each hemisphere is greatly

folded forming gyri (folds) and sulci (grooves) which increases the surface area of the cerebral cortex. Although the exact location of the sulci and gyri varies between different individuals, there are a number of large gyri and deep sulci which can be identified as constant landmarks.

GREY AND WHITE MATTER The brain and spinal cord contain both grey and

white matter. In the Brain

The grey matter can be found in the cerebral cortex, the basal ganglia and the limbic system. It is made up of the cell bodies, dendrites and synapses of the neurons and are grouped into functionally important nuclei.

The white matter is made up of the myelinated fibres (axons) which connect the different parts of the brain to each other as well as to the spinal cord.

In the Spinal Cord The spinal cord is oval in cross section and consists

of white and grey matter. The grey matter lies centrally and is arranged into ventral, dorsal and lateral grey horns (anterior and posterior horns). It consists of neurons and neurites, neuroglia and blood vessels. It appears grey because of the abundance of neuronal cell bodies.

The white matter surrounds the grey mater and is white in colour due to the presence of myelin, which insulates the nerve fibres.