Anatomy and Physiology

Definition of Anatomy: Anatomy is the branch of medical science which deals with the structure of

the body, its different parts, organs, their shape, size and location in the body.

Definition of Physiology: It is the branch of medical science that deals with the normal functions of

living organisms and their parts.

Parts of Anatomy:

1. Osteology: Study of bones
2. Myology: Study of muscles
3. Splanchnology(pronc. spanology): Study of organs and glands

• Heart is made up of cardiac muscles.

• Largest and longest cartilage is tongue.

• Speed of a sneeze is 165 km/hr.

• We have about 5 lakh sweat glands on our feet.

• Stomach is like the shape of the alphabet ‘J’.

• We must drink about 2.5-3 litres water daily.

• Normal B.P of a human being is 120-80mm/hg.

• The average adult human has about 4.5 to 5.5 liters of blood circulating inside their body

Osteology: It deals with the study of bones, its formation, different types, its function etc.

Bones: Bones are compact tissue. It is white in colour having four layers as follows-

1 First layer(Periosteum): Periosteum is a soft outer covering over the bone’s surface. It provides

blood flow to the bones which lets a bone heal, grow, fight infection and stay healthy. It is made up of

calcium and also makes the bones stronger.

2. Second Layer(Cortical Bone or compact tissue): This layer is hard and thick. It’s job is to protect

body parts underneath it and hold up the muscles around it.

3. Third Layer (Spongy Tissue or Cancellous Bone): Cancellous bone is spongy type of bone

inside the cortical bone.

4. Fourth Layer(Bone Marrow): This layer is deep inside the middle of the cortical and spongy tissue.
It’s job is to make all the blood cells inside our body i.e red cells, white cells and platelets that help to
stop bleeding when we get a cut.

Composition of Bone: Bone is structurally a complex organ and has the following composition

• Water: 25%

• Ossein, Osseomucoid and Osseo Albumin (Organic solids): 35%

• Inorganic salts of calcium: 45%

Calcium salts impart the hardness to bones.

Types of Bones: Bones are mainly of five types. They are: 

1. Long bone
2. Short bone
3. Flat bone
4. Irregular bone
5. Sesamoid bone

1. Long Bone: Long bones are found in limbs. A long bone has two ends. Ends of a long bone are called the epiphysis. These two ends are connected by shaft, which is called diaphysis. Eg. Femur, humerus, radius, ulna.
2. Short bones: Short bones don't have shaft. They contain spongy substance covered by a shell of compact bone. Eg. Phalanges, carpal bones, Tarsal bones.
3. Flat bones: They contain two layers of compact bone with spongy substance between the two layers. Eg. Pelvis, scapula, bones of the skull.
4. Irregular bones: Bones which don't fall into any category are irregular bones. Eg. vertebrae and bone of face
5. Sesamoid bones: They are small bones and develop in tendons of muscles. Eg. Patella of knee joint.
6. 

Skull: Skull consists of two parts (a) Cranial Skull and (b) Facial skull.

Cranial Skull consists of 8(Eight) bones, called cranial bones as follows:

Name of bones	Number
Occipital	1
Parietal	2
Frontal	1
Temporal	2
Sphenoid	1
Ethmoid	1
Total	8

Ethmoid is a small and lightest bone of body. It is a light spongy Bone, cubical in shape situated at the root of the nose wedged in between the orbits.

Frontal skull consists of 14 bones as under:

Name of bones	Number
Nasal Bones	2
Palatine Bone	2
Lacrimal Bone	2
Zygomatic Bone	2
Vomer Bone	1
Inferior Turbinate Bone	2
Maxilla (plural: maxillae)	2
Mandible	1
Total	14

Skeleton: The bony framework of the body is known as a skeleton. Human skeleton consists of 203

bones whereas human body consists of 206 bones. Skeleton can also be divided into two parts:

1. Axial Skeleton: It consist of skull vertebral column, sternum, ribs and hyoid bones.
2. Appendicular skeleton: It consists of upper and lower limbs.

Bones of the skeleton:

Name	No.
Skull	22
Sternum	01
Ribs	24
Vertebrae	33
Upper Limbs(64)
Humerus	02
Radius	02
Ulna	02
Carpal bones	16
Metacarpal	10
Phalanges	28
Clavicle	02
Scapula	02
Lower Limbs(62)
Innominate	02
Femur	02
Tibia	02
Fibula	02
Patella	02
Tarsal bone	14
Metatarsal bone	10
Phalanges	28
Total	206

Length of Spinal cord - 45 cm

Length of Spine - 71 cm

Synovial fluids’ role is to reduce friction

A human rib cage is made up of 24 ribs as under -

1. Real Ribs (7+7)
2. False Ribs (3+3)
3. Floating Ribs(2+2)

Human spine/backbone is made up of 33 irregular bones as under-

1. Cervical (7)
2. Thoracic (12)
3. Lumbar (5)
4. Sacral (5)
5. Coccyx (4)