MBBS Anatomy Syllabus

State the general functions of connective tissue.

Binding and support, protection, insulation, storage (e.g., fat), and transport of substances (e.g., blood). It connects, supports, and surrounds other tissues and organs.

What are the three basic components of connective tissue?

Cells, protein fibers, and ground substance. The fibers and ground substance together form the extracellular matrix, which is the dominant feature of most connective tissues.

Name the three types of protein fibers found in connective tissue and their properties.

Collagen fibers (strong, tough, resist tension), elastic fibers (containing elastin; stretch and recoil), and reticular fibers (fine collagen forming supportive networks/stroma in organs).

Classify the main types of connective tissue proper.

Loose connective tissue (areolar, adipose, reticular) and dense connective tissue (dense regular, e.g., tendons/ligaments; dense irregular, e.g., dermis; and dense elastic).

Name the three types of specialized (supporting/fluid) connective tissue.

Cartilage, bone (osseous tissue), and blood. These have specialized extracellular matrices: firm gel in cartilage, calcified matrix in bone, and fluid plasma in blood.

Name the three types of cartilage and give a location for each.

Hyaline cartilage (articular surfaces, costal cartilage, trachea), elastic cartilage (external ear, epiglottis), and fibrocartilage (intervertebral discs, pubic symphysis, menisci).

Compare the three types of muscle tissue: skeletal, cardiac, and smooth.

Skeletal: striated, multinucleated, voluntary, attached to bones. Cardiac: striated, uninucleate (mostly), branched, involuntary, with intercalated discs, in heart wall. Smooth: non-striated, uninucleate, spindle-shaped, involuntary, in walls of hollow organs/vessels.

What are intercalated discs and where are they found?

Intercalated discs are specialized junctional complexes (containing desmosomes and gap junctions) joining adjacent cardiac muscle cells end-to-end. They allow mechanical anchoring and rapid electrical conduction, enabling the myocardium to contract as a functional syncytium.

Name the two principal cell types of nervous tissue and their roles.

Neurons (nerve cells) generate and conduct electrical impulses (excitable cells). Neuroglia (glial cells) support, nourish, insulate, and protect neurons; they are non-conducting and far more numerous.

Label the main structural parts of a typical neuron.

Cell body (soma/perikaryon) containing the nucleus and Nissl bodies; dendrites (receive signals and conduct toward the cell body); and a single axon (conducts impulses away from the cell body to the axon terminals).

State the major functions of the skeletal system (bones).

Support (framework), protection of vital organs, movement (levers for muscles), mineral storage (calcium and phosphate) and lipid storage (yellow marrow), and hematopoiesis (blood cell formation in red marrow).

Name the two types of bone tissue by density and their locations.

Compact (cortical) bone — dense outer layer forming the shaft (diaphysis); and spongy (cancellous/trabecular) bone — a lattice of trabeculae found internally, especially in the epiphyses and flat bones, housing red marrow.

Describe the structural unit of compact bone (the osteon).

The osteon (Haversian system) consists of concentric lamellae of bony matrix surrounding a central (Haversian) canal carrying blood vessels and nerves. Osteocytes lie in lacunae between lamellae and communicate via canaliculi; perforating (Volkmann's) canals connect adjacent osteons.

Name the four bone cell types and their functions.

Osteogenic (osteoprogenitor) cells — stem cells; osteoblasts — bone-forming cells that secrete osteoid; osteocytes — mature cells maintaining bone matrix; osteoclasts — large multinucleate cells that resorb bone.

Classify bones according to their shape, with an example of each.

Long bones (e.g., femur, humerus), short bones (e.g., carpals, tarsals), flat bones (e.g., sternum, scapula, skull bones), irregular bones (e.g., vertebrae), and sesamoid bones (e.g., patella).

What are sesamoid bones and what is their function?

Sesamoid bones are small bones embedded within tendons (e.g., the patella). They protect the tendon from excessive wear and modify the angle of pull, increasing the mechanical advantage of the muscle.

Identify the main gross parts of a typical long bone.

Diaphysis (shaft), epiphyses (expanded ends), metaphysis (region between diaphysis and epiphysis containing the epiphyseal plate/line), articular cartilage (covers epiphyses), periosteum (outer membrane), endosteum (lines marrow cavity), and the medullary (marrow) cavity.

Distinguish the periosteum from the endosteum.

The periosteum is a dense fibrous membrane covering the external bone surface (except articular ends); its outer fibrous and inner osteogenic layers anchor tendons and aid growth/repair. The endosteum is a thin connective tissue lining the internal surfaces (medullary cavity, trabeculae) and also contains osteogenic cells.

What is the medullary cavity and what does it contain?

The medullary (marrow) cavity is the central hollow space within the diaphysis of a long bone. In adults it contains yellow bone marrow (mainly adipose tissue); in children it contains red marrow for hematopoiesis.

Distinguish intramembranous from endochondral ossification.

Intramembranous ossification: bone develops directly from a fibrous connective tissue membrane (forms flat bones of the skull, clavicle, mandible). Endochondral ossification: bone replaces a pre-existing hyaline cartilage model (forms most bones, including all long bones).

What is the epiphyseal (growth) plate and what is its significance?

The epiphyseal plate is a layer of hyaline cartilage between the epiphysis and diaphysis that allows the bone to grow in length (longitudinal/interstitial growth). When growth ceases it ossifies, becoming the epiphyseal line.

Differentiate the primary and secondary ossification centers in a long bone.

The primary ossification center appears in the diaphysis (shaft) during fetal life and is the first site of bone formation. Secondary ossification centers appear later in the epiphyses (ends), usually after birth.

Define a joint (articulation).

A joint, or articulation, is a site where two or more bones (or bone and cartilage/teeth) meet. Joints hold the skeleton together and give it mobility; their structure determines the type and range of movement permitted.

Classify joints structurally.

Structurally, joints are classified by the binding material and presence of a joint cavity into: fibrous joints (united by fibrous tissue, no cavity), cartilaginous joints (united by cartilage, no cavity), and synovial joints (separated by a fluid-filled cavity, united by a capsule).

Classify joints functionally by degree of movement.

Synarthroses (immovable, e.g., skull sutures), amphiarthroses (slightly movable, e.g., pubic symphysis, intervertebral joints), and diarthroses (freely movable, all synovial joints).

Name the three types of fibrous joints with an example of each.

Sutures (between skull bones), syndesmoses (bones joined by a ligament/interosseous membrane, e.g., distal tibiofibular joint), and gomphoses (peg-in-socket, e.g., a tooth in its alveolar socket).

Name the two types of cartilaginous joints with an example of each.

Synchondroses — bones united by hyaline cartilage (e.g., epiphyseal plate, first sternocostal joint); and symphyses — bones united by fibrocartilage (e.g., pubic symphysis, intervertebral discs).

List the distinguishing structural features of a synovial joint.

A fluid-filled joint (synovial) cavity, articular (hyaline) cartilage covering the bone ends, a two-layered articular capsule (fibrous outer layer and synovial membrane), synovial fluid, and reinforcing ligaments. Many also contain bursae, fat pads, menisci, and nerves/vessels.

What is synovial fluid and what are its functions?

Synovial fluid is a viscous, egg-white-like filtrate of blood secreted by the synovial membrane, rich in hyaluronic acid. It lubricates and reduces friction between articular cartilages, nourishes the avascular cartilage, and absorbs shock.

Name the six types of synovial joints (by shape/movement) with an example of each.

Plane/gliding (intercarpal joints), hinge (elbow, knee), pivot (atlantoaxial, proximal radioulnar), condyloid/ellipsoid (radiocarpal/wrist), saddle (carpometacarpal of thumb), and ball-and-socket (shoulder, hip).