The caliber of veins is as a rule much larger but the walls are thinner than arteries due to a great reduction of the muscular and elastic elements. The collagenous connective tissue is present in much larger amount and constitutes the bulk of the wall. The three coats are present but their boundaries are often […]
The wall of an artery is composed of three tunics or coats which are- innermost coat, middle coat and outer coat. Innermost coat – the Tunica intima consisting of endothelium continuous with that of capillaries, The middle coat – Tunica media consisting mainly of smooth muscle with varying amounts of elastic and collagenous tissue and The outer coat – Tunica adventitia or externa composed
Capillaries are delicate tubes whose average diameter is about 7 to 9 microns. Capillaries branch extensively without change in caliber and these branches anastomose to form extensive networks whose meshes vary in size and shape in different tissues and organs. The greater the metabolic activity of the tissue, the denser is the capillary network. The
The entire system the heart, arteries, veins, capillaries has a common lining, which consists of a single layer of cells forming the endothelium. In the capillaries this single layer of cells forms the entire wall. In the heart, arteries and veins the endothelium is invested with accessory coat of muscle and connective tissue.
The histology of circulatory apparatus consists of a cardio vascular system and lymphatic system. Cardiovascular system consists of A central propelling organ- the heart A series of efferent tubes – the arteries, which by branching constantly increase in number and decrease in caliber and which serve to carry the blood form heart to the tissues, Minute anastamosing tubules – the capillaries into which the arteries
Epithelium In contrast to the more highly differentiated tissues like the nerve cells and skeletal muscle fibres epithelium has a capacity for cell division and repair if the injury is not very extensive. Connective tissue proper Connective tissue proper has the greatest powers for regenerations and repair and is the tissue involved in the healing process
Neuroglia is the interstitial tissue of the nervous system. In the brain and spinal cord the connective tissue is limited to the enveloping membranes the meninges and a slight amount accompanies the blood vessels. The supportive framework the interstitial tissue is formed by a special group of cells and fibers called neuroglia. In ordinary preparations of
Ganglia consist of aggregations of neurons situated outside the central nervous system. Each ganglion is surrounded by a connective tissue capsule which is continuous with the epineurium and perineurium of the peripheral nerve. Connective trabeculae extend from the capsule into the ganglion to form a framework. Within the ganglion the nerve cells are separated into
The relations between two neurons are of the nature of contact rather than complete structural continuity. This junction of two neurons is called a synapse. The synapse may be defined as a point of contact of the cell membrane (plasma membrane) of an axon terminal with the cell membrane of another neuron. The synapse may be
Muscle tendon spindle (Organ of Golgi) found at the junction of muscle and tendon spindle shaped composed of tendon bundles covered by a connective tissue capsule. Into this enter one or several afferent nerve fibres which terminate in arborization around bundles. Muscle spindles and muscle tendon spindles are proprioceptors of position and movement receiving stimuli
