Answer:
a. destroyed
b. osteoclasts
c. proteolytic enzymes
d. hydrochloric acid
e. blood
f. low
Explanation:
Resorption is the loss of substance from any mineralized tissue, mediated by cellular and humoral systems of their own. The four mineralized tissues of our economy, bone, cement, dentin (mineralized fraction of the dentino-pulp functional complex) and enamel, offer different degrees of resistance to resorption. The bone has the greatest lability and the enamel the least. The fact that the bone tissue is the least resistant to resorption is used to move and reposition teeth by controlled forces (orthodontics); and the fact that the enamel is the most resistant has led to think that it does not suffer from resorption.
Osteoclasts They are the spring cells par excellence; they belong to the lineage of the monocitomacrophages. They are large, multinucleated mobile cells, with a clear area and a rough brush border that live for about two weeks and disappear by apoptosis (cell death programmed by fragmentation in membrane particles that allows their phagocytosis without inflammation). They are responsible for the destruction of the organic and inorganic parts of the mineralized bone fraction. They are active both in the processes of the physiological renewal of the bone and in those of its pathological loss.
Answer:
SA Node
Inter-nodal Pathways
AV Node
AV Bundle
Bundle Branches
Purkinje Fibers
The SA nodes functions first for setting pace for the heart, then the inter-nodal pathway make link b/w SA and AV node. AV node is site of delay when contraction of atria occurs. AV bundle is the mean of electrical link b/w atria and ventricle. The conveying of impulse to the inter-ventricular septum occurs through bundle branches, while conveying of impulse throughout and along the walls of ventricle occurs through Purkinje fibers.
Answer:
Option (2).
Explanation:
Zygote is formed by the fusion of the male and female gamete during the process of sexual reproduction. The zygote undergoes further development inside the female womb.
The embryonic period starts from the third week after the conception. The important organs and structure development occur during the embryonic period. The formation of three germ layers occur in this period.
Thus, the correct answer is option (2)
