In this article we will discuss about the meaning and role of peripheral resistance in cardiovascular system. Meaning of Peripheral Resistance: i. It is the resistance offered by vessel wall for flow of blood. ii. The unit used to measure resistance (pressure divided by flow) is dynes/cm. In other words, resistance in cardiovascular system is generally expressed as R units [...]
There are many theories which try to explain the mechanism of auto-regulation of blood flow. They are: 1. Myogenic theory 2. Tissue metabolite theory 3. Tissue fluid pressure theory 4. Renin-angiotensin theory, etc. (this theory is applicable only in kidneys) 1. Myogenic Theory (Fig. 3.53) According to This Theory: i. When there is an increase in pressure, initially there will [...]
The following points highlight the three important stages of swallowing. The stages are: 1. Buccal or Oral Stage 2. Pharyngeal Stage 3. Esophageal Stage. 1. Buccal or Oral Stage: By the action of tongue, and muscles contracting against the palate, the food is converted into bolus which is lubricated by saliva. The bolus is then pushed by the tongue to [...]