Question

1. First, discuss one scenario where vasoconstriction may be triggered in the body. Then, discuss a second scenario where vasodilation may be triggered in the body

2. Why is a four-chambered heart critical to enabling organisms to regulate their own body temperature ( i.e., they are endotherms)?

Answer 1

1)

one scenario where vasoconstriction may be triggered in the body.

Hypotension:

Vasoconstriction is narrowing or constriction of the blood vessels. It happens when smooth muscles in blood vessel walls tighten. This makes the blood vessel opening smaller. Vasoconstriction may also be called vasospasm. Vasoconstriction reduces the volume or space inside affected blood vessels. When blood vessel volume is lowered, blood flow is also reduced. At the same time, the resistance or force of blood flow is raised. This causes higher blood pressure.

Normal haemostasis after trauma involves vasoconstriction, platelet adhesion and aggregation to form a platelet plug, fibrin formation, and fibrinolytic processes which ultimately remove deposited fibrin.

Smooth muscle contraction (ie, vasoconstriction) limits blood flow into the erectile tissue and maintains the male organ in the nonerect (flaccid) state.

scenario where vasodilation may be triggered in the body

Hypertension

Vasodilation is the widening of your blood vessels. It happens when smooth muscles found in the walls of arteries or large veins relax, allowing the blood vessels to become more open. This leads to an increase in blood flow through your blood vessels as well as a decrease in blood pressure.

It happens naturally in your body when an increase in blood flow to tissues in your body is needed. It’s a normal process but it can also be part of health issues.

Erection occurs with the relaxation of arteriolar and sinusoidal smooth muscle (ie, vasodilation).

2)

The four chambered heart keeps oxygenated and de-oxygenated blood well separated from each other which helps in maintaining a constant body temperature but if the heart is less than four chambers, then there is a chance that oxygenated and deoxygenated blood gets mixed which will not maintain particular temperature for the body.