Sun21November0735PM 4

The blood flow to any organ of the body can be determined using the Fick principle.

Which of the following organs has the highest blood flow at rest (ml/minute/100g)?

(Please select 1 option)

Thyroid gland

Heart muscle Incorrect answer selected

Carotid body This is the correct answer

Kidney

Brain

Explanation

The carotid bodies are small clusters of peripheral chemoreceptors that are highly sensitive to changes in the composition of the arterial blood flowing through it. They are located at the bifurcation of the common carotid.

Each carotid body is approximately 5 mm long, ovoid in shape and embedded in the tunica adventitia of the carotid artery. The carotid bodies are primarily sensitive to changes in PaO2 but also PaCO2 and pH. They are also sensitive to changes in blood pressure, blood flow, blood osmolarity and temperature.

The carotid bodies are derived from cells from the neuroectoderm and these secrete dopamine and noradrenaline. Changes in PaO2 result in afferent impulses relaying to the brainstem via glossopharyngeal nerve. They have the highest blood flow (for their size) in the body.

Organ Blood Flow (ml/minute/100 g)

Hepatoportal 58

Kidney 420

Brain 54

Skin 13

Skeletal muscle 2.7

Heart 87

Carotid body 2000

Thyroid gland 560

Blood flow to organs of the body at rest.

Answer Statistics

1

13%

2

6%

3

52%

4

18%

5

13%

Times answered: 249