Histamine secreting cells are found in Connective Tissues.

Explanation:
Histamine secreting cells are known as mast cells. They are a type of white blood cells present in the connective tissues of the body. They are widely distributed throughout the body and are present in various tissues like skin, lungs, digestive system, and other organs.

Functions of Mast Cells:
Mast cells play a critical role in the immune system's response to foreign substances that invade the body. They are involved in the following activities:

1. Inflammatory Response:
Mast cells release histamine and other inflammatory substances in response to injury or infection. These substances cause the blood vessels to dilate and increase permeability, leading to the accumulation of fluid and white blood cells in the area. This results in redness, swelling, and pain.

2. Allergic Reactions:
Mast cells are involved in allergic reactions such as hay fever, asthma, and hives. When the body is exposed to allergens such as pollen or pet dander, mast cells release histamine and other substances that cause inflammation and allergic symptoms.

3. Wound Healing:
Mast cells play a critical role in wound healing. They release growth factors that promote the growth of new blood vessels and stimulate the production of new tissue.

Conclusion:
In summary, histamine secreting cells (mast cells) are found in connective tissues throughout the body. They are involved in various physiological processes, including the immune response, inflammation, and wound healing.