Which bones are formed by intramembranous ossification?

Also known as platelets, are cell fragments in the blood that play a crucial role in blood clotting or coagulation. When a blood vessel is injured, thrombocytes are activated and clump together to form a platelet plug that stops the bleeding. They also release substances that promote blood clotting and help to repair the damaged blood vessel. Therefore, the function of thrombocytes is important in preventing excessive bleeding and promoting wound healing. Options a, c, and d are incorrect because they do not describe the function of thrombocytes.

Lysosomes contribute to phagocytosis in white blood cells by fusing with the phagosome, which is the membrane-bound vesicle that engulfs the foreign particle or pathogen during phagocytosis. The lysosomes contain hydrolytic enzymes that can break down the engulfed material, thereby helping to destroy the invading pathogen. Additionally, lysosomes can also release reactive oxygen species and other antimicrobial molecules that further aid in the destruction of the pathogen.

Vacuoles, endoplasmic reticulum, and Golgi apparatus do not directly contribute to phagocytosis in white blood cells. Vacuoles are used for storage in cells, while the endoplasmic reticulum and Golgi apparatus are involved in protein synthesis and processing.

After birth, blood is primarily produced in the red bone marrow of the infant. Red bone marrow is a spongy tissue found in the hollow centers of certain bones, such as the skull, ribs, pelvis, and long bones of the arms and legs. Red bone marrow is responsible for producing red blood cells, white blood cells, and platelets.

In adults, some of the blood production shifts to other organs such as the spleen and liver. However, in infants, the red bone marrow is the main site of blood cell production until about 5 years of age when it begins to gradually transition to the other organs.

Dermal papillae are small, raised structures in the dermis of the skin. They contain nerve endings, capillaries, and other specialized cells. Dermal papillae are responsible for creating fingerprints, as they push up into the epidermis and create ridges on the surface of the skin. These ridges are what give each person their unique patern of fingerprints. Sudoriferous glands are responsible for producing sweat, Merkel cells are involved in touch sensation, and arrector pili are responsible for the contraction of hair follicles