The defense components of blood against infection and bleeding include all the following except platelets hormones fibrinogen antibodies
The correct answer and explanation is:
The correct answer is hormones.
The defense components of blood against infection and bleeding are mainly platelets, fibrinogen, and antibodies. Each of these plays a crucial role in protecting the body.
- Platelets are critical in preventing bleeding. When a blood vessel is injured, platelets adhere to the damaged area and aggregate to form a temporary plug. This process, known as platelet aggregation, helps reduce blood loss. Platelets also release chemical signals that trigger the coagulation cascade, leading to the formation of a more stable clot.
- Fibrinogen is a protein found in blood plasma. It is converted into fibrin during the clotting process. Fibrin strands form a mesh that strengthens the platelet plug, stabilizing the clot and preventing further bleeding. Fibrinogen is part of the coagulation system, which is essential in wound healing and maintaining hemostasis.
- Antibodies are proteins produced by B cells as part of the immune response. They play a key role in defending the body against infections. Antibodies recognize and bind to specific pathogens, marking them for destruction by other immune cells or neutralizing them directly. This process is known as adaptive immunity.
Hormones, however, are not directly involved in the defense against infection or bleeding. While hormones like adrenaline, cortisol, and others regulate many physiological functions, including immune response and clotting to some extent, they do not directly contribute to the mechanisms that stop bleeding or fight infections. Their role is more regulatory rather than being part of the active defense components like platelets, fibrinogen, and antibodies.
Thus, hormones are not part of the direct defense against infection and bleeding, distinguishing them from the other components in the list.