What is the primary function of lymph nodes?

A. The endocrine system uses hormones for signaling, while the nervous system uses neurotransmitters.: The endocrine system releases chemical messengers (hormones) into the bloodstream that act on distant targets, while the nervous system transmits signals using neurons that release neurotransmitters at synapses for rapid, localized communication.
B. The endocrine system uses electrical signals, while the nervous system uses chemical signals.: The endocrine system relies on chemical hormones rather than electrical impulses; electrical signals are a primary feature of neuronal (nervous) communication.
C. The nervous system generates responses that take longer to occur compared to the endocrine system.: Nervous-system responses are typically rapid and short-lived because of fast electrical conduction and synaptic transmission, whereas endocrine responses are usually slower to start but longer-lasting.
D. Both systems use hormones for signaling but at different speeds.: While the endocrine system primarily uses hormones, the nervous system mainly uses electrical impulses and neurotransmitters; hormones can modulate neural function but the two systems do not both primarily use hormones.

A. To stimulate the breakdown of fats and proteins:Insulin generally promotes anabolic processes (glucose uptake and storage) rather than catabolism of fats and proteins.
B. To increase blood glucose levels during fasting:Insulin lowers blood glucose; hormones such as glucagon raise blood glucose during fasting.
C. To lower blood glucose levels by facilitating cellular uptake of glucose:Insulin promotes glucose uptake by muscle and adipose tissue and stimulates glycogen synthesis, thereby lowering blood glucose.
D. To regulate calcium absorption in the intestines:Calcium absorption is regulated primarily by vitamin D and parathyroid hormone, not insulin.