The only immunoglobulin that has been shown to be able to cross the placenta is IgG. This is important in that it confers short term immunity to the fetus that continues into the first few months of the infant's life. Note that it is common to give Rh-negative anti-Rh IgG injections at about 28 weeks gestation; a booster may also be given at about 34 weeks gestation.

Insulin is produced by beta cells of the pancreatic islets. Insulin's action is to decrease blood glucose, facilitating its uptake into cells. Alpha cells produce glucagon, which has the opposite effect as insulin. Delta cells produce somatostatin, which inhibits many digestive processes. and gamma cells produce pancreatic polypeptide, which regulate pancreatic secretion. 

The pituitary is located just below the hypothalamus. The pituitary and the hypothalamus are connected by nerves and maintain an important working relationship with one another. Both are located near the base of the brain. 

Interleukins (IL) are cytokines that play a role in signaling the immune cells. IL-8 is produced mainly by macrophage and dendritic cells and plays a major role in inflammation as a chemoattractant for neutrophils. IL-1 and IL-6 both induce acute phase proteins. TNF-alpha is involved in the acute phase reaction. It is an endogenous pyrogen (meaning it induces fever) and is also involved in apoptosis and tumor inhibition. 

Lysozymes are a group of defense enzymes found in tears, saliva, mucus, and breast milk. It is considered part of our innate immune systems, as its presence in tears prevents infectious conjunctivitis. Cathelicidin, Defensin-5, and DEFA1 are found in the lysosomes of polymorphonuclear leukocytes (PMN's) and macrophages.

Major histocompatibility complex 1 in a membrane protein that binds to peptide fragments from pathogens such as viruses and bacteria and then displays them on the cell surface in order to alert other immune cells of the presence and nature of infection.

All cells with nuclei express MHC-1. Red blood cells do not have nuclei, and do not express MHC-1 on membranes.

Antibodies are only produced by B cells, specifically by a type of specialized B cell called a plasma cell. B cells belong to a broader category of leukocytes known as lymphocytes, which are agranulocytes.

T lymphocytes are so titled because they mature in the thymus, unlike B lymphocytes, which mature in the bone marrow. The thymus is located in the anterior superior mediastinum, ventral to the heart and dorsal to the sternum. It is most active in the neonatal and pre-adolescent periods, afterwards, it degenerates and is replaced with adipose tissue. 

Lymphoid progenitor cells are produced in all of the following tissues: the liver, the bone marrow, spleen, and gut associated lymphoid tissue (mainly found in the liver and intestines). However, note that the vast majority of all blood cells are produced in the red bone marrow of long bones by hematopoietic stem cells. 

While all of the cells listed may have some indirect involvement in the overall response to a parasitic infection, eosinophils are the only immune cells that are specialized to respond to multicellular parasites, especially helminths such as hookworms and pinworms.