Apocrine glands are restricted in men to hairy regions of the body, and are lined by a single layer of tall columnar cells with acidophile cytoplasm (thriving in a relatively acid environment).
2. The largest of the three major salivary glands, it is located in front and below the ear and behind the jaw bone.
The other two glands are the submandibular located deep in the mandible, or jaw bone (submaxillary), and sublingual (underneath the tongue).
Borrowed from New Latin pituitarius, from Latin pituitarius, "mucous"; relating to phlegm, from pituita, "phlegm, mucus".
The name for the gland in the brain was adopted from the Latin word for phlegm or mucus, because it was believed in the 1500's and 1600's that the pituitary gland channeled mucus to the nose.
The main endocrine gland
It is a small structure in the head called the master gland because it produces hormones that control other glands and many body functions including growth. The pituitary consists of the anterior and posterior pituitary.
The anterior pituitary is the front portion of the pituitary where hormones secreted by it influence growth, sexual development, skin pigmentation, thyroid function, and adrenocortical function.
These influences are exerted through the effects of pituitary hormones on other endocrine glands except for growth hormone which acts directly on cells.
The effects of under function of the anterior pituitary include growth retardation (dwarfism) in childhood and a decrease in all other endocrine gland functions normally under the control of the anterior pituitary; except the parathyroid glands.
The results of over function of the anterior pituitary include overgrowth (gigantism) in children and a condition called acromegaly in adults.
The posterior pituitary is the back portion of the pituitary which secretes the hormone oxytocin which increases uterine contractions and antidiuretic hormone (ADH) which increases re-absorption of water by the tubules of the kidney.
Underproduction of ADH results in a disorder called diabetes insipidus characterized by the inability to concentrate the urine and, consequently, excess urination leading potentially to dehydration. The urine is "insipid"; that is, overly dilute.
This organ is important in the development of the immune response in the newborn. Its removal during early chilhood has been associated with an increased susceptibility to acute infectious diseases at a later time.
The thymus is essential to the maturation of the thymic lymphoid cells, called T cells. When the T cells enter the circulation, they are the small-sized and medium-sized lymphocytes which may survive for up to five years. These cells are important in the body's cellular immune response.
- The cortex (outer part) secretes various steroid hormones and other hormones that control salt and water metabolism and regulate the use of carbohydrates, proteins, and fats.
- The medulla (inner part) secretes the hormones adrenaline and noradrenaline which, during times of stress, prepare the body for "fight or flight".
The metathorax is the posterior of the three segments in the thorax (area between the head and the abdomen) of an insect, and bears the third pair of legs.
Its principal sclerites (exoskeletal plates) are the metanotum (dorsal), the metasternum (ventral or lower surface of an animal's body), and the metapleuron (lateral) on each side.