Aphy 102 - Midterm Study Guide- Questions With Complete Solutions

What is a hormone and how does it act? correct answer: Hormones are chemical messengers that are responsible for regulation. They are secreted into body fluids, mainly blood. It has specific actions on target tissues, which are any tissue that has specific receptors for that particular hormone. Role of negative feedback in control of hormone secretions correct answer: Most hormones are controlled by negative feedback, in which the hormone feeds back to decrease its own production. This type of feedback brings things back to normal whenever they start to become too extreme. Differentiate between paracrine, autocrine, endocrine, and exocrine glands correct answer: Paracrine - hormones enter the interstitial fluid but affect only neighboring cells.Autocrine - hormones affect only the secreting cell.Endocrine - hormones are secreted from the interstitial fluid into the bloodstream and act on target cells.Exocrine - secretions enter tubes or ducts that lead to body surfaces. Where can the different endocrine glands be found in the body? correct answer: Thymus - in the chest.Pineal gland - in the skull.Reproductive organs - in the pelvis.Pituitary - in the skull. Adrenal glands - in the abdomen.Pancreas - in the abdomen. Describe steroid hormones and their mechanism of action correct answer: Sex hormones and adrenal cortex hormones. Steroid hormones diffuse through cell membranes and enter cytoplasm or nucleus. Then they combine with a re