exam 1 Flashcards
What is endocrinology?
The study of hormones and endocrine organs
How does the endocrine system influence metabolic activity?
By releasing hormones into the bloodstream
What are the main functions of the endocrine system?
- Reproduction
- Growth & development
- Electrolyte, water, nutrient, energy balance
- Mobilization of body defenses
How do the responses of the endocrine system compare to the nervous system?
Responses are slower but last longer than the nervous system
What type of substances do exocrine glands produce?
Non-hormonal substances secreted onto membrane surfaces via ducts
What is the difference between endocrine and exocrine glands?
Endocrine glands are ductless and secrete hormones directly into the bloodstream; exocrine glands have ducts and secrete non-hormonal substances
What are amino acid-based hormones also known as?
Peptide hormones
What is the primary characteristic of steroid hormones?
They are made from cholesterol and are fat-soluble
What is target cell specificity in hormone action?
Hormones will only act on cells that have their specific receptors
What factors determine cell activation by hormones?
- Blood level of hormone
- Relative number of receptors on target cell
- Affinity between receptor and hormone
What is up-regulation in hormone action?
Consistently low hormone presence stimulates the cell to generate more receptors for that hormone
What is down-regulation in hormone action?
Consistently high hormone presence stimulates the cell to lose receptors for that hormone
How do amino acid-based hormones stimulate effects?
They bind to receptors on the cell membrane, activating a signal carrier (G protein) that stimulates the release of a second messenger
What is the primary function of the hypothalamus in the endocrine system?
It regulates homeostasis and connects to the pituitary gland
What hormones are secreted by the anterior pituitary?
- Growth hormone
- Prolactin
- Thyroid-stimulating hormone
- Adrenocorticotropic hormone
- Follicle stimulating hormone
- Luteinizing hormone
What is the role of the posterior pituitary?
Releases antidiuretic hormone and oxytocin
What condition is characterized by hypersecretion of ADH?
Diabetes insipidus
What is the primary function of thyroid hormone?
It is the body’s major metabolic hormone, responsible for raising basal metabolic rate and regulating tissue growth
What are the two major forms of thyroid hormone?
- Thyroxine (T4)
- Triiodothyronine (T3)
What condition results from hyposecretion of thyroid hormone?
Myxedema
What is hyperparathyroidism caused by?
A parathyroid tumor
What hormones are produced by the adrenal cortex?
- Mineralcorticoids
- Glucocorticoids
- Gonadocorticoids
What is the main glucocorticoid hormone?
Cortisol
What is Cushing’s disease?
Hypersecretion of cortisol causing various systemic effects
