Chapter 11: The Endocrine System Dr Glotfelty Medical Terminology Chapter 11: The Endocrine System Dr Glotfelty

Endocrine System Combining Forms acr/o – extremities adren/o, adrenal/o – adrenal glands andr/o – male calc/o – calcium crin/o – to secrete estr/o – female gluc/o, glyc/o, glycos/o – sugar gonad/o – sex glands home/o – sameness kal/i – potassium ket/o – ketones mineral/o – minerals, electrolytes

Endocrine System Combining Forms natr/o – sodium ophthalm/o – eye ovari/o – ovary pancreat/o – pancreas parathyroid/o – parathyroid gland pineal/o – pineal gland pituitar/o – pituitary gland testicul/o – testes thym/o – thymus thyr/o, thyroid/o – thyroid gland toxic/o – poison

Endocrine System Suffixes –crine to secrete –dipsia thirst –prandial relating to a meal –tropin to stimulate

Signs and Symptoms Edema: swelling Exophthalmos: protruding eyeballs Glycosuria: sugar in urine Gynecomastia: female breast development in men Hirsutism: excessive hair growth Obesity: overweight (excessive body fat) Syndrome: combination of sign and symptoms

Figure 11. 11 A photograph of a woman with exophthalmos Figure 11.11 A photograph of a woman with exophthalmos. This condition is associated with hypersecretion of the thyroid gland. (Custom Medical Stock Photo, Inc.)

Pancreas Pathology Chronic disorder of carbohydrate metabolism diabetes mellitus (DM) Chronic disorder of carbohydrate metabolism Results in hyperglycemia and glycosuria Two very distinct types: - insulin-dependent - non-insulin-dependent

Acromegaly: chronic hypersecretion of growth hormone in adults; causes enlargement of bones of head and extremities Dwarfism: hyposecretion of growth hormone in children; causes short stature Gigantism: hypersecretion of growth hormone in child; results in very tall adult

Figure 11.13 illustrating the enlarged skull, jaw, and hands typical Acromegaly. Photo of a woman of acromegaly.

Thyroid Gland Pathology goiter enlarged thyroid gland

Figure 11.14 Goiter. A photograph of a male with an extreme goiter or enlarged thyroid gland.

Endocrine System Abbreviations DM: Diabetes Mellitus FBS: Fasting Blood Sugar FSH: follicle stimulating hormone IDDM: insulin dependent diabetes mellitus NIDDM: non-insulin dependent diabetes mellitus K+: potassium Na+: sodium TSH: thyroid stimulating hormone

The Endocrine System Collection of glands that secrete hormones directly into the bloodstream Target Organs: organs that hormones work on Hormones: chemicals Homeostasis: stable, balance Gland Types Exocrine: into ducts Endocrine: into blood Endocrine System consists of 2 adrenal glands, 2 ovaries, 4 parathyroid glands, the pancreas, the pineal gland, the pituitary gland, 2 testes, the thymus gland and the thyroid gland

The Endocrine System Table 11.1 pages 388-389

Figure 11.1 The adrenal glands.

Adrenal Cortex Hormones are referred to as corticosteroids Secreted by adrenal cortex Steroid hormones Three different families of corticosteroids Mineralocorticoids Glucocorticoids Steroid sex hormones

Adrenal Cortex Mineralocorticoid Glucocorticoid Example: aldosterone Regulates sodium (Na+) and potassium (K+) levels Glucocorticoid Example: cortisol Regulates carbohydrates

Adrenal Cortex Steroid sex hormones Androgens, estrogen, and progesterone Regulate secondary sexual characteristics

Adrenal Medulla Inner portion Secretes epinephrine and norepinephrine Epinephrine is also called adrenaline Critical during emergency situations Increases blood pressure Increases heart rate Increases respiration rate

Ovaries Two ovaries located in pelvic cavity of females Secrete female sex hormones, estrogen and progesterone Estrogen is responsible for: Female sexual characteristics Regulation of menstrual cycle

Ovaries Progesterone Maintains suitable uterine environment for pregnancy

Figure 11.2 The ovaries.

Testes Two oval glands located in scrotum Secrete male sex hormone, testosterone Testosterone Produces male secondary sexual characteristics Regulates sperm production

Figure 11.8 The testes.

Pancreas Located along lower curvature of stomach Only organ that has both endocrine and exocrine functions

Pancreas Insulin Produced by beta cells Stimulates cells of body to take in glucose from bloodstream Lowers blood sugar level Occurs after eating a meal and absorbing carbohydrates

Pancreas Glucagon Produced by alpha cells Stimulates liver to release stored glucose into bloodstream Raises blood sugar levels Occurs when body needs more glucose

Parathyroid Glands Secretes parathyroid hormone (PTH) Regulates level of calcium in bloodstream If calcium levels in blood fall too low: Parathyroid hormone levels in the blood increase Stimulate bone breakdown Releasing more calcium into bloodstream

Figure 11.4 The parathyroid glands.

Pineal Gland Small pine cone- shaped gland Part of thalamus region of brain

Pineal Gland Secretes melatonin Not well understood, but plays a role in regulating body’s circadian rhythm 24-hour clock that governs periods of wakefulness and sleepiness

Pituitary Gland Small marble-shaped gland Located underneath brain Divided into anterior and posterior lobes Regulated by hypothalamus

Anterior Pituitary Referred to as “master gland” Secretes hormones that regulate other endocrine glands Thyroid-stimulating hormone (TSH) Regulates function of thyroid gland Adrenocorticotropin hormone (ACTH) Regulates function of adrenal cortex

Anterior Pituitary Gonadotropins FSH Follicle-stimulating hormone (FSH) Luteinizing hormone (LH) FSH Responsible for development of ova and sperm Also stimulates ovary to secrete estrogen

Anterior Pituitary LH Stimulates secretion of sex hormones Plays a role in releasing ova in females

Anterior Pituitary Growth hormone (GH) Prolactin (PRL) Also called somatotropin Stimulates cells to grow and divide Prolactin (PRL) Stimulates milk production in breast Melanocyte-stimulating hormone (MSH) Stimulates melanocytes to produce more melanin

Figure 11.7 The different hormones and target tissues for the anterior pituitary.

Posterior Pituitary Antidiuretic hormone (ADH) Oxytocin Also called vasopressin Promotes water reabsorption by the kidney tubules Oxytocin Stimulates uterine contractions during labor and delivery After birth stimulates release of milk from breast

Thymus Gland Located in mediastinum Part of immune system Also endocrine gland Secretes thymosin

Thymus Gland Thymosin Essential for growth and development of thymic lymphocytes or T cells Critical part of body’s immune system Present at birth and grows to largest size during puberty At puberty begins to shrink and eventually is replaced with connective and adipose tissue

Figure 11.9 The thymus gland.

Thyroid Gland Located on either side of trachea Resembles a butterfly in shape Divided into right and left lobes

Thyroid Gland Thyroid hormones Needs iodine to make hormones Thyroxine (T4) Triiodothyronine (T3) Needs iodine to make hormones These hormones: Regulate energy production Adjust metabolic rate

Thyroid Gland Also secretes calcitonin Regulates level of calcium in bloodstream If calcium levels in blood rise too high: Calcitonin levels in blood increase Increases deposition of calcium into bone Lowers levels of calcium in bloodstream

Thyroid Gland Its action is opposite of parathyroid hormone

Figure 11.10 The thyroid gland is divided into a left and right lobe.

Medical Specialties endocrinology Branch of medicine involving diagnosis and treatment of conditions and diseases of endocrine glands. Physician is an endocrinologist.

Combining Forms Match Up acr/o estr/o kal/i natr/o toxic/o extremities female sodium potassium poison