Medical Terminology: Word Parts and Hormones

Medical Terminology Word Parts

• "acr/o" means at the extremities.
• "ad-" means to, toward.
• "anti-" means against.
• "calc/o" means calcium.
• "cortic/o" means cortex, outer portion.
• "crin/o" means to secrete.
• "-emia" means blood condition.
• "endo-" means inner, within.
• "epi-" means upon, over, above.
• "exo-" means outward.
• "glyc/o, gluc/o" means glucose (sugar).
• "hyper-" means excessive, over, above.
• "hypo-" means below, under, insufficient.
• "iodo" means iodine.
• "lact/o" means milk.
• "medull/o" means inner portion.
• "-megaly" means enlargement, large.
• "nephr/o" means kidney.
• "osteo" means bone.
• "para" means beside, near.
• "ren/o" means kidney.
• "tocia" means labor, childbirth.
• "tri-" means three.
• "ur/o" means urine.

Hormones

• Hormones influence the activities of other tissues or organs throughout the body and are chemicals released in the body.
• Hormones regulate metabolism of carbohydrates, fats, and proteins.
• Hormones help transport substances through membranes.
• They help regulate water and electrolyte balance and blood pressure.
• Hormones play roles in reproduction, growth, and development.

Target Cells and Receptors

• Target organs/cells are able to respond to specific hormones because they have specific hormone receptors that are not on other cells.
• Hormones have a specific effect on specific tissues or cells.
• Some hormones like insulin and thyroid hormones have many target organs/cells.
• Other hormones, such as calcitonin and some pituitary hormones, have only one/few target organs.
• Proteins on cell membranes that bind certain are receptors.
• Because the cell has receptors for that hormone, target cells respond to certain hormones but not to others.

Receptors

• The presence of receptors determines if a hormone will affect an object.
• Receptors are proteins in/on cells into which the hormone “fits.”
• Hormones affect cells with receptors for that hormone.
• Receptors are located on the cell membrane or in the target cell's cytoplasm/nucleus.
• Liver cells have receptors for insulin & glucagon.
• Bone cells have receptors for growth hormone, parathyroid hormone (PTH), & calcitonin.

Endocrine System

• Secretion is the production and release of a substance by a gland/cell.
• Endocrine glands secrete "internally" and secretions enter the bloodstream and travel throughout the body.
• Endocrine glands are ductless.
• Hormones act on target cells some distance away from secreting glands.
• Examples: thyroid gland and adrenal gland.
• Exocrine glands secrete "externally" into ducts that lead to a surface on the body.
• Exocrine glands deliver products to a specific site.
• Examples: sweat glands secrete sweat onto skin surfaces through sweat ducts and stomach cells secrete acid into the digestive tract through ducts.

Endocrine vs Exocrine Glands

• Endocrine glands secrete hormones into body fluids/ bloodstream instead of through ducts.
• Exocrine glands secrete substances into the outside environment/onto body surfaces through ducts.

Endocrine and Exocrine Gland Examples

• Know which glands are endocrine and which glands are exocrine.
• Endocrine glands secrete into the bloodstream and include:
  • Hypothalamus
  • Pituitary gland
  • Thyroid gland
  • Pancreas
  • Adrenal glands
  • Testes
  • Ovaries
• Exocrine glands secrete onto the body surface through ducts.
  • Sweat glands
  • Salivary glands (mouth)
  • Mammary glands (breasts/milk)
  • Lacrimal glands (eyes/tears)
  • Pancreas (digestive enzymes into intestines)
• The pancreas is both an endocrine and exocrine gland.

Endocrine Gland Locations

• The major endocrine glands aren’t physically connected.
• Endocrine glands produce hormones via:
  • Hypothalamus
  • Pituitary gland
  • Thyroid gland
  • Adrenal glands
  • Pancreas
  • Ovaries
  • Testes

Hormone Action

• Hormones are released from endocrine organs into extracellular spaces around endocrine cells.
• Hormones diffuse into the bloodstream and are distributed throughout the body.

Hormones - Chemistry

• Steroid hormones are composed of lipids produced from cholesterol.
  • Examples: Sex hormones and adrenal cortex hormones (cortisol, aldosterone).
• Non-steroid hormones are composed of amino acids & proteins.
  • Examples: epinephrine/norepinephrine, growth hormone, oxytocin, TSH.
• Hormones can be made either of lipids or proteins.

Hormone - Function

• Hormones that don’t enter the target cell bind to receptors on the cell membrane, triggering events inside the cell that cause the hormone's effect.
• Some hormones enter the cytoplasm or nucleus of the cell and cause the target cell to make proteins that produce the hormone's effects.
• Hormones can affect target organs by altering the rate/speed of chemical reactions by changing the activity of enzymes and alter the rate/speed that a substance crosses a membrane.
• Hormones deliver messages by binding to their receptors on or in the target cell.
• The more hormone receptors that bind to, the stronger the response/effect on its target cell.

Hormone Secretion

• Hormone secretion is primarily controlled via negative feedback mechanisms.
• Hormone effects can be short-lived (a few minutes) or may last for days.
• Hormone secretions are regulated precisely.
• Hormones are excreted in urine and leave the body after exerting their effects.
• Enzymes break down hormones, primarily from the liver, to stop their effects.

Negative Feedback of Hormone Secretion

• Negative feedback is the primary method of controlling hormone secretion.
• Prevention of hormone overproduction from negative feedback.
• Hormone hormone level increase cause decreasing hormone secretion.
• Three methods control hormone secretion:
  • Tropic hormones act on glands to regulate hormone secretion.
    • Examples: TSH, growth hormone, and prolactin.
  • The nervous system directly stimulates some glands to their hormones (via nerve impulses).
  • Changing levels of a specific substance in the blood stimulates/inhibits of certain hormones.
    • Examples: Ions, glucose, and calcium.

Negative Feedback Loop

• Rising thyroid hormone (T4 & T3) levels in the bloodstream are detected by the hypothalamus and pituitary gland.
• Increased T4/T3 levels signal that enough thyroid hormone is present, and less TRH and TSH is needed.
• TRH causes TSH released from the pituitary gland is released by the hypothalamus.
• TSH is released from the pituitary gland and causes T4/T3 release from the thyroid gland.

Hormone Control - Three Methods

• Hormones are regulated through different routes:
• Nervous system
• Changing the internal blood environment
• Tropic hormones,

Hormone Control - Negative Feedback

• Hormone secretion is controlled via negative feedback mechanisms.
• Negative feedback ensures the hormone levels remain relatively stable, even when hormone levels might fluctuate slightly.

Pituitary Gland

• The pea-sized pituitary gland sits in the sella turcica in the sphenoid bone at the brain base. "Sella Turcica" means "Turkish saddle".
• It's attached to the hypothalamus by the pituitary stalk called the infundibulum which facilitates communication with the pituitary gland.
• The pituitary consists of two lobes, the interior and posterior.

Hypothalamic Control - Pituitary Gland

• Hypothalamic releasing hormones made in the hypothalamus regulate the anterior lobe.
• The hypothalamus is the only gland that secretes releasing hormones. They travel down the infundibulum to stimulate cells and secrete 6 hormones produced.
• Nerves through the infundibulum regulate the posterior pituitary.
• The hypothalamus produces two hormones, delivered into the posterior for storage.
• Nerve impulses stimulate these hormones to be released.

Pituitary Gland Lobes

• The anterior pituitary lobe releases stimulating hormones to stimulate the pituitary gland for hormone secretion.
• Hormones are made in the hypothalamus and are transported/stored in the posterior pituitary gland, later secreted.

Endocrine Gland Control

• The hypothalamus, an endocrine area of the human brain, controls secretion from many endocrine glands via a 3-step process.
• Hypothalamic releasing hormones act on hormone-secreting cells in the pituitary gland.
• Anterior pituitary hormones stimulate the secretions from the peripheral endocrine glands.

Anterior Pituitary Gland Hormones

• The anterior pituitary consists of glandular tissue and produces six hormones.
• Each is released in response to a releasing hormone from the hypothalamus.
• Anterior hormones:
  • Growth hormone (GH)
  • Prolactin (PRL)
  • Thyroid-stimulating hormone (TSH)
  • Adrenocorticotropic hormone (ACTH)
  • Follicle-stimulating hormone (FSH)
  • Luteinizing hormone (LH)

Hypothalamus, Anterior Pituitary, and Target Organs

• The image is helpful to study.
• Hormones from the hypothalamus:
  • CRH
  • TRH
  • PRIH
  • PRF
  • SS
  • GHRH
• Hormones from the anterior pituitary:
  • ACTH
  • TSH
  • PRL
  • GH
  • FSH
  • LH

Anterior Pituitary Hormones - Functions

• Growth Hormone (GH) stimulates cells to rapidly enlarge and divide causing growth in body tissues, bone, muscle, and some organs.
• Prolactin (PRL) promotes milk production in females.
• TSH stimulates the secretion of thyroid hormones T3 and T4 from the thyroid gland.
• ACTH stimulates the secretion of cortisol from the adrenal cortex.
• FSH causes growth and development of ovarian follicles (containing ova, eggs) in females, and spurs sperm and estrogen production.
• LH causes ovulation (egg release) in females, increases estrogen in women and testosterone in men.

Hormones

• TSH stimulates growth and thyroid hormones. It is controlled in a three-step pathway. The first two pathways are:
  • The level of TH is controlled by the thyrotropin-releasing hormone
  • The level of th is also controlled by thyroid hormones in the pathway

Growth Hormone Disorders

• Dwarfism is when someone is at 4’10 feet or shorter.
• Hypopituitary dwarfism (short) is when there is low growth hormone levels in children. Caused by the deficiency of GH.
• Gigantism (tall) - high GH levels and is generally caused by tumor

Posterior Pituitary Hormones

• The posterior pituitary consists of nerve fibers from the hypothalamus.
• Two hormones are produced by the hypothalamus neurons, stored in the posterior pituitary, transported through the pituitary stalk.
• The posterior pituary hormones are:
  • Antidiuretic hormone (ADH) which is an anti Pee hormone. If you have less of it then urine volume increases
  • Oxytocin lets out milk out of the breast

Action Control

• Look over chart on page for action, location, etc.

Pituitary Gland Control List

• The pituitary gland is not in control of all hormones.
• Anterior Pituitary:
  • Growth hormone
  • Prolactin
  • TSH
  • Cortisol from Cortex
  • Testosterone from Tests
  • Estrogen from Ovaries
• Posterior Pituitary:
  • Oxytocin
  • ADH
• Hormones not secreted by the pituitary gland:
  • Insulin
  • Glucagon Secretions
  • Aldosterone secretion
  • Epinephrine

Pituitary Hormones - Memory Trick

Mnemonic to remember: GOAT FLAP

• Anterior Pituitary
  • G - GH
  • A - ADH
  • T - TSH
  • F - FSH
  • L - LH
  • A - ACTH
  • P - Prolactin (PRL)

Thyroid Gland

• The 2 lateral lobes have an isthmus connection.
• It sets below the larynx to the trachea.
• It has the special ability to remove iodine from blood and it's needed in thyroid hormones.
• The glands produce T4, T3, Calcitonin

Thyroid Gland Structure

• It's made of round tissues called follicles
• Each follicle has one layer of fluid and cavities
• Extra cells lie outside the follicles

Thyroid - Hormones T3, T4, and Calcitonin

• Iodine is a necessary chemical formula for T3 and T4
• T4 contains 4 Iodines, T3 contains 3
• T four increases energy release from carbohydrates increases protein increase growth and increase activity
• T3 is the same, but is more potent.
• Calcitonin lowers blood calcium which is different from T3 and T4

Thyroid Disorders

• A slight abnormality in the amount can cause symptoms.
• Hyperthyroidism makes too much T4 and T3 like is seen in Graves's disease.
• Hypo is the opposite with autoimmune reactions

Disorders - The Thyroid Gland

• Infantile hypothyroidism causes T4 depletion
• Graves leads to excess T3 and T4
• Goiter leads to non-cancerous thyroid growth due to low levels of iodine.

Calcitonin

• Calcitonin lowers blood by slowing osteoclasts.
• In essence, the increased calcium gets deposited and the increased calcitonin stimulates osteoblasts - which increases calcium in the body. Also the effects on PTH have effects on bone.

Parathyroid Glands

• These are located on thyroid and can regulate calcium.
• Secrete PTH
• PTH increases calcium in blood.
• Causes bone break-down
• PTH stimulates blasts and increases the calcium in the bone.

Actions - PTH

• To increase Calcium
• Cause bones to break down
• PTH Stimulates bone tissue
• Increases calcium absorption in kidneys and intestines

The Control Parathyroid

• Look at graph for greater details

Disorders - Parathyroid

• If the hyper thyroid, there is an increase in CA in the blood because bone decreases. If there is less osteoclast less decrease of stimulation

Adrenal Gland

• Towards the kidneys. Sit like a cap! Secrections of cortex and medulla.
• Secrete 4 hormones

Hormone Release - Adrenal Glands

• Adrenal glands create the steroid hormones.
• In addition, the cortex functions as an "outer" source and will make steroids.

Adrenal Medulla

• The Adrenal Medulla (inner portion) secretes two hormones that cause the fight or flight and sympathetic response.

Control of HCS

• This consists largely of a 3-step process. If increased it leads of less of everything.

Pancreas

• The pancreas is both located exocrine and endochrine to the cavity. With both.

Secretions - Pancreas

Endocrine

• Insulin
• Glucagon Exocrine Function:
• Secret Digestive enzymes and into the intestines which is largely the surface of the intestines.

Pancreas Structure

• It largely has 2 portions, one with hormone secretion and one transporting transport juices
• With insulin transport with the blood stream
• The two transport with ducts
• Both transport both hormone by way of liquid stream, and hormones by way of the endocrine section. Making it both sections working.

Control - Blood Sugar

• The insulin decreases blood glucose, when it's high
• While the glucose increases blood when it's low; it uses glycogen which releases back into the system.
• Hyper is High
• HYpo is Low

Diabetes

• Lack of use to insult
• Lack. Of normal insult in the cells. Which leads glucose spills over, and leads damage to the body.

Continue Diabetes

• Type one where it doesn't make insulin, but the second where the body resists the substance

Diabetes tests

• The test are over diabetes. Normally fasting is sugar level. High glucose which may have had insulin resistance

Diabetes - Solutions

• Administrated insulin is required through pump or injection
• The secondary can largely be mitigated by carbohydrates

Lifetime spans

• The lifetime spans are variable across all of the stages and substances, which cause effects across all of the body.