Endocrine Monday, Wk 1

What is endocrinology?

Study of signaling molecules and how they maintain body system homeostasis

Signaling molecules aka _____

Signaling Ligands

What is gigantism?

Occurs when pituitary over produces growth hormone in children

What is acromegaly?

occurs when pituitary starts overproducing growth hormone in an adult

What do signaling molecules do?

Modulate all body system functions, and allow cells and organs to communicate with each other

What do signaling molecules communicate about?

Potentially devastating changes in external and internal environment of organ systems

It could also be said that signaling molecules help keep the body's organ systems in ______?

Homoeostasis

How is homeostasis acheived?

Mechanisms must be in place to adjust/modulate highs and lows of body systems

What two things are very important to be maintained in homeostasis?

Intracellular and extracellular fluids

What are the transcellular fluid akas?

Synovial fluid, pericardial fluid

What two spaces have similar osmolalities?

Intra-vascular space, interstitium

What pump is important for cell osmolality?

Sodium potassium pump

Where do cells live? what substance surrounds them?

Tissue, organ; interstitium

What is the interstitium a part of?

Extracellular fluid or extracellular fluid compartment

There are two types of extracellular fluid; interstitial and blood. What are they?

Interstitial: watery substance that cells sit in

Blood fluid (plasma): contained within blood vessels

What are the three major/key compartments of the body?

Intravascular space, interstitium, intracellular space

What is the normal osmolality of the three body compartments?

roughly the same

What are the three major solutes of the body?

Na+ (sodium), HCO3- (bicarbonate), Cl- (chloride)

What three extracellular fluid structures are very important?

Transcellular, blood/serum, and interstitial fluid compartments

A patient develops diabetes insipidus, and therefore salty blood. This condition is called...

Hypernatremia

What causes hyperosmoality?

Hypernatremia

What happens during hypernatremia?

Capillary is freely permeable to sodium chloride, quickly equalizing with salt

What happens to the interstitium in a patient with hypernatremia?

Flooding of the interstitium; edema/anasarca

What happens to the cell during hypernatremia?

Will become slightly hypertonic

What is osmolality?

Concentration of dissolved solutes (Na+) in a solution expressed as solutes per kilogram

What is tonicity?

The ratio between solute and water in the bodily fluids

What is osmosis?

Water moving from an area of lower solute concentration to higher solute concentration

Why does water move from low to high concentration?

The ratio of water must always be the same on each side of the semi-permeable membrane

What are the 6 different types of ligand?

Steroid hormones, peptide hormones, neurotransmitters, gases, eicosanoids, plant hormones

What fluid components must be in balance in major ions?

Na+, Cl-, HCO3-

What fluid components must be in balance in hormones?

Glucagon, insulin

If any body system lose homeostatic balance, those systems and their tissues will become?

Stressed, damaged/ischemic, dead/necrotic/gangrenous

_____ may occur if homeostasis is not reestablished soon.

Death

What are 4 key body systems that help maintain homeostasis?

Endocrine system, skeletal muscles, blood and circulatory system, lymphatic system

A homeostatic system is made up of three components which are?

Sensors, control center, effectors

Sensors will signal when homeostatic systems are?

In balance

The control or integrating center's function is to?

Receive messages from sensors, processes them, and takes action if needed

What are some examples of the control center?

Brain, hypothalamus, adrenal gland, kidney, thyroid

What is the function of the effectors?

Receives signals from control center and responds in a way to restore homeostasis

Organ system homeostatic mechanisms are maintained via two types of feedback control systems which are?

Negative and positive feedback cycle

Most common type of feedback cycle?

Negative

Negative feedback cycles reestablish homeostasis by?

Turning off some factor that has built up too high of a level causing stress

What negative feedback loop is a classic example of a double negative feedback cycle?

Cortisol

What are two other classic examples of negative feedback cycles?

Body core temperature and blood pressure rising

With high blood sugar (hyperglycemia) it stimulates receptors in the?

Pancreas

The pancreas will sense hyperglycemia and signal _______ cells to release ______

Islets of Langerhans's beta cells; insulin

Insulin stimulate cells of the body to?

Soak up blood sugar

With the release of insulin this will decrease blood sugar levels causing what?

The pancreas would no longer sense high blood sugar, inhibiting secretion of insulin

When blood sugar gets too low (hypoglycemia) the receptors in the pancreas will signal ______ cells to release _____.

Islets of Langerhans's Alpha cells; glucagon

Glucagon stimulates cells in the ____ to release ____

Liver; sugar into the bloodstream

Release of sugar into the bloodstream is called?

Glycogenolysis

Hyperglycemia means ____ is turned off and ____ is turned on .

Glucagon is turned off; insulin is turned on

Hypoglycemia means ____ is turned off and ____ is turned on

Insulin is turned off; glucagon is turned on

How does positive feedback loop occurs?

When the release of a ligand directly or indirectly stimulates more release of the same ligand

Common examples of positive feedback loops

Oxytocin, prolactin, estrogen and luteinizing hormone

Biological males that develop breast tissue is a condition called?

Gynecomastia

What are the 4 parts of the breast?

Base, Body, Nipple, Areola

The breast internally contains a _____ and ____ system which is designed to produce, store and distribute ____.

Glandular and ductal system; milk

The glandular and ductal system lives within a ____ derived from mesoderm.

Stroma

Suspensory ligament of the breast aka

Cooper's ligament

Where is the milk made in the breast (general region)?

Glandular ductal system

Milk is made specifically in a glandular structure called the?

Mammary gland

Each mammary gland contains about ___ lobes, and each lobe contains about ___ lobules.

20; 6

The aka for the mammary lobule is?

Terminal duct lobar unit (TDLU)

The lobule, aka TDLU is considered what kind of gland?

a tubular acinar gland

Each lobule contains ____ secreting structures called ____.

12; alveoli

Alveoli are sacs of secretory cells that make milk just after ____

Parturition

Parturition is?

The process of birthing a baby

Alveoli are sacs of secretory cells made up of what cell type?

Cuboidal epithelial cells

During pregnancy, females experiences high levels of two hormones which are?

Estrogen and progesterone

Estrogen and progesterone block the effects of the hormone that stimulates the alveoli to make milk which is?

Prolactin

The hormone levels of estrogen and progesterone ____ the instance the child and placenta is delivered.

Plunge

Milk drains out of each alveolus into a ____.

Interlobular duct

Multiple interlobular ducts will merge into larger _____.

Lactiferous ducts

Multiple lactiferous ducts will then further drain into a much larger?

Lactiferous sinus

AKAs for lactiferous sinus?

Teat canal, ampulla

How many lactiferous sinuses are there?

15 to 20

The lactiferous sinuses connects to?

The nipple

______ cells cover each of the alveolus.

Myoepithelial cells

Myoepithelial cells can be contracted to?

Eject milk out the breast

What hormone causes myoepithelial cells to contract?

Oxytocin

What type of muscle is the myometrium made up of?

Smooth muscle

The anterior portion of the pituitary is called _____.

Adenohypophysis

The posterior portion of the pituitary is called ____

Neurohypophysis

What are the two parts of the pituitary that make up the stalk/infundibulum?

Pars tubularis (ant. pituitary);

Infundibular stalk (post. pituitary)

What are the two nuclei of the adenohypophysis?

Paraventricular hypothalamic nucleus;

Supraoptic hypothalamic nucleus

Where are the posterior pituitary hormones made?

Hypothalamus

Where are the anterior pituitary hormones made?

Anterior pituitary