A&P II Exam 1; Packets 1 & 2

Endocrine glands secrete what?

Hormones

What system does the endocrine system work with to control body activities and maintain homeostasis?

Nervous system

The endocrine system releases chemical messengers called what?

Hormones

What can hormones be produced by?

Cells, tissues, glands or organs

What does the word hormone mean?

To set in motion

What is the function of hormones?

To regulate the physiological and metabolic activities of cells.

What do circulating hormones release their effect on?

A target cell

Which two systems lack anatomical continuity?

Endocrine and lymphatic

Which system has a quicker response time, Nervous or Endocrine?

Nervous

Which system has a longer duration time, Nervous or Endocrine?

Endocrine

What is the pathway type of the endocrine system?

Extracellular fluid (blood)

What is the pathway type of the Nervous system?

Neurons

What are the 5 major effects of hormones?

1. AIDS in reproduction

2. Growth and development

3. Mobilizing body’s defense against stressors

4. Maintain water and electrolyte balance

5. Regulates cell metabolism and energy levels

What makes endocrine glands different from exocrine glands?

Ductless glands (secreted directly into ECF or blood)

Which glands are both endocrine and exocrine?

Pancreas and testes

What are the 9 endocrine glands?

1. Pituitary gland

2. Pineal gland

3. Thyroid

4. Parathyroid gland

5. Thymus

6. Adrenal gland (suprarenal)

7. Ovaries

8. Pancreas

9. Testes

What gland is important for building immunity when young but atrophies as you age?

Thymus

What makes exocrine glands different from endocrine glands?

Have a duct and do not secrete hormones

What does the exocrine gland, goblet cells, secrete?

Mucus

What does the exocrine gland, sebaceous, secrete?

Sebum / oil

What does the exocrine gland, eccrine, secrete?

Sweat

What does the exocrine gland, ceruminous, secrete?

Ear wax

What does the exocrine gland, salivary, secrete?

Saliva

What does the exocrine gland, lacrimal, secrete?

Tears

What does the exocrine gland, mammary, secrete?

Milk

What does the exocrine gland, testes, secrete?

Sperm

What does the exocrine gland, pancreas, secrete?

Digestive enzymes

What are some additional structures, besides glands, that contain endocrine tissue, or makes hormones?

Hypothalamus, atria (heart), kidney, small intestine, stomach, placenta, skin, adipose tissue

What is the only temporary endocrine gland?

Placenta

Hormones can have two effects, what are they?

Specific or general

What is an example of a specific affect or a localized affect of a hormone?

Oxytocin causes labor contractions

What is a an example of a general effect or an overall effect of or hormones

Growth hormones affect most of the body

When a hormone only affects one or just a few different types of cells, it is called a what?

Specific effect

Hormones that affect many different types of cells have what kind of affect?

General effect

90% of hormones are _______________, and 10% are __________.

Amino acid based hormones, steroids

What are steroids synthesized from?

Cholesterol

What are the 3 classes of amino based hormones?

Monoamines, peptides, and proteins

Thyroxine, epinephrine and norepinephrine are which class of hormone?

Monoamines

Oxytocin and anti-diuretic hormones are a part of which class of hormones?

Peptides

Insulin and prolactin are a part of which class of hormones?

Proteins

What is a long chain of amino acids called (50 or more)

Proteins

What are short chains of amino acids called?

Peptides

Where are receptors on amino acids located?

Outside of cell

Where are receptors on steroids located?

Inside

Monoamines are a modification of which amino acid?

Tyrosine

Steroids are lipid-soluble hormones that are made by which three structures?

Adrenal cortex, ovaries and testes

What are the 3 classes of hormones?

Amino acids, steroids and prostaglandins

What are biologically active lipids associated with nearly all cell membranes?

Prostaglandins

Prostaglandins are potent in very _______ amounts

Small

Which of the three classes of hormones do not travel, instead, they work where they are released, so they are nicknamed “local hormones”?

Prostaglandins

What are some of the effects of prostaglandins?

Increase blood pressure, promotes blood clotting, causes fever, increases pain (all inflammatory processes)

Which medication blocks prostaglandins formation?

Aspirin

What do hormones open in order to change plasma membrane permeability?

Ion channels

Hormones make (or synthesize) what at a cellular level?

Proteins

Hormones activate or deactivate ___________ at the cellular level.

Enzymes

True or False: Hormones increase secretory activity.

True

True or False: Hormones can increase mitosis

True

The ability of a target cell to respond to a hormone depends in the presence of specific _______ on the plasma membrane to which the hormone can bond.

Receptors

The extent of hormone effect on a target cell depends on which 3 factors?

Blood level concentration, number of receptors (on target cell), affinity (between the hormone and receptor)

Are receptors numbers constant, do they stay the same?

No, they vary on the needs of the body

If there are persistent low levels of a hormone, _________ (more / less) receptors are formed, causing ___________.

More, upregulation

If there is prolonged exposure to high levels of a hormone, _________ (more / less) receptors are formed, causing ___________.

Less, down regulation

This process helps prevent overreacting to HIGH hormone concentractions

Down-regulation

This process helps prevent overreacting to LOW hormone concentractions

Up regulation

What are the three different types of interactions that hormones can have on target cells?

Permissiveness, synergism and antagonism

Which interaction of hormones is it when one hormone cannot exert its full effects without another hormone being present?

Permissiveness

What type of hormone interaction is this example: Reproductive hormones cause the development of the reproductive system. Thyroid hormones are also necessary for the normal timely development of the reproductive system. Lack of thyroid hormones will delay reproductive development. Thyroxine has a ____________ effect.

Permissive

What type of hormone interaction occurs when more than one hormone produces the same effects at the target cell and their combined effects are augmented (increased).

Synergism

What type of hormone interaction is this example: Glucagon and Epinephrine both target the liver to release glucose into the bloodstream. Working together they release 150% of what is released when each hormone acts alone.

Synergism

What type of hormone interaction is occurring when one hormone has the opposite effect of another hormone.

Antagonism

What type of hormone interaction is this example: Insulin and Glucagon regulating blood sugar levels. Insulin decreases blood sugar levels and glucagon raises blood sugar levels.

Antagonism

What are the two mechanisms/ systems of hormones actions?

Secondary messenger systems and direct generation activation systems.

Can amino-acid based hormones pass through plasma?

No

Which hormone type is a primary messenger and needs to act through secondary messengers?

Amino-acid based hormones

What are the 6 steps in the secondary messenger systems?

1. Hormone binds to receptor

2. Receptor activates g-protein

3. G-protein activates special enzyme (like adenylate cyclase)

4. Adenylate cyclase converts ATP to cAMP

5. CAMP activates protein kinases that causes cellular changes

6. CAMP diffuses through the cell and acts as secondary messenger

Which hormones are permeable to the plasma membrane?

Lipid-based hormones

Which hormone can synthesize proteins and cause cellular changes that produce a physiological effect?

Lipid-based hormones

Do steroid based hormones require a secondary messenger?

No

Do all amino-acid based hormones have a receptor on the outside? If not what is the exception?

No, iodine is needed for thyroid hormones to become permeable

Hormones are controlled by _________ (positive or negative) feedback

Negative

The amount of hormone produced depends on what?

The body’s needs

The half life of a hormone varies by what amount of time?

A second to a week

What are the 3 possible ways that an endocrine gland can by stimulated?

Hormonal stimuli, humoral stimuli, neural stimuli

What type of endocrine gland stimulation is it when a hormone stimulates another endocrine gland to release its hormones?

Hormonal stimuli

What type of endocrine gland stimulation is it when Changes in the concentration of chemicals, ions or nutrients in the blood stream stimulate another endocrine gland endocrine gland to release its hormone.

Humoral stimuli

What type of endocrine gland stimulation is it when Nerve impulses stimulate another endocrine gland endocrine gland to release its hormones.

Neural stimuli

What type of endocrine gland stimulation is happening in this example: Thyroid stimulating hormone (TSH), a hormone made by the anterior pituitary causes the thyroid gland to release Thyroid hormones (T3 and T4)

Hormonal stimuli

What type of endocrine gland stimulation is happening in this example: Adrenocorticotropic hormones (ACTH) made by the anterior pituitary causes the release of hormones from the adrenal cortex?

Hormonal stimuli

What type of endocrine gland stimulation is happening in this example: When blood levels of glucose are high- this causes the release of the hormone insulin to lower blood glucose levels.

Humoral stimuli

What type of endocrine gland stimulation is happening in this example: When blood levels of calcium ions are high (depleting bone tissue) this causes the released of the hormone calcitonin to lower blood calcium levels.

Humoral stimuli

What type of endocrine gland stimulation is happening in this example: The sympathetic nervous system causes the adrenal gland to release EP

Neural

What type of endocrine gland stimulation is happening in this example: the hypothalamus (a neuroendocrine gland) causes the posterior pituitary to secrete oxytocin and anti-diuretic hormone (ADH)

Neural stimuli

What is the master gland because it controls so many things.

Pituitary gland (hypophysis)

Where is the pituitary gland (hypophysis) located?

The sella truck a of sphenoid bone

What are the divisions of the pituitary gland (hypophysis), that are structurally and functionally independent of each other?

Anterior and posterior lobes

What structure is the posterior lobe of the pituitary gland (hypophysis) attached to?

Hypothalamus by the infundibulum

The anterior lobe of the pituitary gland (hypophysis) Is called the what?

Adenohypophysis

What type of cell tissue is the anterior lobe comprised of?

Glandular epithelial cells

Which lobe of the pituitary gland (hypophysis) is referred to as a “true endocrine gland” because it produces hormones?

Adenohypophysis

What are the portal veins that deliver blood from the hypothalamus to the pituitary gland called?

Hypophyseal portal system