A&P II Exam 1; Packets 1 & 2

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

Nervous system

What can hormones be produced by?

Cells, tissues, glands or organs

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 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

Which glands are both endocrine and exocrine?

Pancreas and testes

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

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 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

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

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

Hypophyseal portal system

Is there a direct neural connection between the hypothalamus and the Adenohypophysis?

No

How do releasing and inhibiting hormones in the hypothalamus travel to regulate the anterior pituitary hormones?

Via the hypophyseal portal system

Which hormone stimulates the anterior pituitary to release hormones?

Releasing hormones

What hormones inhibit the anterior pituitary from releasing hormones?

Inhibiting hormones

The anterior pituitary and hypothalamus have a ___________ connection.

Vascular

Which lobe of the pituitary gland (hypophysis) is composed of neuron cell bodies, axon tracts and axon terminals that store and release oxytocin and antidiuretic hormone?

Posterior lobe (neurohypophysis)

Is the posterior lobe (the neurohypophysis) of the pituitary gland a true endocrine gland?

No

The hormones __________ and _________ are transported down the axons of the ___________ ___________ _________ to the posterior pituitary (neurohypophysis).

Oxytocin and anti-diuretic hormone, hypothalamic hypophyseal tract

The posterior pituitary (neurohypophysis) and the hypothalamus have a _______ connection.

Neural

What is the set of veins that runs from the hypothalamus to the Adenohypophysis (anterior pituitary gland) called?

Hypophyseal portal system

What is the name of the veins that runs from the hypothalamus to the neurohypophysis (posterior pituitary)

Hypothalamic-hypophyseal tract

What are the tropic hormones produced by the Adenohypophysis (anterior pituitary gland)?

TSH, ACTH, FSH and LH

Which hormones regulate the action of other endocrine glands?

Tropic hormones

Which hormones are not tropic hormones produced by the Adenohypophysis (anterior pituitary gland)?

GH and PRL

Most anterior pituitary hormones affect target cells using ______ as their secondary messenger

Cyclic AMP

Is cyclic AMP used by amino acid or steroid based hormones?

Amino acid based

Which anterior pituitary hormones regulate does not use cyclic AMP as their secondary messenger to affect target cells?

GH

What is an additional name for growth hormone?

Somatotropin

Is growth hormone a tropic hormone?

No

What does growth hormone target?

Body cells, bones and skeletal muscle

What does growth hormone stimulate the liver to release?

Insulin-like Growth Factors (IGFs)

Which growth promoting protein stimulated by GH increases the uptake of nutrients from the blood and helps cells pick up amino acids to increase protein synthesis?

Insulin-like Growth Factors (IGFs)

Is GH acting as a direct or indirect mediator in this example: GH stimulates the liver to release growth promoting proteins called Insulin-like Growth Factors (IGFs) which increases the uptake of nutrients from the blood. Insulin-like growth factors help cells pick up amino acids which increased protein synthesis.

Indirect mediator

Which hormone of the anterior pituitary gland (Adenohypophysis) transports fats from fat depots to other body cells?

GH

Which hormone of the anterior pituitary gland (Adenohypophysis) promotes fat catabolism (breaking down lipids)?

GH

Which hormone of the anterior pituitary gland (Adenohypophysis) releases fatty acids into the bloodstream and can be used as fuel for body cells?

GH

In this example is GH acting as a direct or indirect mediator: GH promotes glycogenolysis (glycogen breaking down to glucose). GH promotes carbohydrate catabolism. Glucose is released into the blood stream.

Direct mediator

Is Thyroid Stimulating hormone (TSH) is a ___________ (tropic, gonadotropin, not tropic) hormone?

Tropic

Adrenocorticotropic Hormone (ACTH) is a _________ (tropic, gonadotropic, not tropic) hormone

Tropic

Which of the anterior pituitary gland (Adenohypophysis) hormones stimulates the adrenal cortex to secrete and release its hormones (especially glucocorticoids) that help the body resist stress.

ACTH