Human Physiology Exam I

Front 1

what are the three fluid compartments of the body?

Back 1

1. plasma (ECF)
2. interstitial fluid (ECF)
3. intracellular fluid (ICF)

Front 2

what are the functional compartments of the body?

Back 2

1. the cranial cavity
2. the thoracic cavity
3. the abdominopelvic cavity

Front 3

what are the general functions of the cell membrane?

Back 3

1. physical isolation
2. regulation of exchange with the environment
3. communication between cell and its environment
4. structural support

Front 4

all biological membranes are mostly composed of what?

Back 4

lipids and proteins

Front 5

generally, the more metabolically active a membrane is, the more _________ it contains.

Back 5

protein

Front 6

does the ratio of protein to lipid vary throughout of the body depending on the source/function of a membrane?

Back 6

yes

Front 7

what is the fluid-mosaic model?

Back 7

the contemporary model of membrane structure- phospholipids are arranged in a bilayer in which the hydrophilic heads are on the outside and the hydrophobic tails are hidden in the interior.

Front 8

what is the approximate thickness of all cell membranes?

Back 8

8 nm

Front 9

what are the three types of lipids that make up the cell membrane?

Back 9

phospholipids, sphingolipids, and cholesterol

Front 10

which region of a phospholipid is polar/hydrophilic? which region is nonpolar/hydrophobic?

Back 10

the glycerol-phosphate head of the molecule is polar and hydrophilic.

the fatty acid tail is nonpolar and hydrophobic

Front 11

the phospholipid bilayer orientation is seen in what three structures?

Back 11

1. phospholipid bilayer
2. micelles
3. liposomes

Front 12

what molecules are found on the extracellular surface of a membrane?

Back 12

-protein molecules
-glycoproteins
-glycolipids

Front 13

how are glycoproteins and glycolipids formed on the extracellular membrane of biological membranes?

Back 13

carbohydrates bind to proteins and lipids, forming glycoproteins and glycolipids.

Front 14

what is a miscelle?

Back 14

small droplets consisting of a single layer of phospholipids arranged so that the interior contains fatty acid tails. they are important in the digestion and absorption of fats in the digestive tract.

Front 15

what are liposomes?

Back 15

large spheres with phospholipid bilayer walls. the center is hollow with an aqueous core and can be filled with water soluble molecules. can be used in delivering drugs through the skin.

Front 16

what is a sphingolipid?

Back 16

one of the three main lipids found in biological membranes.

similar to phospholipids in that they too have fatty acid tails, but their heads may be either phospholipids or glycolipids.

Front 17

are cholesterol molecules mostly hydrophobic or hydrophilic?

Back 17

hydrophobic

Front 18

what role does cholesterol play in membrane structure?

Back 18

cholesterol helps make membranes impermeable to small water soluble molecules by inserting itself into the lipid layer between hydrophilic heads of phospholipids. cholesterol also helps keep the membrane flexible over a wide range of temperatures.

Front 19

what are the three types of membrane proteins?

Back 19

1. integral/transmembrane proteins
2. peripheral proteins
3. lipid-anchored proteins

Front 20

what are integral membrane proteins also called?

Back 20

transmembrane proteins

Front 21

what are integeral/transmembrane proteins?

Back 21

membrane proteins that extend all the way across the cell membrane and which are very tightly bound into the membrane

Front 22

what are peripheral proteins?

Back 22

membrane proteins that do not span the entire width of the membrane. instead these proteins are bound loosely to transmembrane/integral proteins or to the polar heads of phospholipids. can be removed without distrupting membrane

ex: enzymes and some structural binding proteins that anchor the cytoskeleton the membrane.

Front 23

what are lipid-anchored proteins?

Back 23

membrane proteins that are covalently bound to lipid tails and insert themselves into the bilayer. often found in association with membrane sphingolipids forming lipid rafts.

Front 24

what is the function of glycoproteins and glycolipids?

Back 24

they form a protective layer known as the glycocalyx

glycoproteins play a key role in the body's immune response

Front 25

Internally, the cell is divided into what two main components?

Back 25

the cytoplasm and the nucleus

Front 26

The cytoplasm of a cell consists of what?

Back 26

-fluid called cytosol
-insoluble particles called inclusions
-membrane bounds structures called organelles

Front 27

inclusions are AKA?

Back 27

nonmembranous organelles

Front 28

are ribosomes membrane bound?

Back 28

no!

Front 29

what are the three cytoplasmic protein fibers? what are they classified based on?

Back 29

the 3 families of cytoplasmic protein fibers are classified by size.

(smallest)

-actin fibers (microfilaments)
-intermediate filaments
-microtubules

(largest)

Front 30

what are microtubules made of?

Back 30

tubulin (protein)

Front 31

what are the purposes of the insoluble protein fibers of the cell? (actin, intermediate, microtubules)

Back 31

-structural support
-movement

Front 32

how does movement of the cell occur?

Back 32

with the aid of protein fibers and a group of specialized enzymes called motor proteins?

Front 33

what are motor proteins?

Back 33

a specialized group of enzymes that aid in cell movement

Front 34

what three structures do microtubules form that are involved in cell movement?

Back 34

-centrioles
-cilia
-flagella

Front 35

what is the cell's microtubule-organizing center?

Back 35

the centrosome

Front 36

what does the centrosome do?

Back 36

it is the cell's microtubule organizing center that assembles monomers of tubulin into microtubules

Front 37

what does the centrosome contain?

Back 37

2 centrioles, each a cylindrical bundle of 27 microtubules arranged in 9 triplets

Front 38

what do centrioles do?

Back 38

direct the movement of DNA strands during cell division

Front 39

what is the cytoskeleton composed of?

Back 39

actin microfilaments, intermediate filaments and microtubules

Front 40

what are the five important functions of the cytoskeleton?

Back 40

1. cell shape
2. internal organization
3. intracellular transport
4. assembly of cells into tissues
5. movement

Front 41

how does the cytoskeleton help cells assemble into tissues?

Back 41

the proteins fibers of the cytoskeleton interact with the extracellular space, linking cells to one another.

Front 42

what are motor proteins?

Back 42

proteins that are able to convert stored energy into directed movement.

Front 43

what are the three groups of motor proteins associated with the cytoskeleton?

Back 43

1. myosin
2. kinesin
3. dynein

pg. 67

Front 44

what is the cytoskeletal motor protein myosin best known for?

Back 44

its role in muscle contraction

Front 45

what movement are the cytoskeletal motor proteins kinesin and dynein associated with?

Back 45

movement along microtubules

dynein produces the whiplike motion of cilia and flagella

Front 46

what is extracellular matrix?

Back 46

the extracellular material secreted by cells of a tissue

composition varies from tissue to tissue

Front 47

what is the composition of ECM?

Back 47

proteoglycans and insoluble protein fibers

Front 48

what are proteoglycans?

Back 48

glycoproteins (carb + protein) that, together with insoluble protein fibers, make up the ECM

Front 49

what are the insoluble protein fibers that, together with proteoglycans, compose the ECM?

Back 49

collagen, fibronectin, and laminin

Front 50

what are CAMs?

Back 50

"Cell Adhesion Molecules" are membrane spanning proteins responsible for both cell-junctions and transient cell adhesions.

Front 51

what are the three cell junctions?

Back 51

1. gap junctions
2. tight junctions
3. anchoring junctions

Front 52

what are gap junctions?

Back 52

a cell junction that allows direct cell-to-cell communication between adjacent cells by creating a cytoplasmic bridge which allows chemical and electrical signals to pass from the cytoplasm of one cell to its neighbor

Front 53

what are tight junctions?

Back 53

occluding junctions designed to restrict the movement of materials between cells that they link.

Front 54

claudins and occludins are proteins involved in which cell junction?

Back 54

tight junctions

Front 55

connexin is a protein found in what cell junction?

Back 55

gap junctions

Front 56

what cell junction forms the blood-brain barrier?

Back 56

tight junctions

Front 57

cadherin proteins are found in what cell junction?

Back 57

cell-cell anchoring junctions (adherins or desmosomes)

Front 58

cell-cell anchoring junctions are either ________ or _________.

Back 58

adherins junctions or desmosomes

Front 59

in anchoring junctions, what is the difference between adherins and desmosomes?

Back 59

adherins link actin fibers in adjacent cells together

desmosomes attach to intermediate filaments of the cytoskeleton.

Front 60

what is the strongest cell-cell junction?

Back 60

desmosomes

Front 61

what are the two types of cell-matrix anchoring junctions?

Back 61

hemidesmosomes and focal ahesions

Front 62

what are hemidesmosomes?

Back 62

a type of anchoring junction that link intermediate fibers of the cytoskeleton to fibrous matrix proteins like laminin.

Front 63

what are focal adhesions?

Back 63

a type of anchoring junction that link intracellular actin to different matrix proteins such as fibronectin.

Front 64

what are the four tissue types?

Back 64

epithelial, connective, muscle, neural

Front 65

in epithelia, the basement membrane (basal lamina) is composed of what?

Back 65

a network of collagen and laminin filaments embedded in proteoglycans

Front 66

what are the 5 functional types of epithelia?

Back 66

exchange
transporting
ciliated
protective
secretory

Front 67

the extracellular matrix of connective tissue is called what? what is it composed of?

Back 67

ground substance- composed of proteoglycans and water in which insoluble proteins are arrangeg

Front 68

what are fibroblasts?

Back 68

connective tissue cells that secrete collagen-rich matrix

Front 69

what are the four fibrous proteins found in connective tissue ground substance (matrix)?

Back 69

-collagen
-elastin
-fibrillin
-fibronectin

Front 70

which type of connective tissue lies beneath the skin and provides elasticity?

Back 70

loose connective tissue

Front 71

which type of connective tissue provides support for small glands?

Back 71

loose connective tissue

Front 72

which type of connective tissue provides strength and flexibility?

Back 72

dense connective tisse

Front 73

what are some examples of dense connective tissue?

Back 73

tendons and ligaments

Front 74

which type of connective tissue contains elastic and reticular fibers?

Back 74

loose connective tissue is composed of collagen, elastic and reticular fibers.

Front 75

where is dense irregular connective tissue found?

Back 75

muscle and nerve sheaths

Front 76

what are the four protein fibers found in connective tissue and what are the characteristics of each?

Back 76

collagen provides strength and flexibility; elastin and fibrillin provide elasticity; fibronectin helps anchor cells to matrix

Front 77

which tissue types are termed "excitable"? why?

Back 77

nervous and muscle tissue are excitable because of their ability to generate and propagate electrical signals called action potentials

Front 78

which two tissue types have the least extracellular matrix?

Back 78

nervous and muscle

Front 79

what is the external lamina?

Back 79

the supportive layer of extracellular matrix found in muscle and nervous tissue.

Front 80

what are the two types of cells found in neural tissue?

Back 80

neurons and glial cells

glial cells are the support cells for neurons

Front 81

which tissue types are termed "excitable"? why?

Back 81

nervous and muscle tissue are excitable because of their ability to generate and propagate electrical signals called action potentials

Front 82

which two tissue types have the least extracellular matrix?

Back 82

nervous and muscle

Front 83

what is the external lamina?

Back 83

the supportive layer of extracellular matrix found in muscle and nervous tissue.

Front 84

what are the two types of cells found in neural tissue?

Back 84

neurons and glial cells

glial cells are the support cells for neurons

Front 85

what are the key themes in physiology?

Back 85

1. homeostasis & control systems
2. biological energy use
3. structure-function relationships
4. communication

Front 86

what are the three main components of a homeostatic control system?

Back 86

1. an input signal
2. a controller (which responds)
3. an output signal

Front 87

what is homeostasis?

Back 87

the maintenance of a relatively stable internal environment

Front 88

do polar molecules move easily across cell membrane?

Back 88

no!

Front 89

do lipids move easily across the cell membrane?

Back 89

yes

Front 90

what two properties of a molecule influence its movement across a cell membrane?

Back 90

1. size of molecule
2. lipid solubility

(lipid soluble molecules readily diffuse across most membranes, while lipid insoluble molecules do no)

Front 91

diffusion involves the movement of molecules from a region of ______ concentration, to a region of __________ concentration.

Back 91

high concentration to low concentration until equilibrium is established.

Front 92

what are some factors affecting rate of diffusion through a cell membrane?

Back 92

-lipid solubility of molecule
-molecular size
-cell membrane thickness
-concentration gradient
-membrane surface area
-composition of lipid layer

Front 93

what is Fick's law of diffusion?

Back 93

the rate of diffusion is proportionate to the surface area X concentration gradient X membrane permeability divided by/ membrane thickness

Front 94

what are the four categories of membrane proteins?

Back 94

1. structural
2. enzymes
3. receptors
4. transporters

Front 95

what are the two types of transporters (membrane protein)?

Back 95

channel proteins and carrier proteins

Front 96

what is the difference between channel proteins and carrier proteins?

Back 96

channel proteins are limited to moving small ions and water.

carrier proteins can move larger molecules that channels can

Front 97

what are the types of gated channels?

Back 97

chemically gated
voltage gated
mechanically gated

Front 98

antiport, symport and uniport are words that describe what?

Back 98

patterns of molecular transport in both facilitated diffusion (carriers) and active transport (secondary active transport)

Front 99

what type of proteins does facilitated diffusion use?

Back 99

carrier proteins

Front 100

how do sugars and amino acids enter or leave a cell?

Back 100

facilitated diffusion

Front 101

what are GLUT transporters?

Back 101

carrier proteins that move glucose across membranes via facilitated diffusion

Front 102

active transport moves molecules from regions of _____ concentration to regions of ________ concentration.

Back 102

low to high; against concentration gradient

(as opposed to passive transport which functions in an opposite fashion)

Front 103

what are the two types of active transport? how do they differ?

Back 103

primary active transport & secondary active transport

in primary active transport the energy required comes directly from the phosphate bond of ATP.

in secondary active transport the energy comes from potential energy stored in the concentration gradient

Front 104

what is the Na-K pump?

Back 104

the sodium potassium pump is a primary active transporter protein that pumps 3 Na out of the cell and 2 K into the cell for every ATP consumed

Front 105

the most common secondary active transport systems are driven by what?

Back 105

potential energy derived from the cellular sodium concentration gradient

Front 106

what is the SGLT transporter? explain.

Back 106

a secondary active transporter that co-transports sodium and glucose into cell

sodium binds to the SGLT transporter and induces a conformational change that creates a site from glucose to bind. glucose binding causes another conformational change that results in both molecules being released into cytosol.

Front 107

where does SGLT harness energy?

Back 107

form the sodium concentration gradient (secondary active transport)

Front 108

are GLUT and SGLT transporters reversible?

Back 108

GLUT (facilitated diffusion) is reversible but SGLT (secondary active transport) isn't because glucose has to follow the sodium gradient.

Front 109

list an example of facilitated diffusion, primary active transport and secondary active transport.

Back 109

facilitated diffusion - GLUT transporter
primary active transport - Na-K ATPase (pump)
secondary active transport - SGLT transporter

Front 110

carrier mediated transport demonstrates what three properties?

Back 110

specificity
competition
saturation

Front 111

how do large macromolecules (that are too big to enter/exit a cell through protein channels or carriers) enter cells?

Back 111

vesicular transport (phagocytosis and endocytosis)

Front 112

what does osmolarity describe?

Back 112

the number of particles in solution

Front 113

what is osmotic pressure?

Back 113

the pressure that must be applied to oppose osmosis

Front 114

what is tonicity?

Back 114

a term used to describe the volume change of cell at equilibrium.

Front 115

what is tonicity dependent on?

Back 115

the relative concentrations of nonpenetrating solutes

Front 116

what is the equilibrium potential?

Back 116

the membrane potential that exactly opposes the concentration gradient of an ion

Front 117

the electrical difference between the ICF and ECF is known as what?

Back 117

resting membrane potential

Front 118

what are the four basic methods of cell-to-cell communication?

Back 118

1. gap junctions
2. contact-dependent signals
3. local communication
4. long distance communication

Front 119

what is a neurocrine?

Back 119

an electrical signal travels along a neuron until it reaches the very end of the cell where it is converted into a chemical signal and secreted by the neuron

Front 120

if a neurocrine has a rapid effect on a target cell it is called what?

Back 120

a neurotransmitter

Front 121

if a neurocrine acts more slowly than a neurotransmitter, as a autocrine or paracrine signal, what is it called?

Back 121

a neuromodulator

Front 122

if a neurocrine diffuses into the blood stream for distribution what is it called?

Back 122

a neurohormone

Front 123

can lipophilic signal molecules diffuse through the phospholipid bilayer of the cell membrane?

Back 123

yes; lipophilic signal molecules can pass through the cell membrane and bind to cytosolic or nuclear receptors

Front 124

can lipophobic signal molecules diffuse through the phospholipid bilayer of the cell membrane?

Back 124

no; lipophobic signal molecules can't pass through the cell membrane and must bind to receptor proteins on the cell membrane

Front 125

what are the four types of membrane receptors?

Back 125

-receptor channels
-receptor-enzyme
-G protein-coupled receptor
-Integrin receptor

Front 126

what are the four types of membrane receptors?

Back 126

-receptor channels
-receptor-enzyme
-G protein-coupled receptor
-Integrin receptor

Front 127

what are the four general steps in signal pathways?

Back 127

1. signal molecule (ligand or first messenger) binds to receptor

2. ligand-receptor binding activates the receptor

3. intracellular signal molecules are activated

4. the last signal molecule initiates synthesis of target proteins or modifies existing target proteins to create a response

Front 128

what are the components of signal pathways?

Back 128

1. signal molecule
2. receptor
3. intracellular signal molecules
4. target proteins

Front 129

what is signal transduction?

Back 129

a "first messenger" signal molecule binds to a membrane receptor which activates "second messenger" intracellular signal molecules to create a response.

Front 130

what is signal amplification?

Back 130

when one signal molecule is turned into multiple second messenger molecules via amplifier enzymes

Front 131

adenylyl cyclase, guanylyl cyclase, and phospholipase c are examples of what?

Back 131

amplifier enzymes (signal transduction)

Front 132

do steroid hormones require signal transduction?

Back 132

no, because they are hydrophilic and can enter directly into the cell themselves through the cell membrane

Front 133

the enzymes of receptor-enzymes are either _____ or _______.

Back 133

protein kinases (tyrosine kinase) or guanylyl cylase (the amplifier enzyme that converts GTP to cyclic GMP)

Front 134

what is an example of a ligand for a receptor-enzyme membrane receptor?

Back 134

insulin

Front 135

in G-protein coupled membrane receptors, inactive G proteins are bound to what? how are they activated

Back 135

inactive- bound to GDP

converting GDP to GTP activates the G protein

Front 136

when G proteins are activated (via the conversion of GDP to GTP) they either...

Back 136

open an ion channel

or

alter enzyme activity on the cytoplasmic side of the cell

Front 137

what are the two most common amplifier enzymes for G-protein coupled receptors?

Back 137

adenylyl cyclase and phospholipase c

Front 138

the tyrosine kinase receptor is an example of what type of membrane receptor?

Back 138

enzyme-receptor

Front 139

what are the second messengers?

Back 139

Ca2+

cAMP
cGMP

IP3
DAG

pg. 186

Front 140

in the G-protein coupled adenylyl cyclase-AMP system, what is the amplifier enzyme? what is the secondary messenger?

Back 140

adenylyl cyclase is the amplifier enzyme

cyclic AMP is the secondary messenger

Front 141

what are the secondary messenger molecules in the phospholipase c G-protein coupled membrane receptors?

Back 141

phospholipase converts a membrane phospholipid into two secondary messenger molecules: DAG and IP3

Front 142

the acetylcholine cation channel of the skeletal muscle is an example of what membrane receptor?

Back 142

receptor-channel

Front 143

for most signal molecules, the target cell response is determined by the _______, not by the ________.

Back 143

receptor (or its associated intracellular pathways), not the ligand

Front 144

what three properties do receptors exhibit?

Back 144

saturation, specificity and competition

Front 145

what three groups do all hormones fall into?

Back 145

-steroid (lipid)
-peptide (protein)
-amino acid

Front 146

what molecule are all steroid hormones derived from?

Back 146

cholesterol

Front 147

what type of hormone is insulin?

Back 147

a peptide

Front 148

are peptide hormones lipophobic or lipophilic? what does this mean?

Back 148

lipophobic -they can not diffuse directly into target cell and must rely on surface membrane receptors

Front 149

what secondary messenger does insulin use?

Back 149

tyrosine kinase

Front 150

why are secondary messenger systems (via cell-surface receptors) so quick compared to intracellular receptors targeted by lipophilic signal molecules?

Back 150

because second messenger systems modify existing proteins

Front 151

although the peptide-derived hormone insulin works via tyrosine kinase activity, how do most peptides hormones work?

Back 151

through cAMP secondary messenger systems

Front 152

where are peptide hormones synthesized?

Back 152

in tissues all over the body

Front 153

where are steroid hormones synthesized?

Back 153

the adrenal cortex (atop each kidney) and in the gonads

Front 154

what cellular feature would you expect cells that secrete steroid hormones to have?

Back 154

lots of smooth ER

Front 155

are steroid hormones lipophilic or lipophobic? what does this mean?

Back 155

lipophilic -they can readily diffuse out/into cell

BUT it also means they can't be stored in vesicles, so they must be synthesized as needed.

Front 156

which type of hormone requires protein carrier molecules in order to effectively transported in the bloodstream?

Back 156

steroid hormones because they are no soluble in plasma or other aqueous body fluids.

Front 157

steroid hormones require carrier molecules to be transported in the bloodstream because they are not soluble. what effect does this have on the half-life of steroid hormones?

Back 157

steroid hormones have an increased half-life because of their association with protein carrier molecules in the blood. the carrier molecules help protect the hormone from enzymatic degradation.

(ex: cortisol vs. epinephrine. cortisol is a steroid based hormone with a considerably longer half life than that of the small AA-derived epinephrine, whose half-life is a matter of seconds)

Front 158

what type of hormone is cortisol?

Back 158

steroid

Front 159

what is the ultimate destination of a steroid receptor-hormone complex?

Back 159

the nucleus, where the complex acts as a transcription factor

Front 160

the amino acid-derived hormones are all derived from one of which two amino acids?

Back 160

tryptophan or tyrosine

Front 161

the AA-derived hormone melatonin is derived from _______, but all of the other aa-derived hormones (catecholamines and thyroid hormones) are derived from ___________.

Back 161

melatonin is the only amino acid-derived hormone derived from tryptophan. all other aa-based hormones are derived from tyrosine.

Front 162

what hormones are derived from single amino acids?

Back 162

TYROSINE:
dopamine (all catecholamines)
norepinephrine
epinephrine

thyroxine (thyroid)

TRYPTOPHAN:
melatonin

Front 163

all reflex pathways have what similar components?

Back 163

- stimulus
- input signal
- integration of signal
- output signal
- response (hormone output in the case of endocrine reflexes)

Front 164

do aa-derived hormones behave like steroid hormone or peptide hormones?

Back 164

the catecholamines (neurotransmitters) bind to cell membrane receptors like peptide hormones

the thyroid hormones behave like steroid hormones, with intracellular receptors that activate genes (require carriers in blood also)

Front 165

which hormones follow the simple reflex pattern in which the endocrine cell directly senses a stimulus and responds by secreting its hormone?

AKA the endocrine cell functions as both sensor (receptor) and integrating center

Back 165

-parathyroid hormone (PTH)
-insulin & glucagon

Front 166

what is the role of PTH (parathyroid hormone)?

Back 166

found in clusters in glands behind the thyroid.

functions to increase blood calcium levels via G-protein coupled Ca2+ receptors on the cell membrane

Front 167

where are insulin and glucagon secreted from?

Back 167

pancreas

Front 168

the anterior pituitary and the posterior pituitary are fused glands derived from what two different sources?

Back 168

anterior pit is a true endocrine gland of epithelial origin

posterior pit is an extension of neural tissue in the brain that secretes neurohormones made in the hypothalamus

Front 169

the posterior pituitary is the storage and release site for what two neurohormones?

Back 169

the peptide hormones oxytocin and ADH (antiduretic hormone or vasopressin)

Front 170

what six hormones are secreted by the anterior pituitary gland?

Back 170

thyrotropin (TSH)
adrenocorticotropin (ACTH)
growth hormone (GH)
prolactin
follicle-stimulating hormone ( FSH)
luteinizing hormone (LH)

Front 171

secretion of all the ant. pit. hormones is controlled by what?

Back 171

hypothalamic neurohormones

Front 172

what is a trophic hormone?

Back 172

a hormone that controls the secretion of another hormone

Front 173

what are the three classes of neurohormones ?

Back 173

1. catecholamines
2. hypothalamic neurohormones secreted from the posterior pituitary
3. hypothalamic neurohormones that control hormone release from the anterior pituitary

Front 174

regarding the hypothalamic-ant. pit. pathway: on what endrocrine gland does ACTH (corticotropin) act on?

Back 174

adrenal cortex --> cortisol

see pg. 230

Front 175

describe the negative feedback mechanism of the release of estrogen

Back 175

ow level estrogen = alerts hypothalamus who releases GnRH = triggers release of FSH then LH, then increase in FSH causes ovaries to release more estrogen

Front 176

what are the consequences of hyperinsulinemia? why?

Back 176

excess glucose in blood; presents with similar symptoms to that of diabetes

WHY?

because the insulin receptors down-regulate and stop responding to insulin (think drug resistance, etc.)

Front 177

how are the trophic hypothalamic hormones that regulate secretion of the anterior pituitary hormones transported?

Back 177

through a special set of blood vessels called the hypothalamic-hypopheseal portal system

Front 178

what are the benefits of blood portal systems?

Back 178

less hormone required

Front 179

what are the three types of hormone interactions?

Back 179

synergism
antagonism
permissive

Front 180

describe a synergistic interaction between hormones. what's an example?

Back 180

when two synergistic hormones are present this type of interaction yields results that are greater than additive.

for example, glucagon elevates blood glucose levels but so do cortisol & epinephrine. when glucagon and epinephrine (or cortisol) are in both present, their effect together is greater than the added effect of both hormones independently.

Front 181

describe a permissive interaction between hormones. what's an example?

Back 181

one hormone can not fully exert its effects unless a second hormone is present.

for example, reproductive system development will be delayed in the presence of GnRH from the hypothalamus (and FSH, LH from ant. pit. etc.) but when thyroid hormone is also present, normal reproductive system development will take place. (thyroid hormone in the absence of the GnRH cascade will have no effect of reproductive system development)

Front 182

describe a antagonistic interaction between hormones. what' s an example?

Back 182

two hormones diminish the effects of each other

for example, glucagon and GH raise blood glucose levels and insulin lowers blood glucose levels. (evidence suggests that GH actually decreases the number of insulin receptors)

Front 183

what is primary pathology/ primary hypo/hyper-secretion?

Back 183

when the tumor (or other dysfunction) is in the last endocrine gland in a reflex it is considered primary pathology and it's secretions are primary hypo/hyper-secretions

ex: tumor in the adrenal cortex leading to primary hypersecretion of cortisol

Front 184

what is secondary pathology/ secondary hypo/hyper-secretion

Back 184

secondary pathology describes when the tumor (or other dysfunction) is in one of the tissues that produces trophic hormones. the consequent secretions are secondary hyper/hypo-secretions.

ex: damage to the pituitary gland and ACTH secretion diminishes leading to secondary hyposecretion of cortisol

ex: