Body systems chapter 32

Question 1

regulator/ conformers for internal environment

Answer 1

regulators- use internal mechanisms to control internal change when there is external fluctuation.
conformers-allows internal body condition to change in accordance with external changes
* animals can be regulators for certain internal conditions while allowing others to conform to the environment

Question 2

thermoregulation

Answer 2

physiological mechanism that allow an organism to maintain INTERNAL temperature within a normal body range.
-endotherms- generate heat metabolically
-ectotherms- gain heat from environment
types of heat- radiation- how organisms lose most of their heat, radiate and absorb heat from the sun- evaporation- cooling effect when liquid evaporates into a gas the heat is lost. -convection-how organisms lose heat the fastest- molecules in contact with each other transfer heat– you can’t add cold, only remove heat

Question 3

temperature adaptations

Answer 3

1. insulation- reduce heat flow from body to environment- hair-feathers- adipose(blubber) -tissure
2. circulatory adaptations- reduction of blood flow near the body surface traps heat within the body core– vasodilation and visoconstriction in blood vessels. plus countercurrent exchange of heat between closely associated blood vessels minimizes heat loss
   * * countercurrent heat exchange- warm blood in arteries in close contact with veins carrying cold blood- this facilitates heat transfer from the arteries to the veins - as blood in the veins approaches the body centre it is almost as warm as the body core.
3. seasonal acclimatization- how organisms change throughout the seasons- shed fur in summer, ectotherms do thermoregulation by using enzymes to change the amount of saturated and unsaturated lipids to keep the membrane fluid– antifreeze and arctic fish

Question 4

endocrine and nervous control

Answer 4

• control and coordinate an animals response to external stimuli.
  endocrine- hormones that travel all thru body to target cells with specific receptors that respond- the effect is slow but long lasting.
  nervous- neutrons send impulses - fast but target cells must have specialized junctions that allow transmission of impulses fast but short effect

Question 5

hormone regulation

Answer 5

hormones released directly into blood stream by endocrine glands (there are no ducts they are secreted) exocrine glands are the ones that dump their secretions into ducts like the salivary glands liver and pancreas.– hormones recognized by specific tissue which is the target and when stimulated will either increase or decrease in activity.
** hormones control-metabolism, homeostasis and growth and reproduction

Question 6

types of hormones

Answer 6

peptide- hydrophilic activate receptors on the target cell surface (cannot diffuse through due to polarity) – fast because they activate enzymes present already in the target cell ex; insulin glucagon oxytocin acth ( effect not long)
-peptide hormone is the first messenger and it binds to receptor in plasma membrane activating signal induction which activates an enzyme
steroid- hydrophobic and can diffuse through membrane- pass through membrane of target cell **they are made of lipids - precursor is cholesterol cause target cell to go through protein synthesis. this effect is slow but long lasting. ex; cortisol, estrogen, testosterone.
- steroid binds to hormone receptor steroid- receptor complex enter nucleus and bind to DNA regulatory site ( promoter) then a protein is transcribed and translated.– endocrine glands release hormones when needed – THIS IS A NEGATIVE FEEDBACK LOOP- secretions are shut off when no longer needed.

Question 7

negative feedback loop

Answer 7

internal body conditions change beyond normal parameters for function body initiates response to NEGATE the problem ex; chime leaves pyloric sphincter and enters duodenum the pH of the chime is low and the acidic contents must be neutralized so the pancreas releases bicarbonate

Question 8

Same hormone different response

Answer 8

hormones with different functions in certain cells
ex-ephinephrin hormone produces different responses in different target cells - target cells with the same receptor but different single transduction pathways or effector proteins have different responses– different receptors also makes different responses ex; prolactin stimulates the production of milk by mammary glands and different roles in different organisms ( regulates fat and reproduction in birds- delays metamorphosis in amphibians and regulates salt/ water balance in fish

Question 9

temperature

Answer 9

body temp too warm– hypothalamus detects and sends impulses —-vasodilation, flat hair, sweat.

body temp too cold- hypothalamus detects–vasoconstriction, hair on end, shivering

Question 10

glucose

Answer 10

high blood glucose levels– pancreas detects– insulin released from Beta cells of the islets of langerhans– which convert glucose into glycogen and cells increase glucose uptake

low blood glucose levels–alpha cells in pancreas detect and secrete glucagon —- cells decrease glucose uptake and the liver converts glycogen to glucose

Question 11

blood pressure

Answer 11

• ***ADH- antidiuretic hormone which is a major player in blood pressure.
• low blood pressure- low blood volume- low amount of H2O——osmoreceptors in hypothalamus detect— impulses sent to post pit to release ADH—- collecting duct of nephron (kidney) reabsorbs water and excretes K ions.
• high blood pressure, high blood volume, large amount of H2O—- osmoreceptors in hypothalamus detect—- inhibit the release of ADH from the post pit—- collecting duct in nephron no longer permeable to water and there is no reabsorption, excess water excreted

Question 12

oxytocin

Answer 12

*** positive feedback loops
uterine stretching— receptors send impulses to post pit to release oxytocin—uterine smooth muscle contractions + feedback loop and this PROMOTES uterine stretching for child birth

infant feeding– post pit releases oxytocin- let down (release )of breastmilk also positive feedback loop

Question 13

sodium in blood

Answer 13

low sodium concentration in blood—– kidney releases and enzyme known as renin— angiotensin 1 is converted by the enzyme renin to angiotensin 2(vasoconstrictor) —- angio tennis 2 causes the adrenal cortex to release aldosterone–nephron collecting duct reabsorbs sodium and secretes potassium

high sodium concentration in the blood— kidney stops secreting renin—- angiotensin 1 does not get converted into angiotensin 2— aldosterone is not released from the adrenal cortex– nephron collecting duct allows sodium to diffuse out of the blood and potassium ions are kept

*** high sodium concentration in blood means that the solute concentration is high, and therefore the blood has a large amount of osmotic pressure which is the ability to draw water in. that is exactly what happens, the blood volume goes up due to the water being pulled in and with a high blood volume comes high blood pressure.

but… blood pressure is always known for ADH , use aldosterone when regarding sodium.

Question 14

thyroxine

Answer 14

low levels of thyroxine—-chemoreceptors in hypothalamus detect and secrete TSHRF-thyroid stimulating hormone receptor factor—–ant pit releases TSH-Thyroid stimulating hormone—– TSH stimulates thyroid in releasing thyroxine
tropic hormones-causes another gland to release their hormone– tshrf also known as trh(thyroid releasing hormone)

Question 15

adrenalin

Answer 15

stress— sympathetic nervous system detects (emergency times) send impulses to the medulla of adrenal gland—–adrenal gland releases epinephrine —- fight/ flight increase heart rate, increase blood pressure blood volume and decrease in digestion

Question 16

describe hypothalamus structure

Answer 16

-ADH and oxytocin made in hypothalamus and stored in post pit.
posterior pituitary -extension of hypothalamus and contains neurosecretory cells that extend from hypothalamus to the end of the post pit. the anterior pituitary is on the back and it is known as the master gland

Question 17

nephron

Answer 17

renal artery connects to afferent arteriole which goes to glomerulus which is surrounded by bowmans capsule (first process) the efferent arteriole leaves the glomerulus. bowman capsule and the glomerulus are known as the renal capsule the filtrate goes into the proximal convoluted tubule and sodium is actively pumped back into the blood, since that happens chlorine ions and water passively diffuse out. the filtrate then enters the descending loop where the water is reabsorbed and once it reaches the loop of henle the loop becomes impermeable to water, including the ascending loop, this is because the solute concentration in the filtrate increases and the water diffuses up and therefore its osmotic pressure does too, so the ascending loop and loop of henle are impermeable to water. this problem is fixed as sodium ions are pumped out actively in the ascending loop and this is known as the counter current mechanism ( so that if the collecting duct becomes permeable to water, the water will not diffuse in). the Distil convoluted tubule is after the ascending loop and at this point the filtrate is isotonic to blood plasma, and this is the bloods last chance to remove toxins and this is where the blood ph is controlled. after the DCT, the collecting duct happens and 44% of the urea is reabsorbed to have a stable blood pressure. as you go down into the renal medulla the solute concentration increases

Question 18

three nephron processes

Answer 18

1. pressure filtration ( occurs at the renal capsule) 80% of all small molecules filter in bowmans capsule no plasma proteins or blood cells are filtered out of blood (also known as formed elements)
   there is vasoconstriction of the efferent arteriole to increase the blood pressure in the glomerulus which increases the amount of filtrate at bowmans capsule
   nutrients and waste both filtered out of blood
2. selective reabsorption-
   molecules are both passively and actively reabsorbed
   -100% of glucose and amino acids are reabsorbed
   - sodium ions are actively pumped out chlorine ions and water follow
   -cuboidal epithelial cells with microvilli facilitate – they absorb sodium ions and pump it out actively
3. tubular secretion- bloods last chance to remove toxins- control blood pH should be around 7.35 and 7.45, if blood is too acidic the distil convoluted tubule reabsorbed hydrogen ions and secretes bicarbonate back into the blood as a buffer HCO3

Question 19

thyroxine

Answer 19

gland- thyroid
target- somatic cells
what it causes it to release- TSH
effect of hormone-increase uptake of O2 increasing the metabolism

Question 20

TSH

Answer 20

gland- ant pit
target- thyroid
what causes it to release- TSHRF
effect of hormone- causes thyroxine to be released

Question 21

prolactin

Answer 21

gland- ant pit
target- mammary glands
what causes it to release-suckling of youth
effect of hormone- stimulates mammary glands to produce milk

Question 22

somatotrophin

Answer 22

gland-ant pit
target- liver bones and other cells
what causes it to release- GHRH growth hormone releasing hormone
effect of hormone- stimulates growth/ cell reproduction

Question 23

oxytocin

Answer 23

gland- post pit
target- uterine or breasts
what causes it to release- uterine stretching or infant feeding
effect of hormone- causes smooth muscle in uterine to stretch or letdown of breast milk

Question 24

glucagon

Answer 24

gland- pancreas
target- liver/ body cells
what causes it to release-alpha cells in pancreas detect low glucose concentration in blood
effect of hormone- liver converts glycogen to glucose and cells decrease glucose uptake

Question 25

insulin

Answer 25

gland- pancreas
target- liver/ body cells
what causes it to release- beta cells in islets of langerhan detect and secrete insulin because theres too much glucose
effect of hormone- liver converts glucose to glycogen and cells increase uptake of glucose

Question 26

hierarchal organization of animal bodies

Answer 26

cells- tissues- organs- organ system
organs can have many roles– pancreas part of digestive and endocrine system
animal tissue - 4 main groups - epithelial, connective, muscle and nervous

Question 27

homeostasis

Answer 27

maintenance of internal balance- physical and chemical properties body 37 C. blood between 7.35-7.45
endotherms -maintains stable body temp
ectotherm- adjust body temp by behavioural means - heat source and environment - they need less food

Question 28

heat loss/gain

Answer 28

thermoregulation

heat transferred from higher temp to lower temp

Question 29

vasodilation

Answer 29

nerve signals relax muscles of the blood vessels walls and increase blood vessel diameter and the blood flow in skin increases so that heat is transferred out of the body.
endotherms heat warms skin and heat transfers to the environment

Question 30

acclimatization

Answer 30

physiological adjustment to environmental changes

adjusting insulation and at a cellular level saturated to unsaturated lipids in membrane to keep it fluid at lower temp

Question 31

hypothalamus

Answer 31

sensors for thermoregulation - group of nerves function like a thermostat- bacteria / viral infection= fever– increase in biological thermostat set point - not in ectotherms may seek hotter environment

Question 32

endocrine

Answer 32

hormones secreted into blood can effect many different cells if they all have the receptors and they are gradual changes `

Question 33

nervous

Answer 33

nerve impulses travel to target cells and along communication lines- AXONS 4 cells can receive impulses- neutrons, muscle cells, endocrine cells, exocrine cells.
if nerve impulses are long- change in voltage
if nerve impulse is short- chemical signals are used. there are pathways that the signal takes

Question 34

neuroendocrine pathways

Answer 34

sensor in nervous system is the HYPOTHALAMUS which connects the nervous and the endocrine system. hypothalamus receives info from nerves and the signal travel to the pituitary gland and the anterior and posterior hormones from ant pit usually regulate other endocrine glands and the post pit is an extension of the hypothalamus and it stores and releases ADH and oxytocin which are made in neurosecretory cells
-hormones made in hypothalamus regulate ant pit

Question 35

adrenal gland ?

Answer 35

on top of kidneys
adrenal medulla- epinephrine
adrenal context–

Question 36

pancreas

Answer 36

insulin to lower blood glucose levels

glucagon to increase blood glucose levels

Question 37

pineal gland

Answer 37

melatonin-biological rythms

Question 38

thyroid

Answer 38

thyroxine T3 T4 metabolism

Question 39

ovaries

Answer 39

estrogen- stimulate uterine lining growth and secondary development of sex characteristics
t

Question 40

testes

Answer 40

androgens- support sperm formation and development of male secondary sex characteristics