Card Set Information
Internal Regulation Homostasis
Internal regulation and homostasis
The need for temperature regulation affects many__?
Homostasis is what?
regulation of an internal environment that keeps conditions such as temperature and acidity (ph) relatively constant.
If the range that is required for a given variable is narrow e.g., temperature- it is referred to as a __?
a: set point = single value that the body works to acheive
Ca++ most abundant mineral in the body- important for __?, muscle contraction, electrical activity of the heart.
If CA++ in blood is low, it will be released from __? -risk factor for osteoporosis & if too high, will be stored __ or __?
a: bone c: bone or excreted
99% of CA++ is stored in?
Ions, O2, glucose, etc are all kept within a tight range of __?
many of the processes are controlled with a negative __? which makes a system ___? and increases homeostasis
a: feedback-loop b: self-regulating
Control center- brain, receives a signal from a sensing component that monitors and responds to changes in the ___ to ___ the deviation?
a:internal environment, e.g., low Ca++
If the control center decreases the amount of the variable = ___? and if increases = __?
a: negative-feedback b: positive feedback
Theyroid hormone is released from the thyroid when the thyroid is stimulated by__?
Thyroid Stimulating Hormone (TSH)
When TSH is high (here, Thyroid hormone is the sensing component) it signals the brain(__)? to stop releasing__? so that the thyroid levels__?
a: hypothalamus b:TSH c: fall
Homeostatic processes in animals trigger ___ and behavioral activities that keep certain ___ in that set range?
a: physiological b: variables
Allostasis- is the processes of__?
a: achieving homeostasis,process of achieving stability an ongoing effort to maintain homeostasis
98.6 degrees Fahrenheit- = normal body temp. but many things such as ___? can alter one's temperature.
a: clothing, emotions, room temp, humidity, meds, and physical activity
Fever temperature is usually over __ in adults?
Basal Metabolism = the energy used to maintain a constant __? and requires huge amounts of _?
a: body temperature b: energy(calories)
Poikilothermic creatures such as amphibians and reptiles (most fish) match their body temps to their___? and are not..?
a: environment b: putting their energy into temp regulation
Poikilothermic animals use ___ methods to try and maintain a steady body temp.
HOMEOTHERMIC- mammals and birds- use ___? that require alot of ___ to maintain more exact body temps.
a: Physiological mechanisms b: energy
Animals generate heat in proportion to ____ but radiate heat in proportion to __?
a: total mass b: surface area
Homeothermic- if air is warmer than body temp, only one physiological mechanism for cooling evaporation is___?
a: sweat- evaporation cools body, doesn't work well in humidity.
** too much sweat = dehydration- risk overheating
Mechanisms to increase temp in cold environment are _?
shivering, decreased blood flow to skin, fluff fur to increase insulation
** behavioral mechanisms: = clothes, huddle, increased activity
Pros of being Homeothermic?
-allows animal to keep muscles warm at all times and therefore ready to move quickly
-reptiles preferred temp = 37c-98.6F
Why don't we want to be hotter than 98.6F?
Enzymes work only within specific temp range
Area of brain responsible for temperature regulation =
Anterior area of Hypothalamus
(POA/AH) stands for?
Pre-optic area/Anterior hypothalamus
Anterior Hypothalamus- detects temperature and primary area to fix ___?
a: temperature-physiologica mechanisms for heating or cooling- sweating, panting, shivering, decreased blood flow to skin, distal extremities
The Anterior Hypothalamus monitors body temp by monitoring its ___?
a: own temp
So if an experimenter warms an animal's Anterior Hyp., with the animal in a cold room,it will still ??
sweat or pant
if one destroys the A-hypo., one has only behavioral mechanisms to maintain body temp e.g., blankets, ice baths, etc.. but no ___?
what is normal humans body temperature between range?
Fever- there is a group of bacteria and viruses that grow really well at what temp?
With infection, WBC's are mobilized and release proteins(cytokines) that are___?
Cytokines set a series of reactions that end up with hypothalamus being stimulated and__?
increasing the bodies temp-increasing the SET POINT
Certain types of bacteria grow less well in higher temps. Low fever improves immune but over about 102-103 degrees ___?
harm outweighs the good
Thirst- H2O makes up about 70% of human body and because solutes in the H2O need to be kept within a narrow concentration range of __?
water must be regulated closely
CAMELS- have a series of physiological adaptations to go without water for long time
*200 L in 3 mins, can lose a 1/4 of their body water and still survive
2 types of thirst?
Osmotic and Hypovelemic
solute concentration in the plasma is too high
* e.g, you eat too much salt and feel thirsty
Osmotic pressure- if solutes too high, the fluid part of the body will be ?
pulled out from the cells
Solutes don't travel freely through ____ but water channels are mostly oen so ___ can travel?
Antidiuretic hormone- (ADH)
Vasopressin- 2 functions: make kidneys hold water- antidiuretic hormone and ?
Constrict blood vessels which increases blood pressure- Vasopressin
vasopressin is released from the ___ gland when the body is dehydrated?
vasopressin is a hormone and travels to the __ where it causes the kidneys to ___ more concentrated urine holding to water.
kidneys b: secrete
Vasopressin is released from the P-gland in response to lower___ ? or increase solute concentrations(osmolarity) in the blood
Vasopressin has osmoreceptors near the 3rd ventricle that ___ concentration in the blood.
info is then sent to the hypo-T which causes__?
detect the solute
b: release or (inhibits) release of vasopressin
these osmoreceptors also send info to the area near the ___?
hypothalamus -lateral preoptic area
Alcohol blocks vasopressin release- so urine is less __?
Hypovolemic thirst- is related to loss of blood volume, hemorrhage/bleeding, ___?
and need to ___?
diarrhea, and sweating
b: replace H2O and solutes
An animal with Osmotic thirst needs water.
An animal with HYPOvolemic thirst wants water and ___?
a:solutes *the craving for salty tastes is "Na+specific hunger"
If offered both salt and water, animlas are good at __?
taking the appropriate mix
Digestion chewing of food. saliva contains enzymes to help breakdown protein.
1-2hrs in small intestine. 95% nutrients absorbed.
large intestine absorbs what?
water minerals back into bloodstream- then eliminated through rectum
Tryptophan = an amino acid found in?
rich protein foods- precurser for seratonin which is a precurser for melatonin
carbs release insulin, which stimulates the uptake of ___ and specific amino acids into the cells but very little tryptofan so more of it stays in the ___?
a: glucose b: blood stream
More tryptophan means more __?
Brain gets info from the ?
mouth, stomach, intestines, fat cells and other areas to regulate eating
Can you be satiated without tasting food?
yes: being fed through tube, but found the meals unsatisfying.
although the chewing helps with feelings of satisfied with a meal, oral factors aren't enough to?
to feel full
Main signal to end a meal is?
expiremnt- inflated a cuff between stomach and duodenum and found that when they blocked the stomach..?
animals ate normal sized meal and then stopped
vagus nerve = part of the parasympathetic ns which supplies the internal organs about
20% efferent fibers-away and also conveys sensory info back to the brain about the state of internal organs about 80% afferent fibers-in.
Conveys info regarding stretching of stomach wals
People who have had to their stomachs removed and have food directly entering the duodenum report?
satiety- = complete satisfaction
So meals end after distention-stretching- of either stomach or ?
duodenum- which aborbs a significant % of nutrients
Duodenum releases hormones that?
stimulate the vagus relaying info to delay next meal.
: constricts sphincter between stomach & duodenum causing stomach to stretch and this stimulates the vagus nerve
: signal the hypothalamus that there is food in the duodenum resulting in decreased hunger.
: these hormones have short-term term effect
2 hormones produced by Pancreas are?
insulin and glucagon
insulin enables glucose to _?
Glucagon causes liver to __?
release glucose from its storage unit, glycogen.
in fall mammals put weight more so for the ones that hibernate. Insulin release causes glucose to enter cells so...?
blood glucose decreases BUT insulin continues to be excreted by pancreas.
High prolonged insulin levels cause?
hunger and mammals continue to eat and makes glycogen and fat
low insulin or prolonged high insulin levels do what __?