Homeostasis Flashcards
first part
Homeostasis
body state in which internal & chemical conditions are maintained within a tolerable range
Ex. of homeostasis
Ion concentration, pH level of nutrients and waste
Homeostatis systems (3)
- Sensor
-Integrator
-Effector
Integrator role
Coordinates response
What group is integrator and sensor
nervous and endocrine
Effector group
tissue or organ
What are the sensors (5)
vision
touch
smell
hearing
taste
CNS
Brain and Spinal cord
PNS
peripheral nerves
Effector role
Works to bring system to normal
Negative feedback system order
stimulus -> Sensor -> integrator -> Effector -> response (effect is canceling the effect of original environmental change)
Too cold? (6)
- Muscles contract; Shivering: heat produced
- No sweat
-effector muscles make hair stand up to trap a layer of warm air
-vasoconstriction
-put clothes on - go inside
Too hot
-No shivering
- Sweating -> energy is lost as water evaporates from the skin
-vasodilation
-takes clothes off
-fan yourself
Vasoconstriction
Muscles in walls of arteries constrict
less blood flows through capillaries in skin
Vasodilation
- muscles in walls of arteries relax
-more blood flow which allows heat energy to be transferred from body into sweat that forms on the surface of skin which evaporates
Positive feed back loop
reinforced ad increasing the change
Does positive feedback result in homeostasis
NO- rarely found in body allows physiological events to occur quickly
Examples of positive feedback
blood clotting, child birth, lactation
Review diagrams of positive feed back (child birth) (blood clotting)
How can you induce childbirth?
Can induce by providing oxytocin or pitocin
Waste removal in Kidney- what waste product where does buildup come from
Ammonia (NH3) is extremely toxic and is created during protein catabolism thorugh the deamination of amino acids
How is urea formed
CO2 is added to 2 NH3 making urea, LESS TOXIC
uric acid
by-product of nucleic acid catabolism (is also excreted by the kidney)
The lungs- waste product when is it produced how is it removed
Carbon dioxide is a waste product formed during aerobic cellular respiration and is exhaled by the lungs
The liver- where is it formed how
lactic acid is a waste product of anaerobic respiration
What is thermoregulation
- regulation of body temp
Body temp is too hot road runner ex.
- Evaporation (liquid using thermal energy from surroundings to become a gas)
- electromagnetic radiation (infrared radiation)
-Conduction (direct movement of heat when in contact with a cooler object)
-Convection (movement of heat through a gas or liquid)
Response to cold
-vasoconstriction
-arteries narrow -> decreased blood flow -> reduced energy (heat loss) through INFRARED
- shivering, rapid muscle contractions released thermal energy metabolically
Pilo erection- goose bumps
-raised hairs trap air against skin
Vasodilation what type of energy release
-body relaxes arteries to inc. blood flow and allow more thermal energy to be lost to the environment through the skin. Sweat removes this thermal energy from its surroundings. You flush (turn red) because more blood is sent to the upper layers of your skin
How do hormones play a role?
Body releases Adrenaline and thyroxine inc. metabolism -> more heat produced
Hypothalamus
Control centre for thermoregulation
Homeotherms
animals that maintain a stable internal environment are called homeotherms
heterotherms
animals that maintain a stable internal temp at times, but have the ability to allow it to fluctuate are called heterotherms. E.g. Hibernation, Torpor
Poikilotherms
animals that have varying body temperatures or body temp which matches external environments are called poikilotherms
Endotherms
Have internal mechanisms to produce heat and regulate temperature
Ectotherms
rely on external sources their body temp depends on the environment, regulate by changing behaviours- laying flat in the sun
Homeotherms- ex
Human, warm blooded (endotherm)
Heterothermic- ex
bear, warm blooded/hibernation, (endotherm)
Poikilothermic
lizard, cold-blooded, ectoderm
Metabolic responses- endotherms
maintain their internal temp. by regulating their metabolic activity. They require an almost constant supply of energy
ectotherms metabolic responses
body temp fluctuates more, and become inactive in cold weather
HOw much basal metabolic rate is used to offset thermal energy loss and keep warm in (ecto or endo therms)
25 % ENDOTHERMS
therefore endotherms must have more mitochondria than ectoderms
thermoreceptors in the ——– and ——- do what
skin and within the body alert the nervous system to any changes in temp
Basal Metabolic rate
amount of energy expended at rest (how many cals is needed to complete basic functioning)
Torpor
a shorterm state of reduced metabolic rate and body temp. This lowers demand for energy during inactive times
- able to wake up quickly to avoid danger- or if opportunity exists exit den to feed
Hibernation
- characterized by a decrease in metabolic rate and body temp (as much as 20 degrees C) but is longer terms
Artic Ground squirrel
longest rodent hibernation body temp can drop to nearly 0 degrees C
Estivation
seasonal, utilization of torpor during summer when it is very hot and water is limited
Water Balance - Water gain
- Drinking fluids
-Eating food
-Metabolic water (produced)
Water Balance- Water loss
-Urine
-Sweat
-Breathing
-Feces
Atlantic Salmon
- spend 2-3 years in freshwater other in salt water. Salmons natural solute conc. is 1.0% but FW is 0.1% when water enters fish, via respiration through gills, internal env. is diluted, meaning they need to constantly remove water. Then, once fish moves to salt water env. it inc to 3.5 % and water s constantly being lost to environment
Osmotic pressure
occurs when there is a difference in the water concentration across a membrane
Hypoosmotic
swelling and bursting (env is less concentrated)
Hyperosmotic
shrinkage of organism (env is more concen.)
isoosmotic
suitable for survival
Osmoregulation
cells and body fluids maintain their concentrations and osmotic pressure through osmoregulation, waste is a big contributor to water loss and lead to a solute imbalance
Marine Bony Fish
Fish have lower salt concentration inside than outside, so they are hyoptonic to the sea water
- water moves out of the fish to try and balance out the pressure
combatting water loss
-Produce small volumes of concentrated urine (small kidney- few glomeruli)
-low filtration rate- only small amounts of water lost through urine
-drink sea water to compensate for loss of water
-salt is then excreted out of the cells in their gills (chloride secretory cells)
Fresh water fish
- Have a higher salt conc. inside than outside
-hypertonic to the sea water
-water moves into fish to try and balance out pressure
Fresh fish combatting water Gain
Produce large volumes of dilute urine
-large kidneys, lost of glomeruli (helps to compensate for water gain)
-drink freshwater through mouth and gills then remove via diluted urine
-specialized cells (chrloide secretory) in gills that absorb salts from surrounding water
Kangaroo rat
desert animals must be efficient at water conservation, since it is hot, dry, and water is scarce
Physiological adaptations (kangaroo rat)
- dry mouth and nasal passages to reduce loss during respiration
-high concentration of ADH in blood
-long loops of henle in kidney tubules
-large intestine extremely efficient at reabsorbing water from waste
-does not sweat
Behavioural Adaption
-remains inactive in its underground burrow during the day to avoid the heat
-air underground is cooler and moister than air above
-active at night when temp is lower
Excretion
everything we do requires energy and produces waste. If the waste are not removed from the body they become toxic to the point of death
-process of getting rid of metabolic waste is called excretion
Wastes that need to be removed may include..
Ammonia, urea, and uric acid (all nitrogenous wastes
deamination
this is a part of amino group which is removed and converted into ammonia (NH3) in the liver
rest is turned into carbohydrate
How is urea made
Ammonia is toxic cannot build up in body so combined with CO2 and converted to urea only slightly toxic
What is the excretory system composed of?
Kidneys, Ureter, Urinary bladder, and urethra
What are the main filtering organ? What are the main transport ones?
Main filtering is kidney, others are mostly transport
The kidney
- 2 kidney bean shape
-fist sized on either side of spinal column on the abdominal wall - at any given moment around 25 % of the bodys blood supply can be found in the kidneys
Renal vein
Brings filtered blood (towards the heart) out of the kidney
Renal artery
brings blood (away from the heart) towards the kidney to be filtered
what are the “filters”
Nephrons
Nephron
two main parts: the tube (nephron) and the blood supply
Ureters
carry urin from kidney to bladder (2)
Urethra
carries urine from bladder & out of the body
The bladder
- muscular sack
stores urin
feel urge to urinate as bladder fills with urine and inc. pressure
(200mL urine urge, 400mL big urge, 600mL wet yourself)
The kidneys- 3 main parts
Cortex
medulla
renal pelvis
Cortex
darker in colour (outer layer) filtering takes place here (dense capillary network)
Medulla
Lighter in colour contains tubules of the nephrons and collecting ducts
renal pelvis
central chamber where ruine briefly collects before passing out down the ureters
Useful substances: ???
E.x. Glucose
Are reabsorbed back into blood from tubules in the medulla and cortex
filtered blood goes back into the circulatory system via renal vein remaining unwated substances (urea) pass along the tubules the into the bladder via ureters
