Chapter 44 and 40- Regulating the internal environment Flashcards
Homeostasis
Maintaining a stable internal environment
What are some factors that animals must hold relatively constant?
• 4 things
- temp
- glucose
- blood pressure
- pH
How can homeostasis be measured?
• 3 steps
1. Sensor: Detects increased BP •deliver action potentials 2. Control center: Brain (medulla) •action potentials 3. Effector: perform response (decrease BP - dilate vessel)
Negative feedback
Input and Output are in opposite directions
3 elements of homeostasis
- Osmoregulation
- Excretion
- Thermoregulation
Osmoregulation
•definition
•what kind of animals
•2 strategies
- achieving proper water and salt balance
- live in diverse environments: aquatic, freshwater, marine, terrestrial
- Osmoconformers and osmoregulators
Osmolarity •formula •Human blood •Ocean •Freshwater
- Moles of solute/volume of solvent (H2O) = milliosmoles/liter
- 300
- 1000
- 50
Osmoconformers • solute concentration •main solute •Energy? •example
- same solute concentration as environment (isotonic/iso-osmotic)
- Sodium (Na)
- Spends no energy on osmoregulation
- marine invertebrate
Osmoregulators
•solute concentration
•energy?
•examples
- control solute concentration and differs from environment
- uses ATP
- Terrestrial animals: Freshwater and marine invertebrates
How do freshwater fish osmoregulate? •The problem •The solution: Urine,gills • Solutes and H2O •example
- They gain water
- Urine: dilute
- Gills: take up salt
- Hi solutes in and lo out
- Hi H2O out and lo in
- trout
How do saltwater fish osmoregulate? •The problem •The solution: Urine,gills • Solutes and H2O •example
- water loss
- Urine: concentrated
- Gills: Pumps out salt
- Hi solutes out and lo in
- Hi water in and lo out
- cod
How do terrestrail animals osmoregulate?
•The problem and why?
•how do they gain H2O? lose?
- water loss because they are not surrounded by water
- By eating and drinking
- By sweating, urine, breathing, and feces
Anhydrobiosis
Animals that can survive extreme hydration and live in temporary water
What generates nitrogen-containing waste?
Protein an nucleic acid metabolism
-NH2 amino groups converted to
Ammonia (NH3)
3 types of nitrogenous wastes
- Ammonia
- Urea
- Uric Acid
Ammonia • Toxicity • Energy required to produce it • Water required to eliminate it • Animals that excrete this type of waste
- Highly toxic
- Low energy
- High (diluted in H2O)
- Fish
Urea • Toxicity • Energy required to produce it • Water required to eliminate it • Animals that excrete this type of waste
- Medium
- Medium amount
- Medium amount
- Mammals and amphibians
Uric Acid • Toxicity • Energy required to produce it • Water required to eliminate it • Animals that excrete this type of waste
- Low
- High amounts
- Low (Excreted as a pasty precipitate)
- Birds, reptiles, insects
4 steps for excretion
•Basic feature
•steps
•built on tubes
- Filtration
- Reabsorption
- Secretion
- Excretion
Filtration
Body fluid enter tube and it filtrates the fluid
Reabsorption
•definition
•examples
- Return of substances in filtrate to animal body
* Glucose, AA, Na+
Secretion
•definition
•examples
- add substances to filtrate
* drugs, acid
Excretion
excrete urine from body
4 excretory systems
- protonephridia
- metanephridia
- malpighian tubules
- Kidney
Protonephridia
•present in
•how does it work
•Planaria (phylum Platyhelminthes)
- Body fluid enters the flame bulb
- Cilia inside bulb draw fluid in
- Fluid flows into tubule and through pore in body wall
Metanephridia •present in • 4 steps •how many per segment • what is reabsorbed and by what •what kind of urine is produced
•earthworms and mollusks •1. Internal opening 2. Collecting tubule 3. Bladder 4. External opening •one per segment • Salts (Na+) reabsorbed by collecting tubule • dilute
Malpighian tubules •present in •made of • 5 steps • Advantage
•insects •tubes connected to digestive tract 1. Body fluids (salts, water, waste) enters malpighian 2. Fluid enters intestine 3. Reabsorbs H2O to body 4. Feces and urine combination is left behind 5. 1 waste is excreted from anus • H2O conservation
Kidney
•present in
•the 2 kidneys are what percent of body weight
•how much blood flow do kidneys receive
- vertebrates
- 1%
- 25%
Ureter
Transport urine to bladder
Urinary bladder
Stores urine
Nephrons
•where is it located
•function
•5 structures
•in the renal medulla and renal cortex •produces urine 1. Bowman's capsule (closed end) 2. Proximal convoluted tubule 3. Loop of henle 4. Distal convoluted tubule 5. Collecting tubule duct
Renal pelvis
Collects urine
Proximal convoluted tubule
Center twisted tubule
Distal convoluted tubule
Distance twisted tubule
Urine formation
•2 steps
- Filtration
2. Reabsorption
Filtration in the nephron
Fluid from blood enters Bowman’s capsule and forms filtrate
Reabsorption in nephron
•definition
•how much is returned
•what is it controlled by
- returns substances to body
- 99% is returned
- 2 hormones: antidiuretic and aldosterone
Antidiuretic Hormone (ADH)
Increases H2O reabsorption and conserves H2O
Aldosterone
Increases Na+ reabsorption
If ADH levels are low will you produces a large volume of dilute urine or a small volume of concentrated urine
Large volume of dilute urine
For every __ degrees rise in temperature, enzyme activity __
- 10 C
* increases 2-3 times
Animals exchange heat with their environment by what 4 processes?
- Radiation
- Conduction
- Convection
- Evaporation
Radiation
•how it exchanges heat
•contact
•example
- transfer of heat from a warmer object
- NOT in direct contact with warmer object
- butterfly
Conduction
•definition
•example
Transfer of heat by direct contact with warmer object
•lizard
Convection
•definition
•example
- Transfer of heat by movement of air past a surface
* horses
Evaporation
•definition
•example
- removal of heat from liquid to gas
* humans, dogs
2 thermal characteristics of animals
- Ectotherms
2. Endotherms
Ectotherms
•definition
•examples
Gain heat from environment
•Reptiles, fish, amphibians, all invertebrates
Endotherms
•definition
•examples
- generates its own heat from metabolism
- mammals and birds
- “warm-blooded”
Metabolic rate
the amount of energy used by an animal/time
Who has a greater metabolic rate, endotherms or ectotherms?
Endotherms
Basal metabolic rate
minimum metabolic rate of a fasting, nongrowing endotherm at rest under a comfortable temperature range
How do you determine a temperature range in a basal metabolic rate?
by measuring oxygen consumption
Who consumes more energy per kg of tissue, small or large animals?
Small animals
3 approaches to sex in animals
- Parthenogenesis
- Hermaphroditism (monoecious)
- Biparental reproduction (dioecious)
Parthenogenesis
•definition
•example
- development of an embryo from an unfertilized egg; virgin birth
- honeybees, whip-tail lizards
Hermaphrodites •definition •what does it require •advantage •examples
- One individual has both testes and ovaries and can produce both eggs and sperm
- Requires another individual to reproduce
- Do not need anyone else
- Barnacles, and earthworms
Biparental reproduction
•2 mechanisms
- External fertilization
2. Internal fertilization
External Fertilization
•definition
•Common in what type of animal?
•Why is it uncommon in land animals
- females release eggs into water and males release sperm into the water containing the eggs. The union of the egg and sperm then occurs
- animals that live in water
- Because it can dry out (desiccation)
Internal Fertilization
•definition
•advantage it offers terrestrial animals
- Introduction of males gametes into the female reproduction tract
- The egg and sperm will not dry out
Copulation
Introduction of sperm by the male into female’s body
3 strategies for embryonic development
- oviparity
- ovoviviparity
- viviparity
Oviparity
•definition
•examples
- Eggs are fertilized internally but are deposited outside the mother’s body to complete development
- all birds, most reptiles
Ovoviviparity •definition •what do the embryos obtain •what is released from the mother •examples
- fertilized eggs are retained in mother to complete their development
- all nourishment from egg yolk
- live you are hatched and released
- some bony fish (guppies, mollies), some reptiles, some cartilage fish
Viviparity
•definition
•what do the embryos obtain
•examples
- fertilized eggs are retained in mother to complete their development
- all nourishment from mother’s blood and NOT egg yolk
- most cartilaginous fish, few reptiles, almost all mammals
Seasonal breeders
- reproduce once a year
* definite mating season
3 reproductioncycles
- estrous cycle
- Menstrual cycle
- Induced ovulators
Estrous cycle
- period when female is sexually receptive to males
- females are in estrus
- occurs around the time of ovulation
- males are more constant in their reproductive activity
- example:dog
Menstrual cycle
- no distinct period of sexual receptivity
- may engage in copulation any time during the cycle
- females bleed when they shed their inner lining of uterus during menstruation
- female humans and apes
Induced ovulators
Females ovulate only after copulation
•example:rabbits and cats
Three reproduction patterns in mammals
- monotremes
- Marsupials
- Placental
Monotremes
•definition
•example
- egg laying mammals
* platypus
Marsupials
•how to they give birth
•development
•examples
- to fetuses that are incompletely developed
- is in a pouch of the mother’s skin where the fetuses obtain nourishment from nipples of the mammary glands
- kangaroo and possum
Placental
•where are the fetus’s
•how are they nourished
•example
- remain in the mother for long periods
- by a structure called the placenta
- nutrients and gas exchange between fetus and mother occur in the placenta
- cat, lemur, human
