Midterm 1 Flashcards
Define Acclimation
adjustment to single environmental factor
Define Acclimatization
adjustment to multiple environmental factors
Define thermogenesis
adjustment of metabolic heat production to maintain body temp
Define osmolarity, and describe what it does
it’s the solute concentration in a solution and it determines the movement of water across a selectively permeable membrane (water goes from low solute concentration to high)
How many living animal species are there?
1.3 million
What are the 5 stages of embryonic development? And where does cleavage occur?
1) Zygote
Cleavage
2) 8-cell stage
Cleavage
3) Blastula
4) Gastrulation
5) Gastrula
What characteristic defines Ecdysozoans? (Ecdysis)
they’re invertebrates that shed their exoskeletons in a process called ecdysis
What does the word Arthropod mean?
Jointed feet
How long ago did the common ancestor of all animals live?
It lived between 700-770 million years ago
What Protist resembled the common ancestor of all living animals?
Choanoflagellates
What 3 pieces of evidence suggest that choanoflagellates resemble the common ancestor of all living animals?
1) cell morphology
2) cell morphology unique to animal cells
3) DNA homologous
What 4 things do physical laws constrain?
1) strength
2) movement
3) diffusion
4) heat exchange
What is physiology the study of?
Biological functions
What are the 3 internal exchange surfaces of complex animals?
1) Lungs: wet sponge-like surface for gas exchange
2) Small intestine: finger-like structures to expand surface area, thus increasing nutrient absorption
3) Kidneys: blood filtered across surface of long, narrow blood vessels
Define Regulators and give one example
They use internal control mechanisms to moderate internal changes in the face of environmental fluctuations. Example: Otter
Define Conformers and give one example
They allow their internal conditions to vary with certain external changes, Example: Large-mouth Bass
What do mechanisms of homeostasis do?
They moderate changes in internal environment
Is homeostasis a positive or negative feedback loop? And explain why
Negative because fluctuations above the set point act as stimulus, which is detected by a sensor, and it triggers a response, which returns the variable to the set point
In animals and plants, what rhythm governs physiological changes?
Circadian rhythm
Define Thermoregulation
Maintain internal temp within a certain range
Define ectothermic and give examples
Animals that gain heat from external sources and can tolerate more variation in internal temp. Examples: Fish, invertebrates, amphibians, and non-avian reptiles
Define endothermic and give examples
Animals that generate heat via metabolism, which is more energetically costly as they maintain internal temps even with external fluctuations. Examples: mammals and birds
What are 4 things to balance heat loss and heat gain
1) Radiation
2) Evaporation
3) Conduction
4) Convection
What are 5 adaptations that help animals thermoregulate?
1) Insulation: Skin, blubber, fur, feathers
2) Circulatory adaptations: marine animals = countercurrent exchange, circulate blood near surface
3) Cooling by evaporative heat loss: sweating, bathing, panting
4) Behavioural responses: Postures in invertebrates to min or max solar absorption, honeybees huddling
5) Adjusting metabolic heat production: shivering, moving, nonshivering (mitochondria increases metabolic activity)
Why are specialized compartments for digestion important?
Important as it reduces the risk of an animal digesting its own cells and tissues
What kind of digestion is used by simple animals?
Intracellular digestion where food particles are engulfed by phagocytosis
What kind of digestion is used by complex animals?
Extracellular digestion where food is broken down outside of cells
What is broken down in the alimentary canal due to the amylase in our saliva?
sugars
What do parietal cells and chief cells do in the stomach?
Parietal cells secrete H+ and Cl- separately into the stomach of the lumen and Chief cells secrete inactivated pepsinogen which is activated to pepsin in the lumen of the stomach when coming into contact with HCl
What’s the pH of the stomach and what are gastric juices made of?
pH = 2 and it’s made of HCl and pepsin (protease that breaks down proteins into smaller peptides)
What protects the stomach lining?
mucus
What is the function of the small intestine and the duodem=num in the small intestine?
The small intestine is the longest part of the alimentary canal and it’s where enzymatic digestion occurs. The duodenum of the small intestine is where the chyme from the stomach is mixed with the digestive juices from the pancreas, gallbladder, liver, and small intestine
What does the pancreas secrete
It produces proteases trypsin and chymotrypsin which get activated in the lumen of the duodenum
What does the cecum of the large intestine do?
It aids in the fermentation of plant matter
What does the liver do in glucose homeostasis?
Insulin decreases blood sugar and glucagon increases it. Cabs raise insulin levels, which triggers the synthesis of glycogen. & Low blood sugar causes glucagon to stimulate breakdown of glycogen to release glucose
what’s the first line of defense against infection?
The skin
What are the 6 steps in white clood cell innate defense mechanism?
1) Pseudopodia surrounds pathogen
2) Pathogens are engulfed by endocytosis
3) Vacuole forms encasing pathogen
4) Vacuole and lysosome fuse
5) Lysosome enzymes destroy pathogens
6) Debris from pathogen is released by exocytosis
What are 2 phagocytic cells?
Macrophages and Neutrophils
What is the function of mast cells during the inflammatory response?
They release histamines causing the blood vessels to dilate and become more permeable
What is the function of macrophages and neutrophils during the inflammatory response?
They release cytokines which signal the immune system to respond
Where do T-cells come from?
The Thymus
WHere do B-cells come from?
Bone marrow
What’s the epitope of an antigen?
region on surface of an antigen that’s recognized by B and T-cells
What’s the role of MHCs in the immune response (major histocompatibility complex)?
They are host proteins that display antigen fragments on the surface of the cell so that T-cells can bind to it
What’s the purpose of B-cells?
When they’re activated the secrete antibodies or immunoglobulin (Ig)
Define hyperosmotic
Higher solute concentration inside
Define hypoosmotic
Higher solute concentration outside (double oo for outside)
Define osmoregulation
controls solute concentrations and balances gains and loss of water
Define osmoconformers
are isoosmotic to their environment and don’t regulate their internal osmolarity
Define osmoregulators
expend energy to control water uptake or loss in hyper- or hypoosmotic environments
Define Stenohaline
Cannot tolerate substantial changes in external osmolarity (most animals)
Define Euryhaline
can survive large fluctuations in external osmolarity
Are bony fish Hyper or Hypoosmotic to seawater?
Hypoosmotic
In marine fish, how do they lose water and gain salt?
They lose water by osmosis since they’re hypoosmotic and gain salts by diffusion
In freshwater fish, how do the gain water and lose salt?
The gain water by osmosis since they’re hyperosmotic and they lose salts by diffusion. To balance this, they’re constantly excreting dilute urine and gaining salts from food
What’s the function of the proximal tubule of the kidneys?
it reabsorbs ions, water and nutrients
What’s the function of the descending limb of loop of henle of the kidneys?
reabsorbs water through channels formed by aquaporin proteins, increasing concentration of filtrate
What’s the function of the loop of henle of the kidneys?
Only salt diffuses in interstitial fluid not water, diluting the filtrate
What’s the function of the distal tubule of the kidneys?
regulates K+ and NaCl concentrations of body fluids; this controlled movement of ions regulates pH
What’s the function of the collecting duct of the kidneys?
carries filtrate through the medulla to the renal pelvis where the reabsorption of water and ions occurs.
Is urine hypo or hyperosmotic to body fluids?
hyperosmotic
What does ADH (Antidiuretic hormone) do in relation to the collecting duct within the kidneys?
Regulates blood osmolarity. When blood osmolarity reaches above set point, ADH binds to receptor leading to increase in aquaporins in membrane of collecting duct increasing H20 absorption and returning blood osmolarity to normal.
What does ADH do in relation to the posterior pituitary?
ADH is secreted by posterior pituitary and the hypothalamus generates thirst until you drink water and blood osmolarity returns to normal
What are the components of urine?
Urea and salts
What are the 4 purposes of pheremones?
1) marking trail to food
2) warning of predator
3) defining territory
4) attracting potential mates
What’s the function of thyroid hormone in frogs?
Regulates metabolism and controls metamorphosis of larva into frogs
What’s the function of the pineal gland?
Secretes melatonin which controls light/dark cycles
What are the functions of the hypothalamus?
Receives info from the nervous system and initiates response through endocrine signalling
What are the functions of the posterior pituitary gland?
Releases Oxytocin (regulates milk secretion in mammals/love hormone), and releases ADH (regulates blood osmolarity)
What are the functions of the anterior pituitary gland?
Secretes prolactin (role in milk production), and secretes growth hormone
What’s the function of the pancreas?
Regulates blood glucose levels
What are the functions of the ovaries and testies?
produces most sex hormones; androgens, progestins, and estrogens
What are the functions of the adrenal gland?
Regulates response to stress as it releases epinephrine which breaks down glucose, thus increasing, heart rate, metabolic rate, and blood pressure. Also secretes cortisol, aldosterone, and adrenaline
What’s the function of the parathyroid gland?
secretes parathyroid hormone which regulates blood calcium levels by releasing Ca2+ from the bones and stimulating reabsorption of Ca2+ in the kidneys.
What’s the function of the thyroid gland?
secretes Calcitonin which decreases Ca2+ in the blood by increasing the deposition of ca2+ in the bones and secretion of Ca2+ by the kidneys
Endocrine system helps you use what?
Hormones
What is the correct order of the 4 basic functions of sensory pathways and describe basic function?
1) Reception: sensory receptors interact directly with stimuli
2) Transduction: transforms stimulus energy into membrane potential (receptor potential)
3) Transmission: membrane potential into action potential
4) Integration: Response produced by brain
What are the 5 categories of sensory receptors?
1) Chemoreceptors: taste, and smell
2) Electromagnetic receptors: helpful for migration
3) Thermoreceptors: respond to heat or cold and help regulate body temp
4) Mechanoreceptors: tactile feedback from the skin and skeletal system
5) Pain receptors: detect stimuli that reflect harmful conditions
