animal biology (unit 3) Flashcards
(241 cards)
1
Q
what defines an animal?
A
heterotrophs (no chlorophyll/chloroplasts)
multicellular
no cell walls
capable of movement (at some stage of life)
have HOX (regulatory) genes
2
Q
what necessary functions do animals carry out?
A
reproduction
growth and development
maintaining water and solute concentrations
support and movement
coordination of body functions
transporting matter and energy
gas exchange
protection from environment and pathogens
3
Q
what is the organization hierarchy (from smallest to biggest)
A
molecules
organelles
cells
tissues
organs
organ systems
organisms
4
Q
how is structure related to function?
A
physical and chemical structure influences interactions with other structures and therefor function
5
Q
what are functional tradeoffs?
A
specializing for one function limits the structure’s ability to perform another function - it is impossible to optimize for all parameters
6
Q
what is an example of functional tradeoffs?
A
cartilage is flexible but not as strong, bone is much stronger, but inflexible
7
Q
what are fusiform bodies?
A
banana shapes (grey seal) that reduce drag and has blubber to keep them warm
8
Q
what is an emergent property?
A
a property of an organizational level that the lower levels does not posses
example: something organs can do but not tissue
9
Q
what is the only system that does not exchange with external environment?
A
circulatory system
10
Q
what is the main function of the endocrine and nervous system?
A
respond to stimuli and coordinate body activities
11
Q
what coordinates responses in the body?
A
chemical and/or electrical signaling
12
Q
what is homeostasis?
A
the maintenance of a relatively stable internal environment (minimizes the effect of external changes internal fluctuations)
13
Q
why is homeostasis important?
A
cells have conditions/environment that is optimal for function
14
Q
what is negative feedback?
A
control mechanism where the response opposes the original stimulus
15
Q
what is positive feedback?
A
a control mechanism where the response reinforces the original stimulus
16
Q
what type of feedback does homeostasis rely on?
A
negative feedback
17
Q
what are set points?
A
the normal ranges of physiological parameters
18
Q
when do set points change?
A
puberty
menstrual cycle
circadian rhythm
acclimatization
19
Q
how do animals obtain/store energy?
A
obtain chemical energy and molecular building blocks from food and convert it to ATP to use for cellular work
20
Q
what are resource trade-offs?
A
choosing to allocate resources to one function at the expense of the other (wound healing vs egg production)
21
Q
what is the homeostasis cycle?
A
stimulus -> sensor -> control center -> response
22
Q
what is acclimatization?
A
becoming accustomed to new conditons
23
Q
what is adipose tissue?
A
body fat
24
Q
what is an apical surface?
A
the edge of epithelial tissue that faces the lumen or external environment
25
what is basal surface?
the edge of epithelial tissue that is next to the basement membrane
26
what is epithelial tissue?
form the covering of all body surfaces, line body cavities, hollow organs, and are major tissues in glands
27
what is interstitial fluid?
fluid found in the spaces around the cells
28
what is the extracellular matrix?
a network of proteins and molecules that support cells and tissues
29
what is a model organism?
used to study development of animals since they have similar structurs/mechanisms
30
what are two common model organisms?
frogs and sea urchins
31
what is the basic fertilization cycle?
meiosis produces gametes, which fertilize and become a zygote then goes through mitosis to become a multicellular adult then performs meiosis to produce more gametes
32
what is the importance of the egg cytoplasm?
contains many proteins and mRNA that is essential to early development
33
what is the acrosome?
part of the sperm that contains hydrolytic enzymes to digest through egg
34
how do sperm bind to egg?
the sperm-binding receptor has the same species of ligand as the sperm
35
what are the steps of fertilization?
contact with the jelly coat triggers acrosomal reaction
surface proteins on acrosomal process bind to receptors on egg cell membrane
plasma membranes fuse and trigger fast block to polyspermy
sperm nucleus enter and cortical reaction causes slow block to polyspermy
sperm and egg nuclei fuse to form diploid nucleus of the zygote
36
what is the acrosomal reaction?
acrosome membrane fused with sperm membrane and releases enzymes so sperm can move into the egg
37
what happens when acrosome binds to egg?
acrosomal process elongates and contact is made with the sperm binding receptors and they are able to bind
38
what is polyspermy?
when multiple sperm enter the egg
39
what would polyspermy fuck up?
balance of maternal/paternal chromosomes (only thing the sperm contributes) and interfere with normal zygote development
40
what is the fast block to polyspermy?
a change in the membrane to stop additional sperm from binding (this is temporary)
41
what is the slow block to polyspermy?
molecules in cortical granules clip off receptor molecules
molecules in cortical granules harden vitelline layer
changes in osmatic pressure to draw water into perivitelline space
42
what is the cortical reaction?
contents of the cortical granules being expelled from the egg
43
what is the fertilization envelope?
a physical and chemical barrier that separates the zygote from extra sperm
44
what is cleavage?
rapid cell division with little growth of individual cells (no G1 or G2 phases)
45
what does cleavage accomplish?
it is the process by which a zygote becomes multicellular
46
what is a blastula?
a hollow ball of cells with a fluid filled cavity called the blastocoel (what is produced by cleavage)
47
what is differential gene expression?
the expression of different genes (depending on location and development of cells) which leads to the production of different proteins which changes the structure and behavior of the cell
48
what determines what gene a cell will express?
cytoplasmic determinants (signal from within cell) and inductive signals (signal from outside cell)
49
what are cyoplasmic determinants and how do they create diffference in gene expression?
molecules within a cell that regulate gene expression and can be differently distributed to daughter cells resulting in different gene expression
50
what are inductive signals and how do they create differnce in gene expression?
molecules that create signals to change gene expression that create differences based on where cells are located
51
what is morphogenesis?
the rearrangement of cells or sheets of cells in the embryo
52
what is gastrulation?
developmental stage when three germ layers are established and basic body plan is set up
53
what is organogenesis?
stage in development where the formation of the organs occurs(ex: nuerulation is the formation of the nervous sysem)
54
what are the stages of gastrulation?
cells in the vegetal hemisphere push inwards
outer cells (future endoderm and mesoderm) roll inward
blastocoel collapses and new cavity (archenteron - primitive asshole) is formed
cells at animal pole (future ectoderm) spread over outer surface
55
how is morphogenesis achieved?
through changes in cell position, shape, or survival (including apoptosis) lead to change in tissue as a whole
56
what is a neural plate?
structure with cells linked together by junctional complexes
57
what is the neural tube?
the developing brain and spine
58
what is neurulation?
the formation and shaping of the neural plate
59
what is perivitelline space?
space between the membrane of an egg and surrounding membranous structure
60
what is a cortical granule?
membrane bound organelles located in the cortex of unfertilized egg
61
what is the vitelline layer?
the transparent layer in an egg that is responsible for protein binding during fertilization
62
what is the jelly coat?
the gelatinous layer that surrounds the egg and releases chemicals to activate and guide sperms to egg
63
which systems are responsible for communication and coordinating the body?
nervous and endocrine
64
what is information flow within the body?
chemical and/or electrical signaling between cells
65
what are the three types of skeletal systems?
hydrostatic skeleton (fluid held under pressure in a close body compartment)
endoskeleton (hardened internal skeleton)
exoskeleton (hardened external skeleton)
66
how do hydrostatic skeletons move?
muscles (both longitudinal (extend) and circular (contract)) contract which changes the shape and exerts pressure on water that's inside - this is peristaltic movement
67
what are examples of organisms that have exoskeletons?
mollusk shells, arthropods
68
what are some examples of endoskeletons?
sponges, echinoderms and chordates
69
what is peristaltic movement
longitudinal and circular muscles at contracting and relaxing
70
how do endo and exo skeletons generate movement?
using muscles attached to the hard parts of the skeleton
71
what are antagonist muscles?
pairs of muscles that must react opposite each other (one contracts and one relaxes) to create movement across a joint)
72
what is flexion and extension?
decreases in the angle across a joint (bending your arm) and increases in the angle of your joint (straightening your arm)
73
what is vertebrate skeletal muscle made up of?
muscle fibres cells made of up myofibrils made up of thin (actin) and thick (myosin) filaments
74
what is a special feature of muscle fibre cells?
they have many nuclei because they are created by multiple cells fusing together
75
what are myofibrils?
long fibrous organelles, can be thin or thick
76
what is a sacromere?
myosin and actin organized into units
77
what are thin filaments made up of?
two chains of actin molecules with myosin binding sites (on each actin molecule)
78
what are thick filaments made up of?
multiple myosin molecules with head exposed to bind with actin molecules (tail regions are bundled together)
79
what is the M-line?
the center of the sarcomere that thick filaments are anchored to
80
what is the Z-line?
the part of the sarcomere that the thin filaments are anchored to
81
what is the alternative name for skeletal muscles?
striated muscle - because it has a striped appearance caused by the alternation of thick and thin filaments in sarcomeres
82
how do the filaments interact during muscle contraction?
neither muscles change size, they just slide past each other (sliding filament theory of muscle contraction) the sarcomere contracts which causes the muscle contraction
83
how does the sarcomere contract?
myosin (motor protein) is able to convert ATP into movement - the thick filament pulls the thin filament towards the center
84
what is the difference between the low energy and high energy configurations of sacromere?
the myosin head moves away from its tail
85
what are the steps of myosin moving thin filaments?
the myosin head moves to its high energy configuration
the myosin attaches to the actin molecule (cross-bridge)
ATP -> ADP + P1
myosin moves back to low energy position (pulls actin with it)
myosin attaches to another ATP and releases actin
**repeats**
86
what two proteins are necessary for sacromeres?
tropomyosin and troponin
87
what does tropomyosin do?
prevents myosin heads from binding to actin molecules
88
what does troponin do?
binds to calcium (from message to contract) and is changed in shape to pull tropomyosin off myosin binding sites to allow sliding filament cycle
89
what is locomotion?
active travel from place to place
90
how does the endocrine system send signals?
with hormones through the blood
variety of speed and duration depending on hormone
91
how does the nervous system send signals?
with electric impulses and chemical neurotransmitters through neurons
very fast but short
92
how is specificity achieved in the nervous system signaling?
specificity is achieved by close connection of neurons and target cells
93
how is specificity achieved in the endocrine system signaling?
specificity is achieved by hormone (ligand) receptor interaction
94
what is the nervous system specialized for?
directing immediate and rapid responses
95
what is the endocrine system specialized for?
coordinating gradual changes that effect entire body
96
what are the main components of the nervous system?
nervous tissue made up neurons and glia
97
what do neurons do in the nervous system?
generate and transmit the electrochemical impulses
98
what do glial cells do in the nervous system
maintain homeostasis, form myelin, nourish, support, protect neurons in central and peripheral
99
what are neurons composed of?
cell body with dendrites coming off, and one large axon projecting off the cell body
100
how do neural circuits work?
presynaptic neuron synaptic terminals releases neurotransmitters which fuse to receptors on postsynaptic cell which will respond if enough are received
101
what do dendrites do?
bring information into cell body (electrical impulses)
102
how do dendrites transport electrical impulses?
if enough stimulation is transported, and electrical signal will be generated at axon hillock which is sent down the axon to synaptic terminals which releases neurotransmitters
103
what is cephalization?
elaboration of the central nervous system at the anterior end (only for bilaterally symmetical animals)
104
what are the two parts of the nervous system?
central (brain and spinal cord) and peripheral (cranial nerves, ganglia, spinal nerves)
105
what are nerves?
bundles of axons
106
what are ganglia?
places where cell bodies of many neurons are grouped together (have nerves extending from them)
107
what are the stages of information processing in the nervous system?
sensor sends sensory input (peripheral) to central to perform integration which leads to motor output (peripheral) to the effector
108
what is an internueron?
a neuron entirely within the central nervous system
109
what are the three types of nuerons?
sensory, inter, and motor
110
how does the endocrine system send signals?
endocrine cells secrete hormones into bloodstream that bind to target cells (this will effect physiology and behaviour)
111
how does the endocrine system send signals?
endocrine cells secrete hormones into bloodstream that bind to target cells (this will effect physiology and behavior)
112
what does the hypothalamus do in the endocrine system?
regulates the system (receives signals from different parts of the brain) and sends hormones usually through the pituitary gland which determines what the other endocrine glands will do
113
what is the posterior pituitary made of?
axons of neurosecretory cells that produce hormones and secretes them into bloodstream
114
what is the anterior pituitary made of?
endocrine cells that respond to hormones from hypothalamus (received via portal vessels) by secreting their own hormones
115
what is the hierarchical organization of the endocrine system?
hypothalamus -> pituitary -> other endocrine glands
116
how does the fight or flight response work?
hypothalamus integrates the stress and sends electrical signals through spinal cord to adrenal glands
adrenal medulla produces epinephrine and norepinephrine
117
what is the adrenal medulla?
inner layer of adrenal gland - made of endocrine cells
118
what are the two main types of hormones?
water soluble and lipid soluble
119
what is the speed difference between water soluble and lipid soluble hormones?
water can be synthesized ahead of time (and stored in vacuoles) whereas lipid hormones are not made ahead of time since they can travel through membranes - so water hormones are released much more quickly
120
how do lipid soluble hormones move through blood?
cannot just move through like water soluble, need transport proteins
121
how do water soluble hormones move through membrane?
cannot just move through like lipid soluble, need a receptor on plasma membrane (lipid hormones receptors are on nucleus)
122
what type of action is generated with lipid soluble hormones?
usually effect gene regulation
123
what type of action is generated with water soluble hormones?
always trigger a signal cascade (sometimes with gene regulation sometimes not)
124
what determines the effect a hormone has on the cell?
the signaling pathways within the cell
the type of receptor
125
what are antagonistic hormones?
pairs of hormones whose actions oppose each other to keep a physiological parameter within an acceptable range
126
what is an example of antagonistic hormones?
insulin and glucagon
127
what is bioenergetics?
overall flow and transformation of energy within an organism
128
how is energy lost from the body?
heat from digestion/absorption
heat from cellular respiration
heat from biosynthesis
heat from cellular work
129
what are the stages of chemical reactions in digestion?
digestion and absorption
cellular respiration (to cellular work)
biosynthesis (from carbon skeletons)
130
what is a metabolic rate?
amount of energy used per unit time
131
what is basal metabolic rate?
metabolic rate of a non-growing endotherm that is at rest with an empty digestive tract and with no stress (minimum amount of energy that an animal can be using at a time)
132
what can you use to measure an animals energy use?
heat production
oxygen consumption
carbon dioxide production
food consumption/waste production
133
what is the relation between mass and BMR
metabolic rate increases as mass does (BMR = mass^3/4)
as body mass increases, each kilo is using less and less energy
134
what are the essential components of food for animals?
amino acids, fatty acids, vitamins, and minerals because they are needed but not produced by the animal
as well as nucleic acids, carbs, proteins, lipids to create more within the body
135
what are the main functions carried out by the digestive system?
ingestion (food handling), digestion (breaking down), absorption (nutrient molecules into cells), elimination (removing undigested material)
136
what are the two types of digestion?
mechanical (teeth chewing, stomach churning) is first, then chemical digestion (breaking molecules down into components)
137
what system has the most diverse sturctures?
digestive
138
what are the different types of feeding styles?
suspension and filter feeders
substrate feeders
fluid feeders
bulk feeders
139
how do suspension and filter feeders eat?
always aquatic, consume particles that are much smaller than themselves (some use filters - whales use baleens)
140
how do substrate feeders eat?
live on or in their food (catapillers)
141
how do fluid feeders eat?
through fluid (blood, nectar, etc)
142
how do bulk feeders eat?
eat a meal of large pieces of food (humans, most preditors)
143
what are the two mains parts of the digestive system?
alimentary canal (tube from mouth to ass) and accessory organs
144
what are the main accessory organs?
salivary glands
liver
gallbladder
pancreas
145
what are the main parts of the alimentary canal?
tongue
oral cavity
pharynx
esophagus
small intestine
large intestine
rectum
anus
146
what are sphincters?
a circle of smooth muscle that contracts to close over openings
147
where are sphincters located in digestive tract?
in-between esophagus and stomach
in-between stomach and small intestine
148
what is saliva composed of?
mucus (protects lining of mouth and lubes food)
buffers (prevent tooth decay by neutralizing acid)
antimicrobial agents (lysozyme)
salivary amylase (breaks down carbs)
149
what is the process of digestion?
oral cavity - mechanical and sometimes chemical digestion forms a bolus of food
pharynx opens in trachea and esophagus
epiglottis opens to let bolus into esophagus
peristalsis (wave of contraction and relaxation( push bolus down esophagus
spchicter opens and bolus goes into stomach
stomach contracts and mixes bolus with gastric juice (becomes chyme)
150
what are gastric glands
inside gastric pits - secrete gastric juice
151
what is gastric juice made of?
water (lumen of stomach)
hydrogen and chloride ions (parietal cells)
pepsinogen (chief cells) - converted to pepsin by HCl
mucus (mucus cells)
152
what does pepsin do?
an active enzyme that breaks down protein molecules into polypeptides (pepsin also increase the production of pepsinogen - positive feedback loop)
153
where are carbs digested?
oral cavity
small intestine (pancreatic and epithelial enzymes)
154
where are proteins digested?
stomach
small intestine (pancreatic and epithelial enzymes)
155
where are nucleic acids digested?
small intestine (pancreatic and epithelial enzymes)
156
where are lipids digested?
small intestine (pancreatic enzymes only)
157
how do we not digest ourselves?
mucus provides protection for cells lining the alimentary canal
HCl and digestive enzymes maintained in in active forms until they are released in alimentary canal lumen
rapid turnover of cells in alimentary canal
158
what structures in the esophagus relate to function?
long tube - more absorption/can fold
large circular folds - increase surface area
finger-like projections called villi - increase absorption
microvilli - more absorption
many blood vessels connecting to liver
159
what is the large intestine composed of?
colon (reabsorbs water)
cecum (houses bacteria to ferment plant material - cellulose)
rectum
160
how do the digestive system and endocrine system interact?
release digestive hormones are triggered by presence of food
digestive hormones trigger secretion of gastric juices and digestive enzymes
insulin and glucagon are triggered by blood glucose levels
hormones regulate appetite
161
what is diffusion?
molecules moving randomly (kinetic energy) causing a net flow from [high] to [low] (rate of proportion is inversely related to distance
162
what is the formula for rate of diffusion?
rate of diffusion = surface area / distance
163
what animals need to have a circulatory system?
animals with many cell laters (to transport materials between cells)
164
what are the three universal circulatory system components?
circulatory fluid (hemolymph if open, blood in closed)
set of intervconnecting vessels
muscular pump
165
what are the two types of circulatory systems (explained)?
open: hemolymph circulates throughout the body
closed: blood is contained within system of vessels
166
how do materials get from blood to cells?
closed - diffuse from blood into interstitial fluid and then move into cells
open - circulatory fluid comes in contact with all the organs, etc
167
what is the pulmonary circuit in animals?
the heart - oxygen rich and oxygen poor blood are kept separate (poor on left, rich on right)
168
what are the main parts of the heart that are involved in the cardiac cycle?
superior vena cava (moves deoxygenated blood returning from systemic circuit)
right atrium (pushes blood into right ventricle)
right ventricle (pushes blood out through pulmonary artery)
pulmonary artery (branches off to bring blood to left and right lung)
GAS EXCHANGE
pulmonary veins (moves oxygen rich blood into heart)
left atrium (pushes blood into left ventricle)
left ventricle (pushes blood to aorta)
aorta (branches to send blood to body
169
what are the two types of valves?
atrioventricular valves (separate the atria from ventricles and prevent back flow into atria)
semilunar valves (separate ventricles form arteries and prevent back flow into ventricles)
170
what does diastole mean?
relaxation
171
what does systole mean?
contraction
172
what are the stages of the cardiac cycle?
atrial and ventricular diastole
atrial systole and ventricular diastole
ventricular systole and atrial diastole
173
what is the structure of arteries/veins?
arteries branch into arteriole (bring blood into capillary bed) then debranch into venule which come together to form veins
174
what are the layers in an artery/vein wall ?
endothelium, smooth muscle, connective tissue
175
what is the structure of capillaries?
capillaries have a single layer wall (basal lamina)
176
what is the difference between arteries and veins?
arteries always have thicker walls because they experience higher blood pressures
veins have valves to prevent back flow
177
how is blood flow regulated?
nerve impulses, hormones, local chemicals that affect arteriole diameter and pre-capillary sphincters
178
how many capillaries are usually being used?
10-15% at any one time
179
how does exchange of materials between blood and interstitial fluid work?
thin capillary walls and slow blood velocity allow for diffusion
180
what is blood composed of?
55% plasma
45% cellular elements
181
what is plasma made of?
water
ions
proteins
nutrients, metabolites, and wastes
182
what are the cellular elements of blood made up of?
erythrocytes (red blood cells)
leukocytes (white blood cells)
platelets
183
what are platelets?
bits of broken cells that help with blood clotting
184
how are respiratory surface structures utilized for function?
gills, tracheae, lungs all have very large surface areas (greater than rest of body exterior)
very thin exchange surface (single epithelial layer)
185
how does air/water breathing differ?
water breathers need to be much more efficient (80% vs 20%) because air has a much higher concentration of O2
186
what environments do gills need to function?
respiratory system must be moist
respiratory surfaces of terrestrial animals are enclosed within the body to prevent excess water loss
187
what does the mammalian respiratory system composed of?
nasal cavity connects to pharynx connects to larynx connects to trachea connects to bronchi branch out into bronchiole (surrounded by diaphragm
188
what is the main component of red blood cells?
almost entirely hemoglobin (binds to O2 so red blood cells can transport O2)
189
where is the CO2 in the body?
bound to amin acids of hemoglobin (23%)
in blood plasma as CO2 (7%)
in blood plasma as bicarbonate (70%)
190
what are the two parts of the immune system?
innate immunity (all animals)
adaptive immunity (only vertebrates)
191
what is innate immunity?
rapid response - recognizes a traits shared by lots of pathogens using a small set of receptors
192
what is adaptive immunity?
slower response with recognition of specific pathogen’s traits using lots of receptors
193
what are the four steps of immune responses?
barrier defences (innate)
internal defences (innate)
humoral response (adaptive)
cell-mediated response (adaptive)
194
what are pathogens?
an organism that elicits an immune response from a host cell
195
what are the barrier defences of the immune system?
skin (outer surfaces that inhibit entry by pathogens)
mucous membranes (secretes by internalized external surfaces - traps microbes and other particles
secretions (saliva/tears that wash away microbial colonization and create a hostile chemical environment (like lysozyme, acidic pH, etc)
196
what are the internal defences of the immune system?
phagocytic cells (eat the pathogens)
natural killer cells (release chemicals that trigger apoptosis)
antimicrobial proteins (interferons and complement proteins)
inflammatory response (local - histamine and cytokines, or systemic)
197
what is the humoral response of the immune system?
antibodies defending against infections in body fluids
198
what is the cell-mediated response in the immune system?
cytotoxic cells defend against infection in body cells
199
what is lysosome?
enzyme that attacks bacterial cell walls (in saliva)
200
what are phagocytic cells?
they recognize molecules that are not in host and essential for living for pathogen groups
located in blood, skin, mucous membranes, lymph
when the locate a pathogen, pseudopodia engulf the pathogen and pinch off vacuole to bring it into the cell
vacuole is joined with lysosome and digests it
201
what is the lymphatic system?
series of vessels that mop up excess fluid that is leaked from the capillaries
liquid is called lymph
lymph nodes monitor the fluid for any pathogens
202
what are interferons?
proteins produced by virus infected host cells to trigger surrounding cells to produce chemicals that inhibit viral reproduction (warning messengers)
203
what are complement proteins?
plasma proteins activated by substances on the surface of many microbes
lead to lysis of invading cells
involved in inflammation and in adaptive immunity
204
how does local inflammation work?
histamine triggers vasodilation and increased load vessel permeability in affected area and more white blood cells and proteins can enter interstitial fluid
cytokines further increase blood flow to affected area
inflammation increased amount of blood being brought to area, which brings phagocytic cells, complement proteins, and other antimicrobial proteins
205
how does systemic inflammation work?
only happens in serious infections
releases more white blood cells from bone marrow
resets body’s thermostat to cause fever
206
how does the adaptive immune system achieve specificity?
specificity is achieved through interactions between antigens and antigen receptors
antigens are large molecules found on or around pathogens
antigen receptors are proteins produced by B cells or T cells
207
what are antigens made up of?
multiple epitopes (small accessible portions that bind to antigen receptors) (specific ones for specific receptors)
208
what are antigen receptors made of/from?
from B cells and T cells (forms of white blood cells produced in the bone marrow, T cells mature in thymus)
each cell produces a single type of antigen receptor (bind to a single epitope on a single antigen on a single pathogen)
B cell antigen receptors bind to intact antigens in blood or lymph
T cell antigen receptors only bind to antigen fragments presents on surface of host cells
209
what happens when a antigen receptor meets its epitope?
cell produces many copies of cell that is specific for that epitope (proliferation)
some of those cells are kept as memory (stored in case the antigen is encountered again)
other are effector cells (take action)
210
how do the effective forms of B cells work?
effector B cells are plasma cells (secrete specific antibodies that circulate in the blood looking for the epitope and destroy the pathogen through
neutralization (changes surface structure to prevent virus from gaining access to host cells)
opsonization (bind and act as a marker of flag for other immune cells to increase likelihood that cells will get phagocytosized)
or indirectly through activating complement proteins (leading to lysis)
211
how do the effector forms of T cells work?
helper T cells help activate cytotoxic T cells (binds with antigen to produce cytokines promote further production of cytokines)
cytotoxic T cells carry out destruction of pathogens/infected cells (bind and produce granzymes (enter pathogen and initiate apoptosis) and perforin (form pore in cell so fluid goes in and it explodes))
212
what does ambient mean?
environmental
213
what is a regulator?
an animal that will maintain its own internal temperature no matter the external
214
what is a conformer?
an animal that adapts their internal conditions to match the external ones
215
what are the benefits/cost to being a conformer?
may be able to tolerate greater ranges for physiological parameters
internal stability is possible ins table environment
216
what is thermoregulation?
regulating body temperature
217
what is osmoregulation?
regulating solute and water concentrations
218
why does body temp matter?
enzyme kinetics (have optimal temperatures)
every animal has optimal internal temp range (can be wide or narrow)
219
what is a poikilotherm?
body temp varies with environment
220
what is a homeotherm?
keep relatively stable body temperature
221
what is an endotherm?
rely on metabolism as major heat source
222
what is an ectotherm?
do not produce enough body heat to raise their body temp beyond external temp
223
what organisms are endotherms and homeotherms?
mammals and some birds
224
what organisms are ectotherms and homeotherms?
some tropical reptiles, antarctic and deep sea fish
225
what organisms are endotherms and poikilotherms?
birds mammals that undergo hibernation, some insects
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what organisms are ectotherms and poikilotherms?
most invertebrates, amphibians, reptiles, and fish
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what are the common parings of thermoregulation?
most ectotherms are poikilotherms
most endotherms are homeotherms
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what mechanisms do animals use for thermoregulation?
behavioural responses (both) - shade seeking, sun basking
evaporative heat loss (both) - panting, sweating
vasoregulation (both)
countercurrent heat exchangers
metabolic heat production
insulation (hair, fur, fat)
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what are the types of vasoregulation?
vasodilation (relaxes smooth muscle walls of surface blood vessels to allow more blood to flow from core to surface for cooling)
vasoconstriction (tenses smooth muscle walls of surface blood vessels to reduce blood flow from core to surface to prevent heat loss)
both are achieved via nerve impulses and hormones
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what is concurrent heat exchangers?
heat transferred between fluids flowing in opposite directions (hot arterial blood transfers to cold venous blood)
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what is metabolic heat production?
a mechanism for thermoregulation using
muscle contraction (activity/shivering)
brown adipose tissue (high [mitochrondria] uses cellular respiration to produce heat instead of ATP)
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what is osmoregulation?
control of [individual solute] and [water] and [total solute]
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what is osmosis?
movement of water across selectively permeable membrane (water only)
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what does hypoosmotic and hyperosmatic mean?
hypoosmotic has lower solute and higher free water concentration than the hyperosmotic
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what happens to cells in different levels of osmotic solutions?
hyperosmotic - cell wil lose too much water to surroundings and die :(
hypoosmotic - cell will gain too much water from surrounds and die :(
isoosmotic - no net movement so cell lives :) (cause the solute concentrations are equal)
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how do animals regulate water balance?
osmoconformers are isoosmotic with environment - all are marine, some stable some variable, actively transport specific solutes to maintain homeostasis
osmoregulators maintain stable internal osmolarity - found in marine, freshwater, terrestrial environments, particular internal osmolarity achieved by active transport
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what determines the osmotic challenges an animal faces?
depends on environment:
freshwater risk gaining water
marine risk losing water
terrestrial risk losing water
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how do marine fish osmoregulate?
osmotic water loss through gills (increase internal osmolarity)
eating would be gaining water and solutes back through food - so they drink water (still salty) so they actively excrete salts out of their body (actively transport chloride and sodium follows)
and pee concentrated
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how do freshwater fish osmoregulate?
they gain water through gills and gain water from food (and ions)
they do not drink water - instead they actively transport chloride (sodium follows) into the body
and pee diluted
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what is the osmoregulation challenge to terrestrial animals and how do they deal with it?
dehydration is the primarily challenge:
have adaptations to reduce water loss (body coverings and nocturnal)
eat and drink water
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what is transport epithelia?
one or more layers of epithelial cells specialized to move particular solutes (controlled amounts/specific directions)
have large surface areas (some face external environment, many line tubular networks that connect)
closely connected to circulatory fluid
