Unit 3: Animal Biology Flashcards
1
Q
What are the 5 core concepts of biology as they relate to animal development and physiology?
A
- Structure and function
- Evolution
- Systems
- Information flow
- Transformations of energy and matter
2
Q
What factors make an animal (5 key points discussed)
A
- Multicellular
- heterotrophic: must obtain nutrients from other organisms
- lack cell walls
- capable of movement at one point in life stage
- Possess regulatory hox genes (all have same genes)
3
Q
Is a sponge considered an animal? Why?
A
- yes since it agrees with all requirements for an animal
- can move at the larval stage
4
Q
What functions do animals need?
A
- reproductive/development
- obtain matter and energy / transport it
- gas exchange (breathing)
- protection from external environment
- maintain water/solute concentration
- support/ movement
- coordination of body functions
5
Q
How does structure relate to function?
A
Structure can enable or constrain function
6
Q
How does structure enable function?
A
- a structures physical and chemical characteristics influence its interactions with other structures, and therefore its function
7
Q
How does structure constrain function?
A
- functional tradeoffs
- specialization for one function may limit a structure’s ability to perform another function
- it is impossible to optimize for all parameters
8
Q
What are the two forms of tradeoff?
A
- functional tradeoffs
- resource tradeoffs
9
Q
What is evolution?
A
- through natural selection organisms become adapted to their environment
- structures make sense in the context of the animal’s environment
10
Q
What is the hierarchal organization of structures?
A
molecules, organelles, cells, tissues, organs, organ systems, organisms
11
Q
How do biological structures interact? How might one change in one component of a network impact other components?
A
- interact to form complex systems
- a change can affect other components
eg: issues with cell can cause deflation of cartilage = mobility issues
12
Q
What are emergent properties?
A
- each level of organization has properties exhibited by lower levels
- these are properties that exist due to many different components working together
eg: Structure –> emergent property: cell –> life
13
Q
Provide an example of an emergent property
A
- cardiac muscle contracts
- cardiac muscle + tissue = heart (organ) = coordinated pumps
- heart + blood + vessels = circulatory system –> delivers O2
= rewrites all different components to deliver O2 throughout the body
14
Q
What does exchange of materials look like for a structurally simple animal?
A
- some animals structurally simple enough that all cells are in direct contact with external environment
- don’t need systems for exchange - does it alone
15
Q
What does exchange of materials look like in more complicated bodies ?
A
complicated bodies require organ systems that
- can exchange material with external environment
- can transport material around body
16
Q
What are the systems which allow for exchanging of materials in complex systems? For transport?
A
- digestive system, excretory, reparatory, integumentary
- circulatory system transports material throughout
17
Q
How do animals respond to changes in internal and external environments?
A
- animals have systems that perceive and respond to changes in internal and external environments
- all perception and response requires information flow
18
Q
What is communication in terms of information flow in animals?
A
- perception and response requires information flow
19
Q
How does communication occur?
What are these systems called?
A
chemical and/or electrical signalling between cells coordinates responses at cellular, tissue, organ, and system levels
- called endocrine and nervous systems that control response to stimuli/coordinate body activities
20
Q
What is homeostasis?
- Why are stable environments important?
A
- the maintenance of a relatively stable internal environment (systems help maintain this)
- cells have conditions under which they function optimally, enzymes/membranes sensitive to changes in surroundings
21
Q
Which feedback system does homeostasis rely on?
A
- negative feedback: control mechanism in which response opposes original stimulus
22
Q
What is transformational energy?
A
- regulate changes in asset points and normal ranges of physiological parameters essential to normal body functions
23
Q
What are some examples of regulated changes?
A
- stages of life, cyclic, response to environmental change
24
Q
Where do animals get their energy?
A
Food:
- chemical energy = sugars, fats, proteins, energy stored in bonds
- molecular building blocks (eg: amino acids)
25
What energy 'currency unit' do animals use in their body?
- stood chemical energy is converted to ATP
- also stores energy within bonds
- needed to carry out cellular work necessary for physiological activities
26
how does natural selection favour efficient use of resources?
- organisms have limited energy and material resources
- requires efficient allocation across competing functional demands
- resource trade-offs
27
What are resource tradeoffs?
natural sleeting favours efficient use of resources, requires specific allocation of energy. May need to give one thing up in order to do another
eg: wound healing vs. egg protection
28
What are the 3 embryonic stages ?
- cleavage
- blastula
- gastrulation
29
What is the foundation of diverse cell types and behaviours seen in development? In other words, how can cells which possess the same genomes look and behave differently?
Differential gene expression
30
Why are model organisms broadly representative?
- developmental genes and mechanisms are very similar across animal species
- therefore studying development in model organisms provides knowledge about development in general
31
What is the relationship between genes of drosophila and humans?
- have similar genes that perform similar functions
32
What is fertilization?
- haploid gametes (n) join to form diploid zygote (2n)
33
Describe the steps of fertilization in sea urchins
1) sperm and egg are haploid gametes
2) contact with jelly cat triggers acrosomal reaction
3)surface repotting on acrosomal process binds to receptors on egg cells membranes
4) plasma membranes fuse triggering fast block to polyspermy
5) sperm nucleus enters and cortical reaction causes slow block to polyspermy
6) fusion of sperm and egg nuclei form the diploid nucleus of zygote
34
What is an acrosomal reaction?
- surface proteins on acrosomal process binds to receptors on egg cell membrane - triggers fast block
35
What is cleavage?
- the process by which zygote becomes multicellular
- rapid cell division with little growth of cells
36
What stages of mitosis does cleavage skip? Why?
- skips G1 and G2 phase for rapid division with little growth
37
What is developed from cleavage?
- results in many smaller cells called blastomeres (become blastula)
- cells get smaller with each round of division
- no growth of cells between divisions
38
What is the blastula?
- developed from blastomeres
- hollow ball of cells with a fluid filled cavity called the blastocoel
39
What is differential gene expression?
- cells express different genes depending on their location and stage development
- expressing different genes leads to the production of different proteins which determine structure/behaviour
40
What do the different proteins formed from differential gene expression do?
- determine structure and behaviour of cell at any given time (allows for different traits despite having same genomes)
41
What are the two mechanisms which allow genes to know what genes to express at a given time?
- 1) cytoplasmic determinants - signal comes form within the cell
2) inductive signals - signal comes from outside the cell
42
What are cytoplasmic determinants ?
- molecules within cytoplasms regulates gene expression
- can be differentially distributed to daughter cells resulting in differences in gene expression
43
What mechanism is responsible for an asymmetric cell division?
- cytoplasmic determinants
44
What are inductive signals?
- signal molecules a cell is exposed to depend on its location within the embryo and the stage of development
- as cell develops different conditions allow it to express different traits
45
What is morphogenesis?
- rearrangement of cells r sheets of cells in the embryos
46
What is gastrulation?
- stage when 3 germ layers are established, and basic body plan is set up
47
What is organogenesis? Provide and example
- the formation of the organs
- neurolation ; formation of the nervous system
48
What are the 3 layers formed from castellation called?
ectoderm, mesoderm, endoderm
49
What are the steps of frog gastrulation?
1. Cells in vegetal hemisphere push inward
2. outer cells (future endoderm and mesoderm) roll inward
3. Blastocoel collapses and new cavity - archenteron - is formed
4. cells at animal pole (future ectoderm) spread over the outer surface
50
What forms the endoderm and mesoderm?
- the outer cells of blastula which roll inward
51
What is the archenteron?
- when the blastocoel collapses the new cavity archenteron is formed
52
How is morphogenesis achieved?
- achieved through changes in cell position, shape, and survival
53
What is convergent expression?
- example of cells changing position
- produces a longer, narrower structure
54
Know the formation of the neural tube (review diagram)
- how is the neural tube formed?
- ectodermal cells change shape during neural tube formation
55
what is programmed cell death's role?
- also shapes embryos
- fluorescing cells are undergoing apoptosis eg: removal of webbing between digits
56
What is apoptosis?
the death of cells which occurs as a normal and controlled part of an organism's growth or development.
57
What animals are best to model development?
list one reason why either one of these is effective
Frogs and urchins
- urchins have transparent, external eggs
58
What are the parts of the blastula?
- formed from blastomeres, doesn't change size from og. zygote
- has animal pole and vegetal pole
- animal pole is the 'top' where the stem enters, has smaller cells than the vegetal side
- also contains blastocoel- a fluid filled cavity
59
What are the 3 kinds of morphogenesis?
1) Gastrulation
2) organogenesis
3) programmed cell death
60
True or False: Endodermal cells express different genes than ectodermal cells
True! Despite having the same genes, they express them differently depending on different determinants (cytoplasmic determinants and inductive signals)
61
What are the roles of the nervous and endocrine system?
- major systems that control responses to stimuli and coordinate body functions and maintain homeostasis
62
What are the characteristics of the endocrine system?
- hormonal signal type
- blood transmission
- speed = fast/slow
- specificity is achieved by hormone/receptor interaction (target cells have receptor proteins)
- single travels everywhere in body
63
What are the characteristics of the nervous systems?
- electrical impulse and chemical neurotransmitter signal
- neuron transmission
- very fast
- short duration
- specificity is achieved by close connection of neuron's and target cells (eg: neutrons, muscle, endocrine cells)
- travels to specific location
64
What is the endocrine system for?
- specialized for coordinating gradual changes that effect the entire body
eg: growth and development, reproduction, metabolic progresses, digestion
65
What is the nervous system?
- specialized for directing immediate and rapid response to the environment
eg: rapid locomotion and behaviour
66
What are nervous systems composed of ?
- neurons and glia
67
What are neutrons?
cells responsible for generating and transmitting electrochemical impulses of the nervous systems
68
What are glia?
- cells that maintain homeostasis
- form myelin, nourish, and provide support and protection for neurone in the central and peripheral nervous systems
69
What are the main parts of the nervous system ?
- dendrites, axon, nucleus, synapse : neurotransmitter, synaptic terminal
- presynaptic cell, post synaptic cell
70
What are the steps of communication through the nervous system?
1) electrical impulses are triggered at dendrites
2) with sufficient stimulus to cell body, a new electrical impulse is generated and send down axon
3) neurotransmitter is released and crosses the synapse to bind to receptors on the post synaptic cell
71
What forms the central nervous system?
- brain and spinal cord
72
What dorms the peripheral nervous system?
- cranial ner es, ganglia, spinal nerves
73
What are the 3 stages of information processing ?
1) sensory input
2) integration (central nervous system)
3) motor output (peripheral nervous system) --> effector
74
What are the 3 neurons?
- sensory nurons, interneuron, motoneuron
75
What do endocrine cells do?
- endocrine cells secrete hormones into the bloodstream, affecting target cells to regulate physiology and behaviour
76
What parts of the body produce hormones?
which are the two major endocrine glands?
- organs produce hormones
- major endocrine glands: hypothalamus, pituitary gland
77
What is the hypothalamus?
- a brain region that acts as the "master regulator" of the endocrine system primarily through the pituitary gland
78
What are the parts of the hypothalamus?
hypothalamus, posterior pituitary, anterior pituitary
79
Wha is the posterior pituitary?
- made up of axons of neurosecretory cells of the hypothalamus
80
What are neurosecretory cells?
- neurosecretory cell is a neuron that produces a hormone and secretes it into the bloodstream
- functional overlap between nervous and endocrine system
81
What system is an overlap between nervous and endocrine system?
- the posterior pituitary
82
What is the anterior pituitary?
- made up of endocrine cells that respond to hormones from the hypothalamus by secreting their own hormones
- hypothalamic hormones arrive via portal vessels
83
How do hypothalamic hormones arrive?
via portal vessels
84
What regulates other endocrine glands?
- hormones from the posterior and anterior pituitary glands
85
What is the hierarchal organization of hormone secretion?
hypothalamus -- > posterior/pituitary glands --> other endocrine glands eg: thyroid, adrenals, testes, ovules
86
What systems do the fight or flight systems require?
- requires nervous and endocrine systems
87
What controls the connection between nervous and endocrine systems?
- the hypothalamus
88
How does the hypothalamus affect fight or flight?
- hypothalamus affects endocrine system without pituitary - via spine and then adrenal glands
89
What are some effects of hormones?
- increased heart rate
- breathing rate
-metabolic rate
- blood glucose
- change in blood flow pathogen
90
What does it mean for hormones to differ in structure and solubility?
- a single hormone can produce different effects in different cells
- response of a target cell to a hormone depend on - signalling pathways within target cell
- the type of receptor on target cells
91
What is the difference between water soluble and insoluble hormones?
- water soluble passes through membrane (from secretory cell)
- water insoluble requires proteins/receptors
92
How do endocrine systems maintain homeostasis?
- endocrine systems often use antagonistic hormones to maintain homeostasis
93
What are antagonistic hormones?
- Pairs of hormones whose actions oppose each other
- maintain a physiological parameter within an acceptable range
- ex: insulin and glucagon regulate blood glucose concentration
94
what hormones does the adrenal gland secrete?
- epinephrine and norepinephrine
95
Describe the negative feedback loop of blood glucose
too low = alpha cells of pancreas releases glucagon = live breaks down glycogen, release glucose = blood glucose increases = homeostasis!
Too high = beta cells in pancreas releases insulin = liver removes glucose from blood, stores it as glycogen = blood glucose decreases = homeostasis
96
What is bioenergetics?
The overall flow and transformation of energy within an organism
97
What determines how much energy an animal needs?
- metabolic rate
98
What is the metabolic rate?
- the amount of energy used per unit time
99
What is the basal metabolic rate?
BMR is the metabolic rate of a non-grown endotherm (Warm blooded animal) that is at rest, with an empty digestive tract, and not experiencing stress
ie: the minimum amount of energy to maintain basic functions
100
What determines metabolic rate?
- many factors: sex, age, size, temperature, nutrition
- primaries: activity level, body mass,
101
Does a smaller or larger animal have a greater metabolic rate?
- smaller animals have higher metabolic rate (more activity, larger animals use energy more efficiently)
102
What must an animal's diet do?
- must supply energy, organic molecules, and essential nutrients
103
What is chemical energy in food used for?
- used in cellular respiration to produce ATP or is stored
104
Why are organic molecules needed?
- needed for biosynthesis of nucleic acids, carbohydrates, proteins, lipids
105
What are essential nutrients? from an animals diet?
- essential amnio acids, fatty acids, vitamins, and minerals
106
What are the 4 stages of food processing?
1. Ingestion : mechanical ingestion
2. Digestion: chemical digestion = enzymatic hydrolysis
3. Absorption: nutrient molecules enter body cells
4. Elimination: undigested material
107
Why are the structures associated with ingestion the most diverse?
- various diets
108
what are the 4 main feeding mechanisms?
- suspension/filter feeders
- substrate feeders
- fluid feeders
-bulk feeders
109
What are the components of the digestive system? What is it for?
- alimentary canal + accessory organs
- specialized for sequential stages of food processing
110
What pushes food along?
Peristalsis
111
What separates compartments in the digestive system?
- sphincters between compartments
112
What is the oral cavity? What foes it contain?
- oral cavity is the first site of chemical and mechanical digestion
- contains salivary glands which produce saliva
113
What does saliva contain?
- mucus: protects lining of mouth and lubricates food
- buffers: helps prevent tooth decay by neutralizing acid
- antimicrobial agents: lysozome
- Salivary amylase: enzymatic breakdown of carbs
114
How does food move from the mouth to the stomach?
- swallowing reflex and esophageal peristalsis
115
Describe the states of the epiglottis and esopgogeal sphincter during swallowing
initially up and contracted until swallowing when it opens and relaxed
116
Where does mechanical digestion occur?
in the mouth and continues in the stomach (stomach contracts)
117
What is the epithelium?
- in the stomach, secretes gastric juice
- food mixes with gastric juice to become chyme
118
What is found on the interior surface of the stomach?
- gastric pits on interior surface of stomach, connected to gastric glands
119
What are the components of the gastric glands?
3 specialized cells
- mucous cells, chief cells, parietal cells
- parietal cells release hydrogen and chlorine ions
- chief cells release pepsinogen which when it meets HCl is turned into active pepsin (which encourages production of pepsinogen = positive feedback)
120
What does the liver produce?
Liver proceeders bile, gallbladder stores bile, bile released into small intestine to emulsify fats
121
Why does our alimentary canal not digest itself?
- mucus provides protection for cells lining alimentary canal
- HCL and digestive enzymes maintain inactive forms until released to alimentary canal lumen (stomach lining)
- rapid turnover of cells lining alimentary canal
122
What is the small intestine good for?
- well suited for digestion and absorption
123
What is responsible for nutrient absorption in the small intestine?
- veins carry blood to liver
- large circular folds, villi, and microvilli allow for greater nutrient absorption (larger SA)
124
What is the livers role?
- regulates distribution of nutrients to rest of body
- functions in detoxification
- acts like a "guard post" between what you ingest and the rest of your body
125
Why is the structure of the small intestine so well suited for absorption?
- large surface area, many blood vessels connecting with small intestine carry materials to the liver
126
Describe the large intestine
- composed of the Colin, cecum, and rectum
127
What is the tole of the cecum? Why might it be smaller in carnivores?
- in the large intestine, functions in fermenting ingested plant material (using symbiotic bacteria)
- smaller in carnivores due to its role in plant fermentation, so eats less plants = smaller and intestines are therefore shorter
128
What is the colon's function?
Functions in water reabsorption and formation/elimination of the feces
- majority of water is reabsorbed in the small itenstine, but colon does to
- feces consists on undigested materials and bacteria
129
What are hormones function in the body? What triggers their release in the body, and what do they trigger?
- regulate digestion and energy storage
- triggered by the presence of food, which then trigger the secretion of gastric juices and digestive enzymes
130
What is the role of the hormones insulin and glucagon?
- insulin causes excess energy to be stores as glycogen in liver and muscle, then as fat in adipose cells
- glucagon secreted during energy deficit causes breakdown of liver glycogen then muscle glycogen and fat
- remember feedback loop
131
What hormones are released when we're hungry and full?
insulin and peptide YY are secreted in response to a meal and gherkin is secreted when the stomach is empty
132
How do hormones regulate appetite?
- a satiety centre in brain generates the nerve impulses that makes us feel hungry and full
- leptin is produced by adipose and regulates long term appetite
133
Why do animals eat?
- require external sources in order to produce proteins, acids, etc
- animals are heterotrophic (require external source of energy)
- all physiological functions require energy and/or matter
134
How much energy does an animal need?
- enough to maintain basic metabolic functions
-E.g., maintain cellular activity, blood flow, respiration, temperature
135
How might an animal's energy use be measured?
Heat production, oxygen consumption, carbon dioxide production, food consumption/waste production
136
Which eats more? mouse or elephant?
depends on absolute/total amount or the body mass index
- elephant is larger - need more food overall
- mouse smaller = more activity - higher metabolism - mouse requires more food per kilogram, elephant has a lower BMR per kg
so mouse eats more per unit body mass
elephants eat more in absolute terms
137
What functions are carried out by the digestive system?
ingestion: food handling
Digestion: break down of food into absorbable components
Absorption: nutrient molecules enter body cells
Elimination: removal of undigested material
138
Why are structures associated with ingestion the most diverse?
- Huge variety in sources of food - animals have evolved structures that allow them to exploit these various food sources
139
What is the purpose of the epiglottis? When is it up?
- acts as a 'lid' to trachea, up during swallowing to stop food from entering trachea as it goes to esophagus
140
Does bile digest fat?
No, only breaks it down!
141
An organ responsivee for absorbing food molecules should ...
have large surface area and be well connected to the blood
142
What animals have obesity as an evolutionary trait? Why is it important?
Seal pups become obese for a few weeks - they live off of blubber as they learn to swim and hunt
143
what is diffusion?
- molecules move randomly due to their kinetic energy
- random movement causes a net flow from an area of high concentration to an area of low concentration
144
How is diffusion related to distance?
Rate of diffusion inversely proportional to distance
145
How is rate of diffusion related to surface area?
Rate of diffusion proportional to (surface area/distance)
146
How do animals with many cells exchange materials with the environment? How about animals with most cells in contact with the environment?
- some animals have body size and shape that allows most cells to be in contact with the environment = exchange is easy
- animals with many cell layers require circulatory system to transport materials between all body cells and organs that exchange those materials with the environments
147
What are the 3 basic components of the circulators system in all animals?
1. circulatory fluid
2. Set of interconnecting vessels
3. a muscular pump
148
Why do some materials only need to diffuse over short distances?
Only need to diffuse the distance it takes to get to the circulators system
149
What are the two states a circulatory system can be?
open or closed
149
Describe the circulatory fluid in closed and open systems
Blood in a closed circulatory system (mammals, etc)
- hemolymph in open circulatory systems
150
Describe the circulatory system in mammals and birds
- double circulation: two circuits flow to and from the heart
151
Does deoxygenated and oxygenated blood mix in the heart?
NO!
152
Describe the path of deoxygenated blood
- returns from the systematic recruit via the superior vena cava, through the right atrium, inferior vena cava, into right atrium
- right atrium contracts, blood pushed into right ventricle
- right ventricle contracts, blood pushed into the pulmonary artery sending it to the lungs!
153
Describe oxygenated blood's path
returns from pulmonary circuit via pulmonary vein and flows into the left atrium
- left atrium contract, blood pushed into the left ventricle
- left ventricle contracts, blood pushed into the aorta sending it to the systematic circuit
154
What do valves do?
- ensure unidirectional flow of blood through the heart by closing to prevent back flow
155
What are the kinds of valves? describe them.
- atrioventricular valve (AV) = separate the atria from the ventricles and prevents back flow into atria when the atria relax
- semilunar valves: separate the ventricle from the arteries and prevents back flow into ventricles when the ventricles relax
156
What are the two states of the cardiac cycle?
Diastole = relaxation
systole = contraction
157
What are the steps of the cardiac cycle?
1. Atrial and ventricular diastole
2. atrial systole and ventricular diastole
3. ventricular systole and atrial diastole
158
how does blood vessel structure reflect function? use capillaries to describe this
- increased branching increases surface area: capillaries shave greater area than arteries and veins
- Same volume of fluid flows more slowly through a greater area: velocity is slowest within capillaries
- The increase in area in capillaries causes pressure to drop off: blood is not repressurised until it returns to the heart
So capillaries have greater area, less pressure, slower velocity
159
What regulates blood flow?
- nerve impulses, hormones and local chemicals that affect arteriole diameter and precapillary sphincters
- at any time only 5-10 percent of capillaries have blood
160
Why are capillary walls thing and have slow blood velocity?
allows for exchange of materials between blood and interstitial fluid
161
What is blood? what are its components?
- blood is a tissue consisting of cells suspended in a liquid called plasma
- plasma (55%) = water, ions proteins, nutrients, metabolites, wastes
- cellular elements (45%) = platelets, erythrocytes, leukocytes
162
How are respiratory surfaces specialized for gas exchange?
- gills, trachea, and lungs have very large surface area and thin change surfaced (single epithelial layer)
163
Why does respiratory media vary in O2 concentration?
- O2 based on source
- air has high O2 concentration, water has lower O2 concentration
- animals that obtain from water must be much more efficient
164
Why do animals that breathe O2 from water need to be more efficient?
- much lower concentration of oxygen ins ater
165
How do gills work in terms of respiratory system ?
- gills are efficient at extracting O2 but are unsuitable in terrestrial environemtns
- respiratory surfaces must be moist
166
How do the respiratory systems of gills and terrestrial animals differ?
- respiratory media differs = different efficiencies
- respiratory surfaces of terrestrial animals must be enclose to prevent water loss
167
Know the mammalian respiratory system!
168
What binds oxygen to red blood cells?
O2 binds to hemoglobin to transport in red blood cells
169
How many oxygen binding sites does oxygen have?
4 bindings sites on hemoglobin
170
What materials are red blood cells important for transporting? Describe the CO2 transport in the body
- CO2 and red blood cells
- CO2 produced in body cells travels :
--> Bound to amino acids of hemoglobins (23)
--> In blood plasma as CO2 (7)
--> In blood plasma as bicarbonate (70)
171
172
To maximise diffusion rate, exchange surfaces should have...
C. a large surface area and be thin.
173
What kind of animals do not require a circulatory system? Why?
One example is flatworms/planaria
- most cells are in direct contact with external environment so do not require circulatory system for exchange (particularly in aquatic environments)
174
What are the two circuits involved in mammalian circulation?
Pulmonary circuit and systemic circuit
- pulmonary leads to lungs
-systemic leads to rest of body
175
What are the differences between arteries and veins?
- both made up of connective tussle and smooth muscle
- arteries take blood away from heart to rest of body, are much thicker than veins
- veins take deoxygenated blood back to heart, has valve
176
Why do veins have valves but arteries don't?
Arteries flow has high speed and pressure
177
What are the two methods of body regulation in animals?
- either regulate their physiological parameters or allow their bodies to conform to external conditions
- regulators vs. conformers
178
What are regulators?
- use homeostatic mechanisms to control internal changes
179
What are conformers?
allow for their internal condition to change in response to external changes
- may be able to tolerate greater ranges, internal stability is possible in stable environments
180
Which regulation method has a greater capacity ?
generally conformers have a greater range and can tolerate greater ranges in conforming to their external temperature
181
What does thermoregulation regulate? Osmoregulation?
1. temperature
2. body water, solute concentration
182
What is thermoregulation? Why does it matter?
- maintenance of an internal temperature within a tolerable range
- temperature matters because biochemical and physiological recesses are sensitive to changes in temperature, each animals species has an optimal internal temperature range
183
How might external temperature impair a body's functioning?
- inhibits physiological and chemical processes (enzymes eg) that can impair functioning and lead to death
184
What is a poikilotherm?
- body temperature varies with environment (most fish and reptiles)
185
What are homeotherms?
Relatively constant body temperature (most mammals and birds)
186
What are the 2 thermal strategies based on source of heat?
Endotherms: rely on metabolism as major heat source
and ectotherms : rely primarily on external environment as major heat source
187
Are endotherms and poikilotherms isolated from each other?
no, endotherms can be poikilotherms and ectotherms can be homeotherms
188
What does thermal regulation require?
- equal rate of heat gain and heat loss
- anatomical/physiological processes
- behavioural responses
189
What are the anatomical/physiological processes in thermoregulation?
Evaporative heat loss
Circulatory adaptations
Metabolic what production
Insulation
190
Describe evaporative heat loss
- water lost from most surfaces cools/carries heat away
- augmentation: panting and sweating
191
Describe circulatory adaptations
- Vasoregulation: common to endotherms and ectotherms
- Countercurrent heat exchanged in birds and mammals
192
What is vasoregulation? Describe constriction and dilation
- dilation or constriction of blood vessels achieved via nerve impulses and hormones
- Vasodilation: relaxes smooth muscle walls of surface blood vessels = more blood flow to cool at surface
- Vasoconstriction: tenses smooth muscles walls of surface blood vessels - reduces blood flow to prevent heat loss
193
What is a counter current heat exchanger?
- Heat is transferred between fluids in opposite directions
- heat from warm arterial blood transferred to cooler venous blood as it return to body core
194
What is a potential problem for the goose in maintaining body heat? What solves this?
- feet are cold in water!
- internal organs in the feathered area, specific counter current vessels that go to feet (cools as it goes down, heat as It goes back up)
195
Describe metabolic heat exchangers
- all metabolic activity produces heat - endotherms have much higher metabolic rate than ectotherms
- muscle contractions: shivering, activity
- brown adipose tissues - high concentration of mitochondria, cell reparation produces heat instead of ATP
- hypothalamus thermostatic function in human thermoregulation
196
Which animal with the same size, one an ectoderm and one an endotherm, would have a higher metabolic rate?
- endotherm
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What is osmoregulation?
- the control of solute concentrations and the balance of water gain and loss from the body
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Describe the homeostasis cycle
hot internal temperature --> signal sent to hypothalamus --> sends signals through hormones or nervous signals to produce sweat and/or vessels to dilate = temperate decrease
Low internal temperature --> hypothalamus triggers shivering = body temp increases
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What is insulation?
- fur feather and fat are a major adaptation to maintain heat
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What are some behavioural adaptations to maintain thermoregulation?
- shade seeking/sun basking, migration to cooler or warmer regions, nocturnal
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What might be some reasons for migration?
- to maintain body temperature, or food/reosurce sources,
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would blubber in whales have more or fewer vessels than humans?
Fewer in order to prevent heat loss at the surface - keep blood and heat at internal organs, whales don't often need to cool off
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What are the physiological parameters involved in osmoregulation?
- body water (volume) eg:, blood, interstitial fluid, within cells
- total solute concentration
- individual concentration of solutes
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What are the solutes involved in osmoregulation?
- calcium, potassium sodium, certain amino acids, water soluble hormones
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What is osmosis?
- the movement of water across a selectively permeable membrane
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What is a hyper osmotic solution? A hypo osmotic solution?
Hyperosmotic solution: higher solute concentration, lower free H2O concentration
(hyperosmotic fluid)
Hyoosomtic solution: Lower solute concentration, higher free H2O concentration
(hypo osmotic solution)
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What is a hyper osmotic fluid in reference to animal cells?
higher solute outside of cells, water leaves cells by osmosis, cells shrivel and die
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What is a hypo osmotic fluid in reference to animals cells?
- lower solutes outside cell (higher inside), water enters cells through osmosis, cells that gain too much water burst and die
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What is isoosmotic fluid? How would an animal cell react?
- same solutes inside and outside, no net movement of water into or out of cells
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What are the two ways that animals maintain water balance?
- osmoconformers : isosmotic with heir environment, no tendency to lose ro gain water, all are marine, some have stable osmolarities white others tolerate variable osmolatieis, actively transport specific solutes to maintain homeostasis
and osmoregulators:
- maintain a stable internal osmloarity
- found in marine, freshwater, and terrestrial environments
- particular osmolarity achieve by active transportation of solutes in or out, water follows
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How are energy costs of osmoregulation minimized?
- reduced by minimizing osmotic differences between body fluids and surrounding environments
- freshwater molluscs have lower internal osmolarities than Marine
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Why aren't all animals osmoconformers?
Adaptation idk
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What are the osmoregulatory challenges of animals in different environments?
freshwater osmoregulatorys gain water
- marine osmorrgulators lose water
- terrestrial animals lose water
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Describe osmoregulation in marine fish
- see diagram and notes
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Describe osmoregulation in freshwater fish
- see diagram and notes
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Describe the osmoregulation of marine fish cells
- marine fish are hypo osmotic relative to sea water (hyperosmotic fluid)
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Describe the osmoregulation of freshwater fish cells
- hyperosmotic relative to the lake/river (hypo osmotic fluid)
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what are some terrestrial adaptations to prevent dehydration?
- body coverings
- nocturnal
- maintain water balance by drinking and eating moist food and producing metabolic water through cellular respiration
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How do animals control the solute concentration of an internal body fluid?
- transport epithelia: one or more layers of epithelial cells specialized for moving particular solutes in controlled amounts in specific directions
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Describe transport epithelia's surface area. Why is it like this?
large surface areas, some face external environment directly (gills)
- many line tubular networks that connect to the outside by an opening on the. body surface.
- transport epithelia are closely connected to circulatory fluid
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Describe salt glands
- Seabirds, sea turtles, and marine iguanas remove excess salt, taken in when drinking sea water, through salt secreting glands
- Salt glands have transport epithelia that rely on countercurrent exchange
- Salt concentration is always higher in the blood vessel than the secretory tubule
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Do transport epithelial cells have a large surface area or a small surface area? Why?
Large to aid in osmoregulation
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What is innate immunity?
- recognition of traits shared by broad ranges of pathogens, using a small set of receptors
- rapid response
- has barrier defences and internal defences
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Can innate immunity be found in invertebrates?
YES. It's found in all animals.
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What are the barrier defences of innate immunity?
skin, mucous membrane, secretion
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What are the internal defences of innate immunity?
- phagocytic cells, natural killer cells, antimicrobial proteins, inflammatory response
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What is adaptive immunity? where is it found?
- recognition of traits specific to particular pathogens using a vast array of receptors
- slower response
- has humeral response and cell mediated response
- found in vertebrates only
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Describe the responses in adaptive immunity
- humoral response: antibodies defend against infection in body fluids
- Cell mediated response: cytotoxic cells defend against infection in body cells
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What are barrier defences?
- prevent most pathogens from entering the body
- skin/shells/cuticle: thickened outer surface inhibits entry by pathogens
- mucous membranes: mucus secreted by internalized external surfaces traps microbes and other particles
- secretions: saliva, tears - washing actions prevents microbial colonisation, hostile chemical environment (lysosome, acidic pH )
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Describe phagocytotic cells
- recognize molecules characteristic of a set of pathogens, destroy pathogens by phagocytosis
- recognize molecule is absent from vertebrates and is an essential component of certain groups of pathogens
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Why is it important for the component of the pathogen recognize by phagocytosis cells to be essential to the pathogen?
If it wasn't essential for the pathogens natural selection would weed it out and the pathogen would still survive and evade detection
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How do phagocytosis cells destroy pathogens?
- recognize pathogen, destroys through phagocytosis
- located in the blood, skin, mucous membranes, lymph
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What are natural killer cells?
-component of internal defence
- recognize surface proteins of virus-infected or cancerous cells
- release chemicals that cause adopts in infected/cancerous cells
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What are antimicrobial proteins? Provide 2 examples
- component of internal defence
- attack pathogens or impede their production
- ex: interferons and complement proteins
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How do interferons and complement proteins work?
- interferons: secreted by virus infected cells, trigger surrounding cells to produce chemicals that inhibit viral reproduction
- complement proteins:
1) plasma proteins activated by substance on surface of microbe,
2) leading to lysis of invading cells,
** also involved in inflammation and adaptive immunity
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Describe local inflammation. What are some examples of stuff released in local inflammation?
- signalling molecules released by injured or infected tissue causing local inflammation
eg; histamine and cytokines
- signalling molecules cause capillaries to dilate and increase blood flow
- phagocytosis cells (neutrophils) activate complement proteins and other antimicrobial proteins to fight infection
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What are the two kind of inflammatory response?
- local inflammation and systemic inflammatory responses
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Describe the signalling molecules for local inflammation
Histamines: triggers vasodilation and increased blood vessel permeability in affected area = more white blood cells an proteins
Cytokines: further increased blood flow to the affected area
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Describe the systemic inflammatory response
- triggered by serious infection
- release more white blood cells from the bone marrow, reset body's thermostat (fever)
- send more blood to required areas (swelling)
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Where are white blood cells created?
bone marrow!
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What component are used to fight infection in small infection?
- complement proteins and other antimicrobial proteins
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Describe adaptive immunity
- involved pathogen specific recognition
- specificity achieved through interactions between antigen and antigen receptors
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What are antigens?
- large molecules found on the surface of specific pathogens or secreted by those pathogens
- antigens contain multiple epitopes (a small accessible portion of an antigen that binds to an antigen receptor)
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What are antigen receptors?
- proteins produced by B cells or T cells
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What are B cell and T cells?
- lymphocytes
- Each B or T cell produces a single type of antigen receptor
- each antigen receptor binds to a single epitope of a single antigen
- variable regions of antigens receptors produce the specific of the antigen binding site
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What are lymphocytes? Where do they mature?
- white blood cells produced in the bone marrow
-- Be cells mature in the bone marrow, T cells migrate to the thymus for maturation
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What is the humoral response?
- B cell antigen receptors bind to intact antigens in the blood or lymph
- these antigens may be on the surface of pathogens or may be antigens secreted by pathogens
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What is the cell mediated response?
- T cell antigen receptors can only bind to antigen fragments presented on the surface of the host cells
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Describe the proliferation of B and T cells
- B cells and T cells proliferate when they encounter their specific epitome
- proliferates into memory cells and effector cells
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What are memory cells?
- result of proliferation of B and T cells
- long lived cells that give rise to effector cells if the same epitope is encountered again
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What are effector cells?
- short lived cells that take effect immediately against the pathogen or antigen
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What are antibodies?
- effector forms of B cells are plasma cells which secret antibodies
- soluble forms of the antigen receptor: specific for the same epitope as the original B cell
- mark pathogens for inactivation or destruction
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What happens when antibodies mark pathogens for inactivation?
- neutralizations prevents pathogen entry into cells
toxins can also be neutralised by antibodies
- Opsonisation: Antibody binding increases the ability of phagocytic cells to recognize the pathogens
- Leads to increased phagocytosis of pathogens
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What causes pore formation?
-antibodies activate complement system
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What are the effector forms of T cells?
- effector forms of T cells are helper T cells and cytotoxic T cells
- cytokines from Helper T cells help activate B cells and cytotoxic cells
- Cytotoxic T cells secrete proteins that lead to cell death
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What do cytoxic T cells do?
Bind to infected cells and secrete perforin and granzymes
Perforin: causes pores to form in cell membrane of infected cells
Granzymes: initiate apoptosis
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What is the primary response to antigen A?
- produces antibodies to A
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What is the secondary immune response to antigen A?
- produced antibodies to A, primary immune response to antigen B produces antibodies to B
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What are the 3 kinds of skeletal structures?
- hydrostatic: fluid under pressure compressed within closed comaprtment
- endoskeleton: hardened internal skeleton
- exoskeleton: hardened external skeleton
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How do skeletons and muscles coordinate movement?
- skeletons generate movement by using muscles attached to hard parts of the skeleton
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What are antagonistic muscles?
- antagonistic muscles are pairs of muscles which oppose each others movement across a joint
eg., triceps and biceps
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Describe the hierarchal organization of musculoskeletal system
skeletal muscle --> muscle fibres (AKA multi nucleated cells) --> myofibrils --> sarcomere (myosin and actin)
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Describe the thin and thick filaments
Thin filament = actin, double strand
Thick filament = myosin (molecules of myosin with heads exposed)
- compose sarcomere, held by 2 lines, striated muscles
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How does actin and myosin filaments move against each other?
they slide against each other
mason uses ATP to bind to receptor sites on actin and uses actin to move toward centre of sarcomere
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How does the skeletal muscle know when to contract?
- skeletal muscle contraction intimated by motor neurons
- stimulates release of Ca2+ which binds to troponin complexes, moves tropomyosin to expose binding sites on actin filament which allows for myosin binding (and muscle contraction)
- troponin complex binds with calcium and moves the tropomyosin to expose the active site on actin
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What is locomotion? What forces play a part in locomotion?
locomotion: active travel form place to place
- to move animal must overcome gravity and friction forces
- environment determines which is the dominant force to overcome (air/terrestrial=gravity, water=friction (drag) )
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How does natural selection impact locomotion?
- natural selection develops adaptations that reduce the energy needed for locomotion
- both behavioural and anatomical adaptations : slow descent in water, springy tendons, fusiform body shape, etc.
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Describe locomotion on land and the adaptations
- gravity is the dominants force opposing motion on land
- terrestrial animals develop strong skeletal muscles and muscles to stay upright
- maintain balance: 2 legs vs. multilegs
- adaptations: springy tendons
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Describe locomotion in air
- dominant force to overcome is gravity
- wing lift must overcome gravitational downward pill
- adaptations : flying animals are lighter and have fusiform shape (birds have no teeth, no bladder, air in bones)
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Describe locomotion in water
- most aquatic animals buoyant = easy tor resist gravity, but water is dense/viscous so drag (friction) is a problem
- adaptation: fusiform body shape reduces drag
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What is the functional unit of the muscle?
the sarcomere (composed of filaments : actin and myosin)
- entire chain is myofibril, made up of sarcomere, filaments of sarcomere held by Z lines
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Does the actin and myosin of a sarcomere change length in muscle contraction?
no, the sarcomere shrinks but the filament does not change length
- the filaments CHANGE LENGTH, and overlap but do not shrink : length of filaments remain the same while the muscles become a littler shorter and fatter
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