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Form and function
Anatomy = form
Physiology = function
Examples:Capillaries and alveoli: 1 cell thick, allow gas ex.Muscle cells: long fibers, allow long lever armRBC: smooth, round allow flow through vesselsSkin: many cells thick, allow for scrapes without lots
of blood loss
Body plans
Need: exchange with environment
Need: aqueous environment for each cell
Protist: 1 cell: exchange across cell membrane
Adaptations
Elephant: millions of cells must get glucose and oxygen.Aqueous solution for all cells = interstitial fluid
Increase surface area within organ system by:Folds and protrusions
Tissue
4 types of tissue
Muscle: contractile
Nervous: conduct impulses
Epithelial: lines things, secretion
Connective: holds things together
Muscle tissue
Muscle:
Most abundant tissue
Smooth, cardiac (desmosomes), skeletal
Proteins: actin and myosin
Second messenger: Ca++
ATP needed for contraction
Connective tissue
Connective tissue: cells in a matrix with proteins
Blood to bone Matrix: liquid to solid
Fibers: collagen, elastic, reticular
Epithelial tissue
Epithelial: linings, secretes
Tight junctions: no leaking, small intestine
Desmosomes: anchor: skin
Simple to stratified
Organs
No organs: sponges and cnidariansHave groups of different tissue types together for
more complex function.
Bioenergetics
Flow of energy through animal
Metabolic rate: amount of Energy per unit timeMeasure by heat lostOr oxygen consumed
Bioenergetic strategies
Endothermic: maintain body temperature:BirdsMammals
Exothermic: warmed by external sourceSome very stable If in a stable environment Invertebrates, fish
Differ in source of warmth
Metabolic rate
Amount Energy needed per gram of body weight inversely related to body sizeMouse has high metabolic rateElephant has low metabolic rate. BUT, requires more
energy overall
Metabolic rate
Smaller animals have higher metabolism: greater surface to volume ratio: harder to maintain body temperature.
BMR
Basal metabolic rate: at rest
Endotherm: 1,600 – 2,000Kcal/day
Maximum rate: can not sustain for long
Use: ATP that’s already presentThen make some anaerobically by glycolysisStart to break down glycogen in liver and muscle
cells
Homeostasis
Maintain stable internal environmentReceptor – control center- effector
Conformers: may let one variable change with environment.
Feedback loops
Positive feedback: childbirth
Negative feedback: 1 product of reaction goes back and shuts down earlier step in reaction
Homeostasis: thermoregulation
Body temperature monitored in hypothalamus receptor
Information integrated in CNS Integration center
Effector organs: If cold: skeletal muscle: shiver
Erector pili: hair stands up Smooth muscle: close capillary beds in periphery
If hot: sweat gland
Adaptations for thermoregulation
1. insulation: feathers, hair, fat
2. circulatory: vasodilate, vasoconstrict, concurrent heat exchange (birds, marine mammals)
3. cooling by evaporation
4. behavior
5. hormones
acclimatization
Adjust to new environment over a few daysGrow thicker furChange metabolic rateEctotherms: change at cellular level: make different
enzymes Change proportions of sat/unsat fats Heat-shock proteins: protect other proteins from
denature