Ch. 40: Animal Body plans and Homeostasis Flashcards
Animal form and function are correlated at
all levels of organization
Feedback control maintains…
the internal environment in many animals
Homeostatic processes for …
thermoregulation involve form, function, and behavior
Energy requirements are related to…
animal size, activity, and environment
Size and shape are constrained by
- physical laws and the necessity of exchange with the environment
- SA to V ratio has to be reasonable, dictates size of organism
Hierarchical organization of body plans
- Atoms
- Macromolecules
- Cell
- Tissue: collection of “like”-cells that serve a common function
- Organ: collection of 2 or more tissues that function to serve a common goal
- Organ Systems: 2 or more Organs that work together to perform a common function
- Organism: all organ systems working together (keep organism alive and reproduce)
- Population: group of some species living in some area
- Communities: all organisms in a shared area
- Ecosystem: abiotic and biotic in a defined region/area
- Biosphere: planet Earth
11 organ systems in mammals
1) Circulatory
2) Respiratory
3) Excretory
4) Muscular
5) Skeletal
6) Nervous
7) Integumentary
8) Reproductive
9) Endocrine
10) Digestive
11) Immune
4 tissue types
1) Epithelial Tissue
2) Connective Tissue
3) Muscular Tissue
4) Nervous Tissue
Epithelial Tissue
covering, skin
- covers free surfaces (anything exposed to a space)
- i.e. skin, gastrointestinal system, blood vessels
- tend to exhibit polarity (plasma membrane)
functions: protective, absorption, secretion, modified as sensory structures
Structures:
1) Membranes: skin = cutaneous membrane
2) Glands
- endocrine: ductless, recreate into blood (hormones)
- exocrine: ducts drain to apiral surface (sweat glands, true sweat, oily sweat)
Connective Tissue
Suspended in matrix, blood
- scaffolding to hold tissues together
- cells suspended in a secreted matrix
=> cell: fibroblast: CT proper
=> condrocytes: cartilage
=> osteocytes: bone
Matrix: ground substance: polysaccharides
=> glycoproteins + water + salts
=> liquid <=> solid
i.e. blood bone
fibers (proteins)
- collagen: thick
- elastin: elastic
- reticulin: thin
- loose connective tissue (elastic, under skin)
- fibrous connective tissue
- bone: can change shape
- cartilage: helps give structure
- fat: called adipose tissue (cells = adipocytes) (insulation, excess food storage)
Muscle Tissue
contractile, heart
- produces contractile force
- skeletal, smooth, cardiac
Nervous Tissue
Neurons: conduct action potential neuroglia - communication among tissues and data - acquisition system: internal conditions and external conditions (environment) - Glial cells: "glue" / scaffolding
Homeostasis
maintain fairly stable internal conditions necessary for survival
- relates to 2nd law of thermo (entropy) because it function to maintain order
- Walter Cannon, “The Wisdom of the Body” 1990
- keeping cell as dis-equilibrium
Negative Feedback
reduce magnitude of stimulus
stimulus elicits a response that oppose original stimulus
- increase in blood sugar
- insulin
- glucagon
Positive Feedback
amplify magnitude of stimulus
response increases stimulus
- blood clotting
- contractions during labor
Ectothermy
source of heat from outside
can be either temperature regulators or temperature conformers
- fish
regulates behavior
Endothermy
generally generate heat internally
regulates temperature
-sea walrus
Bioenergetics
energy flow and transformation at any biological level of org.
Basal Metabolic Rate (BMR)
endotherm: minimum rate
Standard Metabolic Rate (SMR)
ectotherm: rate at temperature
Animal Size and Metabolic Rate
Small = lower BMR Large = higher BMR
(opposite for 1 kg or body mass)
Animal Size and Metabolic Rate
Small = lower BMR Large = higher BMR
(opposite for 1 kg or body mass)
(Small = higher BMR)
(Large = lower BMR)
Relate Fick’s law to the design of the intestinal epithelium, which is a smile columnar epithelium with a “brush border”
i.e. the apical surface of the cell membrane exhibits microvilli
F = DA * (∆p/ ∆x)
- 1 layer
- large-brick-shaped cells of simple columnar epithelia are often found where recreation or active absorption is important
- lines intestines, digestive secretory juices, absorbing nutrients
Why would you expect to find a layer of connective tissue just underneath the stratified squamous keratinized epithelium of human skin?
- loose connective tissue to bind epithelia to underling tissues and holds organs in place
- connective tissue: collagen, elastin, reticulin
- mores elastin: help to connect muscle to epithelium
Why are the actions of insulin and glucagon considered to be homeostatic?
Homeostatic: refers to any process that living things use to maintain fairly stable internal conditions necessary for survival
insulin:
- glucose increase in body
- pancreas secrete insulin
- insulin increase tells liver to convert glucose to glucagon
- insulin also stimulates glucose uptake by cells
- blood-glucose level goes back to normal
glucagon:
- glucose decreases in body
- pancreas secrete glucagon
- liver breaks down glucagon to glucose
- blood-glucose level rises back to normal
What is the principle difference between how the nervous system sends signals versus the endocrine system?
nervous system: sends signals through nerves/neurons/ impulses
endocrine system: sends signals through hormones
Why can an ectotherm be either a temp regulator or a temp conformer?
- ectotherm: source of heat comes from outside
- regulate behaviorally
- i.e. bearded dragon moves from sun to shade
- conformer: temperature changing with environment
- cooler temps: move slower (physiologically)
A lizard receives heat from a nearby tree. what type of heat transfer is this?
IR radiation
- IR from objects in environment
Why do birds/humans “fluff” feathers/hair to keep warm?
F = DA * (∆p/ ∆x)
where increase ∆x or length of hair/fur to keep warmer
- diffusion will decrease with increase length
- overall decreasing flow
Trace the energy flow from ingestion to dissipation in ground squirrel
Organic molecules in food
==> Digestion and Absorption (heat and energy lost in feces)
==> Nutrient molecules in body cells (energy lost in nitrogenous waste)
==> Cellular Respiration and Carbon Skeletons
==> CS => Biosynthesis
==> CR => ATP
==> ATP => Cellular work (heat) and Biosynthesis
==> Biosynthesis (heat and nutrient molecules in body cells)
Cellular Arrangement (layering) of epithelial tissue
1) simple: one cell layer
2) stratified: two or more layers
3) pseudo stratified: 1 cell layer that looks like 2 or more layers
- in trachea, ciliated, secretory/absorptive to heat/water/moisture
Shape of epithelial tissue
1) Cuboidal: short diffusion path (i.e. kidney)
2) Columnar: (grow) simple, absorptive, small/large
intestine = H2O; gut
3) Squamous: (laying down/ elongated)
- skin (stratified squamous)
- esophagus, oral cavity
- also simple squamous found on lungs
- need to get gases out quickly
Solar Radiation
light
UV
IR
IR radiation
IR from objects in environment
Convection
heat transfer via air or water currents
Conduction
direct (transfer) from environment
Condensation and Metabolism
also ways to input energy
Temp and Thermal Energy budgets
Chemical Energy Budget
Input:
- food: amount, caloric density, assimilation efficiency
Storage:
- Somatic growth (get bigger => more so kids)
- Reproductive (gametes, female)
- Reserves (fat/adipose)
Output:
- Feces, urine
- Work: moving yourself
- metabolism: any energy requiring mechanism
Metabolism
sum total of all biological reactions in an organism
Anabolic
biosynthetic (requires E)
Catabolic
breakdown (releases E)
Countercurrent circulation / countercurrent exchange
pari artery and vine next to one another to transfer heat, P_O2, etc. in countercurrent circulation
