Transcript Chapter 40

Basic Principles of Animal Form and
Function
Not a process of conscious invention but the
result of a pattern of development programmed
by the genome
 Physical constraints on size and shape – physical
laws that govern strength, diffusion, movement,
and heat exchange
 Ex) fusiform body shape/convergent evolution
 http://www.captseaweed.com/dolphinvideos.html#stampede
 http://www.discovery.com/tv-shows/sharkweek/videos/how-sharks-swim/
 http://www.livescience.com/24122-why-insectsare-not-bigger.html

 Exchange
with the Environment – such as?
- recall lab with agar cubes
 How
is exchange accomplished in more
complex animal?
 https://cms.webstudy.com/WebstudyFileSyst
em/testovaci/GetFile/293875/Ch%2022/Ch22
a/figure_22_22b_labeled.jpg
 http://sphweb.bumc.bu.edu/otlt/MPHModules/PH/Ph709_RespiratoryHealth/Termi
nalBronchiole-Alveoli.png
 http://biowiki.ucdavis.edu/@api/deki/files/
2070/Figure_41_03_03.png?revision=1
What are the advantages of a complex body plan
compared to a simpler one?
 Hierarchical
Organization of Body Plans –
cells tissues organs organ system(table
40.1 p. 855)
 Largest organ? Function?
 Multifunctional organ? Function?
 Tissue Structure and Function – 4 main
categories
1. epithelial
2. connective
3. muscle
4. nervous
 Epithelial
Tissue – outside covering/lines
organs and cavities
 tight junctions
 barrier against mechanical injury, pathogens,
and fluid loss
 Cell shape – cuboidal, columnar, or squamous
 Simple, stratified, or pseudostratified
 Shape is related to function
Connective tissue – bind and support other
tissues in the body/sparse population of cells
scattered throughout an extracellular matrix
 6 major types – loose c.t., cartilage, fibrous c.t.,
adipose tissue, blood, and bone
 Connective tissue fibers – collagenous, elastic,
and reticular
 Collagenous – strength and flexibility
 Elastic – easily stretched, but resilient
 Reticular – thin and branched/join c.t. to
adjacent tissue
 Cell types – fibroblasts –secrete protein of
extracellular fibers and macrophages – roam to
engulf foreign particles and debris of dead cells

 Muscle
Tissue – responsible for body
movement/actin and myosin/energy
consuming
 Types – skeletal, cardiac, and smooth
 Nervous tissue – to sense stimuli and transmit
signals in the form of nerve impulses from
one part of animal to another
 Neurons, glial cells
 Coordination
and control – endocrine and
nervous/gradual vs immediate and rapid
response
 Hormones – only cells with receptors
respond/cells can have more than 1 receptor
type/slow acting but can be long lasting
 Nerve impulse – axons
 Impulse received by: other neurons, muscle
cells, endocrine cells, and exocrine cells
 Both chemical and electrical
 Fast acting, short duration
 Regulating
and Conforming – regulate
internal conditions despite fluctuations in
the environment/internal conditions conform
to external conditions
 May regulate some internal conditions and
not others
 http://www.bbc.co.uk/education/guides/zg
2xxnb/revision/6
Homeostasis – steady state or internal balance
 Ex) body temperature, pH of blood, solute concentration
of glucose in blood
- Mechanisms – see Fig. 40.8 – set point, stimulus, sensor,
response
- Feedback Loops – negative(a response that reduces the
stimulus) vs positive(amplify the stimulus – do not usually
contribute to homeostasis)
- Ex) exercise  produce heat sweat evaporative
cooling
- acclimatization – temporary change during an animal’s
lifetime
http://www.higherpeak.com/altitudechart.html

 Thermoregulation
– critical to survival – why?
 Endothermy and ectothermy – birds and
mammals vs amphibians, lizards, snakes,
turtles, many fishes, and most invertebrates
 Heat generated by metabolism vs gained
from environment
 Variation in body temperature – poikilotherm
vs homeotherm(constant body temperature)
 Balancing heat loss and gain – conduction,
convection, radiation, and evaporation
 Insulation
– reduces flow of heat between an
animal and its environment
 Ex) hair, feathers, layers of fat
 Circulatory
Adaptations – regulate blood
flow/heat flow
 Vasodilation – increase in diameter of blood
vessels
 Vasoconstriction – reduces blood flow and
heat transfer
 Countercurrent exchange – the flow of
adjacent fluids in opposing directions that
maximizes transfer rates of heat or solutes
 Cooling
by evaporative heat loss – water
absorbs heat when it evaporates
 Panting, sweating
 Behavioral responses – hibernation, migration
 Sun or shade for ectotherms
 Bees huddle together