Lecture 3 Flashcards
An animal’s body plan limits
its size, shape and ability to
interact with the environmen
Animals with an asymmetrical body plan are
“aquatic,
sessile, filter feeder”
Animals with a radial body plan are also aquatic
“but they
are often motile and they are filter feeders or they actively
search for food. They have no cephalization so their movement is not
forward/backward oriente”
All vertebrates have bilateral body plan
”* They have cephalization so their movement is forward/backward
* They are all motile and they all active search for fo”
- Bilateral symmetry also means that
“an animal has an anterior,
posterior, dorsal and ventral side”
Aquatic bilateral animals have
“a fusiform shape to minimize
drag in water (convergent evolution)”
Aquatic animals are constrained by
the density of water
“Terrestrial animals are constrained by
“
gravity
“Given that insects are the most populous of all bilateral animal
species”
“we can say that most animals have an exoskeleton for
support”
An exoskeleton is a hard covering or shell that
“protects the
animal and provides attachment sites for muscle”
Exoskeletons are most often made of
“chitin or calcium
carbonate”
Ingrowths called apodemes are the sites of muscle attachment
- Allow animals to move legs, claws, wings, et
To grow
these animals must molt
“Having an exoskeleton limits an animal’s size
“
- Doubling body size equals an 8x increase in weight
All chordate animals
have an endoskeleton
An endoskeleton is comprised of
“internal bone or cartilage that
supports body weight and movement”
Muscles attach to the endoskeleton
to facilitate movement
Animals with an endoskeleton do not molt
They have determinant growth
As body size increases, bone and muscle increase
“Speed and agility are a balance between body size and
bone & muscle mass”
“The amount of energy expended over a given time is
called”
the Metabolic Rate (measured in joules or calories)
“In animals, converting consumed macromolecules to ATP,
glycogen or fat gives off energy”
in the form of heat
Carbohydrates, protein, and lipids are all converted to
”* ATP for immediate energy
* Glycogen and fat for long-term energy stor”
2nd Law of Thermodynamics states that
“energy cannot be
converted from one form to another with 100% efficient”
- Standard Metabolic Rate
in ectotherm
Endothermic animals use this heat to
“maintain thermal
homeostasis”
- Basal Metabolic Rate in
endotherms
- Standard Metabolic Rate
in ectotherm
Small endotherms have greater
“surface area to body mass ratio
than large endotherms”
Small endotherms lose heat
faster than large endotherms
Small endotherms have higher BMR
” than large endotherms
* Per body weigh”
The more active an animal
the higher the BMR/SMR
The diet of an animal is determined by its
BMR/SMR
Aquatic animals exchange water, nutrients, and waste
“with their watery
surroundings through diffusion”
But diffusion is only efficient if
“the distance water, nutrients, and waste have to
travel is small”
Diffusion is inefficient over large distances
Surface to volume ratio
This limits the size of aquatic animals that rely on diffusion only
Most single cell organisms can use diffusion efficiently, unless they are too big
Animals evolved to be multicellular to resolve the diffusion problem
”* This allowed animals to be larger!
* Having specialized cells, tissues, organs also resolved the diffusion problem”
What is homeostasis?
Maintaining a stable state inside an animal’s body
Maintaining a stable state inside an animal’s body
”* Blood glucose
* Hydration
* Temperature
* Blood calcium levels”
“Homeostasis is maintaining dynamic equilibrium around a set point
“
“this is controlled by negative feedback nervous and endocrine
systems”
Homeostasis is maintained around a set point
“or value that remains
mostly constant”
Deviation from the set point causes
“physiological changes in the body
to return back to the set point”
“Deviation from the set point causes physiological changes in the body
to return back to the set poi”
”* Normal body temp for a horse is approximately 100.5° F – this is the set point
* If the temp drops too low, the horse will shiver to increase temp
* If the temp increases too much, the horse will sweat to reduce temp
* Both physiological responses help return temp to the set p”
Any time a change occurs that deviates from the set point
“receptors
sense the change and signal physiological adjustments”
Positive feedback regulation
“pushes the body further out of
homeostasis by maintaining the stimulation that deviated from the
set poin”
If a level is too high, positive feedback
continues to increase the level. Example: blood coagulation
Negative feedback regulation return the body to the set point
“by
changing the direction of the stimulation that deviated from the set
point”
“Negative feedback regulation return the body to the set point by
changing the direction of the stimulation that deviated from the set
point”
”* If a level is too high, negative feedback brings the level down
* If a level is too low, negative feedback brings the level back up
* Example blood glucose level”
” Endothermic animals use metabolism to maintain their body
temperature”
”* Shiver to increase temperature, sweat/pant to decrease
temperature
* They have feathers, fur, and/or subcutaneous fat to help control
body temperature
* Require 90% more calories than a similar sized ectotherm.”
”* Ectothermic animals do not use metabolism to maintain their body
temperature”
”* They bask in the sun to raise body temperature or seek shade to
lower body temperature
* Require only 10% of the calories required by a similar sized
endotherm.”
Poikilothermic animals
“allow their body temperature to fluctuate depending
on the environment. These are typically ectotherms, but not alwa”
Homeothermic animals
“whether endotherms or ectotherms, maintain a
constant body temperatur”
The nervous system, specifically the hypothalamus
“controls
thermoregulation. (What about animals that do not have a sophisticated nervous system?)”
To maintain homeostatic thermoregulation
“animals must be able to conserve
heat when it is cold outside and dissipate heat when it is hot outsid”
When it is cold outside:
”* Thick fur/feathers and fat
* Creates in insulating layer of air next to their skin
* Fat layer helps to maintain body temp
* Vasorestriction forces blood to the core of the body so heat is not lost through the skin
* Shivering is a last resort
* Ectotherms seek warmer area”
When it is hot outside:
”* Panting or sweating
* Vasodilation brings blood (and heat) to skin, heat dissipates
* More surface area = more heat dissipation
* Ectotherms seek cooler area”
“How form and function sustain life and shape responses to
environmental conditions”
“Keep in mind that “environmental conditions” is not just outside the animal
but inside as well
* Remember homeostasis”
” Multicellular animals have specialized cells that form specific
tissues. “
- Organ systems maintain homeostasis
Tissues form organs
Organs form organ systems
“Obtain O2, and nutrients and move them to cells throughout the
body.”
Remove CO2 and other types of waste from cells
“Coordinate hormone
“
production, transport, absorption
“There are many systems that function within animals, we will focus
on 9 of those systems”
”* Musculo-skeletal system
* Digestive system
* Circulatory system
* Respiratory system
* Urinary system
* Nervous system
* Sensory system
* Reproductive system
* Immune system”
- Not all animals have all of these systems.
“Some simple animals do
not even have tissues, much less organs and organ syste”
Musculoskeletal system
“Provides support for the animal’s body, internal organs, and the
ability to move”
Invertebrates, if they have a musculoskeletal system
“have an
exoskeleton”
“Invertebrates, if they have a musculoskeletal system, have an
exoskeleton”
”* Some have hydrostatic system that uses water pressure for movement–
remember echinoderms?”
”* Invertebrates with a hard chitin or calcium exoskeleton have muscles that
attach to points inside the exoskeleton.”
Contraction creates movement
Vertebrate have an endoskeleton
Bones, ligaments, tendons, cartilage, muscle
Tendons join
muscle to bone
Ligaments join
bone to bone
“Contraction of muscle shortens the muscle, pulling on the bone,
“
“resulting in
movement”
Digestion of consumed food begins in
“the mouth, stomach,
intestines”
Hydrolyzes large macromolecules (protein, carbs, fat)
“into their
smaller components (amino acids, glucose, fatty acids, etc.”
Those smaller components are absorbed into the blood
“and
transported to cells throughout the body”
Cellular respiration in mitochondria
produce ATP
The digestive system works closely with
the circulatory system. Not all animals have a digestive system
”
Circulatory system”
“Transports nutrients and gases throughout the body. Not all animals have a circulatory system
“
The heart is the “motor” of the circulatory system
“creating the
circulation of blood through blood vess”
Arteries carry oxygenated blood
away from the heart to the body
Veins carry deoxygenated blood
from the body to the heart
Capillaries connect arteries to veins
They have thin walls that allow diffusion of gases, nutrients, water, etc.
The circulatory system works with the respiratory system
“the
digestive system, and the urinary syste”
Respiratory system
This system absorbs oxygen and remove carbon dioxide
Oxygen is absorbed
and transported to cells throughout the body
Carbon dioxide, a waste product
“is transported from cells, and
released out of the body”
The respiratory system works closely with
“the circulatory system in
most animals”
The complexity of the respiratory system
“is directly correlated to the
size of the anima”
Urinary system
“Eliminates waste from the body, regulates blood volume and blood
pressure, control levels of electrolytes and metabolic waste, and
regulates blood pH”
Urinary system organs
Kidneys, bladder, urethra
urinary system Works closely with
“the circulatory system. Again, some simple animals do not have a true urinary system
“
Nervous system
“Coordinates its actions and sensory information by transmitting
signals to and from different parts of its bod”
Nervous system Processes sensory information
“from both outside and inside the
body”
Nervous systems vary in
“different types of animals, Brain, nerves
“
Sensory system
“Is considered part of the nervous system responsible for processing
sensory information. “
“A sensory system consists of sensory
neurons, neural pathways”
“and parts of the brain involved in
sensory perception and interoceptio”
Sight, sound, smell, taste, touch, internal signals from the body
“There is a wide range of sensory systems within the animal
kingdom”
Reproductive system
Anatomical organs involved in sexual reproduction.
“Many non-living
substances such as fluids, hormones, and pheromones “
“are also
important accessories to the reproductive system”
“Unlike
most organ systems, the sexes of differentiated species often have
significant differences. “
“These differences allow for a combination of
genetic material between two individuals, which allows for the
possibility of greater genetic fitness of the offspring”
Gonads that produce eggs and sperm
“Varying types of reproductive systems throughout the animal
kingdom”
Immune system
“Network of organs, cells and proteins that defends the body against
infection”
Immune system includes
Viruses, bacteria, fungus, protists
