Chapter 40 Flashcards
How do animals regulate their internal state even in changing or harsh environments?
Adaptations in form,function, and behavior help maintain an animals internal environment ; adaptations limit variation in temp as well as other things
Different adaptations of animals
Form (anatomy): insulating reduces heat loss ; Function (physiology): shivering produces heat ; Behavior: packing together reduces exposure
What is anatomy?
Biological structure
What is physiology?
biological function
What are some necessities for animals?
To obtain nutrients and oxygen, fight off infection, and survive to produce offspring
What is convergent evolution?
A type of evolution that results in similar adaptations of diverse organisms facing the same challenge
What kind of materials are exchanged thorough the plasma membrane of animal cells?
Nutrients, waste products, and gases
Proportional rate of exchange
Rate of exchange is proportional to a cell’s surface area, while amount of material that must be exchanged is proportional to a cells volume
How do more complex animals accomplish exchange at the cellular level?
By having specialized surfaces that are extensively branched and folded
Hierarchical organization of the body (smallest to largest)
Cells - tissues - organs - organ systems - organism
Different organ systems in mammals
Digestive, circulatory, respiratory, immune and lymphatic, excretory, endocrine, reproductive, nervous, integumentary, skeletal, muscular
Main types of animal tissues
Epithelial, connective, muscle, nervous
Where is epithelial tissue?
Covers the outside of the body and lines the organs and cavities within the body
Different shapes of epithelial tissue
Cuboidal, columnar, squamous
Different arrangement of epithelial cells
Simple, stratified, pseudostratified
What does connective tissue do?
It holds many tissues and organs together and in place
What are two things that connective tissue contains?
Fibroblasts ; macrophages
What do fibroblasts do?
They secrete fiber proteins
What do macrophages do?
They engulf foreign particles and cell debris by phagocytosis
What are the six major types of connective tissue?
Loose connective tissue ; fibrous connective tissue ; bone ; adipose tissue ; cartilage ; blood
What do muscle cells consist of?
Filaments of the proteins actin and myosin, which together enable muscles to contract
Three types of muscle tissue and their purpose
Skeletal (voluntary movement) ; smooth (involuntary movement) ; cardiac (contraction of heart)
Function of nervous tissue and what it contains
Functions in the receipt, processing, and transmission of information ; contains neurons (transmits nerve impulses), and glial cells or glia which support cells
What does it mean if an animal is a regulator?
They use internal control mechanisms to control internal change in the face of external fluctuation
What does it mean if an animal is a conformer?
That they may regulate some environmental variable while conforming to others
What are some examples in humans that use homeostasis?
Body temp, blood pH, and glucose concentration
How does homeostasis work?
It is maintained at a set point, and a fluctuation above or below this set point serves as a stimulus which is detected by a sensor. A control center then generates output that triggers a response, which helps return the variable to the set point
Def of negative feedback
Control mechanism that “damps” a stimulus (homeostasis)
Def of positive feedback
Amplifies a stimulus and does not play a major role in homeostasis (ex: helps drive childbirth)
Difference between endothermic and ectothermic
Endothermic animals generate heat by metabolism and can maintain a stable body temp even with large fluctuations but is more energetically expensive ; ectothermic animals gain heat from external sources and tolerate greater variation in internal temp poikilotherms)
Body temp of poikilotherm verse homeotherm
Poikilotherm varies with its environment ; homeotherm is relatively constant
Processes by which organisms exchange heat
Radiation, evaporation, convection, conduction
Five adaptations that help animals thermoregulate
Insulation, circulatory adaptation, cooling by evaporative heat loss, behavioral responses, adjusting metabolic heat production
What does insulation do?
It reduces the flow of heat between an animal’s body and its environment
Examples of circulatory adaptations
Vasodilation is when blood flow int he skin increases, facilitating heat loss ; vasoconstriction is when blood flow in the skin decreases, lowering heat loss
Countercurrent exchange
The exchange of heat between fluids flowing in opposite directions (reduces heat loss)
What is thermogenesis?
The adjustment of metabolic heat production to maintain body temperature ; It is increases by muscle activity such as moving or shivering
What is nonshivering thermogenesis?
Takes place when hormones cause mitochondria to increase their metabolic activity
What is brown fat?
It is a type of tissue that is specialized for rapid heat production ; the amount found in human adults depends on the temp of the surrounding environment
What is torpor?
The physiological state of decreased activity and metabolism ; driven by ambient temp, helps save energy while avoiding difficult/dangerous conditions
What is hibernation?
Long-term torpor that is an adaptation to winter cold and food scarcity ; metabolic rates can be 20 times lower ; biological clock stops during hibernation
What is estivation?
Simmer torpor, which enables animals to survive long periods of high temps and scarce water
What is bioenergetics?
The overall flow and transformation of energy in an animals
Autotrophs vs heterotrophs
Autotrophs harness light energy to build energy-rich molecules ; heterotrophs harvest chemical energy from food
What are the two major systems for coordinating and controlling responses to stimuli?
The endocrine and nervous systems ; endocrine coordinates gradual changes that affect the entire body ; nervous is suited for directing immediate and rapid responses to the environment
