Bio II Ch 40

Animal form and function; not in exam 5, but in MCAT

anatomy

biological structure — varies widely! Many ways to solve the problem.

physiology

biological function —- can be determined from studying anatomy.

_____ and ______ also affect the way an animal interacts with its environment

• size and shape

• have to do with the environment it lives in

• shape determines function

convergent evolution

• not the product of being closely related. they are far away relatives, it is the environment that results in the same selected anatomy

describe open systems

• as organisms we need exchange with the environment

• rate of exchange is proportional to a cell’s surface area

• same need, different response

flat animals vs more complex organisms

• need to exchange gases

• for us, we still have the same needs (gas exchange, filtration, etc.) but have separate structures to take care of it

• exchange can happen at different levels

describe hierarchical organization of body plans

• cells → tissues → organs → organ systems

• a complex body plan helps an animal living in a variable environment to maintain a relatively stable internal environment

how respond to environment?

• regardless of levels, we heavily regulate our system to stay within a specific

what kind of tissues do we have?

• epithelial

• connective

• muscle

• nervous

epithelial tissues

• cover the outside of the body and lines the organs and cavities within the body

• not only exposed to bacteria on our skin, but also in the digestive system through what we eat

how might epithelial tissues be arranged?

• (see the image)

• the less complex (pseudostratified columnar epithelium), the more efficient it can exchange

connective tissue

• holds many tissues and organs together and in place

three types of connective tissue fiber

• collagenous fibers (elasticity)

• reticular fibers (build matrix, holding all in place)

• elastic fibers (flexibility and resitance)

what kind of cells are part of this tissue?

• fibroblasts

• macrophages

kinds of connective tissues

• loose connective tissue — keeping together external parts

• fibrous — in tendons and ligaments

• blood — white and red blood cells

• cartilage — connecting more

• adipose — produces fat, insulation

• bone — mineralized structure, builds up skeleton

muscle tissue

• responsible for nearly all types of body movement

types of muscle tissue

• skeletal muscle (voluntary movement)

• smooth muscle (involuntary movement)

• cardiac muscle (heart contractions)

nervous tissue

• interaction and response to environment

• functions in how we receive, process, and transmit information

what kind of cells in nervous tissues?

• neurons! with cell body, dendrites, axon

• also glia cells that support all the nervous system

how do we coordinate the response to our environment?

• two systems working together:

  • endrocrine and nervous

endocrine system

• hormones!

  • molecule that travels in the blood stream

• specificity

• slow acting

• long lasting effects

• well adapted for coordinating gradual changes that affect the entire body

nervous system

• transmits information

  • very fast

• electrical signal

• suited for directing rapid responses to the environment

how does feedback control work?

feedback control maintains the internal environment in many animals, maintaining homeostasis

organisms use homeostasis to maintain a “steady state” regardless of external environment

In humans:

• body temperature

• blood pH

• glucose concentration

  • diabetes → when we cannot keep our glucose concentration in the right range

what is thermoregulation?

the process by which animals maintain an internal temperature w/i an normal range

• endothermic

• ectothermic

endothermic

• mammals!

• generate heat by metabolism

ectoderms

• conformers

• gain heat from external sources/environment

what adaptations allow endotherms to regulate temp?

• insulation

• circulatory adaptations

• cooling by evaporative heat loss

• behavioral response

• adjusting metabolic heat production

insulation

• skin

• feathers

• fur (hair) → characteristic of mammals

• blubber

circulatory adaptations

• not present before endotherms, mammals, ambians

• vasodilation

  • increase diameter of vessels to lose heat if hot

• vasoconstriction

  • reduce diameter of vessels to save some heat

• countercurrent exchange - how can blood flow in two different directions?

  • warm blood → blood flow

  • cool blood → heat transfer

behavioral responses

• penguins: “stick together!”

adjusting metabolic heat productions

• by moving, we can adjust our temperature by moving, shivering

• nonshivering thermogenesis

  • hormones → mitochondria → heat

  • does not need movement

• brown fat

  • animals that hibernate

• reptiles are ectotherms, can warm up eggs by shivering

describe negative feedback