introduction and general principles

Question 1

what is physiology

Answer 1

the study of functions of organisms or how life works

Question 2

what are the two levels of explanations for biological adaptations

Answer 2

1) mechanic/proximate
2) evolutionary/ultimate

Question 3

Explain the terms proximate and evolutionary explanations and give an example of each

Answer 3

1) proximate- how does something work? looks at composition and function
2) evolutionary- how does something get to be that way? looks at role of evolution or natural selection

Question 4

what is an adaptation

Answer 4

an adaptation is an adjustment of an organism in part or in whole to changes in environment or to external stress and improves likelihood or survival

Question 5

why arent adaptations always optimal or logical

Answer 5

1) may be vestigial where they were useful in the past but not in the present however do not affect survivorship so aren’t selected against e.g. some genes

2) usually adaptations are historical comprimises so not always most logical solution e.g. human spinal column provides flexability and support but it is a suboptimal design e,g prinched nerves, slipped disks

Question 6

Describe the Krogh principle

Answer 6

For every adaptation there will be another species where the adaptation has been studied more conveniently for example neurones studied in the Giant squid as they are larger but reflect same structure as human neurones which are smaller

Question 7

what is meant by Teleology or a teleostatic approach

Answer 7

an explanation of mechanisms in terms of purpose- it assumes all traits have a logical purpose and are ideal but this is not always the case

Question 8

how is physiology an integrative discipline

Answer 8

1) looks at physics e.g. electrical impulses and fluid dynamics
2) chemistry = chemical reactions
3) biochemistry= biological reactions
4) organism ecology

Question 9

how is physiology an comparative disapline

Answer 9

works in a horizontal sense by comparing features of different organisms allowing an understanding of
- trade offs
- constraints
- which functions are universal

Question 10

what are the basic functions of life

Answer 10

cells which either in unicellular or multicellular organsims perform
1) self organisation
2)self regulation
3)self support and movement
4) self replications

Question 11

what is the difference between fundamental cells and speacalised cells

Answer 11

speaclasied cells allow for the survivourship of the entire organsim compared to fundamental which allow the survivorship of the cell itself

Question 12

what are the four major tissue types

Answer 12

1) epithelial - cells speacalised in material exchange
2) connective - supports, connects and anchors body parts
3) muscular - cells specalised for control and force (skeletal, smooth and caradiac)
4) nervous- cells specalised for initiation and transsmission of electrical impulses

Question 13

how are organs constructed from tissues

Answer 13

made up of 2 or more primary tissues which have similar structures and functions

Question 14

how does surface area change with size and why is it important

Answer 14

as size increases surface area decreases
- require need for circulatory or respiration systems
- special skeletal mechanisms - increased mass to support
- larger organsims retain heat easier as less SA
- more stress on larger organisms

Question 15

define homeostasis and give an example of why it is important

Answer 15

the maintenance of desired state in the face of external disturbance
- . cells not in contact with external enviro so need resources from internal environment which is maintained by homeostasis
- each cell needs homeostasis so survive and each specialised cell contributes to systems which maintain internal environment

Question 16

describe a negative feedback system with antagonistic effectors

Answer 16

negative feedback= a regulatory mechanism where the response opposes the original change and main mechanisms for homeostasis
some effectors which produce change control using 2 opposing control units such as shivering and sweating

Question 17

what is anticipation and acclimatization

Answer 17

1) anticipation = the prediction of a disturbance before the regulated state has changed producing a response in advance of set point changing such as skin detecting temp before change in internal core temp
2) acclimatization = the altering of existing feedback systems to work better in a new situation

Question 18

what are some flaws in negative feedback systems and how can they be improved

Answer 18

• cant always be in perfect state as needs to detect change before correcting it producing a delayed responce
• some components of a system may not work in a new environment

can be fixed by using anticipation and acclimatisation

Question 19

describe how rest and positive feedback systems create useful change

Answer 19

they are used for non-homeostatic regulation e.g. muscles in digestive tract
1) reset- changes the set point of the negative feedback system either temporarily, permently or cyclically e.g. fever causes increased set temp point to fight bacteria

2) positive feedback- continues to increase the original change which is useful when set point is no longer appropriate e.g. contractions in pregnancy

disruptions to this can lead to illness or death

Question 20

what are intrinsic and extrinsic controls

Answer 20

intrinsic= occurs locally in cells and tissues for rapid control of basic needs

extrinsic= mainly neural or hormonal for coordinating multiple body parts often over riding intrinsic control for the good of the whole

Question 21

why is it important that the brain doesn’t exclusivley control all of an animals functions

Answer 21

avoids unneccesary delays in responce and avoids reduced precision of generalised whole body responces