AP Biology3/8/13

Chp.40:An Introduction to Animal Structure and Function

Diverse Forms, Common ChallengesAll organisms

need to perform certain functions:

1. Gas exchange with environment

2. Obtain and digest food

3. Eliminate Waste

LE 40-3

Diffusion

Mouth

Diffusion

Two cell layersSingle cell

Diffusion

Gastrovascularcavity

Structure and Function….Similar structures

have evolved multiple times to deal with similar functions

Ex: Convergent evolution in swimming animals

LE 40-4

Digestivesystem

Circulatorysystem

Excretorysystem

Interstitialfluid

Cells

Nutrients

Heart

Animalbody

RespiratorysystemBlo

od

CO2FoodMouth

External environment

O2

50 µ

m

A microscopic view of the lung reveals that it is much more spongelike than balloonlike. This construction provides an expansive wet surface for gas exchange with the environment (SEM).

10 µm

Inside a kidney is a mass of microscopic tubules that exchange chemicals with blood flowing through a web of tiny vessels called capillaries (SEM).

The lining of the small intestine, a digestive organ, is elaborated with fingerlike projections that expand the surface area for nutrient absorption (cross-section, SEM).

Unabsorbedmatter (feces)

Metabolic wasteproducts (urine)

Anus

0.5 cm

….Anatomy and PhysiologyAnatomy:

structurePhysiology:

function

Animal Anatomy and PhysiologyMost animals are composed

of specialized cells organized into tissues that have different functions

Tissues make up organs, which together make up organ systems

Different tissues have different structures that are suited to their functions

Tissues are classified into four main categories: epithelial, connective, muscle, and nervous

Organ systemsOrgan: organization of

tissuesMesentaries: suspension

of organs (connective tissue)

Thoracic cavity (lungs and heart)

Abdominal cavity (intestines)

Diaphragm (respiration)Organ systems…...

(See Table 40.1)

Digestive-food processingCirculatory-internal distributionRespiratory-gas exchangeImmune/Lymphatic-defenseExcretory-waste disposal;

osmoregulationEndocrine-coordination of

body activitiesReproductive-reproductionNervous-detection of stimuli Integumentary-protectionSkeletal-support; protectionMuscular-movement;

locomotion

Bioenergeticsthe flow of

energy through an animal, limits behavior, growth, and reproduction

Internal regulationInterstitial fluid:

internal fluid environment of vertebrates; exchanges nutrients and wastes

Homeostasis: “steady state” or internal balance

Regulation Negative feedback:

change in a physiological variable that is being monitored triggers a response that counteracts the initial fluctuation; i.e., body temperature

Positive feedback: physiological control mechanism in which a change in some variable triggers mechanisms that amplify the change; i.e., uterine contractions at childbirth

Homeostatic Regulation of cellular fluid

Metabolism: sum of all energy-requiring biochemical reactions

Catabolic processes of cellular respiration (breaking down)

Calorie; kilocalorie/CBasal Metabolic Rate

(BMR): minimal rate powering basic functions of life (endotherms)

Standard Metabolic Rate (SMR): minimal rate powering basic functions of life (ectotherms)

This photograph shows a ghost crab in a respirometer. Temperature is held constant in the chamber, with air of known O2 concentration flowing through. The crab’s metabolic rate is calculated from the difference between the amount of O2 entering and the amount of O2 leaving the respirometer. This crab is on a treadmill, running at a constant speed as measurements are made.

Similarly, the metabolic rate of a man fitted with a breathing apparatus is being monitored while he exercises on a stationary bike.

Endotherms: bodies warmed by metabolic heat

Ectotherms: bodies warmed by environment

Examples: (In general)1. Endotherms –

1. Birds, mammals2. Ectotherms –

1. Fish, reptiles, amphibians

Vs.• Homeotherm –

constant body temp• Poikilotherm –

variable body temp

800,000

Endotherms

340,000

An

nu

al e

ner

gy e

xpen

dit

ure

(k

c al /

yr)

Basal(standard)metabolism

ReproductionTemperatureregulation

Growth

Activity

60-kg female humanfrom temperate climate

4-kg male Adélie penguinfrom Antarctica (brooding)

4,000

0.025-kg female deer mousefrom temperateNorth America

4-kg female pythonfrom Australia

8,000

Ectotherm

Total annual energy expenditures. The slices of the pie charts indicate energy expenditures for various functions.

Energy expenditures per unit mass (kcal/kg•day). Comparing the daily energy expenditures per kg of body weight for the four animals reinforces two important concepts of bioenergetics. First, a small animal, such as a mouse, has a much greater energy demand per kg than does a large animal of the same taxonomic class, such as a human (both mammals). Second, note again that an ectotherm, such as a python, requires much less energy per kg than does an endotherm of equivalent size, such as a penguin.

En

ergy

ex p

e nd

itu

r e p

e r u

nit

mas

s(k

cal/

kg •

day

)

438

233

36.55.5

Python

Human

Deer mouseAdélie penguin

Homework due Monday Chp.40 Guided Reading: Animal Structure & Function

Did not use…

Tissues: groups of cells with a common structure and function (4 types)

1- Epithelial: outside of body and lines organs and cavities; held together by tight junctions

Tight Junctions – impermeable to water

Epithelial Tissues

basement membrane: dense mat of extracellular matrix

mucous membrane1. Simple: single layer of

cells2. Stratified: multiple tiers

of cellsa) Cuboidal (like dice)b) Columnar (like bricks on

end)c) Squamous (like floor tiles)

Connective Tissues

Bind and support other tissuesScattered cells through matrixMatrix - non-living material for the nourishment of

cellsFibers. Not all types of connective tissues are

fibrous though. Examples are adipose tissue and blood. Adipose tissue gives "mechanical cushion" to our body. The matrix of blood is plasma.

Connective Tissues

1. Loose connective tissue: binds epithelia to underlying tissue; holds organs

2. Fibrous connective tissue: parallel bundles of cells

3. Cartilage: collagen in a rubbery matrix (chondroitin); flexible support

4. Bone: mineralized tissue by osteoblasts

5. Blood: liquid plasma matrix; erythrocytes (RBC’s) carry O2; leukocytes (WBC’s) immunity

Nervous TissueSenses stimuli and

transmits signals from 1 part of the animal to another

Neuron: functional unit that transmits impulses

Dendrites: transmit impulses from tips to rest of neuron

Axons: transmit impulses toward another neuron or effector

Muscle Tissues4- Muscle: capable of

contracting when stimulated by nerve impulses; myofibrils composed of proteins actin and myosin; 3 types:

A- Skeletal: voluntary movement (striated)

B- Cardiac: contractile wall of heart (branched striated)

C- Smooth: involuntary activities (no striations)

Lumen ofstomach

Mucosa: an epitheliallayer that lines thelumen

Submucosa: a matrix ofconnective tissue thatcontains blood vesselsand nerves

Muscularis: consistsmainly of smooth muscletissue

Serosa: a thin layer ofconnective and epithelialtissue external to the muscularis0.2 mm

Org

ans

– C

onta

inin

g m

ulti

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tiss

ues