animal form & function

Animal Form & Animal Form & FunctionFunction

Chapter 40Chapter 40 Levels of organizationLevels of organization

– Tissues (group of cells with common Tissues (group of cells with common structure & function)structure & function)

– Organs (functional units of tissues)Organs (functional units of tissues)– Organ systems (organs that work Organ systems (organs that work

together)together)

4 main types of tissue:4 main types of tissue:– 1) Epithelial1) Epithelial

Sheets of tightly packed cells, covers the Sheets of tightly packed cells, covers the body, lines organs, and protectsbody, lines organs, and protects

One side is always bound to a basement One side is always bound to a basement membranemembrane

Other side faces air or fluid environmentOther side faces air or fluid environment– 2) Connective 2) Connective

Supports and bindsSupports and binds Cartilage, tendons, ligaments, bone, & bloodCartilage, tendons, ligaments, bone, & blood

3) Muscle3) Muscle– Body movementBody movement– Muscle filaments are made of actin & myosin Muscle filaments are made of actin & myosin

(proteins)(proteins)– The fibers contract when stimulated by a nerveThe fibers contract when stimulated by a nerve– Most abundant tissue in animalsMost abundant tissue in animals– 3 types: 3 types:

Skeletal – used for movement & is voluntarySkeletal – used for movement & is voluntary Smooth – found in organs & is involuntary Smooth – found in organs & is involuntary Cardiac – in heart & is involuntaryCardiac – in heart & is involuntary

4) Nervous4) Nervous– Functional unit is a nerve cell (neuron)Functional unit is a nerve cell (neuron)– Senses stimuli & transmits signals from Senses stimuli & transmits signals from

one part of the body to anotherone part of the body to another

2 major systems that coordinate and control 2 major systems that coordinate and control the tissue, organ, and organ systems of the tissue, organ, and organ systems of animals:animals:– 1) Endocrine1) Endocrine

Hormones are chemical messengersHormones are chemical messengers Carried in the blood to all parts of the bodyCarried in the blood to all parts of the body Hormones have specific functions, but only with cells Hormones have specific functions, but only with cells

with specific receptorswith specific receptors Come from glands (pituitary, thyroid, etc.)Come from glands (pituitary, thyroid, etc.)

– 2) Nervous 2) Nervous Transmit information between locationsTransmit information between locations 3 types of cells receive nerve impulses: neurons, 3 types of cells receive nerve impulses: neurons,

muscle cells, & endocrine cellsmuscle cells, & endocrine cells

Homeostasis – constant internal Homeostasis – constant internal environmentenvironment

The body has a The body has a ““set pointset point”” (i.e. body (i.e. body temp), sensors to detect any temp), sensors to detect any variation in the set pt, & variation in the set pt, & physiological responses to help physiological responses to help return to the set ptreturn to the set pt

Physiological responses:Physiological responses:– 1) Negative feedback loop1) Negative feedback loop

Respond to stimulus in a way that reduces the Respond to stimulus in a way that reduces the stimulusstimulus

Ex: in response to exercise, the body temp Ex: in response to exercise, the body temp rises, which initiates sweatingrises, which initiates sweating

– 2) Positive feedback loop2) Positive feedback loop A variable triggers mechanisms that amplify A variable triggers mechanisms that amplify

rather than reverse the changerather than reverse the change Ex: childbirth – stimulates uterine contractionsEx: childbirth – stimulates uterine contractions

Thermoregulation = how animals Thermoregulation = how animals maintain their internal temperaturemaintain their internal temperature– Endotherms (mammals/birds) use heat Endotherms (mammals/birds) use heat

generated by metabolism (warm generated by metabolism (warm blooded)blooded)

– Ectotherms (invertebrates, fish, reptiles) Ectotherms (invertebrates, fish, reptiles) use heat from external sources (cold use heat from external sources (cold blooded)blooded)

Chapter 41Chapter 41 4 classes of essential nutrients:4 classes of essential nutrients:

– 1) Essential amino acids1) Essential amino acids 12 of 2012 of 20

– 2) Essential fatty acids2) Essential fatty acids– 3) Vitamins3) Vitamins– 4) Minerals4) Minerals

4 main stages of food processing:4 main stages of food processing:– 1) Ingestion1) Ingestion

Taking in foodTaking in food– 2) Digestion2) Digestion

Breaking down foodBreaking down food– 3) Absorption3) Absorption

Cells take up small moleculesCells take up small molecules– 4) Elimination4) Elimination

Passing of undigested materialPassing of undigested material

Simple animals utilize a Simple animals utilize a gastrovascular canalgastrovascular canal– Single opening for food and wastesSingle opening for food and wastes– Worms & hydras use thisWorms & hydras use this

Complex animals use alimentary Complex animals use alimentary canalscanals– One-way digestive tubes that have 2 One-way digestive tubes that have 2

openingsopenings

Movement of food through the DS is Movement of food through the DS is controlled by peristalsiscontrolled by peristalsis– Waves of contractions by smooth muscleWaves of contractions by smooth muscle

Food is taken into the mouthFood is taken into the mouth– Releases salivaReleases saliva

Aids in swallowingAids in swallowing Begins chemical digestionBegins chemical digestion Contains amylase (breaks down starch & Contains amylase (breaks down starch &

glycogen)glycogen)

The chewed food forms a BOLUSThe chewed food forms a BOLUS The bolus then enters the pharynx The bolus then enters the pharynx

(throat)(throat) During swallowing, the EPIGLOTTIS During swallowing, the EPIGLOTTIS

covers the trachea so food goes covers the trachea so food goes down the ESOPHAGUSdown the ESOPHAGUS

Esophagus moves food to the Esophagus moves food to the stomach through peristalsisstomach through peristalsis

Stomach – stores food and secretes Stomach – stores food and secretes gastric juices:gastric juices:– 1) Hydrochloric acid1) Hydrochloric acid

pH of 2pH of 2 Breaks down meat and plantsBreaks down meat and plants Kills most bacteriaKills most bacteria

– 2) Pepsin2) Pepsin Hydrolyzes proteinsHydrolyzes proteins

End result of the stomach work is End result of the stomach work is acid chyme which is moved to the acid chyme which is moved to the small intestinesmall intestine

Duodenum – major site of chemical Duodenum – major site of chemical digestion (1digestion (1stst section of SI) section of SI)– Works with pancreas & liverWorks with pancreas & liver– Pancreas produces a bufferPancreas produces a buffer– Liver produces bile (fat breakdown)Liver produces bile (fat breakdown)

Chemical breakdown in duodenum:Chemical breakdown in duodenum: 1) Carbs1) Carbs

– amylasesamylases 2) Proteins2) Proteins

– Pepsin/trypsinPepsin/trypsin 3) Nucleic Acids3) Nucleic Acids

– Hydrolysis of DNA/RNAHydrolysis of DNA/RNA 4) Fats4) Fats

– Bile/lipaseBile/lipase

Chapter 48Chapter 48 Nerve cell = neuronNerve cell = neuron

– Composed of:Composed of: Cell body – contains nucleus & organellesCell body – contains nucleus & organelles Dendrites – cell extensions that receive Dendrites – cell extensions that receive

incoming messagesincoming messages Axons – transmit messagesAxons – transmit messages

– Many axons are covered by a fatty myelin sheathMany axons are covered by a fatty myelin sheath– Speeds rate of transmissionSpeeds rate of transmission

Synapse = junction between neuronsSynapse = junction between neurons Neurotransmitters are chemical Neurotransmitters are chemical

messengers that bind to receptorsmessengers that bind to receptors Sensory receptorsSensory receptors

– Collect information about the world Collect information about the world outside the body as well as inside (ex: outside the body as well as inside (ex: rods/cones of eyes & pressure receptors rods/cones of eyes & pressure receptors in the skin)in the skin)

Sensory neuronsSensory neurons– Transmit information from sensors to Transmit information from sensors to

the brain/spinal cordthe brain/spinal cord InterneuronsInterneurons

– Connect sensory & motor neuronsConnect sensory & motor neurons

Chapter 49Chapter 49 Evolution of nervous systemEvolution of nervous system

– Cnidarians have a nerve netCnidarians have a nerve net– Cephalization clusters sensory neurons & Cephalization clusters sensory neurons &

interneuronsinterneurons– Flatworms have a small brain & longitudinal Flatworms have a small brain & longitudinal

nerve cord (simplest Central Nervous nerve cord (simplest Central Nervous System)System)

– Annelids (earthworm) & arthropods have a Annelids (earthworm) & arthropods have a ventral nerve cordventral nerve cord

– Vertebrates have a hollow dorsal nerve cordVertebrates have a hollow dorsal nerve cord

ReflexReflex– Simple automatic nerve circuit in Simple automatic nerve circuit in

response to a stimulusresponse to a stimulus– Ex: The stimulus is detected by a Ex: The stimulus is detected by a

receptor in the skin, conveyed via a receptor in the skin, conveyed via a sensory neuron to an interneuron in the sensory neuron to an interneuron in the spinal cord, which synapses with a spinal cord, which synapses with a motor neuron, which will cause the motor neuron, which will cause the effector, a muscle cell, to contracteffector, a muscle cell, to contract

Conscious thought is not required in Conscious thought is not required in a reflexa reflex

Cerebrospinal fluid (CSF) circulates Cerebrospinal fluid (CSF) circulates through a central canal in the spinal through a central canal in the spinal cord & ventricles of the brain – cord & ventricles of the brain – cushions the brain & spinal cordcushions the brain & spinal cord

Gilia – support neuronsGilia – support neurons– Astrocytes (support neurons)Astrocytes (support neurons)– Oligodendrocytes (form myelin sheaths in CNS)Oligodendrocytes (form myelin sheaths in CNS)– Schwann cells (form sheaths in PNS)Schwann cells (form sheaths in PNS)

Gray matterGray matter– Mainly neuron cell bodies & unmyelinated Mainly neuron cell bodies & unmyelinated

axonsaxons White matterWhite matter

– White due to the myelin sheathsWhite due to the myelin sheaths

Main Brain AnatomyMain Brain Anatomy 1) Brainstem 1) Brainstem

– Medulla oblongata, pons, midbrainMedulla oblongata, pons, midbrain– Controls homeostatic functions – Controls homeostatic functions –

breathing ratebreathing rate– Conducts sensory & motor signals Conducts sensory & motor signals

between the spinal cord and higher between the spinal cord and higher brain centersbrain centers

– Regulates arousal and sleepRegulates arousal and sleep

2) Cerebellum2) Cerebellum– Coordinates motor, perceptual, & Coordinates motor, perceptual, &

cognitive functionscognitive functions– BalanceBalance

3) Cerebrum3) Cerebrum– Largest part of the brainLargest part of the brain– Has left/right hemispheresHas left/right hemispheres– Covering of gray matter over white Covering of gray matter over white

mattermatter– Information processingInformation processing– Thinking, learning, rememberingThinking, learning, remembering

Other brain partsOther brain parts ThalamusThalamus

– Main center through which sensory & motor Main center through which sensory & motor information passes to & from the cerebruminformation passes to & from the cerebrum

Hypothalamus Hypothalamus – Regulates homeostasisRegulates homeostasis– Feeding, fighting, fleeing, reproducing, circadian Feeding, fighting, fleeing, reproducing, circadian

rhythms rhythms Cerebral cortexCerebral cortex

– controls voluntary movement & cognitive functionscontrols voluntary movement & cognitive functions Corpus callosumCorpus callosum

– Enables communication between left/right Enables communication between left/right hemisphereshemispheres

Chapter 51Chapter 51 BehaviorBehavior

– What an animal does and how it does itWhat an animal does and how it does it– Result of genetics & environmentResult of genetics & environment– Essential for survival & reproductionEssential for survival & reproduction– Subject to natural selectionSubject to natural selection

EthologyEthology– Study of animal behaviorStudy of animal behavior

2 levels of analysis in the study of 2 levels of analysis in the study of behavior:behavior:

1) Proximate1) Proximate– The “how” questions & include effects of The “how” questions & include effects of

heredity, genetic-environmental interactions, heredity, genetic-environmental interactions, & sensory-motor mechanisms& sensory-motor mechanisms

2) Ultimate2) Ultimate– The “why” questions & studies of origin of The “why” questions & studies of origin of

behavior, change over time, & reproductive behavior, change over time, & reproductive successsuccess

Innate behaviorInnate behavior– Developmentally fixed – unlearnedDevelopmentally fixed – unlearned– Nursing in mammalsNursing in mammals

Fixed action pattern (FAP)Fixed action pattern (FAP)– Sequence of unlearned acts that is largely Sequence of unlearned acts that is largely

unchangeable & carried to completion when unchangeable & carried to completion when startedstarted

– Triggered by sign stimuliTriggered by sign stimuli– EX: male stickle-back fish which attack red EX: male stickle-back fish which attack red

objects – the red object is the sign stimulus, objects – the red object is the sign stimulus, attack is FAPattack is FAP

KinesisKinesis– Simple change in activity in response to stimulusSimple change in activity in response to stimulus– Ex: pillbugs to moistureEx: pillbugs to moisture

TaxisTaxis– Automatic movement toward or away from a Automatic movement toward or away from a

stimulusstimulus– Ex: moths to lightEx: moths to light

MigrationMigration– ComplexComplex– Attributed to detection of Earth’s magnetic field or visual Attributed to detection of Earth’s magnetic field or visual

cuescues

Circadian rhythmsCircadian rhythms– Occur dailyOccur daily

SignalSignal– A behavior that causes a change in the behavior A behavior that causes a change in the behavior

of another – basis for animal communicationof another – basis for animal communication– 1) Pheromones – chemical signals1) Pheromones – chemical signals– 2) Visual Signals – warning flashes, markings2) Visual Signals – warning flashes, markings– 3) Auditory Signals – sounds, screeches, growls3) Auditory Signals – sounds, screeches, growls– 4) Waggle dance – done by honeybees4) Waggle dance – done by honeybees

http://www.youtube.com/watch?v=-7ijI-g4jHg

51.251.2 LearningLearning

– Modification of behavior based on Modification of behavior based on experiencesexperiences

ImprintingImprinting– Combination of learned & innate components Combination of learned & innate components

that are limited to a sensitive period in an that are limited to a sensitive period in an organisms life and is generally irreversible organisms life and is generally irreversible

– Konrad LorenzKonrad Lorenz http://www.youtube.com/watch?v=2UIU9XH-mUI&

feature=related

HabituationHabituation– Loss of responsiveness to stimuliLoss of responsiveness to stimuli– Simple form of learningSimple form of learning

Cognitive mapCognitive map– Internal representation of spatial Internal representation of spatial

relationship among objects in an relationship among objects in an animal’s surroundingsanimal’s surroundings

Associative learning:Associative learning:– Ability of many animals to associate one Ability of many animals to associate one

feature of their environment with feature of their environment with another featureanother feature

– Two types:Two types:

1) Classical Conditioning1) Classical Conditioning– Learning to associate certain stimuli Learning to associate certain stimuli

with reward or punishmentwith reward or punishment– PavlovPavlov

2) Operant conditioning2) Operant conditioning– Occurs as an animal learns to associate Occurs as an animal learns to associate

one of its behaviors with a reward or one of its behaviors with a reward or punishmentpunishment

– B.F. SkinnerB.F. Skinner

Skinner BoxSkinner Box

51.351.3 Both environment and genetics Both environment and genetics

contribute to behaviorcontribute to behavior

51.451.4 Survival and reproductive successSurvival and reproductive success

– Foraging behaviorForaging behavior Not only eating, but mechanisms used in Not only eating, but mechanisms used in

searching for, recognizing, & capturing foodsearching for, recognizing, & capturing food– Optimal foraging modelOptimal foraging model

A compromise between benefits of nutrition A compromise between benefits of nutrition & cost of obtaining food& cost of obtaining food

Mating systems – variesMating systems – varies– 1) Promiscuous – no strong pair-bonds1) Promiscuous – no strong pair-bonds– 2) Monogamous – one male/one female2) Monogamous – one male/one female– 3) Polygamous – one individual mating 3) Polygamous – one individual mating

with otherswith others

51.551.5 AltruismAltruism

– When animals behave in ways that reduce their When animals behave in ways that reduce their individual fitness but increases the fitness of individual fitness but increases the fitness of other individuals in the populationother individuals in the population

– Ex: blue jay giving an alarm callEx: blue jay giving an alarm call Inclusive fitnessInclusive fitness

– Total effect an individual has on proliferating its Total effect an individual has on proliferating its genes by producing its own offspringgenes by producing its own offspring

– Provides aid that enables other close relatives Provides aid that enables other close relatives to produce offspringto produce offspring

– ““kin selection”kin selection”