1Structure and FunctionStructure and Function

BIO 3450BIO 3450

Introduction and TerminologyIntroduction and Terminology

Levels of OrganizationLevels of Organization ChemicalChemical CellularCellular TissueTissue OrgansOrgans System LevelSystem Level OrganismicOrganismic LevelLevel

Combine

SpecializeFunction

Process

GoalLIFE!

Organ Organ SystemsSystems Life ProcessesLife Processes

MetabolismMetabolism ResponsivenessResponsiveness

MovementMovement GrowthGrowth

DifferentiationDifferentiation ReproductionReproduction

2Basic Life ProcessesBasic Life Processes All living things have certain characteristics that All living things have certain characteristics that

distinguish them from nonliving things.distinguish them from nonliving things.

Metabolism:Metabolism: is the sum of all chemical processes is the sum of all chemical processes that occur in the body, including catabolism and that occur in the body, including catabolism and anabolism.anabolism. CatabolismCatabolismBreaking downBreaking down AnabolismAnabolism. Building up. Building up

Basic Life Processes contBasic Life Processes cont

Responsiveness Responsiveness ::is the ability to detect and is the ability to detect and respond to changes in the external or internal respond to changes in the external or internal environmentenvironment NeuronsNeurons--impulseimpulse MuscleMuscle

Movement Movement ::includes motion of the whole includes motion of the whole body, organs, single cells, or even organelles body, organs, single cells, or even organelles inside cells.inside cells.

Basic Life Processes contBasic Life Processes cont Growth: Growth: increase in sizeincrease in size

Differentiation:Differentiation: unspecialized state to a unspecialized state to a specialized state.specialized state.

Reproduction Reproduction refers either to the formation ofrefers either to the formation of New cellsNew cells New IndividualNew Individual

Stress and HomeostasisStress and HomeostasisWhere are we headed?Where are we headed?

Homeostasis / StressHomeostasis / Stress Feedback LoopsFeedback Loops

Control CenterControl Center ReceptorReceptor EffectorEffector

3Control of HomeostasisControl of Homeostasis

Homeostasis is continually being disrupted Homeostasis is continually being disrupted byby external stimuliexternal stimuli

Temperature variation, noise, traumaTemperature variation, noise, trauma internal stimuliinternal stimuli

psychological stressespsychological stresses Exercise, low blood sugar, dehydration etcExercise, low blood sugar, dehydration etc

Disruptions are Disruptions are usuallyusually mild & temporarymild & temporary If homeostasis is not maintained, death If homeostasis is not maintained, death

may resultmay result

CONTROL OF HOMEOSTASISCONTROL OF HOMEOSTASIS

HomeostasisHomeostasisisis regulated by the nervous regulated by the nervous system and endocrine system, acting together or system and endocrine system, acting together or independently.independently. Nerve impulses cause rapid changes, Nerve impulses cause rapid changes, Hormones usually work more slowly.Hormones usually work more slowly.

Examples: Examples: Breathing centers monitor CO2 / O2 Breathing centers monitor CO2 / O2 TemperatureTemperature pHpH blood pressureblood pressure

Components of Feedback LoopComponents of Feedback Loop

Receptor Receptor Control Control

centercenter

EffectorEffector

Negative FeedbackNegative Feedback

Positive FeedbackPositive Feedback

Types of Feedback LoopsTypes of Feedback Loops

4Control of Homeostasis is byControl of Homeostasis is byFeedback SystemsFeedback Systems

If a response If a response reversesreverses the original the original stimulus, the system is a stimulus, the system is a negative negative feedback system.feedback system.

If a response If a response enhancesenhances the original the original stimulus, the system is stimulus, the system is a a positive feedback positive feedback system.system.

Homeostasis of Blood PressureHomeostasis of Blood Pressure

NEGATIVE

FEEDBACK

LOOP

Stress

Increase BP

Barroreceptors

Interpretation

Effect

Negative Feedback SystemsNegative Feedback Systems

A negative feedback system A negative feedback system reversesreverses a a change in a controlled condition.change in a controlled condition.Example : Homeostasis of Blood Pressure (BP): Example : Homeostasis of Blood Pressure (BP): Activity of the Activity of the effectoreffector produces a result, produces a result,

that..that.. OpposesOpposes the original stimulus, and results in the original stimulus, and results in

a decrease in blood pressure.a decrease in blood pressure.

Positive Feedback during ChildbirthPositive Feedback during Childbirth Stretch receptors in walls of the Stretch receptors in walls of the

uterusuterus Brain releases a hormone Brain releases a hormone

(oxytocin) into bloodstream (oxytocin) into bloodstream targeting targeting

Uterine smooth muscle Uterine smooth muscle contracts more forcefullycontracts more forcefully

More stretch More stretch more hormone more hormone more contraction more contraction etc.etc.

The cycle ends with birth of the The cycle ends with birth of the baby & decrease in stretchbaby & decrease in stretch

5Positive Feedback SystemPositive Feedback System

The positive feedback system The positive feedback system reinforcesreinforces a a change in a controlled condition.change in a controlled condition.ExampleExample

Normal childbirth provides a good example of Normal childbirth provides a good example of a positive feedback systema positive feedback system

Activity of the Activity of the effectoreffector produces a result, produces a result, that..that..

Reinforces Reinforces the original stimulus, an increase the original stimulus, an increase in uterine contraction.in uterine contraction.

Basic Anatomic TermsBasic Anatomic Terms

Anatomical PositionAnatomical Position

Anatomical PositionAnatomical Position uprightupright

facing the observer, facing the observer, head levelhead level

eyes facing forwardeyes facing forward feet flat on the floorfeet flat on the floor

arms at the sidesarms at the sides palms turned forward palms turned forward

(ventral)(ventral)

Planes and SectionsPlanes and Sections Planes are imaginary flat surfaces that are Planes are imaginary flat surfaces that are

used to divide the body or organs into used to divide the body or organs into definite areas definite areas

Principal planes include: Principal planes include: midsagittalmidsagittal (medial) and (medial) and parasagittalparasagittal frontal (coronal)frontal (coronal) transverse (crosstransverse (cross--sectional or horizontal) sectional or horizontal) obliqueoblique

6Planes and Sections of the BrainPlanes and Sections of the Brain(3(3--D anatomical relationships revealed)D anatomical relationships revealed)

Transverse Transverse

FrontalFrontal

MidsagittalMidsagittal / / sagittalsagittal

Directional TermsDirectional Terms

Anterior / Posterior (Dorsal / Ventral)Anterior / Posterior (Dorsal / Ventral) Superior / InferiorSuperior / Inferior Medial / LateralMedial / Lateral IpsilateralIpsilateral / / ContralateralContralateral Proximal / DistalProximal / Distal Superficial / Deep Superficial / Deep

Dorsal or PosteriorDorsal or Posterior at the back of the bodyat the back of the body The brain is posterior The brain is posterior

to the forehead.to the forehead.

Ventral or AnteriorVentral or Anterior at the front of the at the front of the

bodybody The sternum is The sternum is

anterior to the heart.anterior to the heart.

Dorsal or VentralDorsal or Ventral Proximal or DistalProximal or Distal ProximalProximal

nearer to the attachment of nearer to the attachment of the limb to the trunkthe limb to the trunk

Ex. The knee is proximal to Ex. The knee is proximal to the ankle.the ankle.

DistalDistal farther from the attachment farther from the attachment

of the limb to the trunkof the limb to the trunk

Ex. The wrist is distal to the Ex. The wrist is distal to the elbow.elbow.

7Major Directional TermsMajor Directional Terms

See Definitions page See Definitions page 1414

Thoracic Region / CavityThoracic Region / Cavity

Encircled by ribs, sternum, vertebral column and muscleEncircled by ribs, sternum, vertebral column and muscle Divided into 2 pleural cavities by mediastinum Divided into 2 pleural cavities by mediastinum Mediastinum contains all thoracic organs except lungsMediastinum contains all thoracic organs except lungs

AbdominopelvicAbdominopelvic Region / CavityRegion / Cavity

Inferior portion of ventral body cavity below Inferior portion of ventral body cavity below diaphragmdiaphragm

Encircled by abdominal wall, bones & muscles of Encircled by abdominal wall, bones & muscles of pelvispelvis

Abdominopelvic Abdominopelvic Regions & QuadrantsRegions & Quadrants

Describe locations of organs or source of painDescribe locations of organs or source of pain TicTic--tactac--toe grid or intersecting lines through toe grid or intersecting lines through

navelnavel

8Body RegionsBody Regions

Abdominal Quadrants (Med. Terminology)Abdominal Quadrants (Med. Terminology) RUQRUQ LUQLUQ RLQRLQ LLQLLQ*Clinical Application:*Clinical Application: AppendicitisAppendicitis