Introduction to Introduction to AnatomyAnatomy

DefinitionsDefinitions

Anatomy – Study of body structures Anatomy – Study of body structures and their relationships to each other.and their relationships to each other.

Always involves question “What is Always involves question “What is it?”it?”

Physiology – Study of how the body Physiology – Study of how the body structures work together to maintain structures work together to maintain life.life.

Involves the question “How does it Involves the question “How does it work?”work?”

Levels of OrganizationLevels of Organization

Atoms Atoms Molecules Molecules Cells Cells Tissues Tissues Organs Organs Organ Organ Systems Systems Organisms Organisms

H + C + O H + C + O C C66HH1212OO66

Muscle Cells Muscle Cells Muscle Tissues Muscle Tissues

Heart Heart Circulatory System Circulatory System HumanHuman

Chemical levelAtoms combine to form molecules

1

2

3

4

Cellular levelCells are made up of molecules

Tissue levelTissues consist of similar types of cells

5 Organ system levelOrgan systems consist of different organs that work together closely

Organ levelOrgans are made up of different types of tissues

6 Organismal levelThe human organism is made up of many organ systems

Atoms

Molecules

Smooth muscle cell

Smooth muscle tissue

Connective tissue

Smooth muscle tissue

Epithelial tissue

Blood vessel (organ)

Heart

Blood vessels

Cardiovascular system

Levels of Structural Organization

Figure 1.1

Organ SystemsOrgan Systems

12 Different Organ Systems12 Different Organ Systems Each specializes in carrying out a Each specializes in carrying out a

specific functionspecific function

Example – Muscular system specializes Example – Muscular system specializes in movingin moving

Skeletal system specializes in supportSkeletal system specializes in support

                                                                                                                                                                     

                                              

Structure and FunctionStructure and Function

There is an intimate relationship There is an intimate relationship between structure and function. between structure and function. One determines the other. One determines the other.

Explain how the structure of each Explain how the structure of each of the following determines the of the following determines the function for which it can be used.function for which it can be used.

a. forka. fork b. hand b. hand c. incisorsc. incisors

Functions of LifeFunctions of Life Separate internal and external Separate internal and external

environmentsenvironments MoveMove Respond to stimuli & communicateRespond to stimuli & communicate Digest foodDigest food Carry out chemical reactions in cells Carry out chemical reactions in cells

(metabolism)(metabolism) Excrete wastesExcrete wastes ReproduceReproduce GrowGrow

All functions help to maintain All functions help to maintain homeostasishomeostasis

Homeo = “same”Homeo = “same” Stasis = “same”Stasis = “same”

Homeostasis – keep a Homeostasis – keep a stable internal stable internal environment even environment even though things inside though things inside and outside the body and outside the body are changingare changing

Communication is Essential for Communication is Essential for HomeostasisHomeostasis

2 systems control communication:2 systems control communication:

– NervousNervous– EndocrineEndocrine

Stimulus Stimulus

The change in the environment The change in the environment

It needs to be reported to the bodyIt needs to be reported to the body

Examples – change in temperature, Examples – change in temperature, change in glucose levels, change in change in glucose levels, change in water levelswater levels

3 parts of homeostatic control 3 parts of homeostatic control mechanisms:mechanisms:

Receptor – receives information from Receptor – receives information from the environment as a stimulusthe environment as a stimulus

Control center – analyzes info; Control center – analyzes info; decides if anything needs to be donedecides if anything needs to be done

Effector – responds to the control Effector – responds to the control center to make a change if necessarycenter to make a change if necessary

ExampleExample

Receptor – Sun (the stimulus) Receptor – Sun (the stimulus) warms your body. Temperature warms your body. Temperature receptors in skin send info to receptors in skin send info to brain.brain.

Control center – Brain sees that Control center – Brain sees that body is getting too warm. body is getting too warm. Sends signal to effectors to cool Sends signal to effectors to cool the body.the body.

Effectors – Sweat glands. Effectors – Sweat glands. Release sweat to cool body.Release sweat to cool body.

FeedbackFeedback

The effector causes a change.The effector causes a change.

Results of the change then Results of the change then FEEDBACK to the control center.FEEDBACK to the control center.

2 Types of Feedback2 Types of Feedback

1. Negative – Most common type in 1. Negative – Most common type in body.body.

Output from the effector shuts off the Output from the effector shuts off the stimulus.stimulus.

Helps keep things stable.Helps keep things stable.

Works just like the air conditioning Works just like the air conditioning system.system.

Negative system--stimulus causes Negative system--stimulus causes a response which reduces the a response which reduces the

stimulus. stimulus.

THE HOMEOSTATIC THE HOMEOSTATIC CONTROL OF BLOOD CONTROL OF BLOOD GLUCOSE LEVELS is a GLUCOSE LEVELS is a

negative feedback systemnegative feedback system

2.2. Positive feedback– rare in body.Positive feedback– rare in body.

The output of the effector causes more The output of the effector causes more of the change.of the change.

Not useful in homeostasis.Not useful in homeostasis.

Helps bring about rapid changes.Helps bring about rapid changes.

Examples – in laborExamples – in labor

- in blood clotting- in blood clotting

Positive feedbackPositive feedback: stimulus causes a : stimulus causes a response which increases the stimulus. This response which increases the stimulus. This system pushes the conditions to an extreme.system pushes the conditions to an extreme.

Homeostatic ImbalanceHomeostatic Imbalance

Causes diseaseCauses disease The body cannot tolerate drastic The body cannot tolerate drastic

changeschanges Occurs naturally as we age – Occurs naturally as we age –

homestatic systems do not work as homestatic systems do not work as wellwell

Systems can be damaged or injuredSystems can be damaged or injured

Language of AnatomyLanguage of Anatomy

Position and Directional TermsPosition and Directional Terms Regional TermsRegional Terms Body Planes and SectionsBody Planes and Sections Body Cavities and MembranesBody Cavities and Membranes

Position TermsPosition Terms

Anatomical position – helps describe Anatomical position – helps describe body parts.body parts.

Resembles standing at attention Resembles standing at attention except palms face forward and except palms face forward and thumbs point away from bodythumbs point away from body

Directional TermsDirectional Terms

Explains where one body structure is Explains where one body structure is in relation to another.in relation to another.– Proximal – closer to the midlineProximal – closer to the midline– Distal – farther from the midlineDistal – farther from the midline– Superior – closer to the headSuperior – closer to the head– Inferior – closer to the feetInferior – closer to the feet– Anterior – closer to the frontAnterior – closer to the front– Posterior – closer to the rearPosterior – closer to the rear

Regional TermsRegional Terms

Two main regions:Two main regions:– AxialAxial: head, neck, and truck: head, neck, and truck

– AppendicularAppendicular: limbs (arms and : limbs (arms and legs)legs)

Body PlanesBody Planes

To study anatomy, body can be cut To study anatomy, body can be cut along a along a planeplane (flat surface). (flat surface).

SagittalSagittal (“arrow”) (“arrow”) planeplane divides divides body vertically into left and right body vertically into left and right sections. sections.

If sagittal plane is on midline = If sagittal plane is on midline = midsaggitalmidsaggital

More planes . . . More planes . . . Frontal plane – divides body vertically Frontal plane – divides body vertically

into anterior (front) and posterior (back).into anterior (front) and posterior (back).

Transverse plane – a horizontal plane Transverse plane – a horizontal plane that divides the body into superior (top) that divides the body into superior (top) and inferior (bottom)and inferior (bottom)

Transverse plane through Transverse plane through mid sectionmid section

Body CavitiesBody Cavities

Axial portion of body contains 2 large Axial portion of body contains 2 large cavities:cavities:

1. 1. Dorsal body cavityDorsal body cavity – contains – contains brain and spinal cordbrain and spinal cord

2.2. Ventral body cavityVentral body cavity is divided is divided into 2 subdivisions:into 2 subdivisions:

a. a. thoracic cavitythoracic cavity: chest, : chest, contains heart and lungscontains heart and lungs

b. b. abdominopelvic cavityabdominopelvic cavity: : 2 2 partsparts

i. Abdomen – most organsi. Abdomen – most organsii. Pelvis – bladder & ii. Pelvis – bladder & reproductive structuresreproductive structures

Membranes in CavitiesMembranes in Cavities

Ventral body cavity lined with Ventral body cavity lined with serous membraneserous membrane – thin, double – thin, double layeredlayered

Same membrane covers organsSame membrane covers organs Layers of membrane separated by Layers of membrane separated by

serous fluidserous fluid – reduces friction – reduces friction

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Medical ImagingMedical Imaging

Allows visualization of structures Allows visualization of structures without surgerywithout surgery

Useful for confirmation of diagnosisUseful for confirmation of diagnosis Examples of imaging techniquesExamples of imaging techniques

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Conventional RadiographyConventional Radiography

A single burst of A single burst of xraysxrays

Produces 2-D image Produces 2-D image on filmon film

Known as Known as radiography or xrayradiography or xray

Poor resolution of soft Poor resolution of soft tissuestissues

Major use is Major use is osteologyosteology

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Computed Tomography (CT Computed Tomography (CT Scan)Scan)

Moving x-ray beamMoving x-ray beam Image produced on a Image produced on a

video monitor of a video monitor of a cross-section cross-section through bodythrough body

Computer generated Computer generated image reveals more image reveals more soft tissue detailsoft tissue detail– kidney & gallstoneskidney & gallstones

Multiple scans used Multiple scans used to build 3D views to build 3D views

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Ultrasound (US)Ultrasound (US) High-frequency sound High-frequency sound

waves emitted by hand-waves emitted by hand-held deviceheld device

Safe, noninvasive & Safe, noninvasive & painlesspainless

Image or sonogram is Image or sonogram is displayed on video displayed on video monitormonitor

Used for fetal ultrasound Used for fetal ultrasound and examination of pelvic and examination of pelvic & abdominal organs, & abdominal organs, heart and blood flow heart and blood flow through blood vesselsthrough blood vessels

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Magnetic Resonance Imaging Magnetic Resonance Imaging (MRI)(MRI)

Body exposed to high-Body exposed to high-energy magnetic fieldenergy magnetic field

Protons align Protons align themselves relative to themselves relative to magnetic fieldmagnetic field

Pulse of radiowaves Pulse of radiowaves used to generate an used to generate an image on video monitorimage on video monitor

Can not use on patient Can not use on patient with metal in their bodywith metal in their body

Reveals fine detail Reveals fine detail within soft tissueswithin soft tissues

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Positron Emission Positron Emission Tomography(PET)Tomography(PET)

Substance that emits Substance that emits positively charged positively charged particles is injected particles is injected into bodyinto body

Collision with Collision with negatively charged negatively charged electrons in tissues electrons in tissues releases gamma raysreleases gamma rays

Camera detects Camera detects gamma rays & gamma rays & computer generates computer generates image displayed on image displayed on monitormonitor