An Introduction to Studying the Human Body

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An Introduction to Studying the Human Body

• Classification of Living Things
• Humans and many other animals are vertebrates
• Characterized by a segmented vertebral column
• Common characteristics suggest the same path in
  evolution
• Homeostasis
• The goal of physiological regulation and the key
  to survival in a changing environment

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1-1 Anatomy and Physiology Directly Affect Your
Life

• Anatomy
• Is the oldest medical science
• 1600 B.C.
• Physiology
• Is the study of function
• Biochemistry
• Biology
• Chemistry
• Genetics

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1-3 Anatomy and Physiology

• Anatomy
• Describes the structures of the body
• What they are made of
• Where they are located
• Associated structures
• Physiology
• Is the study of
• Functions of anatomical structures
• Individual and cooperative functions

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1-4 Relationships between Anatomy and Physiology

• Anatomy
• Gross anatomy, or macroscopic anatomy, examines
  large, visible structures
• Surface anatomy exterior features
• Regional anatomy body areas
• Systemic anatomy organ systems
• Developmental anatomy from conception to death
• Clinical anatomy medical specialties

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1-4 Relationships between Anatomy and Physiology

• Anatomy
• Microscopic anatomy examines cells and molecules
• Cytology study of cells and their structures
• cyt- cell
• Histology study of tissues and their structures

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1-4 Relationships between Anatomy and Physiology

• Physiology
• Cell physiology processes within and between
  cells
• Organ physiology functions of specific organs
• Systemic physiology functions of an organ system
• Pathological physiology effects of diseases

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1-5 Levels of Organization

• The Chemical (or Molecular) Level
• Atoms are the smallest chemical units
• Molecules are a group of atoms working together
• The Cellular Level
• Cells are a group of atoms, molecules, and
  organelles working together
• The Tissue Level
• A tissue is a group of similar cells working
  together
• The Organ Level
• An organ is a group of different tissues working
  together

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1-5 Levels of Organization

• The Organ System Level
• An organ system is a group of organs working
  together
• Humans have 11 organ systems
• The Organism Level
• A human is an organism

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Figure 1-1 Levels of Organization
Cellular Level
Chemical and Molecular Levels
Heart musclecell
Protein filaments
Complex protein molecule
Atoms in combination
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Figure 1-1 Levels of Organization
Organismlevel
Organ systemlevel
Organ Level
Tissue Level
The heart
Cardiac muscletissue
Thecardiovascularsystem
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1-5 Levels of Organization

• The Organ Systems
• Integumentary
• Major Organs
• Skin
• Hair
• Sweat glands
• Nails
• Functions
• Protects against environmental hazards
• Helps regulate body temperature
• Provides sensory information

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1-5 Levels of Organization

• The Organ Systems
• Skeletal
• Major Organs
• Bones
• Cartilages
• Associated ligaments
• Bone marrow
• Functions
• Provides support and protection for other tissues
• Stores calcium and other minerals
• Forms blood cells

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1-5 Levels of Organization

• The Organ Systems
• Muscular
• Major Organs
• Skeletal muscles and associated tendons
• Functions
• Provides movement
• Provides protection and support for other tissues
• Generates heat that maintains body temperature

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1-5 Levels of Organization

• The Organ Systems
• Nervous
• Major Organs
• Brain
• Spinal cord
• Peripheral nerves
• Sense organs
• Functions
• Directs immediate responses to stimuli
• Coordinates or moderates activities of other
  organ systems
• Provides and interprets sensory information about
  external conditions

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1-5 Levels of Organization

• The Organ Systems
• Endocrine
• Major Organs
• Pituitary gland
• Pancreas
• Gonads
• Endocrine tissues in other systems
• Functions
• Directs long-term changes in the activities of
  other organ systems
• Adjusts metabolic activity and energy use by the
  body
• Controls many structural and functional changes
  during development

• Thyroid gland
• Adrenal glands

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1-5 Levels of Organization

• The Organ Systems
• Cardiovascular
• Major Organs
• Heart
• Blood
• Blood vessels
• Functions
• Distributes blood cells, water and dissolved
• materials including nutrients, waste products,
  oxygen, and carbon dioxide
• Distributes heat and assists in control of body
  temperature

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1-5 Levels of Organization

• The Organ Systems
• Lymphatic
• Major Organs
• Spleen
• Thymus
• Lymphatic vessels
• Lymph nodes
• Tonsils
• Functions
• Defends against infection and disease
• Returns tissue fluids to the bloodstream

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1-5 Levels of Organization

• The Organ Systems
• Respiratory
• Major Organs
• Nasal cavities
• Sinuses
• Larynx
• Trachea
• Bronchi
• Lungs
• Alveoli

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1-5 Levels of Organization

• The Organ Systems
• Respiratory
• Functions
• Delivers air to alveoli (sites in lungs where gas
  exchange occurs)
• Provides oxygen to bloodstream
• Removes carbon dioxide from bloodstream
• Produces sounds for communication

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1-5 Levels of Organization

• The Organ Systems
• Digestive
• Major Organs
• Teeth
• Tongue
• Pharynx
• Esophagus
• Stomach
• Small intestine
• Large intestine
• Liver
• Gallbladder
• Pancreas

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1-5 Levels of Organization

• The Organ Systems
• Digestive
• Functions
• Processes and digests food
• Absorbs and conserves water
• Absorbs nutrients
• Stores energy reserves

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1-5 Levels of Organization

• The Organ Systems
• Urinary
• Major Organs
• Kidneys
• Ureters
• Urinary bladder
• Urethra
• Functions
• Excretes waste products from the blood
• Controls water balance by regulating volume of
  urine produced
• Stores urine prior to voluntary elimination
• Regulates blood ion concentrations and pH

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1-5 Levels of Organization

• The Organ Systems
• Male Reproductive
• Major Organs
• Testes
• Epididymides
• Ductus deferentia
• Seminal vesicles
• Prostate gland
• Penis
• Scrotum

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1-5 Levels of Organization

• The Organ Systems
• Male Reproductive
• Functions
• Produces male sex cells (sperm), suspending
  fluids, and hormones
• Sexual intercourse

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1-5 Levels of Organization

• The Organ Systems
• Female Reproductive
• Major Organs
• Ovaries
• Uterine tubes
• Uterus
• Vagina
• Labia
• Clitoris
• Mammary glands

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1-5 Levels of Organization

• The Organ Systems
• Female Reproductive
• Functions
• Produces female sex cells (oocytes) and hormones
• Supports developing embryo from conception to
  delivery
• Provides milk to nourish newborn infant
• Sexual intercourse

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1-6 Homeostasis

• Homeostasis
• All body systems working together to maintain a
  stable internal environment
• Systems respond to external and internal changes
  to function within a normal range (body
  temperature, fluid balance)

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1-6 Homeostasis

• Mechanisms of Regulation
• Autoregulation (intrinsic)
• Automatic response in a cell, tissue, or organ to
  some environmental change
• Extrinsic regulation
• Responses controlled by nervous and endocrine
  systems

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1-6 Homeostasis

• Receptor
• Receives the stimulus
• Control center
• Processes the signal and sends instructions
• Effector
• Carries out instructions

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Figure 1-2 The Control of Room Temperature
RECEPTOR
Informationaffects
Normalconditiondisturbed
Thermometer
STIMULUSRoom temperaturerises
CONTROL CENTER(Thermostat)
HOMEOSTASIS
Airconditionerturns on
Airconditionerturns off
Normal roomtemperature
RESPONSERoom temperaturedrops
20
30
40
Normalrange
Room temperature (C)
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Normalconditionrestored
EFFECTOR
Sendscommandsto
Air conditionerturns on
Time
In response to input from a receptor (a
thermometer), a thermostat(the control center)
triggers an effector response (either an air
condi-tioner or a heater) that restores normal
temperature. In this case,when room temperature
rises above the set point, the thermostatturns
on the air conditioner, and the temperature
returns to normal.
With this regulatory system, roomtemperature
fluctuates around theset point.
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1-7 Negative and Positive Feedback

• The Role of Negative Feedback
• The response of the effector negates the stimulus
• Body is brought back into homeostasis
• Normal range is achieved

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Figure 1-3 Negative Feedback in the Control of
Body Temperature
RECEPTORS
Informationaffects
Temperaturesensors in skinandhypothalamus
Normaltemperaturedisturbed
CONTROL CENTER
STIMULUSBody temperaturerises
HOMEOSTASIS
Thermoregulatorycenter in brain
Vesselsdilate,sweatingincreases
Vesselsconstrict,sweatingdecreases
Normal bodytemperature
RESPONSEIncreased heat loss,body
temperaturedrops
37.2
Normaltemperaturerestored
EFFECTORS
Normalrange
Body temperature (C)
Sendscommandsto
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Sweat glands in skin increase secretion
Blood vessels in skin dilate
36.7
Time
Events in the regulation of body temperature,
which arecomparable to those shown in Figure
1?2. A control centerin the brain (the
hypothalamus) functions as a thermostatwith a
set point of 37C. If body temperature
exceeds37.2C, heat loss is increased through
enhanced blood flowto the skin and increased
sweating.
The thermoregulatory center keepsbody
temperature fluctuatingwithin an acceptable
range, usuallybetween 36.7 and 37.2C.
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1-7 Negative and Positive Feedback

• The Role of Positive Feedback
• The response of the effector increases change of
  the stimulus
• Body is moved away from homeostasis
• Normal range is lost
• Used to speed up processes

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Figure 1-4 Positive Feedback Blood Clotting
Clottingaccelerates
Positivefeedbackloop
Blood clot
Chemicals
Chemicals
This escalating processis a positive
feedbackloop that ends with theformation of a
blood clot,which patches the vesselwall and
stops the bleeding.
As clotting continues,each step
releaseschemicals that furtheraccelerate the
process.
The chemicals start chainreactions in which
cells,cell fragments, andsoluble proteins in
the blood begin to form a clot.
Damage to cells in theblood vessel wall
releaseschemicals that begin theprocess of
blood clotting.
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1-7 Negative and Positive Feedback

• Systems Integration
• Systems work together to maintain homeostasis
• Homeostasis is a state of equilibrium
• Opposing forces are in balance
• Dynamic equilibrium continual adaptation
• Physiological systems work to restore balance
• Failure results in disease or death

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Table 1-1 The Roles of Organ Systems in
Homeostatic Regulation
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1-8 Anatomical Terminology

• Superficial Anatomy
• Locating structures on or near the body surface
• Anatomical Landmarks
• Anatomical position hands at sides, palms
  forward
• Supine lying down, face up
• Prone lying down, face down

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1-8 Anatomical Terminology

• Superficial Anatomy
• Anatomical Landmarks
• References to palpable structures
• Anatomical Regions
• Body regions
• Abdominopelvic quadrants
• Abdominopelvic regions
• Anatomical Directions
• Reference terms based on subject

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Figure 1-5a Anatomical Landmarks
Frontal orforehead
Nasal or nose
Ocular, orbitalor eye
Cranialor skull
Otic or ear
Cephalic or head
Buccal or cheek
Facialor face
Cervical or neck
Oral or mouth
Mental or chin
Thoracic orthorax, chest
Axillary or armpit
Mammaryor breast
Brachialor arm
Trunk
Abdominal(abdomen)
Antecubitalor front of elbow
Umbilicalor navel
Anterior view
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Figure 1-5a Anatomical Landmarks
Antebrachialor forearm
Pelvic(pelvis)
Trunk
Carpal or wrist
Palmar or palm
Manualor hand
Pollexor thumb
Digits(phalanges)or fingers (digitalor
phalangeal)
Inguinalor groin
Pubic(pubis)
Patellar or kneecap
Femoralor thigh
Cruralor leg
Tarsal orankle
Digits (phalanges)or toes (digital orphalangeal)
Pedalor foot
Hallux orgreat toe
Anterior view
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Figure 1-5b Anatomical Landmarks
Cephalicor head
Acromial orshoulder
Cervicalor neck
Dorsal orback
Olecranalor backof elbow
Upperlimb
Posterior view
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Figure 1-5b Anatomical Landmarks
Upperlimb
Lumbaror loin
Glutealor buttock
Lower limb
Popliteal orback of knee
Suralor calf
Calcaneal orheel of foot
Plantar orsole of foot
Posterior view
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Figure 1-6a Abdominopelvic Quadrants and Regions
Left UpperQuadrant(LUQ)
Right UpperQuadrant(RUQ)
Left LowerQuadrant(LLQ)
Right LowerQuadrant(RLQ)
Abdominopelvic quadrants. The fourabdominopelvic
quadrants are formed by twoperpendicular lines
that intersect at the navel. Theterms for these
quadrants, or their abbreviations, are most
often used in clinical discussions.
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Figure 1-6b Abdominopelvic Quadrants and Regions
Righthypochondriacregion
Left hypochondriacregion
Epigastricregion
Umbilicalregion
Left lumbarregion
Right lumbarregion
Hypogastric(pubic)region
Rightinguinalregion
Left inguinalregion
Abdominopelvic regions. The nine
abdominopelvicregions provide more precise
regional descriptions.
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Figure 1-6c Abdominopelvic Quadrants and Regions
Liver
Stomach
Gallbladder
Spleen
Large intestine
Small intestine
Appendix
Urinarybladder
Anatomical relationships. The relationship
betweenthe abdominopelvic quadrants and regions
and thelocations of the internal organs are
shown here.
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Figure 1-7 Directional References
Cranial
Superior
Right
Left
Proximal
Posterioror dorsal
Anterioror ventral
Medial
Lateral
Caudal
Proximal
Distal
Distal
Inferior
A lateral view.
An anterior view. Arrowsindicate important
directionalterms used in this textdefinitions
and descriptionsare given in Table 1?2.
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Table 1-2 Directional Terms
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1-8 Anatomical Terminology

• Sectional Anatomy
• Planes and sections
• Plane a three-dimensional axis
• Section a slice parallel to a plane
• Used to visualize internal organization and
  structure
• Important in radiological techniques
• MRI
• PET
• CT

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Figure 1-8 Sectional Planes
Frontal plane
Sagittal plane
Transverse plane
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Table 1-3 Terms That Indicate Sectional Planes
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1-9 Body Cavities

• Essential Functions of Body Cavities
• Protect organs from accidental shocks
• Permit changes in size and shape of internal
  organs
• Ventral body cavity (coelom)
• Divided by the diaphragm
• Thoracic cavity
• Abdominopelvic cavity

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Figure 1-9 Relationships among the Subdivisions
of the Ventral Body Cavity
Ventral Body Cavity
Provides protection Allows organ movement
Linings prevent friction
Subdivides during development into
Abdominopelvic Cavity
Thoracic Cavity
Surrounded by chest wall anddiaphragm
Peritoneal Cavity
Extendsthroughoutabdominal cavityand into
superiorportion of pelviccavity
Mediastinum
Right Pleural Cavity
Left Pleural Cavity
Surrounds right lung
Contains thetrachea, esophagus,and major vessels
Surrounds left lung
Abdominal Cavity
Pelvic Cavity
Contains many digestive glandsand organs
Contains urinarybladder,reproductiveorgans,
lastportion ofdigestive tract
Pericardial Cavity
Surrounds heart
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1-9 Body Cavities

• Serous Membranes
• Line body cavities and cover organs
• Consist of parietal layer and visceral layer
• Parietal layer lines cavity
• Visceral layer covers organ

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1-9 Body Cavities

• The Thoracic Cavity
• Right and left pleural cavities
• Contain right and left lungs
• Mediastinum
• Upper portion filled with blood vessels, trachea,
  esophagus, and thymus
• Lower portion contains pericardial cavity
• The heart is located within the pericardial cavity

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Figure 1-10a The Ventral Body Cavity and Its
Subdivisions
POSTERIOR
ANTERIOR
Pleuralcavity
Thoraciccavity
Pericardialcavity
Diaphragm
Peritonealcavity
Abdominopelviccavity
Abdominalcavity
Pelviccavity
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Figure 1-10b The Ventral Body Cavity and Its
Subdivisions
Visceralpericardium
Heart
Air space
Pericardialcavity
Balloon
Parietalpericardium
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Figure 1-10c The Ventral Body Cavity and Its
Subdivisions
ANTERIOR
Pericardial cavity
Pleural cavity
Right lung
Left lung
Parietalpleura
Mediastinum
Spinal cord
POSTERIOR
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1-9 Body Cavities

• The Abdominopelvic Cavity
• Peritoneal cavity chamber within abdominopelvic
  cavity
• Parietal peritoneum lines the internal body wall
• Visceral peritoneum covers the organs

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1-9 Body Cavities

• The Abdominopelvic Cavity
• Abdominal cavity superior portion
• Diaphragm to top of pelvic bones
• Contains digestive organs
• Retroperitoneal space
• Area posterior to peritoneum and anterior to
  muscular body wall
• Contains pancreas, kidneys, ureters, and parts of
  the digestive tract

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1-9 Body Cavities

• The Abdominopelvic Cavity
• Pelvic cavity inferior portion
• Within pelvic bones
• Contains reproductive organs, rectum, and bladder