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Anatomy & Physiology IChapter 1
Anatomy: The study of form (structure) Subdivisions:
Gross Anatomy - study of structures that can be seen with the naked eyeNeuroanatomy – study of nervous system structureMicroscopic Anatomy – study of structures that are too small to see with the naked eye
Cytology – study of cellsHistology – study of tissues
Physiology: The study of function at many levels
Subdivisions are based on organ systems neurophysiology (physiology of nervous system)endocrinology (physiology of hormones)pathophysiology (mechanisms of disease)
The Human Body
All living things are organized.
AtomsMoleculesOrganellesCellsTissue Organ Organ System Organism
MoleculeAtoms
Chemical levelAtoms combine to form molecules.1
OrganelleMoleculeAtoms
Chemical levelAtoms combine to form molecules.
Cellular levelCells are made up ofmolecules.
Smooth muscle cell
12
OrganelleMoleculeAtoms
Chemical levelAtoms combine to form molecules.
Cellular levelCells are made up ofmolecules.
Tissue levelTissues consist of similartypes of cells.
Smooth muscle cell
Smooth muscle tissue
12
3
OrganelleMoleculeAtoms
Chemical levelAtoms combine to form molecules.
Cellular levelCells are made up ofmolecules.
Tissue levelTissues consist of similartypes of cells.
Organ levelOrgans are made up of different typesof tissues.
Smooth muscle cell
Smooth muscle tissue
Connective tissue
Blood vessel (organ)
Epithelialtissue
Smooth muscle tissue
12
3
4
Cardiovascularsystem
OrganelleMoleculeAtoms
Chemical levelAtoms combine to form molecules.
Cellular levelCells are made up ofmolecules.
Tissue levelTissues consist of similartypes of cells.
Organ levelOrgans are made up of different typesof tissues.
Organ system levelOrgan systems consist of differentorgans that work together closely.
Smooth muscle cell
Smooth muscle tissue
Connective tissue
Blood vessel (organ)
HeartBloodvessels
Epithelialtissue
Smooth muscle tissue
12
3
4
5
Cardiovascularsystem
OrganelleMoleculeAtoms
Chemical levelAtoms combine to form molecules.
Cellular levelCells are made up ofmolecules.
Tissue levelTissues consist of similartypes of cells.
Organ levelOrgans are made up of different typesof tissues.
Organ system levelOrgan systems consist of differentorgans that work together closely.
Organismal levelThe human organism is made upof many organ systems.
Smooth muscle cell
Smooth muscle tissue
Connective tissue
Blood vessel (organ)
HeartBloodvessels
Epithelialtissue
Smooth muscle tissue
12
3
4
56
Atoms – the smallest units (building blocks) of matter.Molecules – make up organelles and other cellular components
macromolecules – proteins, carbohydrates, fats, DNA
Organelles – microscopic structures in a cell that carry out its individual functionsCells – smallest unit of life
CellsThe smallest units of an organism that carry out all the basic functions of lifePerform all activities necessary to maintain life
Metabolism, digestion, assimilation, excretion, reproduction
Tissues A mass of similar cells and cell products that form discrete region of an organ and performs a specific function
Four Tissue ClassesEpithelial: covers and protectsConnective: binds and supports other tissuesMuscle: movementNervous: connects sensory structures to motor structures
OrgansStructure composed of two or more tissue types that work together to carry out a particular function Cells integrated into tissuesServe a common functionExamples
BrainHeartLungsPancreas
An Organ System is a group of organsProtection, support, and movement
Integumentary - Skeletal - Muscular
Coordination and controlNervous - Endocrine
CirculationCardiovascular - Lymphatic
Nutrition and fluid balanceRespiratory - Digestive - Urinary
Production of offspringReproductive
The Human Body
NailsSkin
Hair
(a) Integumentary System Forms the external body covering, and protects deeper tissues from injury. Synthesizes vitamin D, and houses cutaneous (pain, pressure, etc.) receptors and sweat and oil glands.
Bones
Joint
(b) Skeletal System Protects and supports body organs, and provides a framework the muscles use to cause movement. Blood cells are formed within bones. Bones store minerals.
Skeletalmuscles
(c) Muscular System Allows manipulation of the environment, locomotion, and facial expression. Main- tains posture, and produces heat.
Brain
NervesSpinalcord
(d) Nervous System As the fast-acting control system of the body, it responds to internal and external changes by activating appropriate muscles and glands.
Pineal gland
PituitaryglandThyroid
glandThymus
AdrenalglandPancreas
Testis
Ovary
(e) Endocrine System Glands secrete hormones that regulate processes such as growth, reproduction, and nutrient use (metabolism) by body cells.
(f) Cardiovascular System Blood vessels transport blood, which carries oxygen, carbon dioxide, nutrients, wastes, etc. The heart pumps blood.
Heart
Bloodvessels
Lymphaticvessels
Red bonemarrow
Thoracicduct
Thymus
Spleen
Lymphnodes
(g) Lymphatic System/Immunity Picks up fluid leaked from blood vessels and returns it to blood. Disposes of debris in the lymphatic stream. Houses white blood cells (lymphocytes) involved in immunity. The immune response mounts the attack against foreign substances within the body.
Nasalcavity
Bronchus
Pharynx
Larynx
Trachea
Lung
(h) Respiratory System Keeps blood constantly supplied with oxygen and removes carbon dioxide. The gaseous exchanges occur through the walls of the air sacs of the lungs.
Liver
Oral cavity
Esophagus
Largeintestine
StomachSmallintestine
RectumAnus
(i) Digestive System Breaks down food into absorbable units that enter the blood for distribution to body cells. Indigestible foodstuffs are eliminated as feces.
Kidney
Ureter
UrinarybladderUrethra
(j) Urinary System Eliminates nitrogenous wastes from the body. Regulates water, electrolyte and acid-base balance of the blood.
Prostategland
Ductusdeferens
Penis
Testis
Scrotum
Ovary
Uterinetube
Mammaryglands (inbreasts)
Uterus
Vagina
Overall function is production of offspring. Testes produce sperm and male sexhormone, and male ducts and glands aid in delivery of sperm to the femalereproductive tract. Ovaries produce eggs and female sex hormones. The remainingfemale structures serve as sites for fertilization and development of the fetus.Mammary glands of female breasts produce milk to nourish the newborn.
(k) Male Reproductive System (l) Female Reproductive System
All cells depend on organ systems to meet their survival needs Organ systems work cooperatively to perform necessary life functions
Digestive system Takes in nutrients, breaks them down, and eliminates unabsorbed matter (feces)
Respiratory systemTakes in oxygen and eliminates carbon dioxide
Food O2 CO2
Cardiovascular systemVia the blood, distributes oxygen and nutrients to all body cells and delivers wastes and carbon dioxide to disposal organs
Interstitial fluid
Nutrients
Urinary systemEliminates nitrogenouswastes andexcess ions
Nutrients and wastes pass between blood and cells via the interstitial fluid
Integumentary system Protects the body as a whole from the external environment
Blood
Heart
Feces Urine
CO2
O2
Metabolism and Its Regulation
All the life-sustaining chemical reactions that occur within body cellsTypes of metabolism
Anabolism – reactions that build (synthesize) larger, more complex structures from simpler substances.
Similar to building a pearl necklace from individual pearls.In cells, anabolic reactions require ATP for energy.
Catabolism – reactions that breakdown larger, more complex substances to simpler substance.
Similar to removing each individual pearl from a pearl necklaceCatabolic reactions, like glycolysis, release energy. This energy can be used in cells to make ATP.
stable internal conditions regardless of external conditions
fluctuates within limited range around a set point
Homeostatic Control Mechanisms – Mechanisms that help to maintain homeostasisThe body has hundreds of homeostatic mechanisms, including mechanisms to control:
Body temperature, blood sugar, blood pH, water balance, blood pressure, electrolyte balance, etc.
When these mechanisms don’t work normally, the result can be disease, dysfunction or death.
Involve continuous monitoring and regulation of many factors (variables)
Nervous and endocrine systems accomplish the communication via nerve impulses and hormonesUsually involves negative feedback loop
Negative feedback loops have 3 componentsReceptorControl CenterEffector
Body senses a change and activates mechanisms to reverse itThe response reduces or shuts off the original stimulusExamples:
Regulation of body temperature and blood pressure (two nervous system mechanism)Regulation of blood volume by ADH (an endocrine mechanism)
1. Receptor (sensor)Monitors the environment and responds to stimuli (changes in controlled variables)Reports changes to the control center
2. Control centerDetermines the set point at which the variable is maintainedReceives input from receptor when variable is out of rangeDetermines appropriate response; delivers instructions to the appropriate effector
3. EffectorReceives signal (command) from control center Provides the means to respond Response acts to reduce or enhance the stimulus (feedback)
Stimulusproduceschange invariable.
BALANCE
IMBALANCE
IMBALANCE
1
Stimulusproduceschange invariable.
Receptordetectschange.
Receptor
BALANCE
IMBALANCE
IMBALANCE
1
2
Stimulusproduceschange invariable.
Receptordetectschange.
Input: Informationsent along afferentpathway to controlcenter.
Receptor
ControlCenter
BALANCE
Afferentpathway
IMBALANCE
IMBALANCE
1
2
3
Stimulusproduceschange invariable.
Receptordetectschange.
Input: Informationsent along afferentpathway to controlcenter.
Output:Information sent alongefferent pathway toeffector.
Receptor Effector
ControlCenter
BALANCE
Afferentpathway
Efferentpathway
IMBALANCE
IMBALANCE
1
2
34
Stimulusproduceschange invariable.
Receptordetectschange.
Input: Informationsent along afferentpathway to controlcenter.
Output:Information sent alongefferent pathway toeffector.
Responseof effectorfeeds backto reducethe effect ofstimulusand returnsvariable tohomeostaticlevel.
Receptor Effector
ControlCenter
BALANCE
Afferentpathway
Efferentpathway
IMBALANCE
IMBALANCE
1
2
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5
Sweat glands activated
Shiveringbegins
StimulusBody temperaturerises BALANCE
Information sentalong the afferentpathway to controlcenter
Information sentalong the afferentpathway to controlcenter
Afferentpathway
Afferentpathway
Efferentpathway
Efferentpathway
Information sentalong the efferentpathway toeffectors
Information sentalong the efferentpathway to effectors
StimulusBody temperature falls
ReceptorsTemperature-sensitivecells in skin and brain
ReceptorsTemperature-sensitivecells in skin and brain
EffectorsSweat glands
EffectorsSkeletal muscles
Control Center(thermoregulatory
center in brain)
Control Center(thermoregulatory
center in brain)
ResponseEvaporation of sweatBody temperature falls;stimulus ends
ResponseBody temperature rises;stimulus ends
Sitting up in bed causes a drop in blood pressure in the head and upper thorax
Receptors in the arteries near the heart alert the control center in the brainstem
Control center in the brain sends nerve signals to the heart (effector)The effector (the heart) receives a command signal to increases the heart rate. This returns the blood pressure to normal
Failure of this to feedback loop may produce dizziness in the elderly
Blood drains fromupper body, creatinghomeostatic imbalance
Baroreceptors aboveheart respond to dropin blood pressure
Baroreceptors send signalsto cardiac center of brainstem
Blood pressure risesto normal; homeostasisis restored
Person risesfrom bed
Cardiac centeraccelerates heartbeat
Receptors sense decreased blood volume (as occurs with dehydration)
Control center in hypothalamus stimulates pituitary gland to release antidiuretic hormone (ADH)
ADH causes the kidneys (effectors) to return more water to the blood
The response enhances or exaggerates the original stimulus
May exhibit a cascade or amplifying effect
Usually controls infrequent events e.g.:
Enhancement of labor contractions by oxytocin
Platelet plug formation and blood clotting
Self-amplifying cycleleads to greater change in the same directionfeedback loop is repeated – change produces more change
Normal way of producing rapid changes occurs with childbirth, blood clotting, protein digestion, fever, and generation of nerve signals
Head of fetuspushes against cervix
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1
Oxytocin stimulates uterinecontractions and pushesfetus toward cervix
Nerve impulsesfrom cervixTransmittedto brain
Brain stimulatespituitary gland tosecrete oxytocin
Positive feedbackcycle is initiated.
Break or tearoccurs in bloodvessel wall.
1
Positive feedbackcycle is initiated.
Break or tearoccurs in bloodvessel wall.
Plateletsadhere to siteand releasechemicals.
1
2
Positive feedbackcycle is initiated.
Positivefeedbackloop
Break or tearoccurs in bloodvessel wall.
Plateletsadhere to siteand releasechemicals.
Releasedchemicalsattract moreplatelets.
1
23
Feedback cycle endswhen plug is formed.
Positive feedbackcycle is initiated.
Positivefeedbackloop
Break or tearoccurs in bloodvessel wall.
Plateletsadhere to siteand releasechemicals (clotting factors).
Releasedchemicalsattract moreplatelets.
Platelet plugforms.
1
23
4
Fever > 104 degrees Fmetabolic rate increasesbody produces heat even fasterbody temperature continues to risefurther increasing metabolic rate
Cycle continues to reinforce itself
Becomes fatal at 113 degrees F
Disturbance of homeostasis Increases risk of disease Contributes to changes associated with aging May allow destructive positive feedback mechanisms to take over (e.g., heart failure)
Anatomical Position - Standard frame of reference for anatomical descriptions & dissection
Anatomical Divisions – The two fundamental divisions of the human body (axial & appendicular)
Body Regions – Regional terms designate specific areas
Directions - Consistent terms are used to designate position and direction to avoid inaccuracy.
Planes - implies an imaginary flat surface passing through the body
Cavities - Internally, the body is divided into spaces, or cavities, that contain organs.
Standard anatomical body position:Person stands erectface & eyes facing forwardFeet flat on floor, slightly apartArms at sidesPalms face forward (forearms in supine position)
When supinatedpalms face forward or upwardradius & ulna are parallel
When pronatedpalms face rearward or downwardradius & ulna are crossed
supine prone
Axial region = head, neck & trunkthoracic region = trunk above diaphragmabdominal region = trunk below diaphragm
divided into 4 quadrants / 9 regions by tic-tac-toe grid
Appendicular region = upper & lower limbsupper limb - arm (brachial region), forearm (antebrachial region), wrist (carpal region), hand (manual region), fingers (digits)lower limb - thigh (femoral region), leg (crural region),ankle (tarsal region), foot (pedal region), toes (digits)
Cervical
Pubic(genital)
CephalicFrontalOrbitalNasalOralMental
ThoracicAxillaryMammarySternal
AbdominalUmbilicalPelvicInguinal(groin)
Upper limbAcromialBrachial (arm)AntecubitalAntebrachial (forearm)
Carpal (wrist)Manus (hand)PalmarPollexDigital
Lower limbCoxal (hip)Femoral (thigh)PatellarCrural (leg)Fibular or peronealPedal (foot)Tarsal (ankle)MetatarsalDigitalHallux
ThoraxAbdomenBack (Dorsum)
Cervical
Back (dorsal)
Scapular
Vertebral
Lumbar
Sacral
Gluteal
Perineal (between anus and external genitalia)
Upper limb
Acromial
Brachial (arm)
Olecranal
Antebrachial (forearm)
Manus (hand)
Metacarpal
Digital
Lower limb
Femoral (thigh)
Popliteal
Sural (calf)
Fibular or peronealPedal (foot)
Calcaneal
Plantar
Cephalic
Otic
Occipital (back of head)
ThoraxAbdomenBack (Dorsum)
Nuchal (back of neck)
Plane: Flat surface along which body or structure is cut for anatomical studySagittal plane
Divides body vertically into right and left partsProduces a sagittal section
Midsagittal (median) planeLies on midline
Parasagittal planeNot on midline
Plane implies an imaginary flat surface passing through the body
Sagittal plane divides body into right and left regionsmidsagittal (median) plane divides body or organ into equal halvesparasagittal plane divides body into unequal parts
Frontal (coronal) plane divides body into anterior & posterior portionsTransverse (horizontal) plane divides the body into superior & inferior portions
Section implies actual cut or slice to reveal internal anatomy
Transverse plane
Median (midsagittal) plane
Frontal plane
Liver
Spleen
Pancreas
Aorta
Vertebralcolumn
Spinal cord
Subcutaneous fat layerBody wall
Rectum IntestinesLeft andright lungs
Liver HeartStomach
SpleenArm
(a) Frontal section (through torso)
(b) Transverse section (through torso, inferior view)
(c) Median section (midsagittal)
Dorsal cavityProtects nervous systemTwo subdivisions:
Cranial cavityEncases brain
Vertebral cavityEncases spinal cord
Ventral cavityHouses internal organs (viscera)Two subdivisions (separated by diaphragm):
Thoracic cavityAbdominopelvic cavity
Cranialcavity(contains brain)
Dorsalbodycavity
Vertebralcavity(contains spinal cord)
Cranialcavity
Superiormediastinum
Pericardialcavity withinthe mediastinum
Pleuralcavity
Vertebralcavity
Abdomino-pelviccavity
Ventral bodycavity(thoracic andabdominopelviccavities)
Abdominal cavity(contains digestiveviscera)
Diaphragm
Pelvic cavity(contains urinary bladder, reproductive organs, and rectum)
Thoraciccavity(containsheart andlungs)
(a) Lateral view (b) Anterior view
Dorsal body cavityVentral body cavity
Thoracic cavity subdivisions:Two pleural cavities
Each houses a lungMediastinum
Contains pericardial cavitySurrounds thoracic organs
Pericardial cavityEncloses heart
Abdominopelvic cavity subdivisions:Abdominal cavity
Contains stomach, intestines, spleen, and liverPelvic cavity
Contains urinary bladder, reproductive organs, and rectum
Cranialcavity(contains brain)
Dorsalbodycavity
Vertebralcavity(contains spinal cord)
Cranialcavity
Superiormediastinum
Pericardialcavity withinthe mediastinum
Pleuralcavity
Vertebralcavity
Abdomino-pelviccavity
Ventral bodycavity(thoracic andabdominopelviccavities)
Abdominal cavity(contains digestiveviscera)
Diaphragm
Pelvic cavity(contains urinary bladder, reproductive organs, and rectum)
Thoraciccavity(containsheart andlungs)
(a) Lateral view (b) Anterior view
Dorsal body cavityVentral body cavity
Thin, double-layered membrane separated by serous fluid
Parietal serosa lines internal body wallsVisceral serosa covers the internal organs
Outer balloon wall(comparable to parietal serosa)Air (comparable to serous cavity)
Inner balloon wall(comparable to visceral serosa)
Heart
Parietalpericardium
Pericardialspace withserous fluidVisceralpericardium
(b) The serosae associated with the heart.
Right upperquadrant(RUQ)
Right lowerquadrant(RLQ)
Left upperquadrant(LUQ)
Left lowerquadrant(LLQ)
Abdominopelvic QuadrantsAbdominopelvic QuadrantsDivisions used primarily by
medical personnel
Epigastricregion
Umbilicalregion
Rightlumbarregion
Leftlumbarregion
Righthypochondriac
region
Lefthypochondriac
region
Hypogastric(pubic)region
Right iliac(inguinal)
region
Left iliac(inguinal)
region
Liver
Gallbladder
Ascending colon oflarge intestine
Small intestine
Appendix
Cecum
Diaphragm
Stomach
Descending colonof large intestine
Transverse colonof large intestine
Initial part ofsigmoid colon
Urinary bladder
(a) Nine regions delineated by four planes (b) Anterior view of the nine regions showing the superficial organs
Abdominopelvic RegionsAbdominopelvic RegionsNine divisions used primarily by anatomists