This document provides an introduction to human anatomy and physiology. It defines anatomy and physiology, and describes the subdivisions of anatomy including gross (macroscopic) anatomy, microscopic anatomy, and clinical anatomy. It also discusses the levels of organization in the human body from the chemical level to the tissue, organ, and system levels. Key body cavities like the cranial, thoracic, abdominal, and pelvic cavities are outlined. Major body organs in each cavity are identified. Anatomical terminology, planes, quadrants, and medical imaging techniques are also summarized.

1. AN INTRODUCTION TO
THE HUMAN BODY
Avnesh Kumar Singh

2. Anatomy and Physiology
Anatomy (Greek anatomē) is the
the scientific study of the
structure of human or animal
bodies.
 science of structure
Physiology (Latin- Physio) the scientific
study of how living things function.
 science of body functions

3. Subdivisions of Anatomy
Anatomy is divided in to two:
1. Gross anatomy (Macroscopic anatomy): it is
subdivided into:
a) surface anatomy (the external body),
b) regional anatomy (specific regions of the body),
c) systemic anatomy (specific organ systems)
2. Microscopic anatomy: It is subdivided into:
a) cytology (the study of cells) and
b) histology (the study of tissues)
c) Pathology (Study of disease)

4. Surface Anatomy
 Surface Anatomy (also called superficial anatomy and
visual anatomy) is the study of the external features of
the body of an animal. It deals with anatomical features
that can be studied by sight, without dissection.

5. Regional Anatomy
 Regional anatomy (Topographic anatomy) is
the study of the interrelationships of all of the
structures in a specific body region, such as the
abdomen.

6. Microscopic Anatomy
 Histology is the study of tissues.
 Cytology, like histology, uses a
microscope, but restricts thestudy
to individual cellular structures.
 Pathology is the study of
anatomical changes dueto
disease .

7. Clinical Connection
 An autopsy isa postmortem (afterdeath) examinationof
the bodyand internal organs performed bya pathologist.

8. Levels of Organization

9.  The chemical level of organization
 Atoms
 Molecules
 The Cell is next in complexity, in fact many billionsof
times more complex thanmolecules.
 Cells (and this is important!) are the basic structural
and functional units of an organism.

10.  Tissues are groupsof cells thatwork togethertoperform a
similar function.
 Epithelium
 ConnectiveTissue
 Muscle
 Nerves

11.  Organs are structurescomposed of twoor more
different typesof tissues.
 Organ systemswork cooperatively toperform necessary
life functions.

12. O2 CO2
Digestive system
Via the blood, distributes oxygen
and nutrientstoall bodycells and
delivers wastes and carbon
dioxide to disposalorgans
Interstitial fluid
Nutrients
Nutrients and wastespass
between blood and cells
via the interstitialfluid
Integumentary
system
Protectsthe bodyasa
whole from the
externalenvironment
Feces Urine
CO2
Urinary system
O2Eliminates
nitrogenous
wastes andexcess
ions
Takes in nutrients, breaks
them down, andeliminates
unabsorbed matter(feces)
Food
Cardiovascular system
O2
Respiratory system
Takes in oxygenand
eliminates carbondioxide
CO2
Levels of Organization
System Level

13. rgan
 An organism consistsof a collectionof
systems.
 Six important lifeprocesses:
 Metabolism
 Responsiveness
 Movement
 Growth
 Differentiation
 Reproduction
 In health, all parts of the body must be
functioning together in a process called
homeostasis.

14. 1. Metabolism: All chemical reactions that occur in
body cells
 Catabolism and anabolism
2.Responsiveness: The ability to sense and respond to
stimuli
 Withdrawal reflex
3.Movement (contractility)
 Of body parts (skeletal muscle)
 Of substances (cardiac and smooth muscle)

15. 4. Growth: Increase in size of a body part or of organism
5. Reproduction:
 Cellular division for growth or repair
 Production of offspring
6. Differentiation is the development of a cell from an
unspecialized to specialized state. Cells have specialized
structures and functions that differ from precursor cells.

16. Survival Needs
1. Nutrients
 Chemicals for energy andcell building
 Carbohydrates, fats, proteins, minerals,vitamins
2. Oxygen
 Essential for energy release (ATPproduction)
3. Water
 Most abundant chemical in thebody
 Site of chemical reactions
4. Normal body temperature
 Affects rate of chemicalreactions
5. Appropriate atmosphericpressure
 Foradequate breathing and gasexchange in the lungs

17. Homeostasis
 A condition of equilibrium (balance) in the body’s
internal environment. It isadynamiccondition meant
to keep body functions in the narrow rangecompatible
with maintaining life.

18.  Body fluids are defined as dilute, waterysolutions
containing dissolved chemicals inside or outside of the
cell. Maintaining the volume and composition of body
fluids is important.
 Intracellular Fluid (ICF) is the fluid withincells
 Extracellular Fluid (ECF) is the fluid outsidecells
 Interstitial fluid is fluid present between tissues

19.  Some important bodyfluids:
 Blood Plasma is the ECF within bloodvessels.
 Lymph is the ECF within lymphaticvessels.
 Cerebrospinal fluid (CSF) is the ECF in the brainand
spinal cord.
 Synovial fluid is the ECF injoints.
 Aqueous humor is the ECF ineyes.

20.  Cellularfunctiondependson the regulationof the
composition of the interstitialfluid.
 Composition of interstitial fluid changes assubstances
move between plasma and the interstitialfluid.
 Movement back and forthacross capillarywalls provides
nutrients (glucose, oxygen, ions) to tissue cells and
removes waste (carbondioxide).

21.  Control of homeostasis is constantly being challengedby:
 Physical insults such as intense heator lack of oxygen
 Changes in the internal environment such as adrop in
blood glucose due to lack offood
 Physiological stress such as demands of work or school

22. Anatomical Terminology
 Anatomical Position
 In theanatomical position, the subject stands
erect facing theobserverwith the head
level, the eyes facing forward, feet flaton
the floor directed forward, and the arms
at their sides, palmsforward.
 All anatomical descriptions arein
reference to thisposition.

23.  Directional Terms
 Superior
 Inferior
 Above, top, toward head
 Below, bottom,
away from head

24.  Directional Terms
 Anterior(Ventral)
 Posterior(Dorsal)

25.  Nearest to the origination
 Farther from
origination
Directional Terms
 Proximal
 Distal

26.  DirectionalTerms
 Superficial
 Deep
Deep
Superficial Superficial
 Towards the surface
 Towards the core of the body
Superficial
Superficial

27.  DescriptiveTerms
 Visceral
 Parietal
 Pertaining to a covering over an organ
 Pertaining to a covering against a
cavity wall
Parietal
Visceral

28.  Regional Names
 Cranial
 Cervical
 Cubital
 Carpal
 Patellar
 Orbital
 Thoracic
 Inguinal
 Skull
 Neck
 Elbow
 Wrist
 Front of knee
 Eye
 Chest
 Groin
Anatomical Terminology

29. Body Planes
 Body Planes are imaginary flat surfaces thatseparate
the body or body part into portions. There are three
majorplanesat rightangles tooneanother:
 Sagittal (midline)
 Transverse (horizontal)
 Frontal (coronal)

30. Body Planes
A midsagittal section ofthe
human brain
A frontal (or coronal)brain
section
A transverse (or horizontal)brain
section

31. Body Cavities
 Embryologically, the human organs develop within two
major body cavities:
 The brain and spinal cord
develop in a dorsal cavity.
 The remaining body organs
are found in the ventral
body cavity.

32.  Cranial cavity is formed by the cranialbones.
 Protects the brain
 Vertebral canal is formed by bones of vertebralcolumn.
 Contains the spinalcord
 Meninges
 Layers of protective tissue
that line the cranial cavity
and vertebralcanal

33.  Thoraciccavity is formed by the sternum, ribs, and the
thoracic portion of the bonyvertebral column.
 Also called chestcavity
 Stabilized by theinternal
and external muscles of
thechest

34.  Othercavitiesarecontained within the thoraciccavity:
 Mediastinal cavity
 Located in thecentral partof the thoraciccavity
 Left and Right Pleuralcavities
 Twofluid-filled spaces that surround eachlung

35. Legend:
1. Cranial cavity
2. Thoracic cavity
3. Adbominal cavity
4. Pelvic cavity
5. Ventral body cavity
(both thoricic cavity
and abdominopelvic
cavities)
6. Abdominopelvic cavity
a. Superior mediastinum
b. Vertebral cavity
c. Pleural cavity
d. Pericardial cavity
within the mediastinum
e. Diaphragm

36.  Pericardial cavity is itself located within the middle partof
the mediastinal cavity in the thoracic cavity (like a set of
Russian nesting dolls of decreasing size—one placedinside
theother).

37.  Abdominopelvic Cavity extends from the diaphragmto
the groin and is encircled by the abdominal wall and
bones and muscles of thepelvis.
 Divided into twoportions:
 Abdominal cavity contains the stomach, spleen,liver,
gallbladder, small and largeintestines.
 Pelviccavity contains the urinary bladder, internal organs of
reproductive system, and portions of thelarge intestine.

38.  Other bodycavities
 Oral (mouth) cavitycontains the tongue and teeth.
 Nasal cavity is partof the upperairways .
 Orbital cavities contain the eyeballs and various nerves and
blood vessels.
 Middleearcavitiescontain thesmall bones of the middle
ear.
 Synovial cavities are found in freely moveable joints like the
large joints of the shoulder andhip.

39. Major Body Organs
 Brain
 Spinal Cord
 Thyroid Gland
 Thymus

40.  Lungs
 Trachea
 Superior venacava
 Inferior venacava
 Aorta
 Heart

41.  The diaphragm is a powerful skeletal muscle thatdivides
the thorax
(thoraciccavity)
from theabdomen
Diaphragm
(abdominal cavity).

42.  Trachea
 Esophagus
 Stomach
 Liver
 Small Intestine
 Large Intestine

43.  Kidneys
 Urinary bladder

44. Major Body Organs
 Ovaries
 Uterine tubes
 Uterus
 Testes

45. Abdominopelvic Quadrants & Regions
 Identification of quadrants and regions in the
abdominopelvic cavity helps clinicians describe the
location of the many abdominal and pelvic organs.
 There are 4 abdominopelvic quadrants and 9 regions.
 The dividing lines between these are centered on the
umbilicus (“belly button”).

46. Abdominopelvic Quadrants & Regions
 Vertical and horizontal lines pass through theumbilicus
 Right upper quadrant(RUQ)
 liver
 Left upper quadrant(LUQ)
 spleen and leftkidney
 Right lower quadrant(RLQ)
 appendix
 Left lower quadrants(LLQ)
 leftovary ( )

47. Abdominopelvic Quadrants & Regions
 Dividing theabdomen and pelvis into regions is done using a Tic-
Tac-Toegrid. It is a little morecomplex than using quadrants,
but is also morespecific
 There are nine
abdominopelvic
regions

48. Abdominopelvic Quadrants & Regions

49. Medical Imaging
 Techniquesand procedures used tocreate imagesof the
human body
 Allow visualization of structures inside thebody
 Diagnosis of anatomical and physiologicaldisorders
 Conventional radiography (X-rays) have been in usesince
the late 1940’s

50. Medical Imaging
 Radiography is doneusing X-rays to produce animage
of interior structures. They are inexpensive andquick
 Hollow structuresappear black orgray
 Do not pass easilythrough dense structure (bone)
 At low dose, useful forsoft
tissue (breast)
 Mammography (breast)
 Bone densitometry (bone
density)

51.  Magnetic Resonance Imaging (MRI) is done using an
extremely powerful magnetic field. It is a safeprocedure
butcannot be used on patientscontaining metal.
 Used for differentiating normal and abnormaltissues
(tumors, brain abnormalities, blood flow)
 2D and 3D color imagescan beviewed on avideo monitor.
Medical Imaging

52. Medical Imaging
 Computed Tomography or CT-Scans are done using a
computertoorganize x-rays to form a 3D image. It isused
to visualize soft tissue in more detail than conventional
radiography.
 Tissue intensitiesshow
varying degrees ofgray.
 Whole-body CT scans
expose the body to ahigh
dose of x-rays.

53. Medical Imaging
 Ultrasound Scanning (sonography) is done usinghigh
frequency sound waves. It is noninvasive andpainless.

54. Medical Imaging
 Radionuclide Scanning is done bygiving a radioactive
substance (radionuclide) intravenously.
 Gamma rays emitted by tissues that take up the radionuclide
are detected by a camera and displayed on a video monitor.
Thecolor intensityrepresents theamountof uptake.
 Single-photo-emission
computerized tomography
(SPECT) is a specialized
form of this technique.

55. Medical Imaging
 Positron Emission Tomography (PET scan) is done by
injecting a substance emitting positively charged particles
into the body. The collision between positrons andnegatively
charged electron in body tissues produce gammarays
used to formacomputerassisted
image.
 Used to study physiologyof
body structures (metabolism)

56. Medical Imaging
 Endoscopy is done using a lighted instrumentwith a lens
projecting an image on to amonitor.
 Colonoscopy is a studyof the interiorof thecolon.
 Laparoscopy is a studyof theorgans
in the abdominopelviccavity.
 Arthroscopy isa studyof the
interior of a joint(knee).

57. Clinical Connection
 Noninvasive Diagnostic Techniques are used toinspect
different aspects of thebody:
 Isoften done toaccess structureand function and to search
for the presence ofdisease.
 Palpation is gently touching body surfaces withhands.
 Auscultation is listening to body sounds(stethoscope).
 Percussion is tapping on the body surfacewith fingertipsand
listening toechoes.

58. Thank You