This document provides an introduction to human anatomy and physiology. It discusses the levels of organization of the human body from atoms to organ systems. It describes the 11 organ systems and their functions in maintaining homeostasis. It also outlines the major body cavities and membranes that divide and line them. Key terms related to anatomical positioning and directions in the body are defined.

1. Introduction to
Human Anatomy
& Physiology
Chapter 1

3. UNDERSTANDING WORDS
append-
to hang something: appendicular-pertaining to
the upper limbs and lower limbs.
cardi-
heart: pericardium-membrane that surrounds the
heart.
cerebr-
brain: cerebrum-largest part of the brain.
cran-
helmet: cranial-pertaining to the part of the skull
that surrounds the brain.
dors-
back: dorsal-position toward the back of the
body.
homeo-
same: homeostasis-maintenance of a stable
internal environment.
-logy
the study of: physiology-study of body functions.
meta-
change: metabolism-chemical changes that occur
within the body.
nas-
nose: nasal-pertaining to the nose.
orb-
circle: orbital-pertaining to the portion of skull
that encircles an eye.

4. UNDERSTANDING WORDS
pariet-
wall: parietal membrane-membranethat lines the wall of a
cavity.
pelv-
basin: pelvic cavity-basin-shaped cavity enclosed by the
pelvic bones.
peri-
around: pericardial membrane-membranethat surrounds
the heart.
pleur-
rib: pleural membrane-membranethat encloses the lungs
within therib cage.
-stasis
standing still: homeostasis-maintenance of a stable
internalenvironment.
super-
above: superior-referringto a body part located above
another.
-tomy
cutting: anatomy-studyof structure, which often involves
cutting or removingbody parts.

5. Introduction
● Modern medicine began long-ago with the observations of function and malfunctions
of the body, this was likely discovered due to human curiosity of the ill.
● Over time modern medicine has evolved with medicine like herbs and ‘potions’ to
cure illnesses like headaches, coughs, fevers, etc.
● Most terms defining human body parts, the locations of those parts, and the function
have originated from Greek and Latin words.
● The information that is known about the human body is based on the scientific
method
○ An approach to investigating the natural world.
○ Includes the testing of a hypothesis and then rejecting it or accepting it.

6. Anatomy & Physiology
● Anatomy: The branch of science that deals with the structure
(morphology) of the body parts.
● Physiology: The functions of the body parts.
● The Human Organism: Each body part forms a well-organized
unit, and each part functions in the unit’s operation.

8. Levels of Organization
● Everything that joins together to form the human body is considered to be
composed of chemicals.
● Chemicals consist of particles called atoms.
● Atoms join together to form molecules.
● Small molecules that have combined in complex ways to form larger
macromolecules.
○ Proteins, Carbohydrates, Lipids, Nucleic Acids
● All human cells and complex organisms contain structures called
organelles.
○ Carry out specific activities and are composed of macromolecules.
● A cell is the basic unit of life.

9. Levels of Organization (continued)
● Tissues are groups of cells that have common functions that are
organized into layers or other structures.
● Organs are groups of different tissues that interact and form
together
○ Complex structures with specialized functions
● Organ systems are groups of organs that function closely together.
● Organ systems together make up living things called Organisms
○ For example, people (you)
● Three Levels of Organization:
○ Atomic Level
○ Molecular Level
○ Cellular Level

11. Characteristics of Life
● The human body gains energy by ingesting (taking in), digesting
(breaking down), absorbing, and assimilating the nutrients that is in
food.
● By the process of respiration, we use the energy in these nutrients for
vital bodily functions such as movement, growth, and repair of tissues;
ending with excretion of wastes.
● The physical and chemical events that obtain, release, and use energy
are a major part of metabolism.

12. Characteristics of Life: Process & Examples
● Movement: Change in position of the body or of a body part; motion of an
internal organ
● Responsiveness: Reaction to a change inside or outside the body
● Growth: Increase in body size without change or shape
● Respiration: Obtaining oxygen removing carbon dioxide and releasing
energy from foods (Some forms of life do not use oxygen in respiration)
● Digestion: Breakdown of food substances into simpler forms that can be
absorbed and used
● Absorption: Passage of substances through membranes and into body
fluids
● Circulation: Movement of substances in body fluids
● Assimilation: Changing absorbed substances into chemically different
forms
● Excretion: Removal of wastes produced by metabolic reactions

13. Day 1 End of
Notes

14. Maintenance of Life
● The structures and functions of almost all body parts help maintain life.
● There are five requirements of organisms:
○ Water
○ Foods
○ Oxygen
○ Heat
○ Pressure
● The five requirement of an organism alone are not enough to ensure
survival, both the quantities and qualities of each are also important.
● Homeostasis plays an important role in the human body

15. Requirements of Organisms
● Water
○ The most abundant chemical in the body
○ Required for many metabolic processes and provides the environment in which most of
them take place
○ Transports substances within the organism and is important in regulating body
temperature
○ Found inside cells
● Food
○ Substances that provide the body with necessary chemicals (nutrients) in addition to
water
○ Can be used as energy sources, others supply raw materials for building new living
matter, and still others help regulate vital chemical reactions.
● Oxygen
○ A gas that makes up about one-fifth of ordinary air
○ It is used to release energy from food substances
○ This energy drives metabolic processes

16. Requirements of Organisms
● Heat
○ A form of energy
○ A product of metabolic reactions, and the degree of heat present partly determines
the rate at which these reactions occur
○ The more heat, the more rapidly chemical reactions take place.
● Pressure
○ An application of force to something
○ Atmospheric Pressure: The force on the outside of the body due to the weight of air
above it.
■ More important in breathing
○ Hydrostatic Pressure: Organisms living under water; A pressure a liquid exerts, due to
the weight of water above them.
■ Heart action produces blood pressure which forces blood through blood vessels.

18. Homeostasis
● The condition of a stable environment is called homeostasis.
● Homeostatic Mechanisms: When the body maintains
homeostasis through a number of self-regulating control
systems.
○ Share three components:
■ Receptors: Provide information about specific conditions
(stimuli) in the internal environment
■ Set Point: Tells what particular value should be
■ Effectors: Bring about responses that alter

19. Homeostatic Mechanisms
● Share three components:
○ Receptors: Provide information about specific conditions (stimuli) in
the internal environment
○ Set Point: Tells what particular value should be
○ Effectors: Bring about responses that alter

20. Homeostatic Mechanisms
How it works:
○ If the receptors measure deviations from the set point, effectors are
activated that can return conditions toward normal.
○ As the conditions return to normal the set point lessens and the effectors
slowly shut down.
○ This response is called the Negative Feedback Mechanism.
■ Ex: A thermostat, which senses temperature changes, signals the
furnace to start and the air conditioner to stop whenever the room
temperature drops below the set point. But starts again when the
temperature is above the set point.

21. Homeostatic Mechanisms
● Although most feedback mechanisms are negative, there are
positive feedback mechanisms.
● Positive Feedback Mechanisms:
○ A process that moves conditions away from the normal state.
○ Usually produce unstable conditions, might seem incompatible with
homeostasis.
■ Ex: In blood clotting, the chemicals that carry out clotting
stimulate more clotting, minimizing bleeding.
■ Ex: Increase in strength of uterine contractions during
childbirth, helping to bring the new individual into the world.

22. Organization of the Human Body
● The human organism is a complex structure composed
of many parts.
○ Body Cavities
○ Layers of membranes within these cavities
○ A variety of Organ Systems

24. Body Cavities
● The human organism can be divided into the axial portion and the
appendicular portion.
● Axial Portion includes the head, neck, and trunk
○ Within the axial portion are four body cavities:
■ Cranial Cavity: Houses the brain
■ Vertebral Cavity: Contains the spinal cord within the sections of the
backbone (vertebrae)
■ Thoracic Cavity (Chest)
■ Abdominopelvic Cavity (Abdomen and Pelvic)
● Appendicular Portion includes the upper and lower limbs

25. Body Cavities
● Diaphragm: A broad, thin skeletal (voluntary) muscle and separates the
thoracic cavity from the abdominopelvic cavity
● Mediastinum: A region that separates the thoracic cavity into two
compartments, which contain the right and left lungs. Contains the heart,
esophagus, trachea and thymus
● Abdominal Cavity: Contains upper portion of the Abdominopelvic cavity.
Includes the stomach, livers, spleen, gallbladder, kidneys, and most of the
small and large intestines.
● Pelvic Cavity: The portion of the abdominopelvic cavity enclosed by the
hip bones. It contains the terminal portion of the large intestine, the
urinary bladder, and the internal reproductive organs.

26. Body Cavities
● Smaller cavities within the head include:
○ Oral Cavity: containing the teeth and tongue
○ Nasal Cavity: located within the nose and divided into right and
left portions by a nasal septum. Several air-filled sinuses
connect to this cavity (frontal and sphenoidal sinuses)
○ Orbital Cavities: Containing the eyes and associated skeletal
muscles and nerves.
○ Middle Ear Cavities: Containing the middle ear bones

27. Anatomical Terms
● Bilateral Symmetry - As a result of this organizational feature
the right and left sides of the body are mirror images.
● Contralateral Side - means "opposite" and is used to designate
an anatomic part on the uninjured or opposite side of the body.
● Anatomical Position- the body is standing, facing forward, hands
palm forward (urinated).
● Mid-Sagittal - Exact Midline of the body

28. Anatomical Terms
● Superior - Towards the head end of the body; above.
● Inferior - Away from the head end of the body; lower.
● Anterior (Ventral) - Front
● Posterior (Dorsal) - Back

29. Anatomical Terms
● Medial- Toward the midline of the body
● Lateral - Away from the midline of the body
● Proximal - Nearer the point of attachment of an extremity to the trunk
or the point of origin of a part.
● Distal - Farther from the point of attachment of an extremity to the
trunk or the point of origin of a part

31. Thoracic and Abdominopelvic Membranes
● Parietal: refers to the membrane attached to the wall of a cavity
● Visceral: refers to the membrane that is deeper, toward the interior, and
coversan internal organ, such as the lungs
● The walls of the right and left thoracic compartments, which contain the
lungs, are lined with a membrane called the Parietal Pleura.

32. Thoracic and Abdominopelvic Membranes
● Visceral Pleura: a membrane that covers each lung.
● The parietal and visceral pleural membranes are separated by a thin
film of watery fluid, which they secrete.
● Pleural Cavity: the space between the parietal and visceral
membranes; invisible, no actual space exists here

33. Thoracic and Abdominopelvic Membranes
● The heart, which is located in the broadest portion of the
mediastinum, is surrounded by the pericardial membranes.
● Visceral Pericardium: Covers the heart’s surface and is separated
from a parietal pericardium by a small volume of fluid
● Peritoneal Cavity: the potential space between these membranes

35. Organ Systems
The human body consists of several organ systems. Each of which include a set of interrelated
organs that work together to provide specialized functions that contribute to homeostasis
● Integumentary System
● Skeletal System
● Muscular System
● Nervous System
● Endocrine System
● Cardiovascular System
● Lymphatic System
● Digestive System
● Respiratory System
● Urinary System
● Reproductive System

36. Organ Systems - Body Covering
● Integumentary System
○ Protects the underlying tissues to help regulate body temperature,
house a variety of sensory receptors, and synthesize certain
products.
○ Include the skin and various accessory organs
■ Hair, nails, sweat glands, and sebaceous glands.

37. Organ Systems - Support and Movement
● Skeletal System
○ Provide frameworks and protective shields for softer tissues, are
attachments for muscles and act with muscles when body parts
move.
○ Consists of bones, as well as ligaments and cartilages that bind
bones together.
● Muscular System
○ By contracting and pulling their ends closer together, provide
forces that move body parts, also maintain posture and are the
major source of body heat.
○ Consists the muscles of the body.

38. Organ Systems - Integration and
Coordination
● Nervous System
○ The cells of the nervous system communicate with each other and with
muscles and glands using chemical signals, called neurotransmitters.
○ Nerve cells extend from the brain or spinal cord to muscles or glands,
stimulating them to contract or to secrete products
○ Consists of the brain, the spinal cord, nerves, and sense organs
● Endocrine System
○ Includes all the glands that secrete chemical messengers called hormones.
○ A particular hormone that affects only a particular group of cells are called
target cells.
○ Organs of the endocrine system include: the pituitary gland, thyroid,
parathyroid, and adrenal glands; and the pancreas, ovaries, testes, pineal
gland, and thymus.

39. Organ Systems - Transport
● Cardiovascular System
○ Includes the heart, arteries, veins, capillaries, and blood.
○ Blood transports gases, nutrients, hormones and wastes. It carries oxygen
from the lungs and nutrients from the digestive organs to all body cells.
■ Also transports hormones and carries wastes from the body cells to
the excretory organs, where the wastes are removed from the blood
and released to the outside.

40. Organ Systems - Transport
● Lymphatic System
○ Composed of the lymphatic vessels, lymph nodes, thymus, spleen and a
fluid called lymph.
○ Transports some of the tissue fluid back to the bloodstream and carries
certain fatty substances away from the digestive organs and into the
bloodstream.
■ Cells of the lymphatic system are called lymphocytes, they defend
the body against infections by removing disease-causing
microorganisms and viruses from tissue fluid.

41. Organ Systems - Absorption and Excretion
● Digestive System
○ Absorb nutrients and oxygen and excrete various wastes.
■ Break down food molecules into simpler forms that can pass
through cell membranes and thereby absorbed into the bodily
fluids. Materials not absorbed are eliminated.
○ Organs included: mouth, tongue, teeth, salivary glands, pharynx,
esophagus, stomach, liver, gallbladder, pancreas, small intestine, and
large intestine

42. Organ Systems - Absorption and Excretion
● Respiratory System
○ Move air in and out of the lungs and exchange gases between the blood
and the air.
■ Oxygen passes from air within the lungs into the blood, and
carbon dioxide leaves the blood and enters the air,
○ Organs included: the nasal cavity, pharynx, larynx, trachea, bronchii,
and lungs are parts if this system.

43. Organ Systems - Absorption and Excretion
● Urinary System
○ Consists of the kidneys, ureters, urinary bladder, and urethra.
■ Kidneys remove wastes from blood and help maintains the
body’s water and electrolyte concentrations.
■ Other portions of the urinary bladder store urine and
transport it outside the body.

44. Organ Systems - Reproduction
● Reproductive
○ The process of producing offspring (progeny). Cells reproduce when they
divide and give rise to new cells.
○ Male and female work together to produce a new organism.
○ Male:
■ Organs include: the scrotum, testes, epididymides, ductus deferentia,
seminal vesicles, prostate gland, bulbourethral glands, penis, and
urethra.
■ These parts produce and maintain sperm cells (spermatozoa), and
transfer sperms cells into female reproductive tract.

45. Organ Systems - Reproduction
● Reproductive
○ The process of producing offspring (progeny). Cells reproduce when they
divide and give rise to new cells.
○ Male and female work together to produce a new organism.
○ Female:
■ Organs include: ovaries, uterine tubes, uterus, vagina, clitoris, and
vulva.
■ These parts maintain the female sex cells (egg cells, or oocytes),
transport the female sex cells within the female reproductive system
for the possibility of fertilizing an egg.
● Also supports the development of embryos, carries fetuses to
term, and functions in the birth process.

47. Anatomical Terminology
Precise terms to describe anatomy.
● Anatomical Position: Standing erect, face forward, with the upper
limbs at the sides and the palms forward.
● “Right” and “left” refers to the right and left of the body in
anatomical position

48. Relative Positions
Terms or relative position describe the location of one body part with respect
to another.
● Superior: a body part is above another part
● Inferior: a body part is below another part
● Anterior: toward the front
● Posterior: toward the back
● Medial: refers to the middle or closer to midline; equal right and left halves
● Lateral: towards the side, away from the midline

49. Relative Positions
Terms or relative position describe the location of one body part with respect to
another.
● Bilateral: paired structures, one on each side
● Ipsilateral: structures on the same side
● Contralateral: structures on the opposite side
● Proximal: part that is closer to a point of attachment to the trunk than another body
part
● Distal: part that is farther to a point of attachment to the trunk than another body
part
● Superficial: near the surface
● Deep: more internal than superficial

50. Body Sections
Observing the relative locations and organization of internal body parts
requires cutting or sectioning the body along various planes.
● Sagittal: refers to a lengthwise plane that divides the body into right and
left portions
● Transverse (Horizontal): refers to a plane that divides the body into
superior and inferior portions
● Frontal (Coronal): Refers to a plane that divides the body into anterior
and posterior portions

51. Body Regions
A number of terms designate body regions (9).
● Epigastric Region: the upper middle portion
● Right and Left Hypochondriac Region: lie on each side of the epigastric region
● Umbilical Region: the middle portion
● Right and Left Lateral (Lumbar) Region: lie on each side of the umbilical region
● Pubic (Hypogastric) Region: the lower middle portion
● Right and Left Inguinal (Iliac) Region: lie on each side of the hypogastric region
*Note: The abdominal area is also often subdivided into four quadrants: right upper, right lower,
left upper and left lower quadrants.

52. Commonly Used Terms
● Abdominal: the region between the
thorax and pelvis
● Acromial: the point of the shoulder
● Antebrachial: the forearm
● Antecubital: the space in front of the
elbow
● Axillary: the armpit
● Brachial: the arm
● Buccal: the cheek
● Calcaneal: the heel
● Carpal: the wrist
● Celiac: the abdomen
● Cephalic: the head
● Cervical: the neck
● Costal: the ribs
● Coxal: the hip

53. Commonly Used Terms
● Crural: the leg
● Cubital: the elbow
● Digital: the finger or toe
● Dorsal: the back
● Femoral: the thigh
● Frontal: the forehead
● Genital: the reproductive
organs
● Gluteal: the buttocks
● Inguinal: the groin - the depressed
area of the abdominal wall near the
thigh
● Lumbar: the loin - the region of the
lower back between the ribs and the
pelvis
● Mammary: the breast
● Mental: the chin
● Nasal: the nose
● Occipital: the lower posterior
region of the head

54. Commonly Used Terms
● Oral: the mouth
● Orbital: the bony socket of
the eye
● Palmar: the palm of the
hand
● Patellar: the front of the
knee
● Pectoral: the chest
● Pedal: the foot
● Pelvic: the pelvis
● Perineal: the perineum -
the pelvic floor and
associated structures
occupying the pelvic outlet
● Plantar: the sole of the foot
● Popliteal: the area behind the knee
● Sacral: the posterior region
between the hip bones
● Sternal: the middle of the thorax,
anteriorly
● Sural: the calf of the leg
● Tarsal: the ankle
● Umbilical: the navel
● Vertebral: the spinal column

55. Some Medical and Applied Science Terms
● Cardiology: branch of medical science dealing with the heart and heart
diseases
● Cytology: study of the structure, function, and abnormalities of cells. Cytology
and histology are subdivisions of microscopic anatomy.
● Dermatology: study of the skin and its diseases
● Endocrinology: sstudy of hormones, hormone-secreting glands and their
diseases
● Epidemiology: study of the factors determining the distribution and frequency
of health-related conditions in a defined human population

56. Some Medical and Applied Science Terms
● Gastroenterology: study of the stomach and intestines and their diseases
● Geriatrics: branch of medicine dealing with older individuals and their medical
problems
● Gerontology: study of the aging process
● Gynecology: study of the female reproductive system and its diseases
● Hematology: study of the blood and blood diseases

57. Some Medical and Applied Science Terms
● Histology: study of the structure and function of tissues. Histology and
cytology are subdivisions of microscopic anatomy
● Immunology: study of the body’s resistance to infectious disease
● Neonatology: study of newborns and the treatment of their disorders
● Nephrology: study of structure, function, and disease of the kidneys
● Neurology: study of the nervous system and its disorders

58. Some Medical and Applied Science Terms
● Obstetrics: branch of medicine dealing with pregnancy and childbirth
● Oncology: study of cancers
● Ophthalmology: study of the eye and eye diseases
● Orthopedics: branch of medicine dealing with muscular and skeletal systems
and their problems
● Otolaryngology: study of the ear, throat, and larynx, and their diseases
● Pathology: study of structural and functional changes that disease causes
● Pediatrics: branch of medicine dealing with children and their diseases

59. Some Medical and Applied Science Terms
● Pharmacology: study of drugs and their uses in the treatment of
disease
● Podiatry: study of the care and treatment of feet
● Psychiatry: branch of medicine dealing with the mind and its
disorder
● Radiology: study of x-rays and radioactive substances and their
uses in the diagnosis and treatment of diseases
● Toxicology: study of poisonous substances and their effects upon
body parts
● Urology: branch of medicine dealing with the urinary system, apart
from the kidneys (nephrology) and the male reproductive system,
and their diseases

60. Recipe For a Body
● 206 Bones
● 640 Muscles
● 9 Pints of Blood
● All over Skin
● 5 million Hairs
● 10 Toenails
● 10 Fingernails
● 2 Eyes
● 2 Ears
● 1 Nose
● 32 Teeth
Organs
● 1 Stomach
● 2 Lungs
● 1 Liver
● 2 Kidneys
● 1 Spleen
● 1 Gallbladder
● 1 Pancreas
● 2 Intestines
● 1 Heart