Human AnatomyHuman AnatomyHuman AnatomyHuman Anatomy

Chapter 1Chapter 1

The Human Body: An The Human Body: An OrientationOrientation

I. Definitions• Anatomy is the study of the

structure and shape of the body and body parts and their relationships to one another.– Gross anatomy – examining large

easily observable body structures.– Microscope anatomy – examining cells

and tissues using a microscope.

I. Definitions (con’t)• Physiology is the study of how the

body and its parts work or function. – Neurophysiology – explains how the

nervous system works.– Cardiac physiology studies the functions

of the heart.

• Anatomy and physiology are always related. FORM FOLLOWS FUNCTION.

II. Levels of Organization

•Atoms – building blocks of matter. They combine to form:

•Molecules – water, sugars, and proteins.

•Molecules associate in specific ways to form cells.

II. Levels of Organization (Con’t)

• Cells are the smallest units of all living things.• Cells that are similar and have a common

function are called tissues.• An organ is a structure, composed of two or

more tissue types, that performs a specific function for the body.

• A group of organs that cooperate to accomplish a common purpose is called an organ system.

• All 11 organ systems make up an organism.

II. Levels of Organization

Integumentary System• External covering of the body• Waterproofs, cushions and protects• Excretes salts and urea in sweat

and helps regulate body temperature

• Sense organ – pain and pressure

Skeletal System• Bone, cartilage, ligaments, and

joints• Support and protection• Attachment of the skeletal muscles• Hematopoiesis – the formation of

blood cells• Store house of minerals

Muscular System• Only one function – contract• Movement occurs when muscles

contract• Three types of muscle tissue

– Skeletal muscles - movement– Cardial muscles - heart contraction– Smooth muscles – intestines, internal

organs

Nervous System• Fast-acting control system• Consists of the brain, spinal

cord, nerves, and sensory receptors.

• The body must be able to respond to stimuli.

• The Central Nervous system assesses the information received and responds.

Endocrine System• Slow acting control system of the

body.• Produces and releases hormones

into the blood.• Includes pituitary, thyroid, adrenals,

thymus, pancreas, pineal, ovaries, testes, and parathyroid glands.

Cardiovascular System• Made up of the heart and blood

vessels.• Blood is the transporting fluid• Carries oxygen, nutrients,

hormones, and other substances to and from the cells where waste is exchanged and removed.

Lymphatic System• Closely related to the cardiovascular

system.• Includes lymphatic vessels, lymph nodes,

and other organs like the spleen and tonsils.

• Fluid leaks from the blood vessels and this system returns the fluid back to the circulatory system.

• Lymph nodes help cleanse the blood and house the cells involved in immunity.

Respiratory System• Keep the body constantly supplied

with oxygen and remove carbon dioxide.

• Includes nasal passages, pharynx, larynx, trachea, bronchi, and lungs.

• Lungs have tiny air sacs in which gas exchange occurs

Digestive System• Tube within a tube system running from

the mouth to the anus.• Includes the oral cavity (mouth),

esophagus, stomach, small and large intestines, and the rectum.

• Break down food into usable macromolecules.

• Large intestines job is to reclaim water.

Urinary System• The body produces waste which must be

removed.• Nitrogenous wastes (urea and uric acid)

must be removed.• Sometimes called the excretory system• Includes kidneys, ureters, bladder, and

urethra. • Maintains body’s water and salt balance

Reproductive System• Produce offspring• Sperm produced by testes• Eggs produced by ovaries• Fertilization occurs when sperm is

deposited into the female by the penis.

HOMEOSTASIS• The key to understanding the

interactions of the body systems as well as disease and wellness is understanding homeostasis.

• Homeostasis is the body’s ability to maintain relatively stable internal conditions even though the outside world is continuously changing.

The Language of Anatomy

• To accurately describe body parts and position we have to have a reference point that is accepted universally. This is helpful when the coroner finds a body and must describe the body.

• Anatomical position – The assumption that the body is erect with the feet parallel and the arms hanging at the sides with the palms facing forward.

Directional Terms (pg. 12)

Superior/cranial/cephalad Toward the head or upper part of the body or structure; above

Inferior (caudal) Away from the head end or toward the lower part of a body or structure; below

Anterior (ventral) Toward the front of the body (belly)

Posterior (dorsal) Toward the back of the body; behind

Medial Toward or at the midline of the body; on the inner side of

Lateral Away from the midline of the body; on the outer side of

Intermediate Between a medial and lateral structure

Directional Terms (pg. 12)

Proximal Close to the origin of the body part or the point of attachment of a limb to the body trunk

Distal Farther from the origin of a body part or the point of attachment of a lumb to the body truck

Superficial Toward or at the body surface

Deep Away from the body surface; more internal

Anterior Body Landmarks

(pg. 13)Abdominal Anterior body trunk inferior to the

ribs

Antecubital Anterior surface of the elbow

Axillary Armpit

Brachial Arm

Buccal Cheek area

Carpal Wrist

Cervical Neck region

Anterior Body Landmarks

(pg 13)Digital Fingers and toes

Femoral Thigh

Inguinal Area where thigh meets the trunk

Nasal Nose area

Oral Mouth

Orbital Eye area

Patellar Anterior knee

Anterior Body Landmarks

(pg 13)Peroneal Lateral part of the leg

Pubic Genital region

Sternal Breasbone area

Tarsal Ankle region

Thoracic Chest

Umbilical Navel

Posterior Body Landmarks(pg 13)

Cephalic Head

Deltoid Curve of the shoulder

Gluteal Butt

Lumbar Lower back

Occipital Posterior surface of the head

Popliteal Posterior knee area

Scapular Shoulder blade region

Sural The area of the calf muscle

Vertebral Area of the spine

Body Planes (pg 14)

• Body planes and sections can be used to describe either the entire body or any part of the body such as an organ.

• There are several ways to “cut” body.– Sagittal section – cut down the middle to

create left and right sides. (aka midsagittal or median section if the cut makes equal sides)

– Frontal or coronal section – a cut that divides the body into anterior and posterior sides.

– Transverse or cross sections – A cut is made along the horizontal plane dividing the body into superior and inferior parts.