Chapter 1: Organization of

the Body

Virtuvian Man by Leonardo Da Vinci is one of the most famous anatomical drawings in history.

Anatomy and Physiology Anatomy: branch of

science dealing with the form and structure of body parts.

Physiology: branch of science dealing with the study of body functions.

Anatomy and physiology are closely related because an organ’s structure is determined by its function.

Check yourself…anatomy or physiology?

• Digestion• Stomach• Blood pressure• Heart• Muscle• Exercise

Were you right?

• Digestion: physiology• Stomach: anatomy• Blood pressure: physiology• Heart: anatomy• Muscle: anatomy• Exercise: physiology

Remember: If the term is related to structure (how it is constructed) it is anatomy. If it is related to function (job) it is physiology.

Organization of Body Parts

• The chemicals are the smallest

level of organization. The organism

is the largest level of organization.

Chemicals Cells Tissues Organs

Organ systems

Organism

Chemicals• Atoms: The smallest part of elements.

Common atoms in humans include carbon, hydrogen, oxygen, and nitrogen.

• Molecules: Chemically joined atoms. Example: H2O (one molecule of water) is made of two atoms of hydrogen and one atom of oxygen.

1 atom of oxygen1 atom of hydrogen

1 molecule of H2o

Chemicals Continued…

• Macromolecules: Large molecules made of chemically combined smaller molecules.

• Example: molecules of amino acids join together to form proteins. DNA is also a macromolecule.

DNA model

Cells• The smallest unit of life.

Red blood cells carry oxygen.

• Organelles are small structures within cells that perform specific functions within the cell. Mitochondria are the places where energy is released.

Red blood cells

Mitochondrion

Tissues and Organs

• Tissues are composed of similar cells and perform a specific function. Cardiac muscle makes the heart contract.

Cardiac muscle

Normal human heart

Organs are composed of several types of tissue and perform a specific function. The heart Moves blood throughout the body.

Organ Systems and Organisms

• Organ systems are composed of several organs and perform a specific function.

• An organism has many organ systems working together to keep it alive.

Blood flow through the cardiovascular system.

Anatomical Terms

• Understanding them assumes the body is in anatomical position (standing erect, face forward, arms at the sides and palms and toes directed forward).

Relative Positions

• Superior: above another part

• Inferior: below another part

• Anterior (ventral): toward the front

• Posterior (dorsal): toward the back

Planes and Sections of the Body

• Sagital plane: divides the body in half vertically.

• Transverse plane: divides the body in half horizontally.

• Frontal plane: divides the body in half lengthwise into anterior and posterior sections.

Regions of the body

• Cephalic: head• Cervical: neck• Thorax: chest• Abdomen: stomach

area• Limbs: arms and legs

Check yourself…What region?

What region?

What region?

What region?

What region?

Were you correct?Cephalic (head)

Cervical (neck)

Thoracic (chest)

Abdomen (stomach)

Limbs (arms or legs)

Cavities of the Body

• Dorsal (cranial and spinal)

• Ventral (thoracic and abdominopelvic)

Organ Systems

Integumentary

• Made of skin and related structures

• Function: To protect underlying tissue, help regulate body temperature, and contain sense organs.

© Anne Geddes

Skeletal

• Consists of bones, cartilage, and ligaments.

• Functions to protect organs, provide support, production of blood cells.

Muscular System

• Consists of skeletal, cardiac, and smooth muscle.

• Functions in the movement of the body.

Nervous System

• Consists of the brain, spinal cord, and nerves.

• Functions to conduct nerve impulses to and from the brain thus providing the organism with information about its environment and internal conditions.

Endocrine System

• Consists of hormonal glands that secrete chemicals that serve as messengers between body parts.

• Functions with nervous system to maintain a relatively constant internal environment.

Circulatory System

• Consists of heart and blood vessels.

• Functions to carry nutrients and oxygen to the cells and remove waste products to be excreted.

Respiratory System

• Consists of the lungs and the associated airways.

• Functions to bring oxygen into the lungs and to remove carbon dioxide from the lungs.

Digestive System

• Consists of the mouth, esophagus, stomach, small and large intestine and accessory organs.

• Functions to receive food and digest it into nutrient molecules.

Urinary System

• Consists of the kidneys and bladder.

• Functions to rid the body of nitrogenous wastes and helps regulate the fluid level and chemical content of blood.

Reproductive System

• Consists of different organs in males and females.

• Functions to ensure the survival of the species by allowing organisms to reproduce.

Homeostasis

• Mechanisms that keep the internal environment relatively stable.

• One of the fundamental characteristics of living things.

• All the bodies organ systems contribute to homeostasis.

• Controlled by negative feedback mechanisms.

• Disease results when these mechanisms break down.

Negative Feedback Mechanisms

• Requires a receptor that detects when levels are unacceptable and as a result triggers a response.

• Also requires an effector that brings about a response that negates the original conditions that stimulated the receptor.

• Most homeostatic regulatory mechanisms involve negative feedback.

Body Temperature Control• Control of our body temperature involves a

negative feedback loop.• Control center in brain (hypothalamus) functions

as the thermostat whose set point is 37 degrees Celsius.

• When body temperature increases heat loss is increased by sweating and increased blood flow to skin until body temperature returns to normal.

• See text p.12 for an illustration of this concept.

Credits• Background courtesy of NASA: http://antwrp.gsfc.nasa.gov/apod/ap030617.html

• Virtuvian Man (slide 1): http://www.leonardo2002.de/media/original.jpg

• Anatomical Image (slide 2): http://www.nlm.nih.gov/exhibition/dreamanatomy/images/1200%20dpi/I-B-2-01.jpg

• Smilie (slide 3): http://www.smiliegenerator.com/smiliegenerator_eng.html

• Smilie (slide 4) http://bestanimations.com/Signs&Shapes/Smileys/Smileys.html

• DNA animation (slide 7): http://members.lycos.nl/TheDNApage/dnanim.html

• Red blood cells (slide 8): http://www.cellsalive.com/

• Mitochondrion (slide 8): http://www-plb.ucdavis.edu/courses/f01/PLB%2011/PLB11-99/CellStructure/em_mito.jpg

• Cardiac muscle (slide 9): http://www.unomaha.edu/~swick/2740musclehistology.html

• Heart (slide 9): : http://medlib.med.utah.edu/WebPath/CVHTML/CV001.html

• Cardiovascular system (slide 10): http://www.coe.uh.edu/archive/science/science_graphics/sciencegr1.html

Credits…Anatomical image (slide 11): http://www.nlm.nih.gov/exhibition/dreamanatomy/da_g_II-C-07.html

Body Planes (slide 13): http://training.seer.cancer.gov/module_anatomy/unit1_3_terminology2_planes.html

Anatomical Image (slide 14): http://www.nlm.nih.gov/exhibition/dreamanatomy/da_g_I-B-2-10.html

Body Cavities (slide 17): http://training.seer.cancer.gov/module_anatomy/unit1_3_terminology3_cavities.html

Anatomical Image (slide 18): http://www.nlm.nih.gov/exhibition/dreamanatomy/da_g_I-B-2-06.html

Anne Geddes Image (slide 19): http://www.andrea-schroeder.com/AGeddese.html

Skeleton (slide 20): http://training.seer.cancer.gov/module_anatomy/unit3_5_skeleton_divisions.html

Dancers (slide 21): http://training.seer.cancer.gov/module_anatomy/unit4_1_muscle_functions.html

Nervous System (slide 22): http://training.seer.cancer.gov/module_anatomy/unit5_3_nerve_org.html

Endocrine System (slide 23): http://training.seer.cancer.gov/module_anatomy/unit6_3_endo_glnds.html

Credits…• Circulatory System (slide 24):

http://training.seer.cancer.gov/module_anatomy/unit7_1_cardvasc_intro.html

• Respiratory System (slide 25): http://training.seer.cancer.gov/module_anatomy/unit9_4_resp_passages.html

• Digestive System (slide 26): http://training.seer.cancer.gov/module_anatomy/unit10_3_dige_regions.html

• Urinary System (slide 27): http://training.seer.cancer.gov/module_anatomy/unit11_2_uri_components.html

• Reproductive System (slide 28): http://training.seer.cancer.gov/module_anatomy/unit12_1_repdt_intro.html