What is anatomy? –Anatomy is defined as the study of… Structure refers to the shapes, sizes, and characteristics of the components of the human body. The word anatomy comes from 2 words: –Ana which means “throughout” –Tomos which means “to cut” Why these two words????

Types of Anatomy We can divide our study of structure into 2 parts: Study of stuff seen by the naked eye (Gross Anatomy). Study of stuff seen ONLY with the microscope (Microanatomy). –We can divide microanatomy into: »Histology – study of tissues »Cytology – study of individual cells.

Physiology Physiology is defined as the study of function – so human physiology attempts to explain how and why humans function. Physiology is where we figure out how stuff works. How do muscles contract? How do we run? How does our heart beat?

Levels of Structure In order to understand how something is built and how something works, you must look at all of its components and analyze them both individually and together. An organism (such as a human being) may be broken down as illustrated on the left. Cell Tissue Organ Organ System Organism

Levels of Structure The basic unit of life is the cell. All living organisms are composed of one or more cells. The human body contains about 100 trillion cells. There are about 200 different types of cells in the human body. The different types of cells have different features but for the most part, all cells are made up of organelles and various macromolecules (e.g., proteins, lipids, carbohydrates and nucleic acids).

More Levels of Structure Similar cells and cell products come together to form tissues. A structure made of 2 or more tissue types that perform a particular function is an organ. A group of organs with a unique collective function is an organ system. There are 11 of these in the human body.

Integumentary System Structures: -Skin, hair, sweat and oil glands Functions: -Forms the external body covering -Protects deeper tissues from injury -Involved in vitamin D synthesis -Prevents desiccation, heat loss, and pathogen entry -Site of pain and pressure receptors

Skeletal System Structures: –The 206 bones of the human body Functions: –Protects and supports body organs What characteristics might bone have that allows it to support and protect? –Provides a framework that muscles can use to create movement –Hemopoiesis (synthesis of blood cells) –Mineral storage Bone contains 99% of the body’s store of what mineral? (Hint  you can get this mineral from drinking milk)

Muscular System Structures: –The 600+ muscles of the body Functions: –Locomotion –Manipulation of the environment –Maintaining posture –Thermogenesis (generation of heat)

Nervous System Structures: –Brain, spinal cord, and peripheral nerves Functions: –Fast-acting control system of the body –Monitoring of the internal and external environment and responding (when necessary) by initiating muscular or glandular activity

Endocrine System Structures: –Hormone-secreting glands Pituitary, Thyroid, Thymus, Pineal, Parathyroid, Adrenal, Pancreas, Small Intestine, Stomach, Testes, Ovaries, Kidneys, Heart Functions: –Long-term control system of the body –Regulates growth, reproduction, and nutrient use among other things.

Cardiovascular System Structures: –Heart, Blood vessels (arteries, veins, and capillaries) Functions: –The heart pumps blood thru the blood vessels. –Blood provides the transport medium for nutrients (glucose, amino acids, lipids), gases (O 2, CO 2 ), wastes (urea, creatinine), signaling molecules (hormones), and heat.

Lymphatic/Immune System Structures: –Lymphatic vessels, Lymph nodes, Spleen, Thymus, Red bone marrow Functions: –Returning “leaked” fluid back to the bloodstream, –Disposal of debris –Attacking and resisting foreign invaders (pathogens i.e., disease- causing organisms)

Respiratory System Structures: –Nasal cavity, pharynx, trachea, bronchi, lungs Functions: –Constantly supply the blood with O 2, and remove CO 2 –Regulate blood pH

Digestive System Structures: –Oral cavity, esophagus, stomach, small intestine, large intestine, rectum, salivary glands, pancreas, liver, gallbladder Functions: –Ingestion and subsequent breakdown of food into absorbable units that will enter the blood for distribution to the body’s cells

Urinary System Structures: –Kidneys, ureters, urinary bladder, urethra Functions: –Removal of nitrogenous wastes –Regulation of body’s levels of water, electrolytes, and acidity

Reproductive System Structures: –Male: Testes, scrotum, epididymis, vas deferens, urethra, prostate gland, seminal vesicles, penis –Female: Ovary, uterine tube, uterus, cervix, vagina, mammary glands Functions: –Production of offspring

Survival Needs: Stayin’ Alive! For your life to NOT end abruptly, these cells need to have the correct amount of: Oxygen Nutrients Waste removal Heat Ions (sodium, calcium, etc.) Lots of other stuff

Necessary Life Functions Maintain Boundaries Movement Responsiveness Digestion Metabolism Excretion Growth Reproduction

Homeostasis Defined as the body’s ability to maintain stable internal conditions in spite of the changing external conditions. We just said that our body needs to have the right amount of stuff (i.e., temperature, blood [glucose], pH etc.) at all times in order to function properly. First, let’s refer to all this stuff as “different variables” Note: the brackets surrounding the word glucose in the above paragraph mean “concentration of glucose,” i.e., how much glucose is dissolved in a particular fluid (blood in this case)

Let’s use a thermostat as an example In order to keep the temperature in my house at the right level, the thermostat must first measure the current temperature in the house. After the thermostat measures the temperature, it compares the current value to a preset standard value. –If there is no difference then there’s nothing to do. –However, if it’s too hot or too cold, the thermostat has to send a signal to the furnace or air conditioner to change the temperature of the house so that it equals the standard value.

Let’s clarify some stuff. In the previous example we had a: 1.Variable  temperature 2.Measuring implement  thermostat 3.Control center  also the thermostat 4.A preset or standard value for the variable 5.Effectors  the air conditioner and furnace Similar situations arise in the human body where there are lots of variables that we want to maintain at certain precise levels

Negative Feedback The movement of a variable in one direction causes the body to enact processes that cause the variable to move in the opposite direction (so as to return the value to the correct level) – we call it negative feedback

Increased BP Sensed by pressure receptors in aortic arch and carotid sinus Input sent via afferent pathway to medulla oblongata Current BP compared with set point and error signal generated Output sent along efferent pathway to heart and blood vessels Heart rate & force of contraction decrease Blood vessel diameter increases BP DECREASES

Why is Negative Feedback so common in the body? Think about it! Every time a variable starts changing too much, we’ve got to bring it back to normal. We’ve got to counteract its change. THAT’S NEGATIVE FEEDBACK Other examples you will encounter: –Maintenance of blood [Ca 2+ ], blood [Glucose], blood pH, and many others

When does a negative feedback process end? THINK ABOUT IT! A negative feedback process begins when a particular variable leaves its homeostatic range. The process ends when that variable is back within its normal range. Negative feedback processes (or loops) are self-terminating. MAKE SURE YOU UNDERSTAND WHY!

What about Positive Feedback? Positive feedback occurs when the response amplifies or magnifies the stimulus that produced it. In other words, a variable is altered and then the body’s response alters that variable even more in the same direction. How does this differ from negative feedback? Which do you suppose is more common in the body: positive or negative feedback?

Positive Feedback in Childbirth

Positive Feedback in Blood Clotting

What stops a positive feedback loop?

The Language of Anatomy Slide 1.21 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Special terminology is used to prevent misunderstanding Exact terms are used for: Position Direction Regions Structures

Orientation and Directional Terms Slide 1.22 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Table 1.1

Orientation and Directional Terms Slide 1.23 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Table 1.1 (cont)

Body Landmarks Slide 1.24 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Anterior Figure 1.5a

Body Landmarks Slide 1.25 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Posterior Figure 1.5b

Body Planes Slide 1.26 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 1.6

Body Cavities Slide 1.27 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 1.7

Abdominopelvic Quadrants Slide 1.28 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 1.8a

Abdominopelvic Regions Slide 1.29 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 1.8b

Abdominopelvic Major Organs Slide 1.30 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 1.8c