1. Pima Medical Institute BIO 120
Hole’s Essentials of Human Anatomy & Physiology
Lesson 1
Introduction to Human Anatomy and Physiology
David Shier, Jackie Butler, Ricki Lewis, Hole’s Essentials of Human Anatomy & Physiology, 10th Ed. CopyrightThe McGraw-Hill Companies, Inc. Created by Dr. Melissa Eisenhauer, Trevecca Nazarene University

2. .
Introduction:
The early students of anatomy and physiology were most likely concerned with treating illnesses and injuries.
Early healers relied on superstitions and magic. Later, herbs were used to treat certain ailments.
Eventually, after much controversy the study of medicine with standardized terms in Greek and Latin began.
Our earliest ancestors probably became curious about the body during illnesses and injuries. At these times, they visited healers who relied on superstition and magic. Throughout early time, this curiosity led to discoveries of the healing powers of certain herbs and potions, especially to treat coughs, headaches, and other common problems. Not until about 2500 years ago did these superstitious attitudes change and the body was looked at in the new light of modern science. Experiments, accurate observations, and tried techniques rapidly expanded knowledge of the human body. Greek and Latin words were used as a basis to describe body part locations and to explain their functions.
Please review pp Some Medical and Applied Sciences

3. Anatomy and Physiology
Anatomy deals with the structure (morphology) of the body and its parts; in other words, what are things called?
Physiology studies the functions of these parts or asks the question, “how do they work?”
The two disciplines are closely interrelated because the functional role of a part depends on how it is constructed.
The topics of anatomy and physiology are difficult to separate because the structures of body parts are so closely associated with their functions. Body parts form a well-organized unit--the human organism--and each part functions in the unit’s operation.
Anatomy deals with the structure (morphology) of body parts. This includes the shapes, forms, and placement of body organs/appendages. Physiology deals with the functions of body parts, what the body parts do, and how it is accomplished.
Generally, the body parts have evolved in a manner that allows more efficient performance of their function. An example would be the hollow chambers of the heart that are adapted to their function of pumping blood through the tubular blood vessels.

4. Anatomists rely on observation and dissection, while physiologists employ experimentation.
It is more common to discover new information about physiology but anatomical discoveries are being made as well.
New parts of human anatomy are still discovered today, although less frequently. Recently, for example, researchers identified a small piece of connective tissue between the upper part of the spinal cord and a muscle at the back of the head. This connective tissue bridge may be the trigger for pain impulses in certain types of tension headaches.

5. Levels of Organization:
Until the invention of magnifying lenses and microscopes about 400 years ago, anatomists were limited in their studies to what they could see with the unaided eye--large parts. But with these new tools, investigators discovered that larger body structures were made up of smaller parts, which in turn were composed of even smaller ones. Figure 1.3 (above slide 5) shows the levels of organization that modern-day scientists recognize. All materials, including those that make up the human body, are composed of chemicals.

6. 1. Atoms are the simplest level.
Levels of Organization:
The human body is the sum of its parts and these parts can be studied at a variety of levels of organization.
1. Atoms are the simplest level.
2. Two or more atoms comprise a molecule.
3. Macromolecules are large, biologically important molecules inside cells.
4. Organelles are aggregates of macromolecules used to carry out a specific function in the cell.
Chemicals consist of microscopic particles called atoms, which join to form molecules. Small molecules can combine in complex ways to form larger macromolecules.
In the human and other organisms, the basic unit of structure and function is a cell, which is microscopic. Although cells vary in size, shape, and specialized functions, all share certain characteristics. For instance, all cells of humans and other complex organisms contain structures called organelles composed of aggregates (clustered together) of macromolecules, such as proteins, carbohydrates, lipids, and nucleic acid.

7. Levels of Organization Continued:
5. Cells are the basic living unit.
6. Tissues are groups of cells functioning together.
7. Groups of tissues form organs.
8. Groups of organs function together as organ systems.
9. Organ systems functioning together make up an organism.
Cells may be organized into layers of other structures that have common functions. Such a group of cells forms a tissue. Groups of different tissues that interact form organs--complex structures with specialized functions--and groups of organs that function closely together comprise organ systems.
Body parts can be described in terms of different levels of organization, such as the atomic level, the molecular level, or the cellular level. Body parts differ in complexity from one level to the next--atoms are less complex than molecules, molecules are less complex than organelles, tissues are less complex than organs, and so forth.
Chapters 2-6 discuss these levels of organization in more detail.

8. Characteristics of Life
Fundamental characteristics of life are traits shared by all organisms.
It is helpful to consider some of the traits humans share with other organism, particularly with other animals. As living organisms, we can move and respond to our surroundings. We start out as small individuals and then grow, eventually becoming able to reproduce. We gain energy by taking in or ingesting food, by breaking it down or digesting it, and by absorbing and assimilating it. The absorbed substances circular throughout the internal environment of our bodies. We can then, by the process of respiration, use the energy in these nutrients for such vital functions as growth and repair of body parts. Finally, we excrete wastes from the body. All of these processes involve metabolism, the sun total of all of the chemical reactions in the body that break substances down and build them up.

9. Characteristics of life include:
1. Movement (internal or gross)
2. Responsiveness (reaction to internal or external change)
3. Growth (increase in size without change in shape)
4. Reproduction (new organisms or new cells)
5. Respiration (use of oxygen; removal of CO2)
Table 1.1
Movement is the ability to self-initiate position changes of either the entire organism or a part of the organism, externally from place to place and/or internally, such as in peristalsis. Responsiveness refers to the ability of an organism to detect changes either within itself or the environment surrounding it and then react to these changes. Growth generally refers to an increase in body size without important changes to its general shape. Reproduction is the process of making a new organism, as in parents producing offspring. It also discusses the process whereby cells can produce others like themselves to take the place of damaged or destroyed cells. Respiration refers to the process of obtaining oxygen, using the obtained oxygen in release of energy from foods, and removing waste gases that are produced in the process.

10. 8. Circulation (movement within body fluids)
6. Digestion (breakdown of food into simpler forms)
7. Absorption (movement of substances through membranes and into fluids)
8. Circulation (movement within body fluids)
9. Assimilation (changing nutrients into chemically different forms)
10. Excretion (removal of metabolic wastes)
Taken together, these 10 characteristics
constitute metabolism.
Digestion is the chemical change of ingested foods into simpler substances that can be taken in and used by body parts. Absorption is the passage of digested substances through membranes of the intestinal lining. Circulation refers to the movement of substances from one place to another within the body using the body fluids. Assimilation refers to the changing of absorbed substances into forms that are chemically different from those that entered the body fluids. Excretion refers to the removal of wastes produced by body parts during their activities.
The reactions of metabolism enable us to acquire and use energy to fuel life processes.

11. Maintenance of Life Requirements of Organisms:
Life depends on the availability of the following:
a. Water
b. Food
c. Oxygen
d. Heat
e. Pressure
Both the quality and quantity of these factors are important.
Water, the most abundant substance in the body, is required for many metabolic processes. It provides the environment for the metabolic processes to take place and then transports substances within the body. It is also important in regulating body temperature. Food is the substances that provide the body with the necessary chemical nutrients to sustain life, in addition to water. These nutrients are used in a variety of ways by the body. Oxygen, which makes up about one-fifth of air, is used to release energy from food substances. Heat, a form of energy, is a product of metabolic reactions. The rate at which these reactions occur is governed by the amount of heat present. Pressure is a state in which a force is applied to something. Atmospheric pressure plays an important role in breathing. Hydrostatic pressure, the pressure of fluid, plays an important role in the circulatory system.

12. Our cells lie within an internal fluid environment (extracellular fluid)
Our cells lie within an internal fluid environment (extracellular fluid). Concentrations of water, nutrients, and oxygen in the internal environment must be maintained within certain ranges to sustain life. (p. 6, figure 1.4)

13. Homeostasis:
Maintenance of a stable internal environment is called homeostasis.
Homeostasis is regulated through control systems which have receptors, a set point and effectors in common.
Examples include:
a. Homeostatic mechanisms regulate body temperature in a manner similar to the functioning of a home heating thermostat.
b. Another homeostatic mechanism employs pressure- sensitive receptors to regulate blood pressure.
Homeostasis is defined as the tendency of an organism to maintain a stable internal environment. In order to survive, an organism must keep everything in balance. This allows all the body systems to work together in harmony. In other words…body parts function only when the concentrations of water, nutrients, and oxygen and the conditions of heat and pressure remain within certain narrow limits.
Receptors provide information about specific conditions (stimuli) in the internal environment. A set point tells what a particular value should be (such as body temperature at 37 degrees centigrade or, 98.6 degrees Fahrenheit. Effectors cause responses that alter conditions in the internal environment. A homeostatic mechanism works as follows -- if the receptors measure deviations from the set point, effectors are activated that can return conditions toward normal.

14. A homeostatic mechanism
A homeostatic mechanism monitors a particular aspect of the internal environment and corrects any change back to the value indicated by the set point.
(p. 6, figure 1.5)

15. An example of a homeostatic mechanism
A thermostat signals an air conditioner and a furnace to turn on or off to maintain a relatively stable room temperature. This system is an example of a homeostatic mechanism.
Suppose the room temperature is to remain near 20 degrees centigrade, so the thermostat is adjusted to an operating level, or set point, of 20 degrees centigrade. Because a thermostat senses temperature changes, it will signal the furnace to start and the air conditioner to stop whenever the room temperature drops below the set point. If the temperature rises above the set point, the thermostat will stop the furnace and start the air conditioner. As a result, the room will maintain a relatively constant temperature.
The human body temperature is controlled by a temperature-sensitive region of the brain. If the body temperature begins to drop, the brain senses this change and triggers heat-generating and heat-conserving activities. A heat-generating activity would be the shivering of the muscles. A heat-conserving activity would be vasoconstriction. If the brain senses a rise in body temperature, it triggers changes that allow increased loss of body heat. Sweating and vasodilation are examples of this change.
If the pressure-sensitive parts of the blood vessels sense an increase in the blood pressure, the brain will send signals to the heart causing the chambers to contract more slowly and with less force. This will decrease the pressure. If it drops too much, the brain will then send signals to the heart so it will contract more rapidly and with greater force.

16. Many of the body's homeostatic controls are negative feedback mechanisms.
Each individual uses homeostatic mechanisms to keep body levels within a normal range; normal ranges can vary from one individual to the next.
As conditions return toward normal, the deviation from the set point progressively lessens, and the effectors are gradually shut down. Such a response is called negative feedback mechanism, both because the deviation from the set point is corrected (moves in the opposite or negative direction) and because the correction reduces the action of the effectors. This latter aspect is important because it prevents a correction from going too far.
To better understand this idea of negative feedback, imagine a room equipped with a furnace and an air conditioner (see slide 15, figure 1.6, p. 7)
Each individual uses homeostatic mechanisms to keep body levels with a normal range. An example of a general physiological control system would be “shivering”, where muscles contract to produce heat to help warm the body.

17. Vital Signs Reflect essential metabolic activities
Indicated that a person is alive
Assessment includes:
Temperature
Blood pressure
Pulse - rate and type
Respiration - breathing movement
Absence of vital signs signifies death
Health-care workers repeatedly monitor patient’s vital signs--observable body functions that reflect essential metabolic activities.
A person who has died displays no spontaneous muscular movements. Inclusion those of the breathing muscles and beating heart. A dead person does not respond to stimuli, and has no reflexes, such as the knee-jerk reflex and the pupillary reflexes of the eyes. Brain waves cease with death, as demonstrated by a flat electroencephalogram (EEG), which signifies a lack of metabolic activity in the brain.

18. Organization of the Human Body
Major features of the human body include its cavities, membranes, and organ systems.
A human organism is a complex structure composed of many parts. Its major features include several body cavities, layers of membranes within these cavities, and a variety of organ systems.

19. .
Body Cavities:
The body can be divided into an appendicular portion (upper and lower limbs) and an axial portion (head, neck, and trunk), which includes a dorsal and a ventral cavity. Organs within these cavities are called viscera.
A visceral organ is any organ found deep within a cavity

20. b. The ventral cavity is made up of the following: Thoracic cavity
a. The dorsal cavity can be divided into two areas:
Cranial cavity
Vertebral canal
b. The ventral cavity is made up of the following:
Thoracic cavity
The mediastinum divides the thorax into right and left halves.
Abdominopelvic cavity
The abdominopelvic cavity can be divided into the abdominal cavity and the pelvic cavity.
A broad, thin muscle called the diaphragm separates the thoracic and abdominopelvic cavities.
The dorsal cavity is located at the back of the organism. It is subdivided into two parts - the cranial cavity within the skull, which houses the brain; and the vertebral canal, which contains the spinal cord and is surrounded by sections of the backbone (vertebrae).
The ventral cavity is the front part of the organism. It is subdivided into two parts - a thoracic cavity, which houses the lungs and heart; and a abdominopelvic cavity, which houses the stomach, liver, spleen, gallbladder, small and large intestines, urinary bladder, and the internal reproductive organs.
The mediastinum is the region that separates the thoracic cavity into two compartments, which contain the right and left lungs. The remaining thoracic viscera - heart, esophagus, trachea, and thymus gland are located within the mediastinum.

21. Major body cavities - Anterior view

22. c. Smaller cavities within the head include the
c. Smaller cavities within the head include the oral cavity, nasal cavity, orbital cavities, and middle ear cavities.
Oral cavity which contains the teeth and the tongue. Nasal cavity which is located within the nose and divided into right and left portions by a nasal septum. Several air-filled paranasal sinuses are connected to the nasal cavity. Orbital cavities which contain the eyes and the associated skeletal muscles and nerves. Middle ear cavities which contain the middle ear bones.

23. Thoracic and Abdominopelvic Membranes:
1. The thoracic cavity is lined with pleural membranes; the parietal pleura lines the cavities while the visceral pleura covers the lungs. A thin layer of serous fluid separates the two layers.
2. The heart is surrounded by pericardial membranes. The parietal pericardium makes up an outer sac and the visceral pericardium covers the heart. Serous fluid separates the two layers.
3. Peritoneal membranes line the abdominopelvic cavity; a parietal peritoneum lines the wall while visceral peritoneum covers the organs.
The walls of the right and left thoracic compartments, which contain the lungs, are lines with a membrane called the parietal pleura. A similar membrane called the visceral pleura, covers the lungs themselves. A parietal membrane refers to a membrane that is attached to the wall of a cavity. A visceral membrane refers to a membrane that is deeper--toward the interior--and covers internal organs.
The parietal and visceral pleural membranes are separated by a thin film of watery fluid (serous fluid), which they secrete. While no actual space normally exists between these membranes the potential space between them is called the pleural cavity.
The heart, which is located in the broadest portion of the mediastinum, is surrounded by pericardial membranes. A thin visceral pericardium covers the heart’s surface and is separated from a thicker parietal pericardium by a small volume of fluid. The pericardial cavity is the potential space between these membranes.
In the abdominopelvic cavity, the ling membranes are called peritoneal membranes. A parietal peritoneum lines the wall, and a visceral peritoneum covers each organ in the abdominal cavity. The peritoneal cavity is the potential space between these membranes.

24. Thoracic and Abdominopelvic Membranes
Figure 1.8 b, p. 9

25. Serous membranes associated with the heart and lungs
Figure 1.10, p. 11
A transverse section through the thorax reveals the serous membranes associated with the heart and lungs (superior view). A thin visceral pericardium covers the heart’s surface and is separated from a thicker parietal pericardium by a small volume of fluid. The pericardial cavity (see figures 1.8b and 1.10) is the potential space between these membranes.

26. Visceral peritoneum covers each organ in abdominal cavity
In the abdominopelvic cavity, the ling membranes are called peritoneal membranes. A parietal peritoneum lines the wall, and a visceral peritoneum covers each organ in the abdominal cavity. The peritoneal cavity is the potential space between these membranes.

27. Organ Systems Body Covering
a. The integumentary system, including skin, hair, nails, and various glands, covers the body, senses changes outside the body, and helps regulate body temperature.
The human organism consists of several organ systems. Each system includes a set of interrelated organs that work together allowing each system to provide specialized functions that contribute to homeostasis.
Integumentary system protects underlying tissues, helps regulate body temperature, houses a variety of sensory receptors, and synthesizes certain products.

28. Support and Movement
a. The skeletal system is made up of bones and ligaments. It supports, protects, provides frameworks, stores inorganic salts, and houses blood-forming tissues.
b. The muscular system consists of the muscles that provide body movement, posture, and body heat.
The skeletal system provides frameworks and protective shields for softer tissues, serves as attachments for muscles, and acts together with muscles when body parts move. It also has a role in blood cell production and storage of inorganic salts.
The muscular system provides the forces that cause body movements. It also maintains posture and is the main source of body heat.

29. Integration and Coordination
a. The nervous system consists of the brain, spinal cord, nerves, and sense organs. It integrates incoming information from receptors and sends impulses to muscles and glands.
b. The endocrine system, including all of the glands that secrete hormones, helps to integrate metabolic functions.
The nervous system provides the ability to detect changes that occur inside and outside the body. It interprets the sensory impulses and what to do in response to these impulses. It also plays a role in muscle contraction and gland secretions.
The endocrine system secretes hormones that alter metabolism of a target tissue.

30. Transport
a. The cardiovascular system, made up of the heart and blood vessels, distributes oxygen and nutrients throughout the body while removing wastes from the cells.
b. The lymphatic system, consisting of lymphatic vessels, lymph nodes, thymus, and spleen, drains excess tissue fluid and includes cells of immunity.
The cardiovascular system pumps blood throughout the body. The blood serves as a fluid for transporting gases, nutrients, hormones, and wastes.
The lymphatic system transports tissue fluid back to the bloodstream and carries certain fatty substances away from the digestive organs. It also plays a role in immunity.

31. Absorption and Excretion
a. The digestive system is made up of the mouth, esophagus, stomach, intestines, and accessory organs. It receives, breaks down, and absorbs nutrients.
b. The respiratory system exchanges gases between the blood and air and is made up of the lungs and passageways.
c. The urinary system, consisting of the kidneys, ureters, bladder, and urethra, removes wastes from the blood and helps to maintain water and electrolyte balance.
Organs in several systems absorb nutrients and oxygen and excrete various wastes. For example, the organs of the digestive system receive foods from the outside. Then they break down food molecules into simpler forms that can pass through cell membranes and be absorbed. Materials that are not absorbed are transported back to the outside and eliminated.
The respiratory system provides for the intake and output of air and for the exchange of gases between blood and air. More specifically, oxygen passes from the air within the lungs into the blood, and carbon dioxide leaves the blood and enters the air. The nasal cavity, pharynx, larynx, trachea, bronchi, and lungs are parts of this system.
The urinary system removes various wastes from the blood and assists in maintaining the body's water, electrolyte, and acid-base balances.

32. Reproduction a. The reproductive system produces new organisms.
i. The male reproductive system consists of the testes, accessory organs, and vessels that conduct sperm to the penis.
ii. The female reproductive system consists of ovaries, uterine tubes, uterus, vagina, and external genitalia. The female reproductive system also houses the developing offspring.
The reproductive system is responsible for the production of whole new organisms like itself. Cells reproduce when they divide and give rise to new cells. However, the reproductive system of an organism produces whole new organisms like itself.

33. The organ system
The organ systems in humans interact, maintaining homeostasis.

34. Anatomical Terminology
Relative Positions:
1. Terms of relative position describe the location of one body part with respect to another.
2. Terms of relative position include: superior, inferior, anterior, posterior, medial, lateral, proximal, distal, superficial (peripheral), and deep.
To communicate effectively with one another, researchers and clinicians have developed a set of precise terms to describe anatomy. These terms concern the relative positions of body parts, related to imaginary planes along which cuts may be made, and describe body regions.
Superior - The head is superior to the abdomen. Meaning that the body part is above another part or is closer to the head.
Inferior - The legs are inferior to the chest. Meaning the body part is below another body part or is toward the feet.
Anterior - The eyes are anterior to the brain. Meaning toward the front.
Posterior - The brain is posterior to the eyes. Is the opposite of anterior; it means toward the back.
Medial - The nose is medial to the eyes. Refers to an imaginary midline dividing the body into equal right and left halves.
Lateral - The ears are lateral to the eyes. Meaning toward the side with respect to the imaginary midline.
Proximal - The elbow is proximal to the wrist. Describes a body part that is closer to a point of attachment to the trunk than another body part.
Distal - The fingers are distal to the wrist. Is the opposite of proximal. It means that a particular body part is farther from a point of attachment to the trunk than another body part.
Superficial - The epidermis is the superficial layer of the skin. Means situated near the surface.
Peripheral - The nerves that branch from the brain and spinal cord are peripheral nerves. Means outward or near the surface. It describes the location of certain blood vessels and nerves.
Deep - The dermis is the deep layer of the skin. Describes parts that are more internal than superficial parts.

35. Relative positional terms
Relative positional terms describe a body part’s location with respect to other body parts.

36. Body Sections:
1. A sagittal section divides the body into right and left portions.
2. A transverse section divides the body into superior and inferior portions. It is often
called a “cross section”.
3. A coronal section divides the body into anterior and posterior sections.

37. Terms used to describe body regions - anterior & posterior
Some terms used to describe body regions - (a) anterior, (b) posterior regions (figure 1.17, p. 18)
Acromial - point of the shoulder
Antebrachial - the forearm
Axillary - the armpit
Buccal - the cheek
Celiac - the abdomen
Coxal - the hip
Crural - the leg
Femoral - the thigh
Genital - reproductive organs
Gluteal - the buttocks
Inguinal - the depressed area of the abdominal wall near the thigh (groin)
Mental - the chin
Occipital - the lower back region of the head
Orbital - the eye cavity
Otic - the ear
Palmar - the palm of the hand
Pectoral - the chest
Pedal - the foot
Plantar - the sole of the foot
Popliteal - the area behind the knee
Sacral - the posterior region between the hipbones
Tarsal - the instep of the foot
Umbilical - the navel
Vertebral - the spinal column

38. Body Regions 1. The abdominal area can be divided into nine regions.
2. Terms used to refer to various body regions are depicted in Fig. 1.16, p. 17
The abdominal area is also often subdivided into four quadrants (RUQ, LUQ, RLQ, LLQ) as above figure shows.

39. What’s Next?
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