McConnell_HFHF_Ch01.ppt

Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins
Chapter I:
Life, Form, and
Function

McConnell and Hull: Human Form and Human Function
Chapter Objectives
• Form, Function, and Life
– Explain the difference between anatomy and physiology and
offer an example of each.
– List four characteristics of living things.
• The Building Blocks of Life
– Within an organ system, list the building blocks of life,
starting with the smallest.
• Life and the External Environment
– Identify five features of the external environment that are
necessary for life.

Chapter Objectives (cont'd)
• Life and Gradients
– Explain the importance of pressure and concentration
gradients in the body.
• Homeostasis: Maintaining a Healthy Internal Environment
– Define homeostasis
– Name at least one contribution to homeostasis made by the
11 body systems.
– Compare and contrast positive and negative feedback and
offer an example of each.

Chapter Objectives
• The Language of Form and Function
– Use anatomic terms to describe different body functions and
their positions relative to one another.
– Describe the membranes and list some organs found in each
body cavity.
• The Language of Disease
– Identify the signs and symptoms found in the case study.

Form, Function, and Life
• Introduction
– The goal of human anatomy is to understand the structure of
our body and how it relates to our functions.
• Gross anatomy examines structures that can be seen with
the naked eye.
• Microscopic anatomy examines structures that cannot be
seen with the naked eye.
– The goal of human physiology is to explain the internal
mechanisms of the human body.
Back to chapter objectives

Form, Function, and Life (cont’d)
• Human beings share four characteristics of all living organisms
– An organism is a complete life form that can function
independently.
– Four qualities of organisms
1. They are organized.
2. They have a metabolism.
3. They adapt to the environment.
4. They reproduce.

A. Organization
B. Metabolism
C. Adaptation
D. Reproduction

• Form and function are inseparable
– Every form has a function, and every function has
a form.
• Your thumb is rotated 90 degrees from your
other fingers.
• This makes it easy for the tip of your thumb to
touch the tip of your other fingers.

• There is a difference between form and function.

Form, Function, and Life (Review)
• What is the difference between form and function?

Form, Function, and Life (Review)
• Answer: Form refers to the structure of something;
function refers to what something does or how
something works.

The Building Blocks of Life
• Introduction
– Physiologic functions are provided by one or more
subdivisions of the organism:
• The largest division is known as a system or organ
system.
• Organ systems are made up of organs.
• Organs are made up of tissues.
• Tissues are made up of cells.

The Building Blocks of Life (cont’d)
• Cells and their parts are comprised of molecules.
• Molecules contain atoms.
• Cells are the building blocks of life.
• Atoms are the building blocks of everything.

The Building Blocks of Life (cont’d)
1. Organism
2. Systems
3. Organs
4. Tissues
5. Cells
6. Molecules
7. Atoms

The Building Blocks of Life (Review)
• What is the highest level of organization in the human, and what
is the smallest?

The Building Blocks of Life (Review)
• Answer: organism; molecules and atoms

Life and the External Environment
• Astronauts carry their life-sustaining environment with them.

Life and the External Environment (cont’d)
• The following are necessary to sustain life:
– Pressure
– Oxygen
– Heat
– Nutrients and water

Life and the External Environment: Pressure
• Force exerted by solid, gas, or fluid
• Gases and fluids most critical
– Static pressure exerted by weight of a gas or fluid pressing
down on a point within
– Dynamic pressure created by moving gas or fluid

Life and the External Environment: Pressure
(cont’d)
• Atmospheric pressure is exerted by gases in the air
– Static pressure that represents total weight of the air in the
atmosphere
– Keeps gases within our bodies
• Blood pressure created by heart forcing blood through
vessels
• Not the same as water passing through a garden hose
• Circulatory system is a closed system

Life and the External Environment: Oxygen
• Unlocks energy from chemical nutrients in food
• Without oxygen, cells cannot obtain the energy they need.

Life and the External Environment: Heat
• Heat is generated by the body’s chemical reactions (metabolism).
• Just the right amount of heat must be lost.
• Keeping or losing too much heat can raise or lower the body
temperature too much.
• In warm environments, we sweat.
• In cold environments, we shiver.

Life and the External Environment: Nutrients and
Water
• Food supplies necessary chemicals
– Some nutrients burned for energy
– Some nutrients used for building blocks
• Chemicals for life are dissolved in water

Life and the External Environment (Review)
• Life requires oxygen, nutrients, heat, and what else?

Life and the External Environment (Review)
• Answer: water

Life and Gradients
• A gradient is the difference in the quantity or concentration of a
physical value between two areas.
– Substances move from high concentration to low
concentration.
– Death eliminates all gradients

Types of Gradients
• Altitude
– A roof
• Temperature
– Inside the body and out

Types of Gradients (cont’d)
• Pressure
– Inside the astronaut’s suit and space
• Physiologic
– Inside or outside cells
– Inside or outside blood vessels
• Chemical
– Cell membranes

Types of Gradients (cont’d)

Life and Gradients (Review)
• What is a gradient? Give some examples that exist in the human
body.

Life and Gradients (Review)
• Answer: a difference in the quantity of a physical value between
two areas
• Examples: concentration gradients across cell membranes;
temperature gradient between an astronaut’s spacesuit and outer
space

Homeostasis: Maintaining a Healthy Internal
Environment
• The body has 100 trillion cells.
• Cells must communicate with each other and the environment.
• The body’s communication and control efforts to maintain internal
conditions within a narrow physiologic range is known as
homeostasis.

Environment (Review)
• Refer to President
Reagan’s case study.
• How was the
President’s
homeostasis
maintained during his
treatment?

• Answer: homeostatic
adjustments and
medical
interventions, such
as administering
oxygen and IV
blood/fluids were
used

Environment (cont’d)
• All body systems participate in homeostasis
– Compare the human body to an orchestra.
– If one performer’s instrument is out of tune, the whole
performance suffers.
– The same is true for the human body.

Negative Feedback
• Negative feedback is the key to homeostasis
– All physiologic conditions have set points
• Set points must be maintained for optimal health.
• Sensors detect deviations
• Negative feedback reflexively keeps systems regulated

Negative Feedback: Skin Temperature
• Sensors indicate the body temperature is rising
• Sensors send signal to integrating center in the brain
• Brain sends signals to effectors
• Effectors act by increasing sweating and blood flow to skin

Negative Feedback: Skin Temperature (cont’d)
• Negative feedback
helps to keep your
skin at the right
temperature.

Positive Feedback
• Positive feedback accelerates processes to a end point
– Share same elements as negative feedback loops
– Pushes back against a detected change
– The action boosts, rather than diminishes the condition.
• Condition is detected
• Integrating center is signaled
• Effectors take action

Positive Feedback (cont’d)
• Positive feedback
maintains
homeostasis during
childbirth.

• What is the main contribution of the respiratory system to
homeostasis?

• Answer: warms, moistens, and filters inhaled air; helps regulate
acid-base balance; discharges carbon dioxide

The Language of Form and Function
• Medical terms are assembled into smaller units
– Greek and Latin-based terms
• Prefixes, word roots, and suffixes
• Word roots usually the Latin word for a system or organ

The Language of Form and Function (cont’d)
• Anatomic terms describe directions and body planes
– Standard anatomical position
• Standing erect, head upright
• Facing forward
• Arms at sides
• Hands rotated with thumb outside, palm forward
• Toes forward, feet parallel

The Language of Form and Function (Review)
• Which part is more
lateral, the ears or
the nose?

• Answer: the ears

Body Planes
• Body planes are imaginary flat surfaces that divide the body
– Frontal plane—divides anterior and posterior parts
– Sagittal plane—divides into right and left parts
– Transverse plane—divides structures into superior and
inferior parts
– Oblique plane—any plane not perpendicular to a frontal,
sagittal, or transverse plane

Body Planes (cont’d)

Anatomic Terms
• Precisely describe the body
– Body regions are defined by surface anatomy
• Head: skull and face
• Neck
• Trunk or torso: abdomen, pelvis
• Upper limb: shoulder to hand
• Lower limb: buttock to foot

Body Cavities
• Are spaces within the body
– Cranial and spinal cavities are dorsal cavities
– Ventral cavity is divided by the diaphragm
• Abdominal cavity
• Pelvic cavity

Body Cavities (cont’d)
– Double-layered membranes surround many organs of the
thoracic and abdominopelvic cavity
• Pericardium covers the heart
• Pleurae cover the lungs
– Peritoneum covers abdominal and pelvic organs
• Visceral layer
• Parietal layer

– Visualize a fist pushing into a balloon to understand how
organs develop in the fetus
• As the heart forms, it creates a balloon-like sac called the
pericardial cavity
• Lungs push themselves into the pleural cavity
• Mediastinum contains heart and pericardial sac

– Visualize a fist pushing into a balloon to understand how
organs develop in the fetus
• In the abdominopelvic cavity, the liver, spleen, and
intestines form the visceral peritoneum.
• The interior of the “balloon” becomes the peritoneal
space.

• Abdominal regions define parts of the abdominal cavity

• Which structure is more distal—the shoulder or wrist?

• Answer: wrist

The Language of Disease
• All disease is due to some kind of injury.
– Defined as an unhealthful state of abnormal form or function
due to injury
• Injury includes damage to cells from any cause
– Causes include:
• Physical trauma
• Inflammation
• Radiation
• Drugs
• Diet

The Language of Disease (cont’d)
– Defined as an unhealthful state of abnormal form or function
due to injury
• Acute—arises rapidly, lasts a short time, and has distinct
symptoms
– Measles
• Chronic—begins slowly, persists, cannot be prevented or
cured
– Arthritis

The Language of Disease (cont’d)
• Signs—direct measurable observations by an examiner
• Symptoms—complaints reported by patients that are part of
medical history
• Syndrome—collection of signs and symptoms

Pathology
• Pathology—the study of changes in bodily structure and function
as a result of disease
– Purpose
• Discover etiology (cause)
• Understand pathogenesis (natural history and
development)
• Explain pathophysiology (how expressed)
• Describe the lesion

Pathology (cont’d)
• If a disease’s etiology is known it is idiopathic.
• If a disease is a byproduct of a medical diagnosis or treatment, it
is iatrogenic.

The Language of Disease (Review)
• A patient develops a rash after taking a prescribed medication.
The rash clears up when the medication is discontinued. Is the
condition idiopathic or iatrogenic?

The Language of Disease (Review)
• Answer: iatrogenic

McConnell_HFHF_Ch01.ppt

Recommended

Recommended

More Related Content

Similar to McConnell_HFHF_Ch01.ppt

Similar to McConnell_HFHF_Ch01.ppt (20)

Recently uploaded

Recently uploaded (20)

McConnell_HFHF_Ch01.ppt