introduction to the human body tenth edition gerard j. tortora bryan h. derrickson chapter 1...

Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

Introduction to theHuman Body

Tenth Edition

Gerard J. Tortora • Bryan H. Derrickson

Chapter 1Organization of the Human Body


Organization of the Human Body

Anatomy and physiology defined Levels of organization and body systems Life processes Homeostasis Anatomical terms Body cavities


ANATOMY AND PHYSIOLOGY DEFINED


Anatomy and Physiology Defined

Anatomy is the science of structure and the relationships among structures.

Physiology is the science of body functions, that is, how the body parts work.


LEVELS OF ORGANIZATION AND BODY SYSTEMS


Chemical Level

1. Chemical level includes:

Atoms – the smallest units of matter that participate in chemical reactions.

Molecules – two or more atoms joined together.


Cellular Level

2. Cells are the basic structural and functional units of an organism.

Just as words are the smallest elements of language, cells are the smallest living units in the human body.

Types of cells in the human body are muscle cells, nerve cells, and blood cells.


Tissue Level

3. Tissues are groups of cells and the materials surrounding them that work together to perform a particular function.

Cells join together to form tissues. There are four basic types of tissue in the

body: Epithelial tissue Connective tissue Muscular tissue Nervous tissue


Organ Level

4. Organs are composed of two or more different types of tissues, and have specific functions.

Tissues join together to form organs similar to the way sentences are put together to form paragraphs.

Examples of organs are: Stomach, heart, liver, lungs, and brain.


System Level

5. System consists of related organs that have a common function.

Organs join together to form systems similar to the way paragraphs are put together to form chapters.

Example is the digestive system, which breaks down and absorbs molecules in food.


Organismal Level

6. Organismal level is the largest level of organization.

All of the systems of the body combine to make up an organism.

Systems join together to form an organism similar to the way chapters are put together to form a book.


LIFE PROCESSES


Life Processes All living organisms have certain

characteristics that set them apart from nonliving things.

There are six important life processes of humans: Metabolism Responsiveness Movement Growth Differentiation Reproduction


Life Processes

1. Metabolism is the sum of all the chemical processes that occur in the body.

2. Responsiveness is the body’s ability to detect and respond to changes in its environment.

3. Movement includes motion of the whole body, individual organs, single cells, and even tiny organelles inside cells.


Life Processes

4. Growth is an increase in body size. It may be due to an increase in the size of existing cells, the number of cells, or the amount of material surrounding cells.

5. Differentiation is the process whereby unspecialized cells become specialized cells.

6. Reproduction is the formation of new cells for growth, repair, or replacement or the production of a new individual.


HOMEOSTASIS


Homeostasis: Maintaining Limits

Homeostasis is the maintenance of relatively stable conditions, this ensures that the body’s internal environment remains constant despite changes inside and outside the body.

A large part of the internal environment consists of the fluid surrounding body cells, called interstitial fluid.

Each body system contributes to homeostasis in some way.


Homeostasis: Feedback Systems

The body is mainly under the control of two systems: the nervous system and the endocrine system.

The nervous system detects changes from the balanced state and sends messages in the form of nerve impulses to organs that can counteract the change.

The endocrine system corrects changes by secreting molecules called hormones into the blood.


Homeostasis: Feedback Systems

Homeostasis is maintained by means of many feedback systems.

A feedback system or feedback loop is a cycle of events in which a condition in the body is continually monitored, evaluated, changed, remonitored or reevaluated.

3 basic components make up a feedback system: a receptor, a control center, an effector.


Animation

You must be connected to the internet to run this animation.

• Communication, Regulation and Homeostasis

https://vendor_content_uploads.s3.amazonaws.com/Tortora_PAP_143_ISBNEPROF12461/media/html5apps/homeo1a/animation_communication_regulation_and_homeostasis.html


Animation

• Homeostatic Relationships


https://vendor_content_uploads.s3.amazonaws.com/Tortora_PAP_143_ISBNEPROF12461/media/html5apps/sys1a/animation_homeostatic_relationships.html


Homeostasis: Feedback SystemsNegative Feedback Systems: A negative feedback system reverses a

change in a controlled condition. Example: regulation of blood pressure.

Positive Feedback Systems: Unlike a negative feedback system, a

positive feedback system tends to strengthen or reinforce a change in one of the body’s controlled conditions. Example: normal childbirth.


Animation

• Negative Feedback Control of Blood Pressure


https://vendor_content_uploads.s3.amazonaws.com/Tortora_PAP_143_ISBNEPROF12461/media/html5apps/homeo2a/animation_negativefeedback_control_of_blood_pressure.html


Animation

• Positive Feedback Control of Labor


https://vendor_content_uploads.s3.amazonaws.com/Tortora_PAP_143_ISBNEPROF12461/media/html5apps/homeo4a/animation_positive_feedback_control_of_labor.html


ANATOMICAL TERMS


Anatomical Terms The language of anatomy and physiology is

very precise. Anatomical position is when the subject

stands erect facing the observer, with the head level and the eyes facing forward.

The lower limbs are parallel and the feet are flat on the floor and directed forward, and the upper limbs are at the sides with the palms turned forward

In the anatomical position, the body is upright.


Anatomical Position


Anatomical Terms

Two terms describe a reclining body. If the body is lying face down, it is prone.

If the body is lying face up, it is supine. Examples of exact terms that will be used are

in: Body regions Directional terms Planes and sections


Body Regions

The human body is divided into several major regions that can be identified externally: Head Neck Trunk Upper limbs Lower limbs


Directional Terms To locate various body structures, anatomists

use specific directional terms, words that describe the position of one body part relative to another.

Most of the directional terms used to describe the human body can be grouped into pairs that have opposite meanings.

For example, superior means toward the upper part of the body, and inferior means toward the lower part of the body.


Directional Terms


Planes and SectionsThe body has four major planes, that is, imaginary flat surfaces that pass through body parts: Sagittal plane is a vertical plane that divides the

body or an organ into right and left sides. When such a plane passes through the midline

of the body or organ and divides it into equal right and left sides, it is called midsagittal.

If it divides the body or an organ into unequal right and left sides, it is a parasagittal plane.


Planes and Sections Frontal plane or coronal plane divides the

body or an organ into anterior (front) and posterior (back) portions.

Transverse plane divides the body or an organ into superior and inferior portions. This plane may also be called a cross-sectional plane.

Oblique plane passes through the body or an organ at an angle between the other planes.


Planes and Sections


BODY CAVITIES


Body Cavities

Body cavities are spaces within the body that contain, protect, separate, and support internal organs.


Body Cavities


Body Cavities

Cranial cavity is formed by the cranial (skull) bones and contains the brain.

Vertebral canal is formed by the bones of the vertebral column (backbone) and contains the spinal cord.

Thoracic cavity is the chest cavity. Within the thoracic cavity are three smaller cavities: the pericardial cavity, two pleural cavities, and the mediastinum.


Body Cavities


Body Cavities

Abdominopelvic cavity extends from the diaphragm to the groin. As the name suggests, it is divided into two portions: The upper portion, the abdominal cavity contains

the stomach, spleen, liver, gallbladder, small intestine, and most of the large intestine.

The lower portion, the pelvic cavity contains the urinary bladder, portions of the large intestine, and internal organs of the reproductive system.


Body Cavities


End of Chapter 1Copyright 2015 John Wiley & Sons, Inc.

All rights reserved. Reproduction or translation of this work beyond that permitted in section 117 of the 1976 United States Copyright Act without express permission of the copyright owner is unlawful. Request for further information should be addressed to the Permission Department, John Wiley & Sons, Inc. The purchaser may make back-up copies for his/her own use only and not for distribution or resale. The Publishers assumes no responsibility for errors, omissions, or damages caused by the use of these programs or from the use of the information herein.

introduction to the human body tenth edition gerard j. tortora bryan h. derrickson chapter 1...

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