chapter 1: the human body: an orientation

Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

Chapter 1: The Human Body: An Orientation


An Overview of Anatomy

Anatomy The study of the structure of the human body

Physiology The study of body function *Please understand the difference between

structure and function



Anatomical terminology Based on ancient Greek or Latin Provides standard nomenclature worldwide

Branches of anatomy Gross anatomy Microscopic anatomy (histology) Surface anatomy – need to know what a normal

body looks like to identify anomalies, locate veins for venipuncture, etc.



Other branches of anatomy Developmental anatomy-structural changes of aging Embryology – study of development of fetus Pathological anatomy (pathology)- study of disease Radiographic anatomy- study of anatomy using radiographic

imagery, CT, MRI, PET, ultrasound**Why are there so many different imaging techniques? Please understand what each technique images Functional morphology Microscopic – anatomy of structures using various

microscopic instruments. Histology – study of tissues


The Hierarchy of Structural Organization

Chemical level – atoms form molecules Cellular level – cells and their functional subunits Tissue level – a group of cells performing a common

function *Please think about the fact that our bodies are made of

atoms, the same thing as rocks, plants, stars and comets! By understanding the nature of specific atomic structures, you will become aware of how chemistry provides the basis of living systems. Chemistry is a simple matter of balancing electromagnetic charges! You can move a piece of metal by bringing a magnet nearby…movement!



Organ level – a discrete structure made up of more than one tissue. e.g. the heart is made of muscle (obviously), connective tissue, nerves and epithelial tissue (valves)

Organ system – organs working together for a common purpose

Organismal level – the result of all simpler levels working in unison



Figure 1.1


Systemic v. Regional Anatomy

Systemic – study of anatomy by system Regional – study of anatomy by region Most students use a combination of regional and

systemic study


Integumentary System

Forms external body covering Protects deeper tissues from injury Synthesizes vitamin D Site of cutaneous receptors

(pain, pressure, etc.) and sweat and oil glands http://www.youtube.com/watch?v=no_XRnoNGfE

http://www.youtube.com/watch?v=no_XRnoNGfE





Skeletal System

Protects and supports body organs Provides a framework for muscles Blood cells formed within bones Stores minerals http://www.youtube.com/watch?v=vya4wpS2fgk

http://www.youtube.com/watch?v=vya4wpS2fgk




Muscular System

Allows manipulation of environment Locomotion Facial expression Maintains posture Produces heat http://www.youtube.com/user/bigsmokes62#p/a/u/

1/RsWNyqnHQ2I

http://www.youtube.com/user/bigsmokes62

http://www.youtube.com/user/bigsmokes62


Nervous System

Fast-acting control system Responds to internal and external changes


Endocrine System

The Endocrine system works as a regulatory messaging system similar to the nervous system

Remember: cells are isolated! They don’t know what to do unless they are told what to do and either the nervous system or then endocrine system tells them what to do!

Glands secrete hormones that regulate Growth Reproduction Nutrient use


Cardiovascular System

Blood vessels transport blood Carries oxygen and carbon dioxide Also carries nutrients and wastes

Heart pumps blood through blood vessels

Blood vessels are merely the plumbing which brings water, gases and nutrients to the individual cells. It is similar to a city’s water system. The heart is the pump just like our residential water has a pump station so that we have water pressure!

Again, the cells are (mostly) fixed and isolated and they rely on the intelligence of the monitoring systems of the body (the nervous system) to provide it’s needs.


Lymphatic System/Immunity

Picks up fluid leaked from blood vessels Disposes of debris in the lymphatic system Houses white blood cells (lymphocytes) Mounts attack against foreign substances in the

body

The lymphatic system is a highly understudied system in the body. It is in fact one of the most important systems of the body! Without proper functioning of this system, we would die!


LymphedemaThe lymphatic

drainage of the leg is impaired and the fluid collects in the

limb causing it to swell. The cells are

improperly nourished and will become diseased.


Respiratory System

Keeps blood supplied with oxygen Removes carbon dioxide Gas exchange occurs through walls of air sacs in

the lungs

This is a simple system to understand but it also functions in the acid-base balance of the physiology


Digestive System

Breaks down food into absorbable units Indigestible foodstuffs eliminated as feces


Urinary System

Eliminates nitrogenous wastes Regulates water, electrolyte, and acid-base balance

The cells of our body (all 70 trillion of them!) require an exact environment to survive. The urinary system along with the lymphatic system provides this environment directly.


Why do we have body systems? What do they provide? Do we need all of them? How did they come about? What is homeostasis? How does each system contribute to homeostasis?


Male & Female Reproductive Systems

Overall function is to produce offspring Testes produce sperm and male sex hormones Ovaries produce eggs and female sex hormones Mammary glands produce milk


Gross Anatomy – An Introduction

Anatomical position – a common visual reference point Person stands erect with feet together and eyes

forward Palms face anteriorly with the thumbs pointed

away from the body Directional terminology – refers to the body in

anatomical position Standardized terms of directions are paired terms



Figure 1.3



Directional terms Regional terms – names of specific body areas

Axial region – the main axis of the body Appendicular region – the limbs


Orientation and Directional Terms

Table 1.1 (1 of 3)



Table 1.1 (2 of 3)



Table 1.1 (3 of 3)

May be used on exams!


Regional Terms

Figure 1.4a


Regional Terms

Figure 1.4b


Body Planes and Sections

Coronal (frontal) plane Lies vertically and divides body into anterior and

posterior parts Median (midsagittal) plane

Specific sagittal plane that lies vertically in the midline


Body Planes and Sections

Transverse plane Runs horizontally

and divides body into superior and inferior parts

Figure 1.5


Figure 1.6

Oblique Section Through the Trunk

Oblique Plane Divides the body at

an angle between the horizontal and vertical planes


Banana Sectioned into Planes

Figure 1.7


The Human Body Plan

Tube-within-a-tube Bilateral symmetry Dorsal hollow nerve cord Notochord (primative supporting rod) and vertebrae Segmentation Pharyngeal pouches (gills!) Post-anal tail (at some point in development) Characteristics common to all vertebrate


Basic Human Body Plan and StructuresShared with all Vertebrates

Figure 1.8a



Figure 1.8bMay be used on exams!



Figure 1.8c


Body Cavities and Membranes

Dorsal body cavity Cranial cavity Vertebral cavity



Ventral body cavity Thoracic cavity – divided into three parts Be able to describe it’s location and contents! Anterior-sternum,

posterior-thoracic vertebrae, lateral-lungs, superior-1st rib, inferior-diaphragm Two lateral parts each containing a lung surrounded by a

pleural cavity Mediastinum – lies between the lungs and contains the heart

surrounded by the pericardial sac, the trachea, the esophagus, the superior vena cava, the inferior vena cava and various nerves. This is an anatomically important area.



Ventral cavity (continued) Abdominopelvic cavity – divided into two parts

Abdominal cavity – contains the liver, stomach, kidneys, and other organs

Pelvic cavity – contains the bladder, some reproductive organs, and rectum



Figure 1.9a



Figure 1.9b



Serous cavities – a coelomic cavity, like that enclosed by the pericardium, peritoneum, or pleura, not communicating with the outside body, and whose lining membrane secretes a serous fluid. Pleura (enclosing lungs), pericardium(enclosing heart), and peritoneum(enclosing most of abdominal organs but specifically NOT the kidneys!)

Parietal serosa – outer wall of the cavity Visceral serosa covers the visceral organs *Always remember the difference between parietal and

visceral…visceral is ALWAYS against the organ(s)



Figure 1.10a, b

The purpose of the serosal membranes is to reduce friction so that viscera (organs) move freely and stay cool.



Figure 1.10c



Figure 1.10d



Other cavities Oral cavity Nasal cavity Orbital cavities Middle ear cavities Synovial cavities


Other Body Cavities

Figure 1.11


Abdominal Regions and Quadrants

Abdominal regions divide the abdomen into nine regions

Abdominal quadrants divide the abdomen into four quadrants Right upper and left upper quadrants Right lower and left lower quadrants


Abdominal Regions

Figure 1.12a, b


Abdominal Quadrants

Figure 1.12c


Microscopic Anatomy

Microscopy – examining small structures through a microscope Light microscopy illuminates tissue with a beam

of light (lower magnification) Electron microscopy uses beams of electrons

(higher magnification) TEM transmission electron microscopy will

always be sharper than light microscope


Microscopic Anatomy

Figure 1.13


Microscopic Anatomy

Preparing human tissue for microscopy Specimen is fixed (preserved) and sectioned Specimen is stained to distinguish anatomical

structuresAcidic stain – negatively charged dye moleculesBasic stain – positively charged dye molecules


Microscopic Anatomy

Scanning electron microscopy Heavy metal salt stain – deflects electrons in the

beam to different extents Artifacts

Minor distortions of preserved tissues Not exactly like living tissues and organs


Clinical Anatomy – An Introduction to MedicalImaging Techniques

X ray – electromagnetic waves of very short length Best for visualizing bones and abnormal dense

structures

Figure 1.14


Clinical Anatomy – An Introduction to MedicalImaging Techniques

Variations of X ray Fluoroscope – images are viewed on a fluorescent

screenAllows viewing of internal organs as they move

Cineradiography – uses X-ray cinema film to record organ movements


Advanced X-Ray Techniques

Computed (axial) tomography (CT or CAT) – takes successive X rays around a person's full circumference Translates recorded information into a detailed

picture of the body section This technique receives information only from

transverse planes and adds them up to form a 3D image.



Digital subtraction angiography (DSA) imaging provides an unobstructed view of small arteries DSA is often used to identify blockages of arteries

that supply the heart or brain



Positron emission tomography (PET) – forms images by detecting radioactive isotopes injected into the body

Sonography (ultrasound imaging) – body is probed with pulses of high-frequency sound waves that echo off the body's tissues Imaging technique used to determine the age of a

developing fetus



Magnetic resonance imaging (MRI) – produces high-quality images of soft tissues Distinguishes body tissues based on relative water

content

Figure 1.19a

chapter 1: the human body: an orientation

Documents

body organsprovides

normal body

common purposeorganismal

musclesblood cells

group of cells

discrete structure

connective tissue

common function