Lecture 2 the Human Body

8/13/2019 Lecture 2 the Human Body

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The Human Body: Anatomical

Regions, Directions, and Body

Cavities

Lecture 22013


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Overview of Anatomy and Physiology

Anatomythe study of the structure ofbody parts and their relationships to one

another

Gross or macroscopic Microscopic

Developmental

Physiologythe study of the function of thebodys structural machinery


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Gross Anatomy

Regionalall structures in one part of the

body (such as the abdomen or leg)

Systemicgross anatomy of the body

studied by system

Surfacestudy of internal structures as

they relate to the overlying skin


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Microscopic Anatomy

Cytologystudy of the cell

Histologystudy of tissues


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Developmental Anatomy

Traces structural changes throughout life

Embryologystudy of developmentalchanges of the body before birth


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Physiology

Considers the operation of specific

organ systems

Renalkidney function

Neurophysiologyworkings of the nervous

system

Cardiovascularoperation of the heart and

blood vessels

Focuses on the functions of the body,

often at the cellular or molecular level


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Physiology

Understanding physiology also requires a

knowledge of physics, which explains

electrical currents, blood pressure, and the

way muscle uses bone for movement


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Principle of Complementarity

Function always reflects structure

What a structure can do depends on itsspecific form


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Chemical level

Atoms combine to

form molecules

1

2

3

4

Cellular level

Cells are made up of molecules

Tissue level

Tissues consist of

similar types of

cells

5 Organ system level

Organ systems consist of different organs

that work together closely

Organ level

Organs are made up of

different types of tissues

6 Organismal level

The human organism is

made up of many organ

systems

Atoms

Molecules

Smooth m uscle cel l

Smooth

muscle

t issue

Connectivetissue

Smoothmuscletissue

Epithelialtissue

Bloodvessel

(organ)

Heart

Blood

vessels

Cardiovascular

system

Levels of Structural Organization

Figure 1.1


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Levels of Structural Organization

Chemicalatoms combined to form molecules Cellularcells are made of molecules

Tissueconsists of similar types of cells

Organmade up of different types of tissues

Organ systemconsists of different organs

that work closely together

Organismalmade up of the organ systems


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Homeostasis

Homeostasis is the ability to maintain a

relatively stable internal environment in an

ever-changing outside world

The internal environment of the body is in

a dynamic state of equilibrium

Chemical, thermal, and neural factors

interact to maintain homeostasis


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Homeostatic Imbalance

Disturbance of homeostasis or the

bodys normal equilibrium

Overwhelming of negative feedback

mechanisms allowing destructive positive

feedback mechanisms to take over


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Anatomical Position

Body erect

Feet slightly apart

Palms facing forward Thumbs point away

from body

Figure 1.7a


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Directional Terms

Superior and inferiortoward and away

from the head, respectively

Anterior and posteriortoward the front

and back of the body

Medial, lateral, and intermediate

toward the midline, away from the midline,

and between a more medial and lateral

structure


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Directional Terms

Proximal and distalcloser to and

farther from the origin of the body

Superficial and deeptoward and away

from the body surface


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Directional Terms Table 1.1


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Directional Terms Table 1.1


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Regional Terms: Anterior View

Axialhead,

neck, and

trunk

Appendicular

appendages

or limbs

Specific

regional

terminology

Figure 1.7a


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Regional Terms: Posterior View

Figure 1.7b


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Body Planes

Sagittaldivides the body into right and

left parts

Midsagittal or medialsagittal plane that

lies on the midline

Frontal or coronaldivides the body intoanterior and posterior parts

Transverse or horizontal(cross section)

divides the body into superior andinferior parts

Oblique sectioncuts made diagonally


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Body Planes Figure 1.8


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Anatomical Variability

Humans vary slightly in both externaland internal anatomy

Over 90% of all anatomical structures

match textbook descriptions, but:

Nerves or blood vessels may be

somewhat out of place

Small muscles may be missing Extreme anatomical variations are

seldom seen


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Body Cavities

Figure 1.9a


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Body Cavities

Thoracic cavityis subdivided into pleural

cavities, the mediastinum, and the

pericardial cavity

Pleural cavitieseach houses a lung

Mediastinumcontains the pericardial

cavity, and surrounds the remaining

thoracic organs

Pericardial cavityencloses the heart


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Body Cavities

The abdominopelvic cavity is separatedfrom the superior thoracic cavity by the

dome-shaped diaphragm

It is composed of two subdivisions Abdominal cavitycontains the

stomach, intestines, spleen, liver, and

other organs Pelvic cavitylies within the pelvis and

contains the bladder, reproductive

organs, and rectum


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B d C iti


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Body CavitiesFigure 1.9b


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Ventral Body Cavity Membranes

Parietal serosalines internal body walls

Visceral serosacovers the internalorgans

Serous fluidseparates the serosae


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Ventral Body Cavity Membranes

Figure 1.10a


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Other Body Cavities

Oral and digestivemouth and cavities

of the digestive organs

Nasallocated within and posterior to the

nose

Orbitalhouse the eyes

Middle earcontain bones (ossicles) that

transmit sound vibrations

Synovialjoint cavities


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Abdominopelvic Regions

Umbilical

Epigastric

Hypogastric Right and left iliac

or inguinal

Right and leftlumbar

Right and left

hypochondriac Figure 1.11a


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Organs of the Abdominopelvic Regions

Figure 1.11b

Abd i l i Q d t


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Abdominopelvic Quadrants

Right upper (RUQ)

Left upper (LUQ)

Right lower(RLQ)

Left lower (LLQ)

Figure 1.12


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Lecture 2 the Human Body

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