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C H A P T E R

1The Human Body: An OrientationAn Orientation

An Overview of Anatomy

• Anatomy• The study of the structure of the human body

• Physiology• The study of body functiony y

Anatomy - Study of internal and external body structures

• Gross Anatomy

• Surface Anatomy

• Systemic Anatomy

• Regional Anatomy

• Microscopic Anatomy

• Comparative Anatomy

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Chemical levelAtoms combine to form molecules.

Cellular level Cells are made up of molecules.

Tissue levelTissues consist of similar types of cells

Cardiovascular system

OrganelleMoleculeAtomsSmooth muscle cell

Smooth muscle tissue

Blood vesselHeartBlood

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The Hierarchy of Structural Organization

Organ levelOrgans are made up of different types of tissues.

Organ system level Organ systems consist of different organs that work together closely.

Organismal levelThe human organism is made up of many organ systems.

Connective tissue

(organ)Bloodvessels

Epithelialtissue

Smooth muscle tissue

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Figure 1.1

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Body Regions and Directional Terms

• Axial Region: head, cervical (neck), and trunk (thoracic region and abdominal region)

• Appendicular region: upper and lower limbs.

Gross Anatomy—An Introduction

Figure 1.3a

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Gross Anatomy—An Introduction

Figure 1.3b

Orientation and Directional Terms

Table 1.1 (1 of 3)

Orientation and Directional Terms

Table 1.1 (2 of 3)

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Orientation and Directional Terms

Table 1.1 (3 of 3)

Body Planes and Sections

Figure 1.4

Cranial cavity(contains brain

Dorsal bodycavity

Thoraciccavity(contains

Body Cavities and Membranes

Vertebral cavity(contains spinal cord) Abdominal cavity

(contains digestiveviscera)

Diaphragm

Pelvic cavity(contains urinary bladder, reproductive organs, and rectum)

heart andlungs)

(a) Lateral view

Dorsal body cavity

Ventral body cavity

Figure 1.6a

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Body Cavities and MembranesCranialcavity

SuperiormediastinumPleuralcavity

Vertebralcavity

Thoraciccavity(contains

Dorsal body cavity

Ventral body cavity

Pericardialcavity withinthe mediastinum

cavity

Abdomino-pelviccavity

Ventral bodycavity(thoracic andabdominopelviccavities)

Abdominal cavity(contains digestiveviscera)

Diaphragm

Pelvic cavity(contains urinary bladder, reproductive organs, and rectum)

(heart andlungs)

(b) Anterior viewFigure 1.6b

Serous Membranes

Produce a lubricating fluid Allows organs to slide over one another

without friction. Contains infection of one organ from Contains infection of one organ from

spreading to another organ. Covering lungs- pleura Covering the abdominal cavity- peritoneum Covering the heart-pericardium

Body Cavities and Membranes

Outer balloon wall (comparable to parietal serosa)

Air (comparable to serous cavity)

Figure 1.7d

( p y)

Inner balloon wall (comparable to visceral serosa)

(d) Model of the serous membranes and serous cavity

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Lung

Parietal pleura

Ribs

Pleural cavity

Body Cavities and Membranes

Pleural cavity with serous fluid

Visceral pleura

Diaphragm

(a) Serosae associated with the lungs: pleuraFigure 1.7a

Heart

Parietal pericardium

Pericardial cavity

Body Cavities and Membranes

Pericardial cavity with serous fluid

Visceral pericardium

(b) Serosae associated with the heart: pericardiumFigure 1.7b

Peritoneal

Anterior Visceral peritoneum

Liver

Body Cavities and Membranes

Parietalperitoneum

Wall ofbody trunk

Kidney(retroperitoneal)

cavity (withserous fluid)Stomach

(c) Serosae associated with the abdominal viscera: peritoneum

Posterior

Liver

Figure 1.7c

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• 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 oftencalled a “cross section”called a cross section .

3. A coronal section divides the body into anterior and posterior sections.

Abdominal Regions

Liver Diaphragm Spleen

Figure 1.8a, b

Epigastricregion

Umbilicalregion

Rightlumbarregion

Leftlumbarregion

Righthypochondriac

region

Lefthypochondriac

region

Hypogastric(pubic)region

Right iliac(inguinal)

region

Left iliac(inguinal)

region

(a) Nine regions delineated by four planes

Gallbladder

Ascending colon oflarge intestineSmall intestine

Appendix

Cecum

Stomach

Descending colonof large intestine

Transverse colonof large intestine

Initial part ofsigmoid colonUrinary bladder

(b) Anterior view of the nine regions showing thesuperficial organs

Abdominal Quadrants

Right upperquadrant(RUQ)

Right lowerquadrant(RLQ)

Left upperquadrant(LUQ)

Left lowerquadrant(LLQ)

(c) The four abdominopelvic quadrantsFigure 1.8c