The Human Body: An Orientation

Anatomy

The study of the structure and shape of the body and its parts and their relationships to one another.

Gross Anatomy

Study of large structures visible to the eye.

Microscopic Anatomy

Study of minute structures naked to the eye.

Physiology

The study of how the body and its parts work or function.

1. Chemical Level

2. Cellular Level

3. Tissue Level

4. Organ Level

5. Organ System Level

6. Organismal Level

6 levels of structural organization

Integumentary System

Skeletal System

Muscular System

Nervous System

Endocrine System

Cardiovascular System

Lymphatic System

Respiratory System

Digestive System

Urinary System

(Male & Female) Reproductive System

Organ System

Integumentary System

External and primary defense

Skeletal System

Protects and supports body organs, produces rbc and wbc

Muscular System

Manipulation of movement

Nervous System

Control System

Endocrine System

Glands that secretes hormones, communication of all organs

Cardiovascular System

Distribution of blood, transports blood and oxygen

Lymphatic System

balances fluid levels, fights germs, and absorbs fats

Respiratory System

keeps blood constantly supplied with oxygen and removes carbon dioxide, gaseous exchange

Digestive System

breaks down food, absorption of nutrients

Urinary System

eliminates wastes

Reproductive System

production of offspring

Testes

produces sperm and male sex hormone

Ovaries

produces eggs and female sex hormones

Mammary Glands

produce milk

1. Movement

2. Responsiveness

3. Digestion

4. Metabolism

5. Excretion

6. Reproduction

7. Growth

8. Maintaining Boundaries

Processes in the Body

Movement

Substances like blood, food, air, and urine are propelled through internal organs.

 Responsiveness

The ability to sense environmental changes and react to them.

Digestion

Breaking down food into simple molecules for absorption into blood.

Metabolism

All chemical reactions in cells, producing energy (ATP) and cell structures.

Excretion

The process of removing excreta or wastes from the body.

Reproduction

Production of offspring, occurring at cellular or organismal levels.

Growth

Increase in cell or body size through constructive cellular activities.

Maintaining Boundaries

Ensuring the internal environment remains distinct from the external.

1. Nutrients

2. Oxygen

3. Water

4. Thermoregulation

5. Atmospheric Pressure

Survival Needs

Nutrients

Chemical substances used for energy and cell building, obtained via diet.

Oxygen

Essential for releasing energy from foods through cellular respiration.

Water

Provides the liquid environment required for metabolic reactions and transport.

Thermoregulation

Maintaining body temp at ~37°C so chemical reactions can occur optimally.

Atmospheric Pressure

The force of air on the body, necessary for proper breathing and gas exchange.

Processes in the Body

The essential functions required to maintain human life

Survival Needs

The essential environmental and chemical factors required to sustain human life

Superior (cranial)

Toward the head end or upper part of a structure or the body; above.

Inferior (caudal)

Away from the head end or toward the lower part of a structure or the body; below.

Ventral (anterior)

Toward or at the front of the body; in front of.

Dorsal (posterior)

Toward or at the backside of the body; behind.

Medial

Toward or at the midline of the body; on the inner side of.

Lateral

Away from the midline of the body; on the outer side of.

Intermediate

Between a more medial and a more lateral structure.

Proximal

Close to the origin of the body part or the point of attachment of a limb to the body trunk.

Distal

Farther from the origin of a body part or the point of attachment of a limb to the body trunk.

Superficial (external)

Toward or at the body surface.

Deep (internal)

Away from the body surface; more internal.

Median (midsagittal) plane

An imaginary vertical plane that runs straight down the center of the body or organ. It bisects the structure exactly along the midline, dividing it into perfectly symmetrical right and left halves.

Frontal (coronal) plane

An imaginary vertical line that divides the body or its parts into front (anterior) and back (posterior) sections.

Transverse plane

An imaginary horizontal line that divides the human body into upper (superior) and lower (inferior) halves.

Body cavities

are the large fluid-filled spaces inside the human body that hold, protect, and support internal organs

Dorsal Body Cavity

Protects the nervous system organs and is divided into two major subdivisions

Cranial Cavity

Encases the brain

Spinal Cavity

Runs within the bony vertebral column to enclose the delicate spinal cord.

Ventral Body Cavity

Houses the internal organs (viscera) and contains two main subdivisions

Thoracic Cavity

Surrounded by ribs and chest muscles; contains heart and lungs

Abdominal Cavity

Contains stomach, intestines, spleen, and liver

Pelvic Cavity

Contains urinary bladder, reproductive organs, and rectum

Nasal Cavity

Located within and posterior to the nose. Lined with a respiratory mucosa that warms, filters, and moistens incoming air during breathing.

Orbital Cavity

Located in the skull, housing the eyes and presenting them in an anterior position. Contains associated skeletal muscles, nerves, and tear ducts.

Middle Ear Cavity

Carved into the temporal bones. Houses the auditory ossicles (malleus, incus, and stapes) that transmit sound vibrations to the hearing receptors.

Right Upper Quadrant (RUQ)

Left Upper Quadrant (LUQ)

Right Lower Quadrant (RLQ)

Left Lower Quadrant (LLQ)

4 Quadrants of the Abdomen

• Liver
• Gallbladder
• Duodenum

Right Upper Quadrant (RUQ)

• Stomach
• Spleen
• Pancreas

Left Upper Quadrant (LUQ)

• Cecum
• Appendix
• Right Ovary

Right Lower Quadrant (RLQ)

• Sigmoid Colon
• Left Ovary

Left Lower Quadrant (LLQ)

1. Right hypochondriac region

2. Right lumbar region

3. Right iliac (inguinal) region

4. Epigastric region

5. Umbilical region

6. Hypogastric (pubic) region

7. Left hypochondriac region

8. Left lumbar region

9. Left iliac (inguinal) region

9 Regions of the Abdomen

• Liver

• Gallbladder

Right hypochondriac region

Ascending colon of large intestine

Right lumbar region

• Cecum

• Appendix

Right iliac (inguinal) region

• Stomach

Epigastric region

• Transverse colon of large intestine

Umbilical region

• Initial part of sigmoid colon

• Urinary bladder

Hypogastric (pubic) region

• Diaphragm

Left hypochondriac region

• Descending colon of large intestine

Left lumbar region

• Initial part of sigmoid colon

Left iliac (inguinal) region

Homeostasis

maintains the body stability and temperature

Dynamic Balance

The ability of the body to maintain relatively stable internal conditions even though the outside world is continuously changing.

Negative Feedback/Stimulus Reduction

Shutting off or reducing the original stimulus to maintain a stable, healthy internal balance.

Positive Feedback/Stimulus Increase

Increasing or reinforcing the original stimulus or disturbance in the body. Uncommonly seen under normal conditions.

1. Stimulus

2. Receptor

3. Control Center

4. Effector

5. Response

Control System

Stimulus

produces change in variable

Receptor

detects change

Input

Information is sent along afferent pathway to control center

Control Center

determines the level at which a variable is to be maintaines

Response

of effector feeds back to reduce the effect of stimulus and returns variable to hemeostatic label