Chapter 1: The Human Organism

ANATOMY

‑ investigates the structure of the body
‑ to dissect, or cut apart and separate, the parts of the body for study

Two approaches in studying Anatomy

Systemic anatomy
Regional anatomy

Systemic anatomy

study of the body by systems

Regional Anatomy

study of the body by areas

Two ways to examine structures

Surface anatomy

Surface anatomy

study of external features

Anatomical imaging

involves the use of technologies such as x-ray, ultrasound, MRI

PHYSIOLOGY

deals with the process or functions of living things

SIX LEVELS OF ORGANIZATION OF THE BODY

Chemical Level
Cell Level
Tissue Level
Organ Level
Organ System Level
Organism Level

Chemical Level

involves how atoms interact and combine into molecules

Cell Level

molecules combine to form organelles

Cells

basic structure and functional units of organisms

Organelles

small structures that make up some cells

Tissue Level

group of similar cells and surrounding materials

Four types of tissue

epithelial, connective, muscle, and nervous

Organ level

composed of two or more tissue types that together perform one or more common functions

Organ System Level

group of organs classified as unit because of a common function or set of functions

Organism Level

organ systems make up an organism

organism

any living thing considered as a whole, whether composed of one cell, such as bacterium, or of trillions of cells, such as human

Integumentary System

provides protection, regulates temperature, prevents water loss, helps produce vitamin D

Parts of Integumentary System

skin, hair, nails, sebaceous glands and sweat glands

Skeletal System

provides protection and support, allows body movements, produces blood cells, and stores minerals and adipose tissue

Parts of Skeletal System

bones, associated cartilages, ligaments, joints

Muscular System

produces body movements, maintains posture, and produces body heat

Parts of Muscular System

muscles attached to the skeleton by tendons

Nervous System

major regulatory system that detects sensations and controls movements, physiological processes, and intellectual functions

Parts of Nervous System

brain, spinal cord, nerves, sensory receptors

Endocrine System

major regulatory system that influences metabolism, growth, reproduction, and many other functions

Parts of Endocrine System

endocrine glands that secrete hormones

Cardiovascular System

transports nutrients, waste products, gases, and hormones throughout the body; plays a role in the immune response and the regulation of body temperature

Parts of Cardiovascular System

heart, blood vessels, and blood

Lymphatic System

removes foreign substances from the blood and lymph, combats disease, maintains tissue fluid balance, and absorbs dietary fats from the digestive tract

Parts of Lymphatic System

Lymphatic vessels, lymph nodes, other lymphatic organs

Respiratory System

exchanges oxygen and carbon dioxide between the blood and air and regulates blood pH

Parts of Respiratory System

lungs and respiratory passages

Digestive System

performs the mechanical and chemical processes of digestion, absorption of nutrients, and elimination of wastes

Parts of Digestive System

mouth, esophagus, stomach, intestines, accessory organs

Urinary System

removes waste products from the blood and regulates blood pH, ion balance, and water balance

Parts of Urinary System

kidneys, urinary bladder, and ureters

Female Reproductive System

produces oocytes and is the site of fertilization and fetal development; produces milk for the newborn; produces hormones that influence sexual function and behaviors

Parts of Female Reproductive System

ovaries, uterine tubes, uterus, vagina, mammary glands, and associated structures

Male Reproductive System

produces and transfers sperm cells to the female and produces hormones that influence sexual functions and behaviors

Parts of Male Reproductive System

testes, accessory structures, ducts, and penis

SIX CHARACTERISTICS OF LIFE

Organization
Metabolism
Responsiveness
Growth
Development
Reproduction

Organization

specific relationship of the many individual parts of an organism

Metabolism

ability to use energy to perform vital functions, such as growth. Movement, and reproduction

Responsiveness

ability of an organism to sense changes in the environment and make the adjustments that help maintain its life

Growth

increase in size of all or part of the organism; it can result from an increase in cell number, cell size, or the amount of substance surrounding cells

Development

changes an organism undergoes through time

differentiation

change in cell structure and function from generalized to specialized

morphogenesis

the change in shape of tissues, organs, and the entire organism

Reproduction

formation of new cells or new organisms

HOMEOSTASIS

maintenance of a relatively constant environment within the body

homeo

the same

stasis

to stop

Homeostasis mechanisms

maintain body temperature near set point (e.g., sweating or shivering)

variables

range of conditions that affect cell's fluid

set point

average normal value

Negative Feedback

- to decrease
- any deviation from the set point is made smaller or is resisted

Three components of negative-feedback mechanisms

Receptor
Control center
Effector

Receptor

monitors the value of a variable by detecting stimuli

Control center

determines the set point for the variable and receives input from the receptor about the variable

Effector

change the value of the variable when directed by the control center

Positive Feedback

‑ to increase
‑ occur when the initial stimulus further stimulates the response
‑ at times, this type of response is required to re-achieve homeostasis

Body Positions

Anatomical Position
Supine
Prone

Anatomical Position

a person standing upright with the face directed forward, upper limbs hanging to the sides, and palms facing forward

Supine

lying facing upward

Prone

lying facing downward

Body Parts and Regions

Central region
Upper Limb
Lower Limb

Central region

• Head
• Neck
• Trunk
o Thorax (chest)
o Abdomen (belly)
o Pelvis (hips)

Upper Limb

• Arm -shoulder to elbow
• Forearm -elbow to wrist
• Wrist
• Hand

Lower Limb

• Thigh -hip to knee
• Leg -knee to ankle
• Ankle
• Foot

Four Quadrants

Right upper quadrants
Left upper quadrants
Right lower quadrants
Left lower quadrants

Right Upper Quadrant

Liver, stomach, gallbladder, duodenum, right kidney, pancreas, transverse colon, right adrenal gland, small intestine

Left Upper Quadrant

Liver, left adrenal gland, stomach, left kidney, pancreas, spleen, transverse colon, small intestine

Right Lower Quadrant

Small intestine, large intestine, cecum, appendix, right ureter, right reproductive organs (ovary, fallopian tube, spermatic cord)

Left Lower Quadrant

Small intestine, large intestine, left ureter, left reproductive organs (ovary, fallopian tube, spermatic cord, sigmoid colon)

Nine Regions

Right hypochondriac
Epigastric
Left hypochondriac
Right lumbar
Umbilical
Left lumbar
Right iliac
Hypogastric

Right hypochondriac

Liver, right kidney, small and large intestines

Epigastric

Liver, stomach, duodenum, spleen, adrenal glands, pancreas

Left hypochondriac

Liver's tip, stomach, pancreas, left kidney, spleen, small and large intestines

Right lumbar

Ascending colon, small intestine, and right kidney

Umbilical

Duodenum, small intestine, and transverse colon

Left lumbar

Descending colon, small intestine, left kidney

Right iliac

Appendix, cecum, ascending colon, and small intestine

Hypogastric

Bladder, sigmoid colon, small intestine, reproductive organs

Planes

Sagittal plane
Median plane or midsagittal
Transverse or horizontal plane
Frontal or coronal plane

Sagittal plane

runs vertically through the body; separates right and left parts

Median plane or midsagittal

sagittal plane that passes through the midline; equal right and left

Transverse or horizontal plane

parallel to the surface of the ground; dividing superior and inferior

Frontal or coronal plane

vertically from right to left; dividing anterior and posterior

Longitudinal section

cut along the length of the organ

Transverse section

cross section; cuts completely through an organ

Oblique section

cut is made diagonally across the long axis

Body Cavities

Thoracic cavity
Abdominal cavity
Pelvic cavity
Abdominopelvic cavity

Thoracic cavity

surrounded by the rib cage; superior to muscular diaphragm

Mediastinum

divides thoracic into left and right; houses the heart, thymus, trachea, and esophagus

Abdominal cavity

contains stomach, intestines, liver, spleen, pancreas, and kidneys; posterior to muscular diaphragm; bounded by abdominal muscles

Pelvic cavity

enclosed by pelvic bones; urinary bladder, part of large intestines, internal reproductive organs

Abdominopelvic cavity

abdominal and pelvic cavities