The scientific study of the structure and relationships between body parts.
The scientific discipline of how the body and its parts come together to function.
Structural and Functional Organization
Atoms combine to form molecules.
Molecules form organelles, such as the nucleus and mitochondria, which make up cells.
A group of similar cells and the materials surrounding them.
Two or more tissue types that together perform one or more common functions.
Organ System Level
A group of organs classified as one unit because of a common function/set of functions.
Any living thing considered as a whole.
Chemical → Cell → Tissue → Organ → Organ System → Organism
Characteristics of Life
The scientific interrelationships among the parts of an organism and how those parts interact to perform specific functions.
The ability to use energy to perform vital functions.
The ability of an organism to sense changes in the environment and make the adjustments that help maintain its life.
Refers to an increase in size of all or part of the organism.
Changes an organism undergoes through time.
Formation of new cells or new organisms.
The ability of all living systems to maintain stable, internal conditions no matter what changes are occurring outside the body.
Four interacting components of most homeostatic mechanisms:
Stimulus → Receptor → Control Center → Effector
Stimulus - Indicates that the value of the variable has deviated from the set point/normal range.
Receptor - Monitors the value and sends data to the control center.
Control Center - Establishes the set point.
Effector - Acts on the signal from the control center to move the variable back to the set point.
Serves to reduce an excess response and keep a variable within the normal range.
Serves to intensify a response until endpoint is reached.
The response stops the effector.
The response keeps the reaction going.
Ex. Temperature & blood pressure regulation
Ex. Childbirth & blood clotting
A person standing erect with the face directed forward, the upper limbs hanging to the side, and the palms of the hands facing forward.
When a person is lying face upward
When a person is lying face downward
Front of the body
Back of the body
Towards the top
Towards the bottom
Towards the trunk
Further from the trunk
Structures toward the midline
Structures farther away from the midline
Divides the body into left and right sides (vertically)
Median Plane/Mid-Sagittal Plane
Passes through the midline of the body; divides the body into left and right halves
Parallel to the sagittal plane, but off to one side
Divides the body into front and back (vertically)
Divides the body into top and bottom (horizontally)
Body Parts and Regions
Head, neck, and trunk
Arms and legs (upper & lower limbs)
Abdominal quadrants consist of four subdivisions.
Abdominal regions consist of nine subdivisions.
The two main cavities are called the ventral and dorsal cavities.
Ventral Cavity - Consists of the following: the thoracic cavity. abdominal cavity, and the pelvic cavity.
Dorsal Cavity - Contains organs lying more posterior in the body. Can be divided into two portions: (1) the upper portion or the cranial cavity houses the brain (2) the lower portion or vertebral canal houses the spinal cord.
It is surrounded by the rib cage, separated from the abdominal cavity by the diaphragm, and is divided into right and left parts by a median structure called mediastinum.
Bounded primarily by the abdominal muscles and contains the stomach, intestines, liver, spleen, pancreas, and the kidneys.
A small space enclosed by the bones of the pelvis and contains the urinary bladder, part of the large intestine, and the internal reproductive organs.
Mediastinum - Is a partition containing the heart, thymus, trachea, esophagus, and others. Two lungs are located on each side of the mediastinum.
The abdominal and pelvic cavities are not physically separated and sometimes are called the abdominopelvic cavity.
Serous membranes - Secrete fluid that fills the space between the parietal and visceral membranes. The serous membranes protect organs from friction.
Serous membranes lining the thoracic cavity:
Heart: Pericardial cavity - visceral & parietal pericardium - pericardial fluid
Lungs: Pleural cavity - visceral & parietal pleura - pleural fluid
Serous membranes lining the abdominopelvic cavity:
Peritoneal cavity - visceral & parietal peritoneum - peritoneal fluid
Mesenteries & Retroperitoneal Organs
Mesenteries - Are parts of the peritoneum that hold the abdominal organs in place and provide a passageway for blood vessels and nerves to organs.
Retroperitoneal organs - Are found behind the parietal peritoneum and consists of the kidneys, adrenal glands, pancreas, parts of the intestines, and the urinary bladder.
11 Major Organ Systems