Body Organization Flashcards
Chemical level
Atoms bond to form molecules
Cellular level
Molecules combine to form the fluid & organelles of a body cell
Tissue level
Similar cells form a body tissue
Organ level
2+ different tissues combine to form an organ
Organismal level
Many organ systems work to perform functions of an independent organism
Elements
Unique pure substances - components of everything in the universe
Atom
Smallest unit of any element
Molecule
2+ atoms combined
Cell
Smallest independently functioning unit of a living organism
Tissue
Group of many similar cells that work together to perform a specific function
Organ
Distinct structure of the body composed of 2 or more tissue types
Organ system/ body system
Group of organs that work together to perform major functions and meet the physiological needs of the body
Organism
The highest level of organization
Anterior (ventral)
Front or direction toward the front of the body
Posterior (dorsal)
Back or direction toward the back of the body
Superior (cranial)
A position above or higher than another part of the body
Inferior (caudal)
A position below or lower than another part of the body
Lateral
The side or direction toward the side of the body
Medial
Middle or direction toward the middle of the body
Supine
Horizontal position with the body facing upward
Prone
Horizontal position with the body facing downward
Section
2 dimensional surface that has been “cut” from a 3 dimensional structure
Plane
Imaginary 2 dimensional surface that passes through the body
Sagittal plane (lateral plane)
Divides the body/organ vertically into right and left sides
Midsagittal plane
When a sagittal plane runs directly down the middle of the body or an organ
Frontal plane (coronal plane)
Divides the body/organ into an anterior (front) and posterior (rear) portion
Transverse plane (axial plane)
Divides the body or organ horizontally into upper and lower portions. Transverse planes produce images referred to as cross-sections.
Dorsal/Posterior and Ventral/Anterior Cavities
Largest body components
Posterior/Dorsal Cavity
Contains the cranial cavity (brain, pineal and pituitary glands) and the spinal/vertebral cavity (enclosed the spinal cord)
Anterior/Ventral Cavity
Thoracic cavity and abdominopelvic cavity
Thoracic cavity
More superior subdivision of the ventral cavity
Enclosed by rib cage
Contains heart, lungs, trachea, bronchial tubes
Mediastinum
Located between the lungs, contains, heart, trachea, esophagus, bronchial tubes
Pericardial cavity
Within the mediastinum and is formed from the pericardium, which is a double membrane that surrounds the heart
Pleural cavity
A smaller cavity within the thoracic cavity
Lungs are protected by a double membrane called the pleura
The space between the pleura is the pleural cavity
Diaphragm
A muscle that forms the floor of the thoracic cavity and separates it from the more inferior abdominopelvic cavity
Abdominopelvic cavity
Largest cavity in the body, Inferior subdivision of the ventral cavity
Not divided by a membrane
Houses the abdominal and pelvic cavities
Abdominal cavity
Houses digestive organs (stomach, liver, gallbladder, small and large intestines)
Organs are surrounded by a double membrane called the peritoneum
Peritoneal cavity
The space between the double membrane that is the peritoneum
Peritoneum
Adds protection and supports and reduces friction between the abdominal and pelvic organs
Pelvic cavity
Inferior to the abdominal cavity
Contains male or female reproductive organs, urinary system organs (urinary bladder, urethra, ureters), rectum, anus
Spine
Spinal column, vertebral column
Vertebrae separated by intervertebral discs
33 vertebrae (decreases with age to 24)
5 regions, increasing order from top to bottom
Cervical
7 bones
C1-C7
Neck
Thoracic
12 bones
T1-T12
Trunk, essentially
Lumbar
5 bones
L1-L5
Lower back
Sacral
5 fused bones
Sacrum is the fusion of sacral vertebrae
Coccygeal
4 fused bones
Coccyx (tailbone) is the fusion of coccygeal vertebrae
Vertebra
A body, a vertebral arch, seven processes
Body (vertebra)
Front portion of a vertebra
Supports the body’s weight
Vertebral arch
Back portion
The large opening between the vertebral arch and the body contains the spinal cord
Seven Processes
Outgrowths that arise from the vertebral arch, serve various functions, including attachments for muscles and ribs
