Anatomy is the study of external structures while physiology is the study of how these
structures function. Both are very closely linked together. The two sciences must be studied
together in order to gain a better understanding of how the body works. Once you understand
one, you will understand the other.
The levels of organization are molecular🡪cell🡪tissue🡪organ🡪organ system🡪 organism
Major Functions of Organ Systems
Integumentary system: Protection from environmental hazards, temperature control
Skeletal system: support, protection of soft tissues, mineral storage, blood formation
Muscular system: locomotion, support, heat production
Nervous system: directing immediate responses to stimuli, by coordinating the activities of
other organ systems
Endocrine: directing long term changes in the activities of other organ systems
Cardiovascular: internal transport of cell & dissolved materials like nutrients, wastes and gases.
Lymphoid system: defense against infection and disease
Respiratory: delivery of air to sites where gas exchange can occur between the air and
circulating blood
Digestive: processing of food and absorption of organic nutrients, mineral, vitamins, and water
Urinary: elimination of excess of water, salts, and waste products; controls PH
Reproductive: production of sex cells and hormones.
Radiological techniques:
The different radiologic techniques used in the medical field are X-rays, CT/CAT scans,
Angiography, MRIs, PET scans, and sonography.
An X-ray is an electromagnetic wave of short lengths. This technique is best used to see bones
and abnormal dense structures. Structure can be told apart due to their density (air-dark,
fat-less dark, tissues-grey, bone-white, metal-bright white). *if you are trying to view multiple
objects of the same density, contrast is needed* For best observations it is best to take an
anterior-posterior and posterior-anterior view.
Computed (axial) tomography uses a single x-ray source rotating around the body. It completes
1 revolution in a few seconds, & then moves a short distance and repeats the process. In
comparing the images from each point in rotation the computer reconstructs 3-D images of the
body.
Angiography contrast substance highlights vessel structures.
Digital subtraction angiograph (DSA) x-rays are taken before & after radiopaque dye is
injected. The computer “subtracts” details common to both images
Magnetic resonance imaging (MRI) produces high contrast images of soft tissues. It
distinguishes tissues based on relative water content. Hydrogen atoms in our body act as a
magnet, aligning with a strong magnetic field. A pulse then disperses the atoms, which realign
creating an image detected by MRI computers.
Positron emission tomography (PET) forms images by detecting radioactive isotopes (H2O or
sugar) injected into the body. These molecules will identify regions with high metabolic activity.
Sonography (ultrasound imaging) body is probed with pulses of high-frequency sound waves
that echo off the body’s tissues.
Sound can be transmitted or reflected.
Fluid=dark=sound goes through
Soft tissue=gray=sound can be transmitted or reflected
Bone=bright=sound is always reflected
Anatomical position in this position the person stands with the legs together & the feet flat on
the floor. Hands at the sides, palms facing forward.
A person laying down in the anatomical position is said to be supine when lying face up. When
lying face down, the person is prone.
The abdominopelvic surface is divided into four segments (abdominopelvic quadrants), right
lower quadrant (RLQ), left lower quadrant (LLQ), right upper quadrant (RUP), left upper
quadrant (LUQ), or nine regions (abdominopelvic regions) right & left hypochondriac region,
epigastric regions, right & left lumbar region, umbilical region, right & left inguinal region and
hypogastric region.
RUQ: most of liver, gallbladder
LUQ: most of stomach, spleen
RLQ: cecum, appendix, right ureter, right ovary, right spermatic cord
LLQ: left ureter, left ovary, left spermatic cord
Epigastric: left lobe of liver
Right hypochondriac: right lobe of liver, liver fundus
Left hypochondriac: stomach fundus, spleen
Umbilical: small intestine, transverse colon
Right lumbar: ascending colon
Left lumbar: descending colon
Hypogastric: urinary bladder, appendix, major portion of small intestine
Right inguinal: cecum, appendix
Left inguinal: sigmoid colon
Common directional terms
Anterior: nearer to the front of the body
Posterior: nearer to the back of the body
Superior: toward the head
Inferior: away from the head
Proximal: nearer to the attachment of a limb to the trunk
Distal: farther from the attachment of a limb to the trunk
Lateral: farther from the midline
Medial: nearer to the midline
SECTIONAL ANATOMY
sagittal cut: separating right and left
midsagittal: separating right and left equally
parasagittal: separating left and right
unequally
transverse cut: separating superior and inferior
frontal(coronal) cut: separating anterior posterior
oblique cut: separating the tissue at an angle
BODY CAVITIES
Body cavities protect delicate organs and permit changes in size and shape of visceral organs.
In order to be a true cavity there must be TWO membranes.
● Posterior Cavity
o Cranial cavity: brain
o Spinal cavity: spinal cord
● Anterior cavity
o Thoracic cavity
▪ Pleural cavity: lungs
▪ Pericardial cavity: heart
▪ Mediastinal cavity: space btw apex of the lungs. Contains pericardial
cavity.
o Abdominal cavity
▪ Peritoneal cavity: stomach, intestines, spleen, liver)
▪ Retroperitoneal cavity: kidneys
o Pelvic cavity
▪ Urinary bladder