Anatomical Terminology and Body Regions

• Anatomy is the study of the body's structures.
• The word "anatomy" originates from the Greek terms "ana," meaning "up," and "tome," meaning "a cutting.”
• Traditionally, anatomy studies involved dissecting organisms.
• Physiology is the branch of biology focused on the functions and activities of living organisms and their physical and chemical processes.

Branches of Anatomy and Physiology

• Gross Anatomy involves the macroscopic study of the whole body, examining features visible to the naked eye.
• Regional anatomy studies the anatomy of body parts
• Systemic anatomy studies body systems
• Surface anatomy studies what is underneath the surface
• Surface anatomy involves studying the external features of the body through sight, without dissection and is a branch of gross anatomy in addition to endoscopic and radiological anatomy.
• Microscopic Anatomy involves studying anatomy using a microscope.
• Cytology is the specific study of cells.
• Histology is the study of tissues, which are groups of cells.
• Developmental Anatomy studies the origins and development of structures, including embryology, which focuses on embryonic development.
• Pathological anatomy focuses on the study of disease
• Radiographic anatomy studies the relationship between anatomy and radiographic techniques
• Surgical anatomy is a specialized area of anatomy

Human Organization

• The first level of organization is at the chemical with atoms which interact and combine into molecules.
• The second level is cells are the basic structural and functional units of organisms.
• The third level is when tissues are composed of similar cells and the surrounding material.
• Organ is the fourth level which are composed of two or more tissue types performing a common function.
• Organ System is the fifth level which consists of a group of organs classified as a unit due to common function.
• Organism is the sixth level which are complex with organ systems that are mutually dependent upon one another.

Essential Characteristics of Life

• Organization refers to the specific relationship of the many individual parts of an organism.
• Metabolism provides the ability to use energy for vital functions.
• Responsiveness is the organism's ability to sense environmental changes and adjust to maintain life.
• Growth is the increase in size of all or part of an organism.
• Development includes the changes an organism undergoes through time.
• Reproduction forms new cells or organisms.

Homeostasis

• Homeostasis allows the body to maintain a stable set of internal conditions, such as temperature, also known as "Staying the Same”..
• It is also referred to as dynamic equilibrium because it keeps the body constantly moving toward “normal”, within a close range.

Mechanisms of Homeostasis

• The RECEPTOR provides data and recognizes a stimulus, reporting its value, such as temperature.
• The CONTROL CENTER decides how to handle the information, comparing the receptor input to the body's set point and determining necessary adjustments, with the hypothalamus as an example.
• The EFFECTOR carries out the plan, altering the organism's function based on control center output.

Types of Feedback in Homeostasis

• Negative Feedback opposes or negates the original stimulus, returning the organism to equilibrium and is the most common type of feedback.
• Positive Feedback enhances the original stimulus, temporarily moving the organism further from equilibrium, initiates a set of self-perpetuating events, includes an event to break the cycle, and it occurs infrequently, such as childbirth.

Language of Anatomy

• Anatomical Position defines a standard body orientation for anatomical descriptions, it involves standing upright, facing forward, legs parallel, and palms facing forward at the sides.

Body Planes

• Anatomical planes are hypothetical planes for describing structural location.
• Acronym SOFT helps to memorize the four primary types of body planes, which stands for Sagittal, Oblique, Frontal and Transverse
• Frontal/Coronal Plane: An imaginary vertical plane running through the body's center, dividing it into front (anterior) and back (posterior) regions.
• Lateral/Sagittal Plane: An imaginary vertical plane running from front to back, dividing the body into right and left regions.
• Midsagittal/Median Plane: A sagittal plane that divides the body into equal right and left halves.
• Parasagittal Plane: A sagittal plane that divides the body into unequal right and left regions.
• Transverse Plane: An imaginary horizontal plane dividing the body into upper (superior) and lower (inferior) regions.
• Oblique Plane: A plane at any angle other than horizontal or vertical, useful to remember phrase "obliques are odd angles"

Body Cavities

• Body cavities are fluid-filled spaces inside the body that hold and protect internal organs.
• Ventral and dorsal cavities are the two largest cavities
• Dorsal Cavity: Is at the posterior of the body, subdivided into the cranial and spinal cavities.
• Cranial cavity fills most of the upper skull and contains the brain.
• Spinal cavity is a long, narrow cavity inside the vertebral column running down the trunk while containing spinal cord.
• Ventral Cavity: Is the anterior of the trunk and includes lungs, heart, stomach, intestines, and reproductive organs.
• Thoracic and abdominopelvic cavities are the sub divisions of ventral.
• Thoracic Cavity: Is located in the chest with pleural cavities for lungs and the pericardial cavity for the heart.
• Abdominopelvic Cavity: Fills lower trunk, which is subdivided into the abdominal cavity for digestive organs and kidneys, and the pelvic cavity for the reproductive and excretion organs.

Directional Terms

• Directional terms describes the relationships of anatomical structures.
• Anterior: In front
• Axial: Around a central axis
• Bilateral: Involving both sides
• Caudal: Toward the tail
• Contralateral: On opposite sides
• Distal: Away from the origin
• Dorsal: Near the upper surface in the back
• Inferior: Below
• Intermediate: Between two structures
• Ipsilateral: On the same side
• Lateral: Toward the side
• Medial: Toward the mid-line
• Parietal: Relating to a body cavity wall
• Posterior: Toward the rear
• Proximal: Near the origin
• Rostral: Toward the front
• Superior: Above
• Unilateral: Involving one side
• Ventral: Toward the belly
• Visceral: Relating to organs within body cavities
• Superior/Inferior means above or below the head and umbilical respectively.
• Anterior/Posterior means front and back, with the heart being anterior to the spine and posterior to the breast bone.
• Medial/Lateral is midline and toward the side, where the heart is medial to the arm and the arms are lateral relative to the heart.
• Superficial/Deep means toward and away surface.
• Proximal/Distal means closer and further away from the midline.
• Abduction is taking away from the midline where adduction is going towards the midline
• Extension straightens a joint.
• Flexion bends the joint
• Hyperextension is over extension
• Hyperflexion is over bending
• Pronation rotates the forearm so the palm faces down where Supination rotates the forearm so that the palm is facing up
• Rotation is turning a body part around its axis
• Circumduction is a circular movement of any limb
• Dorsiflexion is the ankle flexion
• Plantarflexion are extension ankle
• Eversion – outward turning of the foot
• Inversion – inward turning of the foot

Body Positions

• Anatomical position
  • Standing erect, facing forward, arms at sides, palms forward, legs parallel, toes pointed forward.
• Decubitus position
  • Lying down, specifically according to the part of the resting on a flat surface as in left or right lateral, dorsal or ventral.
• Dorsal Recompant position
  • Lying on back, with legs bent and separated, feet flat
• Fowler position
  • Lying on back, head of bed raised about 18 inches, knees elevated
• Kraske (Jackknife) position
  • Prone with the buttocks raised
• Knee-chest position
  • On knees, head and upper chest on table, arms crossed above head
• Lateral recumbent position
  • The side position with one leg flexed and arm position will vary
• Lithotomy position
  • On back, legs flexed on abdomen, thighs apart
• Prone
  • Lying face down
• Sims position
  • The patient is lying on left side, right leg drawn up high and forward, left arm along back, chest forward resting on bed
• Supine
  • Lying face up on your spine
• Trendelenburg position
  • Lying on back with head lowered by tilting bed back at 45° angle

Movements of the Joints

• Pivot joints allow for the Atlantoaxial joint, C1 and C2 vertebrae articulation, allows the head to rotate left and right, also the proximal radioulnar joint
• Hinge joints allow for flexion and extension Knee, elbow, ankle, interphalangeal joints of fingers and toes
• Condyloid joints allow flexion/extension, abduction/adduction, and circumduction movements. Located In the Metacarpophalangeal knuckle joints of the finger, also the Radiocarpal wrist joint.
• Saddle joints allow flexion/extension, abduction/adduction, and circumduction movements and are first Carometacarpal joint of the thumb and sternoclavicular joint
• Plane joints allow for inversion and eversion of foot, flexion, extension, and lateral flexion of the vertebral column.
• Ball and socket joints allows flexion and extension, abduction and adduction, circumduction, and medial to lateral rotation movements like the shoulder or hip joints

Body Quadrants and Regions

• Regional terms designate specific areas of the body
• Abdominopelvic cavity: is subdivided into four quadrants and nine areas,
• Four quadrants: Right Upper, Right Lower, Left Upper, and Lower Quadrants
• Tenth division: Perineum
• Left Upper Quadrant includes the liver, has the larger portion of the stomach, contains the pancreas, includes the left kidney, encloses the spleen portions of the transverse and descending colon, and parts of the small intestine
• Right upper quadrant is comprised of the liver, includes the gallbladder, has the right kidney, also includes the ascending and transverse colon, and parts of the small intestine.
• Left lower quadrant is composed of the small intestine, also the large intestine, includes the left female reproductive organs, in addition to the left ureter.
• Right lower quadrant the cecum, is found in the appendix, contains a part of the small intestines, also the right female reproductive organs, and terminates with the right
• Abdominal Nine Divisions:
  • Right Hypochondriac: Contains the right portion of the liver, the gallbladder, the right kidney, and small intestine parts.
  • Left Hypochondriac: Contains part of the spleen, the left kidney, part of the stomach, the pancreas, and parts of the colon.
  • Epigastric: Above stomach, region primarily contains the stomach, part of the liver, pancreas, duodenum, spleen, and adrenal glands while region pushes out with breathing/diaphragm.
  • Right Lumbar: Includes the gallbladder, the right kidney, part of the liver, and the ascending colon.
  • Left Lumbar: Consists of the descending colon, the left kidney, and part of the spleen.
  • Umbilical: It contains the navel, and parts of the small intestine, the duodenum, the jejunum, and the illeum, in addition to the transverse colon and the kidneys.
  • Right Iliac: Contains the appendix, cecum, and the right inguinal region, while pain here can be associated with appendicitis.
  • Left Iliac: Contains descending and sigmoid colon with potential for pain being in the left inguinal region.
  • Hypogastric: Below the stomach, the region contains organs around the pubic bone(bladder, sigmoid colon, the anus) and reproductive

Cellular Organization

• Cellular organization refers to the components of the cell and how they are arranged within it.
• In animal cells there is no cell wall and no chloroplast, they have small vacuoles, lysosomes, and centrioles
• Plant cells contain cell walls and chloroplasts along with a large central vacuole with nucleases pushed to one side of the cell.
• Levels of Cellular Organization
• Cell Membrane: functions as a partially permeable barrier, permitting very few particles

Types of Tissues

• Epithelial tissues provide protection from physical, chemical, and biological wear, gatekeepers of the body controlling chemical passage

• The outer layer of your skin

• The outer layer of your skin is the cells that connect with the outside world and the environment, its also the cells that shed off first

• The lining of your small intestines

• The lining of your respiratory tract The lining of your abdominal cavity

• Our sweat glands: sweat protects

• Muscle tissue: provides the movement functions and is classified into three types which are the following

• Skeletal: long cylindrical fiber, striated, many peripherally, located nuclei, is a voluntary movement

• Cardiac: short, branched, striated, single central nucleus, the function is to pump blood

• Smooth: short spindle shaped, no evident striation, single nucleus and each fiber, involuntary movements moves food contracts,

• Connective tissues: provide the structural framework of the human body

  • Loose connective tissue
  • Areolar: holds tissue fluids
  • Adipose: helps with fat/energy storage
  • Reticular

• Muscle tissue:

  • Skeletal muscle is attached to bones with contraction making expressions and posture
  • Cardiac muscles are contractile walls with cells striated with a single nucleus and intrinsic rhythm
  • Smooth muscles have involuntary movements that are in contractile intestines

• Nervous tissue: is characterized as being excitable and is capable of sending and receiving electrochemical signals.

  • Two main classes of cells make up nervous tissue.
    • The neuron
    • Neuroglia: supporting neurons and modulating their information.

Integumentary System Functions

• The integumentary system includes the skin and accessory structures like hairs, nails, and glands.
• The integumentary system covers the outside of the body and consist of these functions
  • Protection
  • Sensation
  • Vitamin D production
  • Temperature regulation
  • Excretion

Skin and Layers

• The skin is the largest bodily organ.

• Epidermis is an outer body covering, chemical barrier from the outside.

• Dermis is a later layer of connective tissue with collagen and elastic fibers.

• Responsible for the structural strength with vessels/glands.

• Hair follicles and are embedded in the dermis

• Epidermis - a stratified squamous epithelium Deepest layers, cells are produced by mitosis

  • The outermost cells the cells underneath & replaces them

• Keratinization – process when the cell change shape and chemical composition while filled with Keratin.

• Stem Cells - that divide

• Keratinocytes - synthesize keratin. and the cell is able

• Melanocytes- synthesize brown/black pigment.

• Tactile Cells - are receptors for touch.

• Dendritic Cells - stratum granulosum

• Layers of the Epidermis are: stratum corneum, stratum lucidum, Stratum granulosum, stratum spinosum, stratum basal

• Stratum Basale rests on basement membrane site of mitosis

• Stratum Spinosum is many layers of Keratinocytes shrinkable in fixed tissues

• Startum Granulosum is 2-5 layers of cells with dark staining

• Stratum corneum

• Stratum Lucidum is only in thick skin.

• Hypodermis

  • Beneath the skin a loose connective tissue contains fats.

• Function: cushion storage

• Skin color is from Melanin

• Two forms:

• Eumelanin – is brownish black

• Pheomelanin - is reddish yellow.

• Blood vessels show through skin

Skin Structure

• Hair: thick and covers most of the body, a characteristic in mammals.

• Shaft: protrudes above skin

• Root & hair bulb: Is below the skin.

• Cortex: Is hard.

• Medulla: soft center. Cuticle a single layer cells that holds the hair. extension of the epidermis deep into the dermis role in tissue repair.

• Muscles and hair follicles are associated smooth muscle cells Arrector Pili with hair perpendicular with "goose flesh. is a white substance.

• Glands have two kinds

• Sebaceous, simple, branched are located at the palms and soles. are a thick secretion

• Nails consist of distal ends of the digits of humans

• A thin plate and stratum corneum cells

• Nail body,

• Nail Root,

• Eponychium/Cuticle

• Nail bed and Matrix

  • Free edge

Test your knowledge of anatomical terminology, body regions, and planes. This quiz covers abdominopelvic regions, body cavities, anatomical movements, and medical imaging techniques with organ locations.