LEVEL OF ORGANIZATION AND BODY CAVITIES

Chemical

The chemical level involves interactions among atoms and their combination into molecules.

Organelle

An organelle is a small structure contained within a cell that performs one or more specific functions

Cell

Cells are the basic functional units of life. All cells share many characteristics, but they differ in structure and function

Tissue

A tissue is a group of cells with similar structures and functions.

Organ

An organ is composed of two or more tissue types that together perform one or more common function.

Organ system

An organ system is a group of organs classified as a unit because of a common function or set of functions.

Organism

An organism is any living thing considered as a whole. Organisms can have anywhere from a single cell to trillions of cells

Cavity

a fluid-filled space in the body that holds and protects internal organs

what does the ventral cavity consist of ?

thoracic, abdominal, and pelvic cavities

Thoracic cavity

surrounded by the rib cage and separated from the abdominal cavity by the diaphragm

Divided into right and left halves by a structure called the mediastinum

what properties does the thoracic cavity consist of?

esophagus, trachea, thymus gland, heart, and both lungs, along with other structures.

abdominal cavity

bounded by the abdominal muscles below the thoracic cavity and contains the stomach, intestines, liver, spleen, pancreas, and kidneys

Pelvic cavity

enclosed by the bones of the pelvis and contains the urinary bladder, part of the intestines, and the internal reproductive organs

Dorsal cavity

back of the human body, and it is subdivided into two cavities: cranial and spinal.

cranial cavity

contains the brain.

spinal cavity

contains the spinal cord.

inferior

A structure below another

superior

A structure above another

anterior

Toward the front of the body

posterior

Toward the back of the body

dorsal

Toward the back

ventral

Toward the front

proximal

Closer to the point of attachment to the body than another structure

distal

Farther from the point of attachment to the body

lateral

Away from the midline of the body

medial

Toward the middle or midline of the body

superficial

Toward or on the surface

Deep

away from the surface

anterosuperior

In front or above

midline

A median line

supine position

Lying flat with face and torso facing upward

prone position

Lying face down

sagittal plane

runs vertically through the body and separates the body into right and left parts.

midsagittal plane

divides the body into two equal halves.

transverse plane

runs parallel to the surface of the ground and divides the body into superior and inferior planes.

coronal plane

sometimes called the frontal plane, runs vertically from left to right and divides the body into anterior and posterior parts.

what are the body planes called?

sagittal, midsagittal, transverse, coronal

what are the 4 body regions?

upper limb, lower limb, central, head

upper limbs

arm, forearm, wrist, and hand.

lower limbs

divided into the thigh, leg, ankle, and foot.

central region

the neck and trunk.

head region

includes the entire head.

tissue

a group of cells with similar structure and function and similar extracellular substances located between the cells

characteristics of connective tissue

extracellular material that separate cells from one another

function of connective tissue

enclosing and separating

connecting tissues to one another

supportive and moving

storing

cushioning and insulating

transporting

protecting

example of connective tissue

cells of the immune system and blood

characteristics of epithelial tissue

classified according to the number of cell layers and shapes

function of epithelial tissue

protecting underlying structures

acting as barriers

permitting the passage of substances

secreting substances

example of epithelial tissue

skin, linings of internal organs

characteristics of muscle tissue

cells of muscles resemble long threads and are called fibers

functions of muscle tissue

providing movement

example of muscle tissue

heart, organs of digestive system

characteristics of neural tissue

cells are composed of dendrites, cell bodies, and axons

functions of neural tissue

coordinating and controlling many body activities

example of neural tissue

brain, spinal cord

homeostasis

the existence and maintenance of a relatively constant environment within the body

what are variables?

Each cell of the body is surrounded by a small amount of fluid, and the normal functions of each cell depend on the maintenance of its fluid environment within a narrow range of conditions, including temperature, volume, and chemical content

negative feedback mechanism

maintains homeostasis. think maintenance of normal blood pressure

positive feedback mechanism

not homeostatic and are rare in healthy individuals. usually creates a cycle leading away from homeostasis and, in some cases, results in death. Inadequate delivery of blood to cardiac muscle