Levels of Organization of the human body

1. Levels of
Organization
of the Human
Body

2. Organelle Level

3. Molecules of different types come together
to form organelles. Organelles are
specialized, membrane-bound structures of
cells. Each organelle has its own function,
and together they carry out the necessary
cellular functions.

4. TYPES OF
ORGANELL
ES OF THE
CELL AND
FUNCTION
S

16. phagocytize (FAG-oh-sit-ize) (eat and
destroy) bacteria do not need the same
relative amounts of organelles also called
WBC. White blood cells need many
lysosomes containing digestive enzymes to
destroy the bacteria.

18. Passive Transport

19. 1. FILTRATION
Filtration is a passive-
transport method that
moves materials across
a cell membrane using
force but no energy.

20. 2. Simple Diffusion
Diffusion is the interpenetration of molecules
between two substances, from an area of higher
concentration to an area of lower concentration

21. Facilitated Diffusion
This passive-transport
method is used for
molecules that cannot
diffuse through the
selectively permeable
membrane on their own

22. 4. Osmosis
An important homeostasis concept is
fluid and electrolyte balance. Cell
membranes are selectively permeable.
As you have seen, some molecules can
move across the membrane by
filtration, some by simple diffusion,
and others by facilitated diffusion.
Some molecules, however, cannot
move across the cell membrane to
equalize their concentration by any
passive means

23. Active Transport

24. Active Transport
Active transport moves materials
across the cell membrane from
areas of low concentration to areas
of high concentration. This
involves moving materials up a
concentration gradient against the
natural trend of diffusion. It
requires the cell’s usable form of
energy contained in ATP
molecules.

26. CELL DIVISION

27. 2 TYPES OF CELL DIVISION

28. Miosis(my-OH-sis) is involved only in sperm and egg
production; it is discussed in the reproductive system
chapters.
Mitosis (my-TOE-sis) is the process all other cells use to
divide, and it is necessary for the development of the
human anatomy, which is composed of 40 trillion cells.

29. TISSUE LEVEL

31. THE 4 BASIC
CLASSIFICATI
ON OF
TISSUES

32. What do you call the Study of
Tissues?

33. What do you call the Study of
Tissues?
Histology

34. EPITHELIAL TISSUES
These tissues cover and line all body surfaces. Epithelial tissues cover
organs, vessels, and ducts and line hollow organs, vessels, and ducts.

35. It is important to know that cells
are three-dimensional objects—
with a width, height, and depth
that can have different shapes.
◦ Epithelial cells can be
squamous (SKWAY-mus) (flat
and thin),
◦ cuboidal (cube-shaped), or
◦ columnar (tall column-shaped).
◦ A basement membrane
separates epithelial tissue from
other tissues.

36. EXAMPLES OF
EPITILIAL TISSUE

37. SIMPLE
SQUAMOUS
EPITHELIAL
TISSUE
LINING THE
ALVEOLI (AIR
SACS) OF THE
LUNG

38. SIMPLE
CUBOIDAL
EPITHELIAL
TISSUE
THAT LINES
THE
TUBULES IN
THE
KIDNEYS.

39. STRATIFIED
SQUAMOUS
EPITHELIAL
TISSUE
LINING THE
MOUTH
AND
ESOPHAGUS
.

40. SIMPLE
COLUMNAR
EPITHELIAL
TISSUE
THAT LINES
THE SMALL
INTESTINE.

41. PSEUDOSTRATIFIED CILIATED COLUMNAR
EPITHELIAL TISSUE THAT LINES MUCH OF THE
RESPIRATORY TRACT. IN
ADDITION TO ITS CILIATED COLUMNAR CELLS
THAT MOVE DEBRIS IN THE RESPIRATORY TRACT,
THIS TISSUE CONTAINS
GOBLET CELLS THAT FUNCTION TO PRODUCE
MUCUS.

42. transitional epithelial
tissue
◦ An exception to the naming of epithelial
tissue is transitional epithelial tissue.
This epithelium is stratified (layered),
but its cell shape is difficult to describe
because it is so changeable. Transitional
epithelial tissue is designed to stretch,
and it lines structures such as the
urinary bladder. If stretched, the cells
appear to be more squamous. If not
stretched, they appear to be more
cuboidal

43. CONNECTIVE
TISSUES
Connective tissues all have cells and fibers in a matrix (background substance).

44. TYPES OF
CONNECTIVE
TISSUES

45. 1. Loose/areolar
connective tissue
◦ has a loose arrangement of fibers
in a matrix with a thick fluid
consistency. A variety of cells are
able to move through the matrix.
It is found, for example, in the
middle layer of the skin (dermis)
and between the serous layers of
the mesenteries.

46. 2. Dense regular
connective tissue
◦ has mostly dense bundles of collagen
(protein) fibers that run parallel to
each other. Fiber-making cells
(fibroblasts) are occasionally
interspersed between fibers. The
cells in this tissue are not able to
move (immobile). This arrangement
of fibers gives strength and
resistance to pulling forces for the
tendons and ligaments composed of
this tissue.

47. 3. Dense
irregular
connective
tissue
◦ has an interwoven pattern to its many
composing fibers. It can be found
supporting the skin’s middle layer, and
the weave of its fibers is much denser
than that of loose/areolar connective
tissue.

48. 4. Adipose
connective tissue
◦ Adipose connective tissue is composed
of lipid-storing fat cells. These cells are
so full of lipids that the nucleus and
other organelles seem to be pushed aside
to allow room for the lipid droplet they
contain. They are active cells that
convert carbohydrates to fats. Adipose
tissue can be found in the deepest layer
of the skin, where it serves as insulation;
in the breast; around organs; and in the
greater omentum.

49. 5. Blood
connective tissue
◦ Blood connective tissue is
composed of red and white
blood cells and platelets in a
very fluid matrix called
plasma. This tissue is covered
extensively in the
cardiovascular system chapter
on blood.

50. 6. Cartilage
connective
tissue
is of three types: hyaline, elastic, and fibrocartilage. The
fibers involved determine their type. All three types of
cartilage have cells surrounded by a very durable gel-like
matrix. These tissues are covered extensively in the
skeletal system chapter.
• Hyaline cartilage connective tissue (HIGH-ah-lin)
• Elastic cartilage connective tissue
• Fibrocartilage connective tissue

51. Hyaline cartilage
connective tissue
(HIGH-ah-lin)
◦ has a very smooth, glassy
appearance. Its collagen fibers
are so fine that they are
virtually invisible. This
cartilage is found at the ends of
long bones, the larynx, the
nose, bronchi, and the
cartilages between the ribs and
sternum.

52. • Elastic cartilage
connective tissue
has elastic fibers running in
all directions. These fibers
allow this cartilage to snap
back to shape if bent.
Elastic cartilage can be
found in the ear and the
epiglottis.

53. • Fibrocartilage
connective tissue
has dense bundles of collagen
fibers all running in the same
direction. These fibers allow this
cartilage to function as a shock
absorber. Fibrocartilage
connective tissue can be found
in the disks between vertebrae
and in the meniscus of the knee.

54. 7. Bone
connective tissue
has bone cells isolated by a
dense, concrete like matrix that
makes bone very hard. Collagen
fibers in the matrix allow a little
bit of flex so that the bone is not
brittle. This tissue is covered
extensively in the skeletal
system chapter.

55. MUSCLE TISSUES

56. 1. Skeletal
muscle tissue
◦ Skeletal muscle tissue
makes up the skeletal
muscles that move the body
and control body openings.
Skeletal muscle cells are
cylindrical, appear striated
(striped), and have multiple
nuclei pushed off to the side

57. Smooth muscle
tissue
◦ can be found in the walls of
hollow organs, veins, and
arteries. This tissue allows hollow
organs to move materials through
them and allows vessels to change
their diameter. Smooth muscle
cells are spindle-shaped (taper at
the ends), do not appear striated,
and have one nucleus per cell

58. Cardiac muscle
tissue
◦ is found in the walls of the heart
and is specially adapted to not
fatigue. Cardiac muscle cells
branch, appear striated, and have
one nucleus per cell. Specialized
junctions between cells
(intercalated disks) allow for fast
transmission of electrical
impulses

59. NERVOUS
TISSUE
◦The body uses nervous tissue for
communication through electrical and
chemical signals. This tissue is
composed of nerve cells called
neurons and many more support cells
called neuroglia that protect and assist
neurons in their function. Neurons
can vary greatly in size and shape.
Nervous tissue is covered extensively
in the nervous system

60. Modes of Tissue
Growth, Change,
Shrinkage, and
Death

61. Tissue Growth
◦ Tissues grow normally in either of two ways: hypertrophy or hyperplasia.
1. hypertrophy, tissues grow because the existing individual cells grow bigger. An
example of hypertrophy is seen in skeletal muscle tissue in adult body builders. Body
builders can greatly increase the size of their muscles, not by increasing the number of
muscle cells but by enlarging their existing cells through training. This accounts for the
apparent muscle tissue growth
2. hyperplasia (high-per-PLAY-zee-ah), tissues grow because more cells are
produced. Hyperplasia is the mode of growth during childhood. Skeletal muscles,
organs, vessels, and other structures grow during childhood because more cells are
produced.

62. Tissue
Change
Tissue type is not absolute. Some
types of tissue may change over a
lifetime. The change of a tissue from
one type to another is called
metaplasia. An example of this can
be seen in the normal development
of the lining of the vagina. A female
child’s vagina is lined by simple
cuboidal epithelial tissue. At puberty,
due to the influence of hormones, the
lining changes from simple cuboidal
epithelial tissue to stratified
squamous epithelial tissue.

63. Tissue Shrinkage and Death
◦ Atrophy (AT-roh-fee) is the shrinkage of tissue due to a decrease in cell size or number. It can
be caused by aging or lack of use. Example broken arm
◦ Necrosis (neh-KROH-sis) is the premature death of tissue, caused by disease, infection,
toxins, or trauma.
◦ Gangrene is tissue necrosis resulting from an insufficient blood supply, often associated with
an infection.
Infarction is the sudden death of tissue, which often results from a loss of blood supply. An
example is a myocardial infarction (sudden death of heart muscle) due to a blocked coronary
artery.
◦ Apoptosis (AP-op-TOE-sis) is programmed cell death. This mode of death removes cells that
have fulfilled their function and are no longer needed. Examples of this type of death can be
seen in the developing fetus.

64. Organ Level

69. System Level