Tissue
– an organization of many cells that act together to perform a common function.
Tissues differ from each other in the size and shape of their cells, in the amount and kind of material between the cells and in the special functions they perform.
Four Kinds of Tissues
- Epithelial tissues
- Connective tissues
- Muscle tissues
- Nervous tissues
Epithelial tissues
- cover and line various parts of the body for protection, transport, absorption and secretion.
Classification as to shape of Epithelium cell:
squamous, cuboidal, columnar, transitional
Classification as to arrangement of Epithelial cells:
a. simple (single layer of cells of the same shape)
b. stratified (layered)
Connective tissues
- are most abundant, most varied and widely distributed in the body.
- bind structures together, form a framework and support for organs and the body as a whole, transport substances, protect against disease, help repair tissue damage, store fat.
- They are found in skin, membranes, muscles, bones, nerves and all internal organs.
They exist as: paper thin webs that hold internal organs, strong tough cords, rigid bones & fluid - blood
Functions of connective tissue:
a. connects and supports tissues
b. transports substances throughout the body
c. defense against microbes and other invaders
d. stores fat
Major types of connective tissues:
- Areolar connective tissue – the “glue” that keeps the organs of the body together; made up of collagen and elastin proteins
- Adipose or fat tissue
- Dense fibrous connective tissue (tendons)
- Bone and cartilage
- Blood and Hematopoietic Tissue
Muscle tissues
- have the ability to shorten or contract for movement.
There are three kinds of muscle tissue:
a. skeletal /voluntary/striated
b. smooth/involuntary/non-striated
c. cardiac muscle tissue
skeletal /voluntary/striated
- muscle cells are long, threadlike fibers with striations and many nuclei per cell
- attached to bones , producing controlled body movements
smooth/involuntary/non-striated
– visceral muscle tissue without striations
cardiac muscle tissue
– striated, involuntary and branched muscle cells with intercalated disks that help the heart contract as one whole unit
Nervous tissues
- provide rapid communication between body structures and control of body functions. Neurons and glial cells comprise nervous tissue.
TYPES OF BODY MEMBRANES
I. EPITHELIAL MEMBRANES
II. CONNECTIVE TISSUE MEMBRANES
EPITHELIAL MEMBRANES
Composed of epithelial tissue (groups of epithelial cells) and an underlying layer of connective tissue
CONNECTIVE TISSUE MEMBRANES
Composed exclusively of connective tissue.
No epithelial cells are present
THREE TYPES OF EPITHELIAL MEMBRANES
- CUTANEOUS MEMBRANE
- SEROUS MEMBRANES
- MUCOUS MEMBRANES
CUTANEOUS MEMBRANE - Skin
- The primary organ of the integumentary system.
- The largest and one of the most important organs of the body.
- Heaviest organ of the body (16% of body weight)
- Has a superficial layer of epithelial cells and a supportive connective tissue underneath.
SEROUS MEMBRANES
Composed of a thin layer of simple squamous epithelium and a basement membrane that holds and supports the epithelial tissue.
A single, continuous sheet lining body cavities and covering organs in those surfaces.
Secrete a thin, watery fluid that helps reduce friction and acts as a lubricant when organs rub against one another or against the walls of the cavity.
Types of Serous Membranes:
. Parietal pleura
. Visceral pleura
. Parietal peritoneum
. Visceral peritoneum
. Visceral Pleura
. Parietal Pleura
Parietal pleura
– membrane forming the inside lining the thoracic cavity
Visceral pleura
– membrane covering the lungs
Parietal peritoneum
– membrane forming the inside lining the abdominal cavity
