Cells and tissues

1. Cells and tissues

2. CELLS – the basic unit of living things CELL THEORY – 1. Cells perform all the vital functions of a living thing. 2. Cells come from other cells. 3. Cells are the basic unit of all living things.

3. Basic Cell Structure NUCLEUS – control center of the cell PLASMA (CELL) MEMBRANE – barrier between the cell and its environment. CYTOPLASM – portion of the cell containing functioning organelles – substance between the nucleus and cell membrane

4. CELL ORGANELLES MITOCHONDRIA – produces energy – power house of the cell Ribosomes – produce proteins – located on the er

5. CELL ORGANELLES Endoplasmic reticulum – transport system of the cell Golgi apparatus (body) – packaging system of the cell

6. CELL ORGANELLES CYTOSKELETON – FRAMEWORK OF THE CELL CENTRIOLES – CONTROL CELL DIVISION OR MITOSIS

7. TISSUES OF THE BODY Epithelial Connective Muscle Nervous

8. EPITHELIAL TISSUE • Tissue of the body responsible for protection, absorption, filtration, and secretion. • Fit tightly together to form continuous sheets. • ALWAYS have on free (unattached) surface called the apical surface. • Lower surface rests on the basement membrane – connects epithelial to connective tissue below. • AVASCULAR – have no blood supply of their own – depend on diffusion for nourishment

9. EPITHELIAL CELL ARRANGEMENT Simple – single layer of cells Stratified – multiple layers of cells

10. TYPES OF SIMPLE EPITHELIUM • SIMPLE SQUAMOUS – found on surfaces involved in rapid diffusion – ex. Between air sacs of lungs and blood capillaries • SIMPLE CUBOIDAL – common in glands; found within the kidneys and ovaries • SIMPLE COLUMNAR – associated with mucous producing layers in the digestive and respiratory tract • PSEUDOSTRATIFIED COLUMNAR – lines the respiratory tract – traps particles and dust

11. TYPES OF STRATIFIED EPITHELIUM • STRATIFIED SQUAMOUS – located in areas that receive a lot of friction such as the esophagus and skin surface • STRATIFIED CUBOIDAL – rare within the body – located in the mammary glands • STRATIFIED COLUMNAR – rare within the body – located in salivary glands

12. SPECIAL EPITHELIAL TYPES TRANSITIONAL GLANDULAR • Forms the inner surface of the bladder – allows for expansion • Forms the secretory layers of the various glands of the body

13. CONNECTIVE TISSUE • Tissues of the body charged with protecting, supporting, and binding things together. • Most connective tissue is well vascularized – meaning it has a good blood supply. Exceptions include the tendons and ligaments. • They are made of many different types of cells surrounded by a NONLIVING substance called the EXTRACELLULAR MATRIX. • This matrix is composed of various types of fibers including elastic, collagen, and reticular fibers.

14. TYPES OF CONNECTIVE TISSUE BONE CARTILAGE Cells surrounded by a very hard matrix composed of calcium FIBROUS CONNECTIVE Form rope-like structures – tendons and ligaments BLOOD Contains cells surrounded by liquid matrix Matrix is more flexible than bone – abundant in joints of the body ADIPOSE TISSUE Tissue specialized to store fat.

15. SKELETAL MUSCLE TISSUE • Muscle tissue that forms the muscles attached to the skeleton. • VOLUNTARY • Cells contain STRIATIONS which represent the high protein content of these muscle cells

16. CARDIAC MUSCLE TISSUE • Muscle cells that comprise the muscle of the heart. • INVOLUNTARY • Contain STRIATIONS • Contain INTERCALATED DISKS which maintain the rhythm of the heartbeat.

17. SMOOTH MUSCLE TISSUE • Muscles the make up the muscular wall of internal organs. • INVOLUNTARY • NON-STRIATED • Slow moving fibers – control a movement called peristalsis

18. NERVOUS TISSUE • Comprised of cells called NEURONS • All neurons receive and conduct impulses. • Their cytoplasm can be drawn out into long extensions that can be as long as 3 feet or more allowing them to conduct impulses over a long distance. • Supporting cells support and protect neurons – these are called glial cells.