1. CELLS & TISSUES Chapter 3 – Pgs. 59-70
Tissue – group of cells working together to perform a specific function
Histology – the study of tissues
Four groups of tissues:
Epithelial – Table 3-6
Connective – Table 3-7
Muscle – Table 3-8
Nerve – Table 3-8

4. Epithelial
Found of the surfaces as covering (skin) or on inner surfaces as lining (digestive tract); many types are capable of secretion (sweat, saliva, digestive enzymes)
Epithelial cells are classified according to shape and arrangement of cells – fig. 3-7

5. Shape squamous – flat, scale like cuboidal – cube shaped columnar – tall and narrow

6. Arrangement simple – single layer of cells of the same shape stratified - many layers of cells of the same shape transitional – several layers of cells with different shapes

7. Simple Squamous – important in the exchange of materials or for absorption; found in capillaries, alveoli (air sacs) – Fig. 3-8

9. Stratified squamous epithelium – Fig. 3-9
makes up epidermis of skin where surface cells are dead (keratinized)
lining of mouth, esophagus, and vagina where surface cells are alive (non-keratinized)
function in protection and barrier for microorganisms

10. Keratinized stratified squamous epithelium

11. Non keratinized stratified squamous epithelium

12. Simple Columnar Epithelial – Fig. 3-10
Single layer of cells taller than wide
linings of stomach, intestines, and respiratory tract
specialized cells called goblet cells secrete mucus
regular cells specialize in absorption

14. Simple Cuboidal (glandular epithelium) – Fig. 3-8, 3-12
single layer of cube-shaped cells
function in secretory activity
glands; cluster or groups of secretory cells
exocrine – release secretions into ducts (ex. Salivary glands)
endocrine – release secretions directly into bloodstream (ex. Thyroid gland)

16. Stratified Transitional Epithelium – Fig. 3-11
surface cells change shape from cuboidal to squamous
found in areas exposed to stress and need to be able to stretch (ex. Urinary bladder)

18. Pseudostratified epithelium (ciliated)
columnar cells that have cilia and look as if there are two cell layers
cilia sweeps mucus trapped dust and bacteria protecting lungs
lines nasal cavities, trachea, and bronchial tubes
also lines fallopian tubes (oviducts) and sweeps ovum from ovary to uterus

20. Connective Tissue
Most abundant tissue type, most varied, common to all is the presence of a matrix in addition to cells – matrix is a structural network or solution of non-living intracellular material (ex. Blood matrix is plasma, bone matrix is calcium salts)

21. Aereola (loose connective tissue) most widely distributed connective tissue
 cells are called fibroblasts which produce protein fibers (collagen and elastin)
Protein fibers and tissue fluid makeup matrix
found beneath epithelial tissues and body systems that have an opening to the environment for protection against microorganisms
functions as “glue” that gives form to internal organs and protection

23. Adipose – Fig. 3-13 cells are called adipocytes
matrix consists of tissue fluid and some collagen fibers
function – storage of lipids/cushion for organs

25. Fibrous Connective Tissue – Fig. 3-14
consists mainly of parallel collagen fibers
strong but flexible
makes up tendons and ligaments
tendon – connects muscle to bone
ligament – connects bone to bone
relatively poor blood supply, slow to heal

27. Bone – Fig. 3-15 cells are called osteocytes
matrix is made of calcium salts and collagen – strong, hard, not flexible
osteocytes, matrix, and blood vessels are arranged in Haversian system
functions – calcium storage, support body, protect internal organs

29. Cartilage – Fig. 3-16 cells called chondrocytes
found on surfaces of joints to prevent friction
found in ear, tip of nose, wall of trachea, and in between vertebrae
function – prevent friction, absorbs shock, permits movement
no capillaries, gets nourishment through diffusion from surrounding tissues

31. Blood – Fig. 3-17 Matrix is blood plasma
plasma contains dissolved salts, nutrients, and waste products
function of plasma – transportation of material around the body
cells of blood
red blood cells carry oxygen
white blood cells destroy pathogens – principle component of the immune system
platelets – prevent blood loss through clotting

32. Red blood cell
White
Blood
cell
Platelet

33. Hemopoietic Tissue
found in red marrow cavities of bone, spleen, tonsils, and lymph nodes
function in formation of blood cells – important in defense against disease
This tissue is a complex mixture of different cell types and a rich lattice

35. Replacement of bone marrow fat with dark red hemopoietic tissue

36. Muscle – specialized for contraction, when muscles contract they shorten and bring about some type of movement

37. Skeletal Muscle (striated or voluntary muscle) – Fig. 3-18
cylindrical, have several nuclei/cell
appear striated b/c of precise arrangement of contracting proteins in cells
muscles are attached to bones and move skeleton
voluntary in movement, respond to nerve stimuli from brain

39. Smooth Muscle (visceral or involuntary) – Fig. 3-20
long, narrow, single nuclei/cell, no striation
involuntary
form walls of blood vessels, and organs such as stomach and intestines
help regulate diameter of blood vessels and propels food down digestive tract

41. Cardiac Muscle (myocardium) – Fig. 3-19
branched, interlocking muscle, faintly striated, 1 nuclei/cell
form walls of chambers of the heart
function – pump blood, maintain blood pressure
contract by themselves and therefore maintain “one” beat
nerve impulses from nervous system function to increase or decrease beat as dictated by certain situations

43. Nerve Tissue – Fig. 3-21
cells are called neurons, supporting cells are neuroglia
function – transmit electrochemical impulses
structure of neuron
cell body – contains nucleus
axon – carries impulses away from cell body
dendrite – carries impulses toward cell body
each neuron has several dendrites that branch in different direction
impulses are transmitted from one neuron to another at the synaptic cleft by chemical messengers called neurotransmitters
make up brain, spinal cord, and nerves
function – sensation, movements, regulation of body functions, organization of information for learning and memory