cells & tissues chapter 3 – pgs. 59-70
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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. Epithelial. - PowerPoint PPT PresentationTRANSCRIPT
CELLS & TISSUESChapter 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
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
Shapesquamous – flat, scale likecuboidal – cube shapedcolumnar – tall and narrow
Arrangementsimple – single layer of cells of the same shapestratified - many layers of cells of the same shapetransitional – several layers of cells with different shapes
Simple Squamous – important in the exchange of materials or for absorption; found in capillaries, alveoli (air sacs) – Fig. 3-8
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
Stratified squamous epithelium – Fig. 3-9
Keratinized stratified squamous epithelium
Non keratinized stratified squamous epithelium
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
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)
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)
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
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)
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
Adipose – Fig. 3-13 cells are called adipocytes matrix consists of tissue fluid and some
collagen fibers function – storage of lipids/cushion for
organs
Fibrous Connective Tissue – Fig. 3-14
consists mainly of parallel collagen fibers
strong but flexible makes up tendons and ligamentstendon – connects muscle to bone
ligament – connects bone to bone
relatively poor blood supply, slow to heal
Bone – Fig. 3-15 cells are called osteocytes matrix is made of calcium slats an collagen – strong, hard, not flexible
osteocytes, matrix, and blood vessels are arranged in Haversian system
functions – calcium storage, support body, protect internal organs
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
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
Red blood cell
WhiteBloodcell
Platelet
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
Replacement of bone marrow fat with dark red hemopoietic tissue
Muscle – specialized for contraction, when muscles contract they shorten and bring about some type of movement
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
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
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
Nerve Tissue – Fig. 3-21 cells are called neurons, supporting cells are
neuroglia function – transmit electrochemical impulses structure of neuron
cell body – contains nucleusaxon – carries impulses away from cell bodydendrite – 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