Body
You’ll never look at a tissue the same way again!!!!
Facts about Body
• Originates during embroyic development in @ 2 weeks after fertilization implantation occurs.
4 Classifications of Body
• Epithelial Tissue-covers surface that lines the body cavity, lines hollow organs, tubes and form glands.
• Connective Tissue-protects and supports the body and helps bind organs together. Also, help to store E and where immune cells reside.
• Muscular Tissue-allows contraction of muscle. • Nervous Tissue-initiates and transmit impulses
which coordinates the body’s activities.
EPITHELIUM
• Cells are packed. Not a lot of extracellular fluid (EF).
• Arranged in sheets, layers of columns • Has a free surface and a basal surface• Avascular-No blood supply (nutrients are
obtained via diffusion. • Nerve supply are sensory neurons.
Epithelium Characteristics
• There are 3 types of Epithelium Surfaces• Apical Surface-”free” or superficial• Lateral Surface-side surface • Basal Surface-basement layer• (order is arranged from superficial >>>deep)
“We a family…”
• There are 4 different types/shapes of Ep. tissue. – Squamous – Cuboidal – Columnar – Transitional-interchanging of all cells
Diagram, name function
Body Layers
BT Layers
Endoderm Mesoderm Ectoderm
Organs in these layers
• Endoderm- “inner skin”-locations include GI track, lining of bladder, and respiratory sys.
• Mesoderm- “middle skin”-locations include skeletal, muscle, and blood dermis of skin.
• Ectoderm- “outer skin”- locations include nervous, skin, and oral cavity.
Functions of Ep.
• Protection • Secretion • Absorption • Excretion • Sensory • Reproduction
Epithelial Tissue
• Will act as a lining, glandular tissue or a membrane.
Glandular Tissue
• Specialize epithelial cells.
• Glandular cells secrete chemicals necessary to maintain homeostasis.
• G.cells secretes into:– ducts (exocrine gland)-i.e: saliva, sweat and
mucus. – Directly into EC matrix (endocrine) i.e:
hormones.
• Penile Urethra duct Sweat gland duct
Ep. Tissue as a Membrane
• Remember Ep. Tissue directly overlies the CT.
• Membrane can be: – Mucous membrane: lines cavities open to the
outside – Serous membranes: line closed cavities – Synovial membrane: joint cavites
What’s the connection?
• What allows epithelia cells to maintain their structure?
• See diagram on pg . 80
Connective Tissue
• Has a nerve supply
• Vascular (except cartilage)
• No free surface
• Matrix secreted from origin(i.e bone secretes calcified material)
Connective Tissue
• 3 basic components:1.)Cells
• Fibroblasts cells- large, flat secretory cells• Macrophages cells- WBC-for defense. Are motile
or stationary• Plasma cells-secrete antibodies• Mast cells-histamines (secreted when capillaries
dilate>swelling=fluid retention• Adipocytes cells-fat cells• White blood cells(WBC)-defense
• 2) Ground substance – Hyaluronic acid-viscous, slippery and
lubricated. – Chondroitin- jellylike substance, more
supportive.
3)Fibers
-Collagen-resistent/tough/in bundles
-Fiber-elastic/smaller/moveable
-Reticular-netting material
Picture of CT
• So, what does all 3 CT components look like all together?
• See Ms. Willis’s rendition
5 types of CT
• I.Blood
• II.Loose
• III.Dense
• IV.Cartilage
• V. Bone
• Listed from least to greatest density.
I. And Areolar said, “Just call me Phil.”
• EC matrix is arranged loosely!!!!
• Types of LCT: 1)Areolar-fibroblasts, macrophages, plasma
and mast cells ar found in this EC matrix.(fig.4.5a)
• Mostly hyaluronic acid • All types (collagen, and elastic)• Mostly found under skin • Associated with adipose and CT
Cottage cheese on the thighs or derriere anyone?
• 2)Adipose- contains fat storage (fig 4.5b)– Yellow bone marrow – Minimal fiber– Deep under the skin – Surrounds organs
II. Dense CT
• EC matrix is densely packed fibers!!!• Types of DCT:
1) Regular(DCCT)(fig 4.5c)• Fibers bundled and parallel to each other • Fibroblasts are predominant cell• (Ex. Form tendons at ends of muscle and some organ)
capsules. 2)Elastic DCT- (fig.4.5d)*Associated with collagen fibers*Allows tissue to stretch and recoil*(Examples: vocal cords, walls of arteries, etc.)STRESS ORIENTATION IN ONE DIRECTION!!
III. “The chicken was so delicious I ate all the meat and the
___________ too!”• Means gristle!!• Avascular• Composed of cells called chrondrocytes located
in the matrix of cartilage (lucunae)• Fig 4.5 e• Why is cartilage resilient?
– Cartilage linked protein called proteoglycans of the matrix trap H20 which makes cartilage springy!!
– If compressed, goes back to orig. shape*Heals slowly. Why?
Cont’d CCT
• Types of cartilage: – 1)Hyaline cartilage “gristle”
• Most abundant • Flexible • Reduce friction, absorbs shock • Relatively weak • (ex. Nose, ribs, epiphyseal plate)2) Fibrocartilage-fibers in bundles*strongest, resists pulling and tearing.*(ex. knee,pubic sympysis,etc.)3)Elastic cartilage*lightweight, provides rigidity*(ex. Ear, trachea)
IV. “I’m not hefty,I’m big _____!”
• Also known as osseus tissue • Hard CT that consists of living cells called
osteocytes located in the spaces of the mineralized matrix.
• Fig 4.5 h• 2 types of bone:
– Compact– Cancellous(We’ll revisit this in the skeletal system)
V. “You won’t take me alive, Lacunae!!”
• Matrix is liquid, no barriers so it flows through blood vessels (BV).
• Some blood cells leaves the blood and wander into other tissues. (ex. Anyone?)
• Will carry food, O2, waste products,etc.
WE WILL REVISIT THIS AREA WHEN WE DISCUSS THE CIR. SYS.
Muscle
• Special characteristic: Its ability to shorten and lengthen due to contractile proteins!!!
• The length a muscle is > than the diameter• Cell/fibers (fig 4.6 a-c)• 3 types of muscle:
– Skeletal- voluntary control• Striated (banded)/ multinucleated
– Cardiac- has unconscious “involuntary” contr.• Shorter fibers/uninucleated/have intercalated disks!!
– Smooth-involuntary control• Forms the walls of hollow organs/in skin and eyes!!
Nervous
• Cells are called neurons which generate and conduct nerve impulses.
• Composed of 3 parts: – Cell body – Dendrite– Axon – Neurolia cells
(mylineated sheath)– Fig 4.7
Aging Tissue
• As one ages, there is a decrease in muscle fibers and neurons.
• Reduced senses
• Cells divide slowly (“I’m falling and I can’t get up!!”)
• Age related changes affect cells at the EC matrix level!!!– Loss of flexilibity in all aspects!!
Inflammation Response
• This is a response to foreign substance being in the body such as bacteria or dead tissues; symptoms include swelling, heat, redness and p!
HOMEWORK-due Friday
1)Name several diseases, symptoms, and/or disorders commonly associated with old age and explain what is occuring physiologically. (Hint see tissue and aging paragraph on pp. 93)– Provide proof (light research, personal
experience,etc.)
2) Name a cell, ground substance and fiber for each type of CT. Include an explanation of the importance of this body tissue. Creativity is welcomed!!