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!!