Connective, Nervous, Muscle Tissues

Seite 1

Biol 221

Connective, Muscle, and Nervous Tissue - Outline

Connective Tissues

Functions of connective tissues:

binding-ligaments attach bones together

support- connective tissues that provides shape of cartilage

protection- physical (ex: bones protecting organs) / immune (ex:all our blood cells are connective tissues, white blood cells provide immunity)

movement - muscle attached to bone by tendons

storage -

transport- blood transports everything

Components of connective tissue

Types of Cells

Fibroblasts - (blasts=making something) THEY MAKE FIBERS AND THE GROUND SUBSTANCE

Macrophages - phagocytes, engulf and destroy

Adipocytes - contain lipids, act as storage , found in tissues with higher fat storage content

Mast cells -histamine (increases blood flow) , heparin ( prevents blood clots), usually secreted when tissue is damaged

Lymphocytes, neutrophils, eosinophils and plasma cells -

Immune Cells- white blood cells

Fibers

Collagen fibers - long, straight, unbranched ,thickest , flexible, stronger than steel

Reticular fibers - branched, thin, tough , flexible , look like a network spiders web

Elastic fibers-thin, branched, strong , stretchable

Ground substance: substance the cells are suspended in

Connective tissue types:

Connective tissue proper

Loose connective tissue: more ground substance

Areolar tissue: (Fig 4.10a) -- found under skin , between organs, very vascular , for support and cushioning

Adipose tissue: (Fig 4.10b)-- loose connective tissue, made up of adipocytes , found around organs , contain lipids , absorbs shock , insulation, energy storage

Reticular tissue: (Fig 4.10c)-- supportive network of reticular fibers , found in spleen, liver, lymph nodes, bones marrow , gives shapes to these organs , provides place for blood cells to accumulate

Dense connective tissue: less ground substance ,more fibers

Dense regular connective tissue: (Fig 4.11a)-- collagen fibers run parallel, making it very strong(mostly) , found in tendons and ligaments

Dense irregular connective tissue: (Fig 4.11b)-- under skin in the deep dermis, around cartilage, bones, over organs, it can support stress from multiple directions

Elastic tissue: -- mainly elastic fibers some collagen, found in the walls of large vessels

Fluid connective tissue:

Blood – (Fig)\

Red blood cells

white blood cellls ---------> cells and fragments

platelets

plasma

Lymph

immune systems

water balance

Supporting connective tissue:

Cartilage – its avascular

chondrocytes (Fig 4.13a)

lacunae

perichondrium

Types of cartilage

Matrix - ground substance

Hyaline cartilage: (Fig 4.14a) -- found between ribs , sternum , nose

Elastic cartilage: (Fig 4.14b) -- flexible, alot of elastic fibers , found in ear

Fibrocartilage: (Fig 4.14c -- made up of alot of collagen fibers, very tough , found between knee and vertebrae ,perichondrium surrounds cartilage)

Bone – (Fig 4.15) -- is connective tissue , different from cartilage because it has alot of calcium cells , calcium phosphate, collagen fibers , vascular

Membranes – composed of epithelium with underlying connective tissue

Types

Mucous membrane (Fig 4.16a) - coated with the secretions of mucous glands , lines the digestive tract to help food pass easiliy, respiratory protection , urinary protection , reproductive tract acts as a protective barrier , all of them communicate with the external enviorment and remain moist

Serous membrane (Fig 4.16b) -- found in cavities , found around organs , (the peritoneal, pleural, and pericardial)

Cutaneous membrane – skin (Fig 4.16c) -- provides protection, dry , , covers the outer surface of the body

Synovial membrane (Fig 4.16d) - found in joint cavities ,produce the fluid within the joint

Fasciae (Fig 4.17)

Muscle Tissue

Functions of muscle tissue

Skeletal- Movement of and stabilization of the skeleton, generates heat, protects organs

Cardiac- Circulates blood and maintains blood pressure

Smooth - Moves food and urine, controls respiratory airways, regulates blood vessel diameter

(STRIATIONS ARE THE WAY PROTEINS LINE UP)

Types of muscle tissue

Skeletal (Fig 4.18a)- voluntary , striated, multiple nuclei

Cardiac (Fig 4.18b)- involuntary , striated , one nucleus

Smooth (Fig 4.18c)-involuntary , lines organs + blood vessels , NO striations , one nucleus

Nervous Tissue (Fig 4.19)

Nervous tissue—specialized for communication by electrical and chemical signals

Consists of neurons (nerve cells) and Neuroglia (gliall)

Review questions:

1. What features do most or all connective tissues have in common to set this class apart from nervous, muscular and epithelial tissue?

The features that all connective tissues share in common is Fibroblasts.

2. List the cell and fiber types found in fibrous connective tissues and state their functional differences.

Cells-

> Fibroblasts- Produce fibers and ground substance

>Macrophages- eat and destroy bacteria. Also activate immune system

>Leukocytes- White blood cells. Attack bacteria

>plasma cells- Produce antibodies

> mast cells- Secrete heparin( inhibit blood clotting) and >Histamine(Increases blood flow by dilating blood vessels)

> adipocytes- Fat cells adipose tissue

Fibers-

> Collagenous fibers-tough and flexible, resist stretching. Tendons, ligaments, and dermis of the skin made of this.

> Reticular fibers- form a sponge like framework for organs

>Elastic Fibers- Made of protein called elastin, which allows to stretch and recoil to shape. This allows skin ad lungs to go back to shape after being stretched.

3. What substances account for the gelatinous consistency of connective tissue ground substance?

collagen

4. What is areolar tissue? How can it be distinguished from any other kind of connective tissue?

Areolar Tissue is a common form of loose connective tissue.

has Numerous blood vessels

5. Discuss the difference between dense regular and dense irregular connective tissue as an example of the relationship between form and function.

Dense regular connective tissues fibers run parallel to each other whereas dense irregular connective tissue seems to run in random directions.

Dense irregular connective tissues function is to withstand stresses applied in unpredictable directions; imparts durability to tissues.

Dense regular connective tissues function is to bind bones together and resist stress; Also tendons attach muscle to bones and transfers muscular tension to bones

6. Describe some similarities, differences, and functional relationships between hyaline cartilage and bone.

Both are a type of cartilage

- Hyaline cartilage flexible while bone is not

- Both offer structure to body

-cartilage is avascular while bone is vascular

7. What are the three basic kinds of formed elements in blood, and what are their respective functions?

Erthrocytes- Red blood cells , deliver oxygen to body

-Leukocytes- white blood cells, Defense against infection and disease

- Platelets- Involved in clotting and other mechanisms for minimizing blood loss

8. What do nervous and muscular tissue have in common? What is the primary function of each?

- Both use Excitability—ability to respond to stimuli by changing membrane potential

- Nervous tissue primary function is Internal communication

- Muscular tissue primary function is contraction when stimulated

9. Name the three kinds of muscular tissue, describe how to distinguish them from each other in microscopic appearance and state a location and function for each.

-Skeletal- Long, threadlike, unbranched cells. Skeletal muscles attached to bones. Function is body movement.

-Cardiac-Short cells, with notched or slightly branched ends. Heart. Function is pumping of blood; under involuntary control.

-Smooth-Short, fusiform cells overlapping each other. Found as sheets of tissues in walls of blood vessels such as the digestive tract. Function is swallowing, contraction of stomach. Expulsion of feces.

11. Which do you think would heal faster, cartilage or bone? Stratified squamous or simple columnar epithelium? Why?

Bone would heal faster than cartilage because it is permeated with blood vessels, whereas cartilage is devoid of blood vessels. Thus, bone receives a better supply of oxygen, organic nutrients, growth factors, and other necessities than cartilage does. Simple columnar epithelium heals faster than stratified squamous epithelium because in the former type, every cell is close to the subepithelial connective tissue, where the nearest blood vessels are located.