Flashcards FA 26 BIO 131 TEST 2

Ectoderm

- Outer layer

- epidermis and nervous system

Endoderm

- Inner layer

- mucous membrane lining GI and respiratory, GI glands

Mesoderm

- Middle

- Gelatinous tissue called mesenchyme

- fibroblast

- cartilage, bone, and blood

Simple Squamous Epithelia

- Single row of thin cells

- Permits rapid diffusion or transport of substances

- Alveoli, glomeruli, endothelium

Simple Cuboidal Epithelia

- Single layer of square(ish) or round cells

- absorption and secretion, mucus production and movement

- liver, thyroid, mammary and salivary, bronchioles, kidney tubules

Simple Columnar Epithelia

- Single row of tall, narrow cells

- oval nuclei on basal half

- brush border of microvilli; goblet cells

- absorption and secretion, mucus production

- lining of GI, uterus, kidney, uterine tubes

Ciliated Pseudostratified Columnar Epithelia

- Looks multilayered, but all cells touch basement membrane

- nuclei at several layers

- cilia; goblet cells

- secretion and propulsion of mucus

- respiratory tract and portions of male urethra

What type of tissue is this?

Connective tissue

What type of tissue is this?

Muscle tissue

What type of tissue is this?

Epithelial tissue

Ground Substance

• Clear gel

• Tissue fluid, extracellular fluid, interstitial fluid

• Water, gases, minerals, nutrients, and waste

Loose Connective Tissue

• Mostly ground substance in space surround cells

  • areolar and reticular

Dense Connective Tissue

• mostly fibers in space surrounding cells

  • dense regular and dense irregular

Collagenous fibers

• tough, flexible, and stretch resistant

• called white fibers due to appearance in fresh tissue

• tendons, ligaments, and deep layer of skin

• less visible in the matrix of cartilage and bone

Reticular fibers

• Thin collagen fibers coated in glycoprotein

• Form framework of spleen and lymph nodes; part of basement membranes under epithelium

Elastic fibers

• Thinner than collagen fibers

• Made of elastin

• Allows stretch and recoil like a rubber band

Skeletal Muscle

• Muscle fibers (cells)

• Striations

• Attached to bone

• Multinucleated

• Alternating dark bands

• Voluntary

Cardiac Muscle

• Heart wall

• Cardiomyocytes

  • short, branched

• intercalated discs

  • join end-to-end

• striated and involuntary

Smooth Muscle

• Short, fusiform cells

• Visceral muscle

  • Walls of hollow organs

• Involuntary

• Once central nucleus

Schwann Cells

• insulation

• saltatory conduction

• nerve repair

• metabolic support

Oligodendrocyte

• produce myelin

Microglia

Immune Surveillance

Ependymal cells

• CSF production

• fluid circulation

• barrier formation

Astrocyte

• regulate chemical levels, blood flow, structural stability

Tight Junctions

• zipperlike, interlocking linkage between two adjacent cells by transmembrane cell-adhesion proteins

  • encircles an epithelial cell near its apical surface

  • epithelial cell to epithelial cell

  • seals off intercellular space

    • difficult or impossible for substance to pass between cells

Desmosomes

• Patch that holds cells together, like a clothing snap

• keeps cells from pulling apart

  • resists mechanical stress

• J-shaped proteins from cytoskeleton

• epidermis and other epithelium

• hemidesmosomes — half desmosomes that anchor basal cells of ET to basement membrane

  • cannot easily peel away

Gap (communication) Junctions

• channel between cells formed by ringlike connexon

• connexon consists of 6 transmembrane proteins

  • like an orange around a water-filled channel

• ions, nutrients, other small solutes

• cardiac and smooth muscle, embryonic tissue, lens, and cornea

Merocrine

• Exocrine gland

• products released as vesicles during exocytosis

• tear glands, pancreas, gastric glands, sweat

Apocrine

• Exocrine gland

• similar to merocrine, but part of cytoplasm broken off along vesicles from apical portion

• mammary glands

Holocrine

• Exocrine Gland

• cells accumulate product, then rupture to release it

• sebaceous glands in scalp

Endocrine Glands

• no ducts, but have many blood capillaries; secrete hormones directly into blood

• hormones are chemical messengers that stimulate cells elsewhere in the body

• thyroid, adrenal, and pituitary glands