Flashcards 2.3-3.2

What are the four basic types of tissue in the body?

Epithelial, connective, muscle, and nervous tissue

What is the main function of epithelial tissue?

To cover surfaces, line cavities, and form glands

What are the key characteristics of epithelial tissue?

High cellularity, polarity, basement membrane, avascular

What is the basement membrane?

A layer anchoring epithelium to connective tissue

How are epithelial tissues classified?

By (Intercellular connections– Cell junctions), (shape), and (number of layers)

What are the three epithelial cell shapes?

Squamous, cuboidal, columnar

What defines simple epithelium and Stratified epithelium?

simple epithelium: Single layer of cells. & Stratified epithelium: several layers of cells

What is the function of simple epithelium?

Absorption, secretion, filtration, and diffusion

What defines stratified epithelium?

to or more layers of stacked cells

What is the function of stratified epithelium?

Protection

What are cell junctions?

Connections between cells or extracellular material

What are the three types of cell junctions?

Gap junctions, tight junctions, desmosomes

What do gap junctions do?

Allow communication between cells

What passes through gap junctions?

Ions and small molecules

What do tight junctions do?

Prevent passage of water and solutes

Where are tight junctions important?

Digestive tract

What do desmosomes do?

Bind cells together

Difference between spot and hemidesmosomes?

Spot connect cells; hemi attach to membrane

What are basement membrane layers?

Basal lamina and reticular lamina

Function of reticular lamina?

Provides strength

How are epithelia classified?

Shape and layers

What is squamous?

Thin and flat

Difference between endocrine and exocrine glands?

Endocrine into blood; exocrine via ducts

What is glandular epithelium?

Glands are collections of epithelial cells that produce secretions

Components of connective tissue?

Specialized Cells, Extracellular protein fibers, ground substance

What is the matrix?

Fibers + ground substance

Function of connective tissue?

Support, protection, Transporting fluids, and Interconnecting other types of tissue

How does connective tissue defend the body?

Protects from microorganisms

Categories of connective tissue?

Proper (Connect and protect), fluid (Transport), supporting (Structural strength)

Function of fluid connective tissue?

Transport

Loose vs dense connective tissue?

Loose more ground substance; dense more fibers

Example of dense connective tissue?

Tendons

Components of connective tissue proper?

Fibers, ground substance, cells

What is ground substance?

Viscous fluid

Examples of loose connective tissue?

Areolar, adipose, reticular

Types of dense connective tissue?

Regular and irregular

Types of fluid connective tissue?

Blood and lymph

Formed elements of blood?

RBCs, WBCs, platelets

Types of cartilage?

Hyaline, elastic, fibrocartilage

Cartilage cells called?

Chondrocytes

Function of bone?

Support and protection

Bone cells called?

Osteocytes

Function of canaliculi (channels through matrix)?

Exchange nutrients/waste with blood

Function of muscle tissue?

Movement

Types of muscle tissue?

Skeletal, cardiac, smooth

Skeletal muscle characteristics?

-Striated voluntary muscle

-Consists of long, thin cells called muscle fibers

-Cells do not divide; instead produced by divisions of myosatellite cells

Do skeletal muscle cells divide?

No

Cardiac muscle characteristics?

Striated, involuntary, branched

Smooth muscle characteristics?

Nonstriated, involuntary

Where is cardiac muscle found?

Heart

Function of smooth muscle?

Move substances(urine, food, reproductive secretions), controls diameter of respiratory

passageways; regulates diameter of blood vessels

Function of nervous tissue?

Conduct impulses

Where is nervous tissue found?

Brain and spinal cord

Parts of a neuron?

Cell body, dendrites, axon

Function of dendrites?

Receive signals

Function of axon?

Send signals

What are neuroglia?

Supporting cells

What are the two parts of integumentary system?

Skin and accessory structures

Layers of cutaneous membrane?

Epidermis (Outer) and dermis (inner)

Examples of accessory structures?

Hair, glands, nails

What is subcutaneous layer?

Loose connective tissue below dermis

What does integument contain?

Blood vessels and receptors

Function of integument?

-Protection of organs

-Excretion of salts, water, and organic wastes

-Maintenance of normal body temperature

-Production of melanin

-Production of keratin

How does skin regulate temperature?

Sweating and blood flow

Function of epidermis?

-protects the dermis,

-prevents water loss and the entry of pathogens

-Sensory receptors

-detect touch, pressure,

-pain, and temperature

Function of dermis?

Papillary Layer: Support and nourish

Reticular Layer: Has sensory receptors that detect touch, pressure, pain, vibration, and temperature.

epidermis tissue is?

-Stratified squamous epithelium

-Avascular, like all epithelia

-Nutrients and oxygen diffuse from capillaries in the dermis

Why is epidermis avascular?

No blood vessels, gets nutrients through basement membrane

What are keratinocytes?

Main epidermal cells

Contain large amounts of keratin

• Occurs on all exposed skin surfaces

What do keratinocytes produce?

Keratin

Thin vs thick skin?

4 vs 5 layers of keratinocytes

Where is thick skin?

Palms and soles

Five epidermal layers?

(From basement membrane to free surface) Basale→ spinosum→granulosum→ lucidum→ corneum

Top epidermal layer?

Stratum corneum

Location of dermis?

Between epidermis and hypodermis

Layers of dermis?

Papillary and reticular

Papillary layer contains?

Capillaries and nerves

Cause of dermatitis?

Inflammation

Reticular layer tissue?

Dense irregular connective tissue

Fibers in reticular layer?

Collagen and elastic

What are tension lines?

Collagen fiber lines

Why important surgically?

A cut made parallel to a tension line remains shut, heals well

Pigments in skin?

Melanin and carotene

Where are pigments?

Epidermis

What is melanin?

UV-protective pigment

Cells that produce melanin?

Melanocytes

What is carotene?

Orange-yellow pigment

Can be converted to vitamin A, required for

• Maintenance of epithelia

• Synthesis of photoreceptor pigments in eye

Carotene converts to?

Vitamin A

Effect of oxygenated blood?

Reddish skin- When blood vessels dilate from heat

What is cyanosis?

Hemoglobin turns dark red when oxygen is released- Bluish skin

Accessory structures?

Hair, glands, nails- Located in dermis, but project to skin surface

Origin of accessory structures?

Dermis

Function of hair?

Protection and sensation

Hair follicles located?

Dermis

Sebaceous glands secrete?

Sebum

Function of sebum?

Lubrication

Apocrine glands location?

Armpits, groin

Why apocrine smell?

Bacteria

Apocrine secretion?

Thick fluid