lab 4, 5, 12

Simple Squamous

LOCATIONS: Mesothelia

lining pleural, pericardial,

and peritoneal cavities;

endothelia lining heart

and blood vessels; portions

of kidney tubules (thin

sections of nephron loops);

inner lining of cornea;

alveoli of lungs

FUNCTIONS: Reduces

friction; controls vessel

permeability; performs

absorption and secretion

stratified squamous

surface of skin, mouth, throat, esophagus, rectum, anus, vagina

protection, pathogens etc

simple cubodial

glands, ducts, kidney, thyriod

secrete and absorb

stratified cubodial

rare, some ducts

merocrine secretion

released by secretory vesicales, exocytosis

• all over body, release water, on forwead

• cool body down

apocrine secretion

shed cytoplasm, mammary glands

holocrine secretion

cells bursting, kill gland cells, cell bursts with product

example, sebaceous gland

4 types of tissue membranes

• mucous membranes

• serous membranes

• cutaneous membranes

• synovial membranes

mucous membranes/ mucosae

• line passageways w external connections

• digestive, respiratory, urinary, reproductive tracts

• moist

  • to reduce friction and allow absorb and secrete

• lamina propia is areolar tissue in mucous membranes (lower part)

lamina propria

areolar tissue in mucous membranes

serous membranes

• line parts that do not open to outside

• thin but strong

Parietal portion lines inner surface of cavity

Visceral portion (serosa) covers the organs

Serous fluid reduces friction

in serous membranes, peritoneum

• lines peritoneal cavity

  • Covers abdominal organs

in serous membranes, pleura

Lines pleural cavities

• Covers lungs

in serous membranes, pericardium

Lines pericardial cavity

• Covers heart

cutaneous membrane

• skin covers body, thick, waterproof

synovial membranes

Line synovial joint cavities

Movement stimulates production of synovial fluid for lubrication

Lack a true epithelium

myosatelite cells

produce new fibers by dividing, for skeletal muscle tissues

intercalated disks

in cardiac muscle, how they are conected

necrosis

tissue destruction, when inflamed and tissue injured

• necrotic tissues and pus accumalte in wound, abcess is pus trapped in an enclosed area

what generates well

Epithelia, connective tissues (except cartilage), and smooth muscle

gap junctions

rapid communication

• small ions and molecules pass

• allow contractions in heart muscles

tight junctions

• btwn two mems

• prevent pass of water and solutes\

• keep stuff in digestive tract

desmosomes

CAMs and proteoglycans link opposing plasma membranes

Spot desmosomes

• Tie cells together

• Allow bending and twisting

Hemidesmosomes

• Attach cells to the basement membrane

fibroblasts

The most abundant cell type

Found in all types of connective tissue proper

Secrete proteins and hyaluronan (cellular cement)

fibrocytes

Second most abundant cell type

Maintain connective tissue fibers

adipocytes

Fat cells

Each cell stores a single, large fat droplet

Mesenchymal cells

Stem cells that respond to injury or infection

Differentiate into fibroblasts, macrophages,

melanocytes

Synthesize and store the brown pigment melanin

macrophaes

Large phagocytic cells of the immune system

Engulf pathogens and damaged cells

Fixed and free

mast cells

Stimulate inflammation after injury or infection

• Release histamine and heparin

Basophils are leukocytes that also contain histamine and heparin

lymphocytes

Migrate throughout the body

May develop into plasma cells, which produce antibodies

microphages

Phagocytic blood cells (neutrophils, eosinophils)

Attracted to signals from macrophages and mast cells

3 types connective tissue fibers

1. Collagen fibers

2. Reticular fibers

3. Elastic fibers

2 major parts of integumentary system

cutaneous membrarane (skin) and accessory structures

parts of cutaneous membrane

outer epidermis

• superdicial epithelium

inner dermis

• connective tissue

accessory structures

originate in dermis and extend to epidermis to skin surface

• hair and hair follicles, exocrine glands, nails

integument

contains blood vessels and sensory receptors

■ Subcutaneous layer (hypodermis)

Loose connective tissue

Below the dermis

layers of cutaneous membrane

epiderms

dermis containing papillary than reticular layer

subcutaneous layer

functions of integument

Protection of underlying tissues and organs

Excretion of salts, water, and organic wastes

Maintenance of normal body temperature

Production of melanin

Production of keratin

Synthesis of vitamin D3

Storage of lipids

Detection of touch, pressure, pain, etc.

Coordination of the immune response

Keratinocytes

• cells of epidermis

• most abundant

• keratin

2 types of skin

Thin skin

• Covers most of the body

• Has four layers of keratinocytes

Thick skin

• Covers the palms of the hands and soles of the feet

• Has five layers of keratinocytes

5 layers in thick skin, bottom to top

Stratum basale

• Stratum spinosum

• Stratum granulosum

• Stratum lucidum

• Stratum corneum

Stratum basale

Attached to basement membrane by hemidesmosomes

Forms a strong bond between epidermis and dermis

Contains epidermal ridges

• Lie next to dermal papillae in dermis

Has many basal cells, or germinative cells

• Stem cells that replace superficial keratinocytes

tactile discs/ tactile merkel cells

specialized structures of stratum basal

with sensory nerve endings

• Found in hairless skin

• Respond to touch

Melanocytes

• Contain the pigment melanin

stratum spinosum

spiny layer

Eight to ten layers of keratinocytes bound by desmosomes

Cells appear spiny in histological sections

Produced by division of cells in stratum basale, some of which

continue dividing

Contains dendritic (Langerhans) cells, which are active in immune

response

stratum granulosum

Three to five layers of keratinocytes

Produced from cells of stratum spinosum

Most cells stop dividing and produce

• Keratin

• Keratohyalin

Forms dense granules

Promotes cellular dehydration and cross-linking of keratin

fibers

After production of proteins, cells die

stratum lucidum

the “clear layer”

Found only in thick skin

Covers stratum granulosum

stratum corneum

the “horny layer”

Exposed surface of skin

Water resistant

15 to 30 layers of keratinized cells

• Keratinization is the formation of protective layers of cells

filled with keratin

New cells move from stratum basale to stratum corneum in 7 to 10

days

Exposed cells are shed after two weeks

2 ways water is lost

Insensible perspiration

• Water diffuses across stratum corneum and evaporates from

skin

• 500 mL per day

• Rate increases if stratum corneum is damaged

(e.g., from burns)

Sensible perspiration

• Water excreted by sweat glands

Epidermal growth factor (EGF)

A peptide growth factor

Produced by salivary glands and duodenum

Used in laboratories to grow skin grafts

■ Functions of EGF

Promotes division of basal cells

Accelerates keratin production

Stimulates epidermal repair

Stimulates glandular secretion

dermis

Located between epidermis and subcutaneous layer

Anchors epidermal accessory structures (e.g., hair follicles and sweat

glands)

Two components

• Outer papillary layer

• Deeper reticular layer

papillary layer

Consists of areolar tissue

Contains capillaries, lymphatic vessels, and sensory neurons

Named for dermal papillae that project between epidermal ridges

Becomes inflamed in dermatitis

• Caused by infection, radiation, mechanical irritation, or

chemicals (e.g., poison ivy)

• May produce itching or pain

reticular layer

Consists of dense irregular connective tissue

Contains collagen and elastic fibers

The dermis contains all cells of connective tissue proper

tension lines/cleavage lines

Produced by parallel bundles of collagen and elastic fibers in the

dermis

Resist forces applied to skin

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

• A cut at a right angle pulls open and scars

dermal blood supply

Cutaneous plexus

• Deep network of arteries along the reticular layer

Subpapillary plexus

• Network of small arteries in papillary layer

• Capillaries drain into small veins that lead to larger veins in

subcutaneous layer

Contusion (bruise)

• Caused by damage to blood vessels in dermis

Subcutaneous layer (hypodermis)

Lies deep to dermis

Connected to reticular layer by connective tissue

Stabilizes position of the skin

Primarily adipose tissue

Large arteries and veins are in superficial region

Site of subcutaneousinjections using hypodermic needles

Distribution of subcutaneous fat determined by sex hormones

central nervous system CNS

• brain and spinal cord

• nervous tissue, connective tissue, blood vessels

• process and coordinate sensory info from inside and outside body

• motor commands control peripheral organs like skeletal muscles

peripheral nervous system PNS

• all nervous tissue outside of CNS and ENS

• delivers sensory info to CNS

• carries motor commands to peripheral tissues/ skeletal muscles

nerves

bundle of axons with connective tissues and blood vessels

cranial nerves

connect to brain

spinal nerves

attach to spinal cord

what are the divisions of PNS

afferent and efferent

afferent division

carries sensory info

from receptors in peripheral tissues/skeletal muscles to CNS

efferent division

• carries motor commands

• from cns to muscles, glands, and adipose tissue

• somatic nervous system SNS

  • controls skeletal muscle contractions

  • volunatary and involuntary (reflexes)

• autonomic nervous system ANS

  • Controls subconscious actions, contractions of smooth

    and cardiac muscle, and glandular secretions

    • Sympathetic division has a stimulating effect

    • Parasympathetic division has a relaxing effect

functional parts of PNS

receptors

• detect change

• neurons or specialized cells

• single cell or eyes, ears etc

effectors

• target organs that respond to motor commands

sympathetic division

• part of ANS

• stimulating effect

• fight or flight

parasympathetic

• relaxing effect

• part of ANS

• rest, digest

Enteric nervous system (ENS)

neurons in digestive tract

Perikaryon

cytoplasm in cell body

Cytoskeleton of perikaryon

Neurofilaments and neurotubules

• Similar to intermediate filaments and microtubules

Neurofibrils

• Bundles of neurofilaments that provide support for

dendrites and axon

nissl bodies

Dense areas of RER and ribosomes in perikaryon

Make nervous tissue appear gray (gray matter)

axoplasm

Cytoplasm of axon

• Contains neurofibrils, neurotubules, enzymes, and

organelles

structures of axon

Axolemma

• Plasma membrane of the axon

• Covers the axoplasm

Initial segment

• Base of axon

Axon hillock

• Thick region that attaches initial segment to cell body

axolemma

• membrane of axon

• covers axoplasm

initial segment

base of axon

axon hillock

thick part attached to beginning of cell body

ependymal cells

help make cerebrospinal fluid

tendons

muscle to bone

ligaments

bone to bone

what type of connective tissue is ligament and tendom

dense regular connective tissue

Collaterals

branch of axon

telodendria

extensions of distal axon

axon terminals

tips of telodendria

axonal axoplasmic transport

Movement of materials between cell body and axon terminals

Materials move along neurotubules within axon

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