Exam 3 Review Slides

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Exam 3 Review Slides

• Lectures 9-12
• Chapters 4 and 5

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Types/Functions of Epithelial Tissue

• Types of epithelium
• 1. Covering and Lining Epithelium
• External Surfaces, e.g., skin, Internal surfaces
• 2. Glandular Epithelium

• Functions of Epithelial Tissue
• Physical protection
• Control of permeability
• Secretion, Absorption, Filtration
• Provide sensation
• Provide specialized secretions (glands)

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Characteristics of Epithelial Tissue

• Specialized contacts with other cells
• Polarity (different ends of cell do different
  things)
• Avascularity (no blood supply)
• Regeneration (can divide to make new cells)
• Cellularity (lots of cells in close contact)

Remember Epithelial tissues always have a free
surface and a basement membrane
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Basal Lamina
Formerly called Basement membrane
Two components Lamina Lucida - glycoproteins
and fine protein filaments - Barrier for passage
of substances from underlying tissue
into epithelium Lamina Densa - bundles of
coarse protein fibers - gives basal lamina its
strength
Lamina thin layer
Figure from Martini, Fundamentals of Anatomy
Physiology, Benjamin Cummings, 2004
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Classification of Epithelial Tissues
Epithelial tissues are classified according to
both their

• Shape
• Squamous (Thin, flat, irregular in shape)
• Cuboidal (Square or cuboidal)
• Columnar (Rectangular, tall)
• Type of layering (stratification)
• Simple (one layer)
• Stratified (two or more layers)
• Note that classification of stratified epithelium
  is based on the shape of the superficial, not
  deep, layers

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Characteristics of Epithelial TissueSpecialized
Contacts
Tight junction forces substances to go through
cells, rather than being able to pass between
them Gap junction allow rapid passage of small
molecules/ions between cells Desmosome binds
cells together firmly so they stay connected
Figure from Martini, Anatomy Physiology,
Prentice Hall, 2001
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Review
NAME OF ET DESCRIPTION STRUCTURE LOCATION FUNCTION
SIMPLE SQUAMOUS a single layer of flattened cells linings of air sacs, capillaries, lymph vessels, body cavities covering ventral organs diffusion, reduction of friction
SIMPLE CUBOIDAL a single layer of cube-shaped cells with large centrally located nuclei linings of kidney tubules, ducts of glands absorption, secretion
SIMPLE COLUMNAR a single layer of tall cells with basally located nuclei, goblet cells, mucrovilli lining of intestine protection, absorption, secretion
PSEUDO- STRATIFIED COLUMNAR a single layer of tall cells with scattered nuclei, cilia, goblet cells lining of trachea, lining of fallopian tube protection, secretion
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Review
NAME OF ET DESCRIPTION STRUCTURE LOCATION FUNCTION
STRATIFIED SQUAMOUS many layers of flattened cells keratinized epidermis non-keratinized lining of vagina, anus, throat, mouth protection
TRANSITIONAL several layers of cells that change shape under pressure lining of urinary bladder and ureters Distensibility (able to stretch)
GLANDULAR simple cuboidal lining the ducts of glands secretion
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Review of Epithelial Tissues

• Glands are specialized epithelium
• Secrete on to a surface (exocrine)
• Secrete into a duct (exocrine)
• Secrete into the blood (endocrine)

• Exocrine glands have several different mechanisms
  of secretion
• Merocrine
• Release of product from vesicles by exocytosis
  none of cell is lost
• Holocrine
• Entire cell is lost packed with secretion and
  then bursts
• Ex Unicellular mucous gland multicelluar
  sweat gland, sebaceous gland, mammary gland, etc.

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Membranes
A membrane is a combination of epithelium and
connective tissue that covers and protects other
structures and tissues. Technically, then, a
membrane is an organ.

• Serous
• line body cavities that lack openings to outside
• reduce friction
• inner lining of thorax and abdomen
• cover organs of thorax and abdomen
• secrete serous fluid

• Mucous
• line tubes and organs that open to outside world
• lining of mouth, nose, throat, digestive tract,
  etc.
• secrete mucus

• Synovial
• surround joint cavities

• Cutaneous
• covers body
• skin

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Review of Connective Tissues
NAME OF CT DESCRIPTION LOCATION FUNCTION
MESENCHYME Embryo gives rise to all other CTs
AREOLAR gel-like matrix with fibroblasts, collagen and elastic fibers beneath ET (serous membranes around organs lining cavities) diffusion, cushioning organs
ADIPOSE closely packed adipocytes with nuclei pushed to one side by fats beneath skin, breasts, around kidneys eyeballs insulation, energy store, protection
RETICULAR network of reticular fibers in loose matrix basement membranes, lymphatic organs support
DENSE REGULAR dense matrix of collagen fibers tendons, ligaments attachment (high tensile strength)
DENSE IRREGULAR loose matrix of collagen fibers dermis of skin strength in several directions
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Review of Connective Tissues
NAME OF CT DESCRIPTION LOCATION FUNCTION
ELASTIC CT matrix of elastic fibers lung tissue, wall of aorta durability with stretch
HYALINE CARTILAGE chondrocytes in lacunae in amorphous matrix embryonic. skeleton, costal cart, tip of nose, trachea, larynx support
FIBRO- CARTILAGE less firm than above intervertebral discs, pubic symphysis tensile strength, shock absorber
ELASTIC CARTILAGE above plus elastic fibers external ear, epiglottis shape maintenance plus flexibility
BONE concentric circles of calcified matrix Bones support, protection, movement, Ca storage, hematopoiesis
BLOOD red cells, white cells and platelets in liquid plasma in heart and blood vessels transport of nutrients, wastes gases
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Connective Tissue (CT) Summary TableThree main
components of ALL types of CT cell, fibers,
ground substance
Name of CT Different types of this CT Main types of cells present Main types of fibers present Consistency of matrix Examples of Locations
CT Proper 1) Areolar (Loose)2) Dense regular3) Dense irregular 4) Adipose 5) Reticular 6) Elastic 1) Fibroblasts2) Fibroblasts3) Fibroblasts 4) Adipocytes 5) Fibroblasts 6) Fibroblasts 1) Collagen, Elastic 2) Collagen 3) Collagen 4) Reticular 5) Reticular 6) Elastic Semi-liquid 1) Skin, between muscles 2) Tendons, ligaments 3) Dermis 4) Body fat areas 5) Stroma of liver, spleen 6) Lungs, airways, arteries/heart
Cartilage 1) Hyaline 2) Fibrocartilage 3) Elastic (All) Chondrocytes 1) Collagen (sparse) 2) Collagen (dense) 3) Elastic All types Semi-solid, gelatinous rubbery 1) Ribs, ends of bones 2) Intervertebral disks 3) Pinna of ear, epiglottis
Bone 1) Dense 2) Spongy (All) Osteocytes Collagen Solid (hydroxyapatite) 1) Outer portions of bone 2) Inner portions of bone
Blood -- 1) RBCs2) WBCs 3) Platelets (cell fragments) Fibrinogen (soluble) Liquid Blood vessels, heart
Lymph -- Lymphocytes Reticular (in stroma of lymphoid organs) Liquid Lymph vessels
-cyte fully differentiated -blast young,
actively synthesizing cell
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Connective Tissue - Major Cell Types

• Fibroblasts
• fixed cell
• most common cell always in CT proper
• large, star-shaped
• produce fibers
• produce ground substance

• Macrophages
• wandering cell
• phagocytic
• important in defense
• derived from circulating monocytes

Mast cells are mediators of inflammation see
later
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Connective Tissue Fibers

• Collagenous fibers
• thick
• composed of collagen
• great tensile strength
• hold structures together
• abundant in dense CT
• tendons, ligaments

• Elastic fibers
• bundles of microfibrils embedded in elastin
• fibers branch
• elasticity
• vocal cords, air passages

• Reticular fibers
• very thin collagenous fibers
• highly branched
• form supportive networks

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The Ground Substance of CT
glucosamine
VERY hydrophilic! Function Very active in
controlling passage of substances through this
portion of the matrix and keeping CT hydrated
GAGs glycosaminoglycans (negatively charged
polysaccharides) a major molecule in ground
substance
Figures from Alberts et al., Essential Cell
Biology, Garland Press, 1998
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Tendons and Ligaments
Tendons Connect muscle to boneLigaments
Connect bone to boneAponeuroses Broad,
fibrous sheets usually attach muscle to muscle
(or bone)
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CT Framework of the Body
Fascia layers of fibrous connective tissue
covering and separating muscle. It connects the
organs of the dorsal and ventral cavities with
the rest of the body
Provide - Strength - Stability - Organ
position - Conduits
Figure from Martini, Anatomy Physiology,
Prentice Hall, 2001
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Muscle Overview

• General characteristics
• Elongated cells with special properties
• Muscle cells (myocytes) muscle fibers
• Contractile (major property of all muscle)
• Use actin (thin) and myosin (thick) for
  contraction
• Three types of muscle tissue
• Cardiac (involuntary)
• Skeletal
• Smooth

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Review of Muscle Types
NAME OF MUSCLE TISSUE DESCRIPTION OF STRUCTURE TYPE OF CONTROL LOCATION FUNCTION
SKELETAL MUSCLE long, thin fibers with many nuclei and striations Voluntary attached to bones to move bones
SMOOTH MUSCLE spindle shaped cells with one centrally located nucleus, lacking striations Involuntary walls of visceral hollow organs, irises of eyes, walls of blood vessels to move substances through passageways (i.e. food, urine, semen), constrict blood vessels, etc
CARDIAC MUSCLE a network of striated cells with one centrally located nucleus attached by intercalated discs - Intercalated disks consist of 1)gap junctions and 2) desmosomes Involuntary heart pump blood to lungs and body
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Nervous Tissue

• found in brain, spinal cord, and peripheral
  nerves

• conduction of nerve impulses

• basic cells are neurons

• sensory reception

• neuroglial cells are supporting cells

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Introduction to Inflammation
HistamineHeparin
Histamine
Restoration of tissue homeostasis after injury or
infections involves two processes, in order 1)
inflammation and 2) repair
Main signs of inflammation Redness, heat, pain,
swelling, and loss of function (Inflammation
-itis)
Figure from Martini, Anatomy Physiology,
Prentice Hall, 2001
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Functions of the Integumentary System

• Functions of the integument
• Protection (from mechanical/chemical/bacterial
  damage, UV radiation)
• Temperature regulation (extreme heat, extreme
  cold) and Fluid conservation
• Excretion
• Vitamin D production
• Sensation (touch, pressure)

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Layers of the Epidermis - Overview
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Thick and Thin Skin
Thin (0.07-0.12 mm)(epidermal thickness)
Thick (0.8-1.4 mm) (epidermal thickness)
Thick skin - palms of hands, soles of feet five
epidermal layers
Thin skin - everywhere else four epidermal
layers (no s. lucidum)
Figure from Martini, Anatomy Physiology,
Prentice Hall, 2001
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Cells of the Epidermis

• Epidermis of the skin is classified as a
  keratinized stratified squamous epithelium
• Cells of the epidermis include
• Keratinocytes (90)
• Keratin a tough, fibrous intracellular protein
  (protection)
• Lamellar granules (waterproofing, extracellular)
• Melanocytes (8)
• Produce melanin (protection from UV radiation)
• Langerhans cells (1-2)
• Migrate to skin from bone marrow
• Participate in skins immune response (dendritic
  cells)
• Merkel cells (lt 1)
• Least numerous specialized epithelial cells
• Function in sensation of touch

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Skin Color

• 1. Genetic Factors
• varying amounts and type of melanin
• varying size/number of melanin granules
• albinos lack melanin (but not melanocytes!)

• 3. Physiological Factors
• dilation of dermal blood vessels (erythema)
• constriction of dermal blood vessels (less pink,
  pale pallor)
• level of oxygenation of blood normal pink
  (fair-skinned) low bluish (cyanosis)
• carotene -gt Vit A (yellow)
• jaundice (yellow)

• 2. Environmental Factors
• sunlight
• UV light from sunlamps
• X rays

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Skin Color and Melanin
Dark-skinned
Fair-skinned
Melanocytes produce melanin - tyrosine ?
melanin - UV radiation up-regulates production
of melanin - Dark-skinned individuals have
same number, higher activity of melanocytes
more pigmented layers of epidermis
Figure from Martini, Fundamentals of Anatomy
Physiology, Pearson Education, 2004
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Keratin and Vitamin D

• Keratin (tough, fibrous intracellular protein)
• Protection
• Water resistance
• Vitamin D3 (sunshine vitamin)
• After UV irradiation epidermal cells in s.
  spinosum and s. basale convert a
  cholesterol-related steroid to Vit D3
  (cholecalciferol)
• Vit D3 ? absorption of calcium and phosphorus
  by small intestine

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Two Layers of the Dermis
1. Papillary layer (near epiderm.) - areolar
connective tissue (CT) - capillaries and sensory
neurons - dermal papillae - fingerprints (with
epi. ridges) 2. Reticular layer - dense,
irregular CT - collagen fiber bundles extend
upward and downward - also contains elastic
fibers and cells of CT proper - accessory organs
of integumentary system (from epi.)
Figure adapted from Martini, Anatomy
Physiology, Prentice Hall, 2001
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Subcutaneous Layer
Basal lamina
- Stabilization of dermis
- Insulation (retains heat)
- Reservoir of blood
Also called hypodermis. This is the superficial
fascia.
- Areolar and adipose tissue
- Male/female hormones
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Hair (pilo-)

• epidermal cells

• tube-like depression

• extends into dermis

• hair root (in dermis)

• hair shaft (outer 1/3)

• hair papilla

• hair follicle

(from epidermis)

• melanin

• arrector pili muscle

Nerves in root hair plexus
A hair in the scalp grows for 2-5 years, about
0.33mm/day
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Hair Follicles
Most hair color
Three types of hair 1. Lanugo long, blond,
fine (fetal, anorexia nervosa) 2. Vellus
short, blond (children) 3. Terminal course,
pigmented (adults)
(Protection)
Some hair color
Figure adapted from Martini, Anatomy
Physiology, Prentice Hall, 2001
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Sebaceous (Oil) Glands

• usually associated with hair follicles

• multicellular, holocrine glands

• secrete sebum, a waxy, oily material

• inhibits growth of bacteria

• lubricates and protects keratin of hair shaft,
  and conditions skin

Sebaceous follicles not associated with hair.
Discharge directly on to skin. On face, back,
chest, nipples and male sex organs.

• absent on palms and soles

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Sweat Glands (Multicelluar)

• also called sudoriferous glands

Sweating with wetness diaphoresis

• apocrine (merocrine secr.) glands - associated
  with hair follicles - thick, odorous secretion

• eccrine (merocrine secr.) glands - most
  numerous - palms, soles, forehead, neck,
  back - directly on to surface - watery
  secretion - for thermoregulation

• ceruminous glands

Specialized (apocrine secretion)

• mammary glands

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Nails
(Perionychium)
Figure from Saladin, Anatomy Physiology,
McGraw Hill, 2007
Know these terms
Hyponychium
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Regulation of Body Temperature
Hyperthermia Abnormally high body
temperature May be caused by - environment
(heat, humidity) - illness (fever gt37.20C,
pyrexia) - anesthesia (malignant h.) Corrected
by loss of heat mainly by radiation (dilation of
blood vessels), evaporation (sweating) Heat
exhaustion (prostration) - Fatigue -
Dizziness - Headache - Muscle cramps -
Nausea - May lead to heat stroke
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Regulation of Body Temperature
Hypothermia Abnormally low body temperature (at
least 20C below normal body temp) May be caused
by - exposure to cold (primary) - illness
(secondary) - surgical induction
(clinical) Cardiac arrest is likely if
temperature falls below 28oC (82oF) Corrected by
mechanisms to retain body heat (see left)


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Healing of Cuts
Figure From Marieb Hoehn, Human Anatomy
Physiology, 9th ed., Pearson
3. Epidermal cell migration and collagen
production
4. Shedding of scab covering of wound with
epithelium
1. Bleeding/clotting
2. Scab formation
Tissue repair can occur by either 1)
regeneration healing with tissue that was
originally present 2) fibrosis healing with
scar tissue
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Healing of Cuts
Figure from Martini, Anatomy Physiology,
Prentice Hall, 2001
1. Bleeding/clotting
2. Scab formation
Tissue repair can occur by either 1)
regeneration healing with tissue that was
originally present 2) fibrosis healing with
scar tissue (carried out by fibroblasts)
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Healing of Cuts
4. Shedding of scab covering of wound with
epithelium
3. Epidermal cell migration and collagen
production
Figure from Martini, Anatomy Physiology,
Prentice Hall, 2001