Transcript No Slide Title

Chapter 5-- Histology
(microscopic anatomy)
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Ch. 5 Study Guide
1. Read Chapter 5 up to page 170 right
before 5.4 Nervous and Muscular Tissue
2. Comprehend Terminology (those in bold in
the textbook)
3. Study-- Figure questions, Think About It
questions, and Before You Go On (sectionending) questions
4. Do end-of-chapter questions
 Testing Your Recall— 1-4, 6-10, 13, 17, 18, 20
 True or False– 1, 2, 5, 6, 10
 Testing Your Comprehension-- #4, #5
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5.1--The study of tissues
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§ The Study of Tissues
1. Whole body contains only 200 different types
of cells
2. Four tissue classes (Def. of tissue--?) See
Table 5.1.
3. Histology (microscopic anatomy)
– study of tissues and how they form organs
4. Organ = structure with discrete boundaries
– composed of 2 or more tissue types
– Examples:
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§ Differences among 4 Tissue Classes
1. Types and functions of cells-• For example: Epithelial, CT, Nervous,
Muscular
2. Characteristics of the matrix
(extracellular material)
• Rubbery, stony, or gelatinous
3. Relative amount of space occupied by
cells versus matrix
• CT vs. muscle and epithelium
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§ Embryonic Tissues
1. Embryo begins as a single cell
– divides into many cells that form layers (strata)
2. Three primary germ layers
A.ectoderm (outer) gives rise to: epidermis +
nervous system
B.endoderm (inner): mucous membranes: GI
tract and respiratory linings; digestive glands.
C.mesoderm (middle) forms mesenchyme
(gelatinuous tissue) and then give rise to
muscle, bone, and blood
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§ Tissue Sectioning (1)
1. Preparation of histological specimens
– fixation
– sections
– mounted on slides & stained
2. Sectioning (slicing) an organ or tissue
reduces a 3-dimensional structure to a 2dimensional slice (see the next 3 slides)
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Tissue Sectioning (2)
1 2 3 4 5
1
2
•Slices 1 & 5
miss the yolk
/ cell nucleus
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3
4
•Cell nucleus
is smaller in
sections 2 &
4
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Tissue Sectioning (3)
A
B
• Image A is a cross
section of elbow
macaroni,
resembling a blood
vessel, piece of gut,
or other tubular
organ.
• Image B is a
longitudinal section
of a sweat gland.
Notice what a single
slice could look like
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§ Types of Tissue Sections (1)
• Longitudinal section
– tissue cut along the
longest direction of an
organ
• Cross section
– tissue cut perpendicular
to the length of an
organ
• Oblique section
– tissue cut at an angle
between a cross &
longitudinal section
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Types of Tissue Sections (2)
Practice at home.
• Would you classify
the egg sections as
longitudinal, cross,
or oblique sections?
• How would the egg
look if sectioned in
the other two
planes? (Fig. 5.2
question)
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5.2--Epithelial tissue
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§ Epithelial Tissue Introduction (1)
1. One or more layers of closely adhering cells
2. (Top) Forms a flat sheet with the upper (______)
surface exposed to the environment or an internal
body cavity
3. (Bottom) Sits on basement membrane (basal
surface of cells); Fig. X
– anchors epithelium to underlying connective tissue
4. (Nourishment) No room for blood vessels; . . .
CT
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What are the
functions of
the basement
membrane?
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§ Epithelial Tissue Introduction (2)
Arrangement and Cell Shape—
1.Simple epithelium
– contains one layer of cells
– named by shape of cells
2.Stratified epithelium
– contains more than one layer
– named by shape of apical cells
Fig. 5.3
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§ 1.Simple Squamous Epithelium—
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1. (Structure) Single row of flat cells (scaly)
2. (Functions) Allows rapid diffusion of
substances; secretes serous fluid
3. (Locations) in alveoli, glomerular
capsule, endothelium (blood vessels and
heart), and serosa (external surface)
such as stomach & intestines
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§ 2. Simple Cuboidal Epithelium—
1. (Structure) Single row of cube-shaped
cells, often with microvilli
2. (Functions) Absorption & secretion;
produces mucus
3. (Locations) Liver, thyroid, mammary,
salivary and other glands, bronchioles, and
most kidney tubules
Fig. 5.5
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§ 3.Simple Columnar Epithelium—
1. (Structure) Single row of tall, narrow cells
– vertically oriented, oval nuclei in basal half
of cell
2. (Functions) Absorption & secretion; secretion
of mucus
3. (Locations) Inner lining of GI tract from
stomach to the anus; ducts of gallbladder;
uterus, and uterine tubes; some kidney tubes;
a few portions of upper respiratory tract
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§ 4. Pseudostratified Epithelium—
1. (Structure) Single row of cells not all of
which reach the free surface; nuclei at
different levels.
2. (Functions) secretes propels mucus
3. (Locations) most of the upper respiratory
system from nasal cavity to bronchi; part of
male urethra
Fig. 5.7
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§ Stratified Epithelia
• Composed of more than one layer of cells &
named for shape of __________ cells
• Deepest cells sit on basement membrane
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§ 5A. Keratinized Stratified Squamous
Fig. 5.8 Skin from
the sole of the foot
• Layers of epithelium covered with compact, ______
squamous cells (no nuclei) packed with protein keratin
• Retards water loss, prevents entrance of organisms
• Forms epidermal layer of skin (esp. soles and palms)
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§ 5B.Nonkeratinized Stratified Squamous
Epithelial
layer
Fig. 5.9
Mucosa
of the
vagina
• Multilayered epithelium that lacks surface layer of
dead cells forming moist, slippery layer
• Locations: tongue, oral mucosa, esophagus & vagina
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Pap smear/test
•
•
•
•
What? Examination of exfoliated cells
Where? The cervix
Why?
How? Loose cells are examined
microscopically for abnormal cells
• Who? Between 30-50 years old
Fig. 28.5
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Fig. 28.5—Pap smears
Which one is
normal cells?
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§ 6. Stratified Cuboidal Epithelium
Fig. 5.10—Sweat
gland ducts
• (Structure) Two or more layers of cells; surface cells
square or round
• (Functions) Secretion and production
• (Locations) Sweat glands, mammary glands, salivary
glands, ovarian follicles, seminiferous tubules
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§ 7. Transitional Epithelium
1. (Structure) Multilayered epithelium with
rounded (not flattened) surface cells
2. (Functions) Allow stretches and distension
3. (Locations) Urinary tract--part of kidney,
ureter, urinary bladder, part of the urethra
Fig. X
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Qs from Before You Go On (p. 162)
Distinguish between simple and stratified
epithelia. Explain why pseudostratified
columnar epithelium belongs in the former
category?
Distinguish a stratified squamous
epithelium from a transitional epithelium.
How do the epithelia of the esophagus
and stomach differ? Respective
functions?
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5.3--Connective tissue
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§ Connective Tissue (CT) Overview
• Most abundant and variable tissue type
• 3 structural elements –
– Consists mostly of (a) G________; (b) F_______
– (c) with widely spaced cells
• Functions of CT:
– Binding of organs --Ex. a tendon connects
muscle to bone
– Support, protection, movement -- Ex. bones
– Storage – (energy, electrolytes) Ex. Fats/bones
– Transport -- Ex. Blood
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§ 1. Ground Substance of C.T.
• Gelatinous or rubbery material found in
between cells – Function?
• Consists of 3 classes of large molecules
– Glycosaminoglycans (GAGs) –
• Polysacharides that attract sodium & hold water
• Ex.--
– Proteoglycan is bottlebrush-shaped molecule
• Forms thick gel that slows the spread of pathogens
– Cell adhesive glycoproteins
• Allow themselves bind to matrix elements
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§ 2. Fibers of C.T.
• Collagen fibers--called white fibers (Fig. 5.13)
– Most abundant protein of the body
– Thick, tough, resist stretch yet flexible
– Ex. tendons, ligaments & dermis
• Elastic fibers--called yellow fibers
– made of E______; recoil like rubberband (elasticity)
– Ex. skin, lungs & arteries; ability to recoil
• Reticular fibers
– Thin collagen fibers coated with glycoprotein
– Ex. form framework for spleen & lymph nodes
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Collagen
Tendons
(collagen)
Figure 5.13
§ 3. Cells of C.T.
• Fibroblasts -- produce fibers & ground substance
• WBCs -- wander (mostly in CT) in search of
bacteria
– Macrophages – large phagocytic cells-- arise from
monocytes (WBC); function? phagocytosis
– Plasma cells -- arise from lymphocytes; antibodyproducing cells
• Mast cells – oval shaped; clustered along blood
vessels; secrete heparin and histamine
• Adipocytes or fat cells --store triglycerides
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5.3--Connective tissue
A. Fibrous CT
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§ Five Types of Fibrous C.T.
Divided into 2 broad categories:
• Loose CT (3 slides followed)
– contains MORE gel-like ground substance
between cells
– 3 types: A--areolar, B--reticular, C--adipose tissue
• Dense CT (2 slides followed)
– FIBERS fill the spaces between cells
– 2 types varying in fiber orientation: D--dense
regular, E--dense irregular
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§ A-- Areolar Tissue
Fig. Mesentery
• Loose arrangement of collagenous and elastic fibers;
scattered cell types; abundant ground substance
• Locations-- Underlying all epithelia; surrounding
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nerves, blood vessels, esophagus, trachea
§ B-- Reticular Tissue
• Loose network of
R_________ and cells
• Forms structural
supportive stroma for
lymphatic organs
• Locations-- lymph
nodes, spleen, thymus
& bone marrow
Fig. Spleen
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§ C-- Adipose Tissue (Fat)
• Large, empty-looking cells dominate with thin
margins; nucleus pressed against cell
membrane; often very pale
• Functions-- Energy storage, insulation, space
filled as cushioning
• Locations-- Subcutaneous fat beneath skin,
breast, heart surface, surrounding organs
Fig. 5.18
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Figure 5.16b
Fig. Adipose tissue
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§ D-- Dense Regular CT
• Structure-- Mainly densely, PACKED,
PARALLEL C__________FIBERS;
compressed fibroblast nuclei; scanty open
space and blood vessels
• Locations-- Tendons & ligaments
Figure 5.16
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D-- Dense Regular CT
Fig. Tendon
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§ E-- Dense Irregular CT
• Densely packed collagen fibers running in
________ directions; scanty open space;
few visible cells and blood vessels
• Function-- Withstands stresses applied in
MANY DIFFERENT DIRECTIONS
• Locations-- Deeper portion of skin;
capsules around organs (ex. Liver, kidney
etc); sheaths around cartilages and bones
Figure 5.17
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E-- Dense Irregular CT
Fig. Dermis of the skin
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5.3--Connective tissue
B. Cartilage, Bone, Blood
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§ Cartilage
• Supportive CT with rubbery matrix
• Chondroblasts produce matrix, surround
themselves, and become Chondrocytes
• No blood vessels; so diffusion must bring in
nutrients & remove wastes; healing . . .
• 3 types of cartilage depend upon FIBER
TYPES
– A--hyaline, B--elastic, and C--fibrocartilage
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§ A-- Hyaline Cartilage
• Clear, glassy matrix; invisible fine
dispersed collagen fibers; chondrocytes
in small clusters enclosed in lacunae
• Supports airway, eases joint movements
• Locations-- Over ends of bones at
movable joints; sternal ends of ribs;
supportive material in larynx, trachea,
bronchi and fetal skeleton
Fig. 5.19
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Figure 5.19b
Fig. Fetal skeleton
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§ B-- Elastic Cartilage
• Hyaline cartilage with weblike mesh of
elastic fibers amid the lacunae; always
has perichondrium (a sheath of C.T.)
• Provides flexible, elastic support
• Locations— Ear + Epiglottis
• Fig. 5.20
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Figure 5.20b
Fig. External ear
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§ C-- Fibrocartilage
• Cartilage containing extensive parallel
Collagen fibers; never has
perichondrium; row of chondrocytes in
lacunae
• Resists compression and absorbs shock in
some joints
• Locations-- Pubic symphysis, menisci
(pads) in knee joint, & intervertebral discs
Fig. 5.21
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Figure 5.21b
Fig. Intervertebral disc
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§ Bone (osseous tissue)
• Spongy bone looks spongy in appearance
– fills heads of long bones
– delicate struts of bone
– ALWAYS COVERED BY COMPACT
BONE
• Compact (dense) bone looks solid
– No space visible to the naked eye
– External surfaces of ALL bones
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§ Compact bone
• Calcified matrix in concentric lamellae
around central (haversian) canal
containing blood vessels
• osteocytes in lacunae between lamellae
connected by canaliculi— delicate
narrowing canals . . .
• Physical support; leverage for muscles;
mineral storage
• Locations-- in skeleton (Fig. 5.22)
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Canaliculi ?
Fig. Compact bone
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§ Blood
• Variety of cells and cell fragments;
some with nuclei & some without
• RBC, WBC, platelets
• Found in heart and blood vessels
Fig. 5.23
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Fig. Blood smear
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