Tissues Flashcards
1
Q
histology
A
study of tissues
2
Q
pathologist
A
looks for tissue changes that indicate disease
3
Q
4 basic tissues
A
epithelial, connective, muscle, nerve
4
Q
epithelial tissues
A
covers surfaces b/c cells are in contact. lines hollow organs, cavities, and ducts. forms glands when cells sink under the surface
5
Q
Connective tissue
A
material found between cells. supports and binds structures together. stores energy as fat. provides immunity to disease
6
Q
muscle tissue
A
cells shorten in length producing movement
7
Q
nerve tissue
A
cells that conduct electrical signals. detects charges inside and outside the body. responds with nerve impulses
8
Q
origin of tissues
A
- Primary germ layers within the embryo
- -endoderm
- -mesoderm
- -ectoderm
9
Q
Tissue derivations
A
- epithelium from all three germ layers
- connective tissue and muscle from mesoderm
- nerve tissue from ectoderm
10
Q
Biopsy
A
removal of living tissue for microscopic examination
- surgery
- needle biopsy
Useful for diagnosis, especially cancer.
Tissue preserved, sectioned and stained before microscopic viewing
11
Q
5 Cell Junctions
A
Tight Junctions, Adherens juctions, gap juctions, desmosomes, hemidesmosomes
12
Q
Tight Junctions
A
- watertight seal between cells
- plasma membranes fused with a strip of proteins
- common between cells that line GI and bladder
13
Q
Adherens Junctions
A
- Holds epithelial cells together
- Structural components
- Plaque (dense layer of proteins inside the cell membrane)
- Microfilaments extend into cytoplasm
- integral membrane proteins connect to membrane of other cell
14
Q
Desmosomes
A
- resist cellular separation and cell disruption and cell disruption
- similar structure to adherens junction except intracellular intermediate filaments cross cytoplasm of cell
- cellular support of cardiac muscle
15
Q
hemidesmosomes
A
half a desmosome
- connect cells to extracellular material- basement membrane
16
Q
gap junctions
A
- tiny space between plasma membranes of two cells
- crossed by protein channels called connexons forming fluid filled tunnels
- cell communication with ions and small molecules
- muscle and nerve impulses spread from cell to cell hearth and smooth muscles of gut
17
Q
Epithelial Tissue- general features
A
- closely packed cells forming continuous sheets
- cells sit on basement membrane
- apical (upper) free surface
- avascular– without blood vessels (nutrients diffuse in from underlying connective tissue)
- good nerve supply
- rapid cell division
- covering/lining versus glandular types
18
Q
basement membrane
A
- basal lamina (from epithelial cells; collagen fibers)
- reticular lamina (secreted by connective tissue cells; reticular fibers)
- holds cells to connective tissue
- guide for cell migration during development
19
Q
Types of epithelium
A
- covering and lining epithelium
- glandular epithelium
20
Q
Covering and lining epithelium
A
- epidermis of skin
- lining of blood vessels and ducts
- lining respiratory, reproductive, and urinary and GI tract
21
Q
Glandular epithelium
A
- secreting portion of glands
- thryoid, adrenal, and sweat glands
22
Q
Classification of epithelium
A
Classified by arrangement of cells into layers
- simple= one cell layer thick
- stratified= many cell layers thick
- pseudostratified= single layer of cells where all cells don’t reach apical surface (nuclei found at different levels so it looks multilayered)
Classified by shape of surface cells
- Squamous- flat
- cuboidal= cube-shaped
- columnar= tall column
- transitional= shape varies with tissue stretching
23
Q
Simple Squamous Epithelium
A
single layer of flat cells
- lines blood vessels (endothelium), body cavities (mesothelium)
- very thin–controls diffusion, osmosis, and filtration
- nuclei centrally located
cells in direct contact with eachother
24
Q
Simple Cuboidal Epithelium
A
- Single layer of cube shaped cells viewed from the side
- nuclei round and centrally located
- lines tubes of kidney
- absorption or secretion
25
Nonciliated Simple Columnar
- Single Layer of rectangular cells
- unicellular glands= goblet cells secrete mucus (lubricate GI, respiratory, reproductive and urinary systems)
- microvilli=fingerlike cytoplasmic projections- for absorption in GI tract (stomach to anus)
26
Ciliated Simple Columnar
- Single layer rectangular cells with cilia
| - mucus from goblet cells moved along by cilia (found in respiratory system and uterine tubes)
27
stratified squamous epithelium
- several layers thick
- surface cells flat
- keratinized= surface cells dead and filled with keratin (skin- epidermis)
- nonkeratinized= no keratin in moist living cells at surface (mouth, vagina)
28
Pap Smear
- collect sloughed off cells of uterus and vaginal walls
- detects cellular changes (precancerous cells)
- annually for women over 18 or if sexually active
29
Stratified cuboidal epitherlium
- multilayered
| - surface cells cuboidal - rare (only found in sweat gland ducts and male urethra)
30
Stratified columnar epithelium
multilayered, surface cells columnar, rare (very large ducts & part of male urethra)
31
transitional epithelium
multilayered, surface cells vary in shape from round to flat if stretched, lines hollow organs that expand from within (urinary bladder)
32
pseudostratified
- single cell layer
- all cells attach to basement membrane but not all reach free surface
- nuclei at varying depths
- respiratory system, male urethra & epidiymis
33
glandular epithelium
- derived from epithelial cells that sank below the surface during development
- Exocrine glands- cells that secrete-- sweat, ear wax, saliva, digestive enzymes onto free surface of epithelial layer; connected to the surface by tubes (ducts); unicellular glands or multicellular glands
- endocrine- secrete hormones into bloodstream; hormones help maintain homeostasis
34
structural classification of exocrine glands
- unicellular are single celled glands- goblet cells
| - multicellular glands- branched (compound) or unbranched (simple); tubular or acinar (flask like) shape
35
Methods of glandular secretion
- merocrine- most glands (cells release their products by exocytosis--- saliva, digestive enzymes & sweat)
- apocrine- smelly sweat & milk; upper part of cell possibly pinches off and dies
- holocrine- oil gland; whole cells die & rupture to release their products
36
Connective Tissues
- cells rarely touch due to extracellular matrix
- matrix (fibers & ground substance secreted by cells)
- consistency vaies from liquid, gel to solid
- does not occur on free surface
- good nerve & blood supply except cartilage & tendons
37
Cell types
```
blast type cells
cyte type cells
macrophages
plasma
mast cells
adipocytes
```
38
Blast type cells
- retain ability to divide and produce matrix (fibroblasts, chondroblasts, osteoblasts)
39
cyte type cells
mature cell that con not divide or produce matrix (chondrocytes and osteocytes)
40
macrophages
- develop from monocytes
| - engulf bacteria and debris by phagocytosis
41
Plasma cells
- develop from B lymphocytes
| - produce antibodies that fight against foreign substances
42
Mast cells
produce histamine that dilate small blood vessels
43
Adipcytes
fatt cells- store fat
44
Connective Tissue Ground Substance
- supports the cells and fibers
- helps determine the consistency of the matrix- fluid, gel or solid
- contains many large molecules- hyaluronic acide is thick, viscous and slippery; condroitin sulfate is jellylike substance providing support; adhesion proteins (fibronectin) binds collagen fibers to ground substance
45
Types of Connective Tissue Fibers
Collagen, Elastin, Reticular
46
Collagen
(25% of protein in your body)
- tough, resistant to pull, yet pliable
- formed from the protein collagen
47
Elastin
(lungs, blood vessels, ear cartilage)
- smaller diameter fibers formed from protein elastin surrounded by glycoprotein (fibrillin)
- can stretch up to 150% of relaxed length and return to original shape
48
Reticular
(spleen and lymph nodes)
- thin, branched fibers that form framework of organs
- formed from protein collagen
49
Marfan Syndrome
- inherited disorder of fibrillin gene
- abnormal development of elastic fibers
- tendency to be tall with very long legs, arms, fingers, and toes
- live threatening weakening of aorta may lead to rupture
50
Embryonic Connective Tissue: Mesenchyme
- Irregularly shaped cells
- in semifluid ground substance with reticular fibers
- gives rise to all other types of connective tissue
51
Embryonic Connective Tissue: Mucous Connective Tissue
- Star shaped cells in jelly-like ground substance
| - found only in umbilical cord
52
Mature Connective Tissue
- loose connective tissue
- dense connective tissue
- cartilage
- bone
- blood
- lymph
53
Loose Connective Tissue
- loosely woven fibers throughout tissues
| - types: areolar, adipose, reticular
54
Loose Connective Tissue: Areolar
Cell types: fibroblasts, plasma cells, macrophages, mast cells and a few WBC
- all 3 of fibers present
- gelatinous ground substance
55
Adipose Tissue
- peripheral nuclei due to large fat storage droplet
- deeper layer of skin, organ padding, yellow marrow
- reduces heat loss, energy storage, protection
- brown fat found in infants has more blood vessels and mitochondria and responsible for heat generation
56
Reticular Connective Tissue
- network of fibers & cells that produce framework of organ
- holds organ together (liver, spleen, lymph nodes, bone marrow)
57
Dense Connective Tissue
- more fibers present but fewer cells
| - types: dense regular, dense irregular, elastic
58
Dense Regular Connective Tissue
- collagen fibers in parallel bundles with fibroblasts between bundles of collagen fibers
- white, tough and pliable when unstained (forms tendons)
- also known as white fibrous connective tissue
59
Dense Irregular Connective Tissue
- collagen fibers are irregularly arranged (interwoven)
- tissue can resist tension from any direction
- very tough tissue- white of eyeball, dermis of skin
60
Elastic connective tissue
- branching elastic fibers and fibroblasts
- can stretch & still return to original shape
- lung tissue, vocal cords, ligaments between vertebrae
61
Cartilage
- network of fibers in rubbery ground substance
- resilient and can endure more stress than loose or dense connective tissue
types: hyaline, fibrocartilage, elastic
62
hyaline cartilage
- bluish-shiny white rubbery substance
- chondrocytes sit in spaces called lacunae
- no blood vessels or nerves so repair is very slow
- reduces friction at joints as articular cartilage
63
Fibrocartilage
- many more collagen fibers cause rigidity & stiffness
| - strongest type of cartilage (intervertebral discs)
64
Elastic Cartilage
- elastic fibers help maintain shape after deformations
| - ear, nose, vocal cartilages
65
Growth & Repair of Cartilage
- Grows and repairs slowly because its avascular
- interstitial growth- chondrocytes divide and form new matrix; occurs in childhood and adolescence
- appositional growth- chondroblasts secrete matrix onto surface; produces increase in width
66
Bone (osseous) Tissue
Spongy- sponge like with spaces and trabeculae (struts of bone surrounded by red bone marrow); no osteons (cellular organization)
Compact bone- solid, dense bone; basic unit of structure is osteon (haversian system)
*protects, provides movement, stores minerals, site of blood cell formation
67
Osteon
lamellae (rings) of mineralized matrix
- calcium & phosphate-- gives it its hardness
- interwoven collagen fibers provide strength
68
osteocytes
in spaces (lacunae) in between lamellae
69
Canaliculi
tiny canals that connect cell to cell
70
connective tissue with a liquid matrix
plasma
71
Cell types
RBC (erythrocytes), WBC (leukocytes), Platelets- provide clotting, immune functions, and carry O2 and CO2
72
Lymph
Interstitial fluid being transported in lymphatic vessels
- contains less protein than plasma
- move cells and substances (lipids) from one part of the body to another
73
Membranes
epithelial layer sitting on a thin layer of connective tissue (lamina propria)
types: mucous, serous, synovial, cutaneous
74
Mucous Membranes
lines a body cavity that open to the outside (mouth, vagina, anus, etc)
- epithelial cells form a barrier to microbes
- tight junctions between cells
- mucous is secreted from underlying glands to keep surface moist
75
Serous Membranes
Simple squamous cells overlying loose CT layer
- squamous cells secrete slippery fluid
- lines a body cavity that does not open to the outside such as chest or abdominal cavity
Examples: pleura, peritoneum and pericardium
- membrane on walls of cavity- parietal
- membrane over organs- visceral layer
76
Synovial Membranes
line joint cavities of all freely moveable joints
| - no epithelial cells- just special cells that secrete slippery fluid
77
Muscle
cells that shorten; provide us with motion, posture and heat
| types: skeletal, cardiac, smooth
78
Skeletal Muscle
cells are long cylinders with many peripheral nuclei
- visible light and dark banding (looks striated)
- voluntary or conscious control
79
Cardiac Muscle
Cells are branched cylinders with one central nuclei
- involuntary and striated
- attached to and communicate with each other by intercalated discs and desmosomes
80
Smooth Muscles
Spindle shaped cells with single central nucei
- walls of hollow organs (blood vessels, GI tract, bladder)
- involuntary and striated
81
Nerve Tissue
Cell types- nerve cells and neuroglial (supporting) cells
- nerve cell structure
- nucleus & long cell processes conduct nerve signals
dentrite- signal travels towards the cell body
axon- single travels away from cell body
82
Tissue Engineering
new tissues grown in the laboratory (skin and cartilage)
| -scaffolding of cartilage fibers is substrate for cell growth in culture
83
Tissue Repair: Restoring Homeostasis
Worn out, damaged tissue must be replaces
- Fibrosis= replacement with stromal connective tissue cells (scar formation)
- Regenerations= replacement with orginal cell types (parenchymal cells)
- some cells can divide (liver & endothelium)
- some tissues contain stem cells that can divide (bone marrow, epithelium of gut & skin)
- some cell types can not divide & are not replaced (muscle and nervous tissue)
84
Conditions affecting tissue repair
Nutrition- adequate protein for structural components; vitamin C production of collagen and new blood vessels
Proper blood circulation- delivers O2 and nutrients and removes fluids & bacteria
With aging- collagen fibers change in quality; elastin fibers fragment and abnormally bond to calcium; cell division and protein synthesis are slowed
85
Sjogrens Syndrome
Autoimmune Disorder producting exocrine gland inflammation
- dryness of mouth and eyes
- 20% of older adults show some signs
86
Systemic Lupus Erythematosus
Autoimmune disorder (causes unknown)
- chronic inflammation of connective tissue
- nonwhite women during childbearing years
- painful joints, ulcers, loss of hair, fever
- life-threatening if inflammation occurs in major organs-- liver, kidney, heart, brain, etc
