Chapter 5 - Tissues Flashcards
(70 cards)
1
Q
In complex organisms, cells are organized into…?
A
Tissues
2
Q
Tissue
A
group of similar cells with a common function
3
Q
Histology
A
the study of Tissues
4
Q
What are the 4 major types of Tissues in the body?
A
- Epithelial tissue
- Connective tissue
- Muscle tissue
- Nervous tissue
5
Q
Epithelial tissue
A
- Cover organs and body surface
- Line cavities and hollow organs
- Make up glands
- Have a free surface on outside, and basement membrane on inside
- Lack blood vessels (avascular), and nutrients diffuse to epithelial
tissue from underlying connective tissue - Cells readily divide; injuries heal rapidly
- Cells are tightly packed
6
Q
Cell Shapes
A
Squamous - flat
Cuboidal - cube-shaped
Columnar - tall
7
Q
Cell Layers
A
simple (one layer of cells), stratified (2 or more layer of cells), or
pseudostratified (appears layered, but is not)
8
Q
Simple squamous epithelium:
A
- Single layer of thin, flat cells
- Substances pass easily through air sacs (alveoli) and capillaries
- Thin and delicate, can be easily damaged
- Found in diffusion and filtration sites
- Makes up walls of air sacs (alveoli) and capillaries
- Lines blood and lymphatic vessels
9
Q
Simple cuboidal epithelium:
A
- Single layer of cube-shaped cells
- Secretion and absorption
- Lines kidney tubules, thyroid follicles, ducts of some glands
- Covers ovaries
10
Q
Simple columnar epithelium:
A
- Single layer of elongated cells
- Nuclei usually at same level, near basement membrane.
- Sometimes have microvilli, cilia, goblet cells (secrete mucus)
- Secretion and absorption
- Lines uterus, stomach, intestines
11
Q
Pseudostratified columnar epithelium:
A
- Single layer, but appears layered
- Nuclei at 2 or more levels
- Cells vary in shape, but all reach basement membrane
- Often has cilia, goblet cells
- Protection from infection
- Lines respiratory passageways
12
Q
Stratified squamous epithelium:
A
- Many cell layers; thick
- Protective layer
- Outermost cells are squamous, deeper cells are cuboidal
- New cells produced in deep layers, push older cell toward free
surface - Outer layer of skin, called the epidermis, is keratinized
- Lines oral cavity, vagina, anal canal
13
Q
Stratified cuboidal epithelium:
A
- 2 to 3 layers of cube-shaped cells
- More protection than 1 layer
- Lines ducts of mammary, sweat, and salivary glands, and
pancreas
14
Q
Stratified columnar epithelium:
A
- Several layers of cells
- Top layer of elongated cells
- Cube-shaped cells in deeper layers
- Lines part of male urethra, ducts of exocrine glands
15
Q
Transitional epithelium(uroepithelium):
A
- Many cell layers
- Cube-shaped and elongated cells
- Changes shape and appearance with increased tension;
stretches - Forms barrier and lining that can expand
- Lines urinary bladder, ureters, and part of urethra
16
Q
Glandular Epithelium:
A
Composed of cells that produce and
secrete substances into ducts or body fluids
17
Q
What are the 2 types of Glands in the body?
A
Endocrine Glands
&
Exocrine Glands
18
Q
Endocrine glands
A
secrete into tissue fluid or blood
19
Q
Exocrine glands
A
secrete into ducts that open onto a surface
20
Q
What are the 2 structural types of Exocrine Glands?
A
Unicellular
&
Multicellular
21
Q
Unicellular
A
Composed of one cell, such as a goblet cell
(secretes mucus)
22
Q
Multicellular
A
Composed of many cells; can be simple or
compound; examples: sweat and salivary glands
23
Q
What are the 3 types of Glandular Secretion?
A
Merocrine Glands
&
Apocrine Glands
&
Holocrine Glands
24
Q
Merocrine glands:
A
Secrete fluid products by exocytosis;
salivary and sweat glands, pancreas
25
Apocrine glands:
Lose small part of cell during secretion;
mammary and ceruminous glands
26
Holocrine glands:
Release entire cells filled with product;
sebaceous glands
27
General characteristics of connective tissues:
* Most abundant tissue type by weight
* Cells are farther apart than epithelial cells
* Contain abundant extracellular matrix between cells, consisting
of protein fibers and a ground substance
* Consistency varies from fluid to solid
* Categories:
* Connective tissue proper
* Specialized connective tissues
* Most have good blood supply, so are well-nourished
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Functions of connective tissues:
* Bind structures together
* Provide support and protection
* Serve as frameworks
* Fill spaces
* Store fat
* Produce blood cells
* Protect against infections
* Help repair tissue damage
29
Fibroblasts
* Most common fixed cell
* Large star-shaped cell
* Secrete fibers into extracellular matrix
30
Macrophages (Histiocytes):
* Usually attached to fibers, but can detach and wander
* Conduct phagocytosis
* Defend against infection
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Mast Cells:
* Large cells, widely distributed
* Release heparin to prevent blood clotting
* Release histamine, which causes inflammatory response
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Fibroblasts produce what 3 fiber types in connective tissue?
Collagen FIbers
Elastic (Yellow) Fibers
Reticular Fibers
33
Collagen Fibers
* Thick threads of collagen, the body’s main structural protein
* Great tensile strength and flexible, slightly elastic
* Found in ligaments and tendons
34
Elastic (Yellow) Fibers:
* Composed of elastin protein; branching
* Can stretch and return to original shape
* Not as strong as collagen fibers
* Found in vocal cords, respiratory air passages
35
Reticular Fibers:
* Thin, branching fibers of collagen
* Form delicate, supporting networks
* Found in spleen, liver
36
Connective Tissue Proper:
* Loose connective tissues:
* Fewer collagen fibers than dense tissues
* Types: Areolar, Adipose, Reticular
* Dense connective tissues:
* Contain abundant collagen fibers
* Types: Dense regular, Dense irregular, Elastic
37
Specialized connective tissues:
* Cartilage
* Bone
* Blood
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Areolar connective tissue:
* Forms thin, delicate membranes
* Cells are mainly fibroblasts, in a gel-like ground substance
* Collagenous and elastic fibers
* In subcutaneous layer
* Beneath most epithelia, where it nourishes nearby epithelial cells
39
Adipose tissue (fat):
* Adipocytes store fat
* Push their nuclei to one side
* Crowd out other cell types
* Cushions and insulates
* Beneath skin (subcutaneous layer), behind eyeballs, around heart and
kidneys, in spaces between muscles
40
Reticular Connective Tissue:
* Composed of network of thin reticular fibers
* Supports walls of internal organs
* Walls of liver, spleen
41
Dense Regular Connective Tissue:
* Closely packed collagenous fibers
* Fine network of elastic fibers
* Most cells are fibroblasts
* Very strong, withstands pulling
* Binds body parts together
* Tendons, ligaments, dermis
* Poor blood supply; slow to heal
42
Dense Irregular Connective Tissue:
* Randomly organized, thick, interwoven collagenous fibers
* Can withstand tension exerted from different directions
* Dermis of skin
* Around skeletal muscles
43
Elastic Connective Tissue:
* Abundant yellow elastic fibers, and some collagenous fibers
* Fibroblasts
* Attachments between bones of spinal column
* Walls of hollow organs, such as large arteries, airways
* Parts of heart
* Elastic quality, stretches
44
Specialized Connective Tissues:
* Cartilage, bone and blood
* Have unique matrix with specialized cells
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Cartilage
* A rigid, specialized connective tissue
* Support, framework, attachments
* Protection of underlying tissue
* Models for developing bone
* Matrix contains collagen in gel-like ground substance
* Chondrocytes (cartilage cells) in lacunae (chambers), surrounded by
matrix
* Lacks blood supply; heals slowly
46
What are the 3 types of Cartilage?
Hyaline, Elastic, and Fibrocartilage
47
Hyaline cartilage:
* Most common type
* Fine collagen fibers in matrix
* Ends of bones in joints, nose, respiratory passages, embryonic
skeleton
48
Elastic cartilage:
* Flexible, due to elastic fibers in matrix
* External ear, larynx
49
Fibrocartilage
* Very tough, due to many collagen fibers
* Shock absorber
* Intervertebral discs, pads (menisci) of knee, and pelvic girdle
50
Bone (Osseous Tissue):
* Most rigid connective tissue
* Solid matrix, composed of mineral (Ca) salts and collagen
* Supports structures
* Protects vital structures
* Produces blood cells
* Stores and releases Ca, P
* Attachment sites for muscles
* Forms skeleton
* Contain osteocytes (bone cells) in lacunae
51
What are the 2 types of bone (Osseous Tissue)?
Compact and Spongy
52
Compact Bone:
* Osteoblasts deposit matrix in lamellae (layers)
* Lamellae occur in rings around central canals
* Osteocytes + matrix + central canal form cylindrical units called
osteons
* Osteocytes send out processes into canaliculi, and share blood
supply
53
Osteons
* Osteons are cemented together to form compact bone
* Central canals contain blood vessels; bone is well-nourished, heals
more quickly than cartilage
54
Spongy Bone:
* Makes up interior part of bone
* Consists of bony plates containing osteocytes, with space between
them for marrow
* Lighter in weight than compact bone
55
Blood
Formed elements (cells and fragments) suspended in fluid
matrix called plasma
Transports substances around body
56
3 Types of formed elements:
* Red blood cells transport gases
* White blood cells defend again infection
* Platelets help in blood clotting
57
What are Membranes?
Membranes are sheets of cells. Epithelial membranes are composed of
epithelial and connective tissue; cover body surfaces and line cavities
58
What are the 3 types of Epithelial membranes? CHECK THIS ONE IN THE POWERPOINT
Serous Membranes
Mucous Membranes
Cutaneous Membranes
Synovial Membranes
59
Serous membranes:
* Line body cavities that do not open to outside of body
* Inner linings of thorax and abdomen; covers organs
* Simple squamous epithelium + areolar connective tissue
* Secrete serous fluid for lubrication, reducing friction
60
Mucous membranes:
* Line cavities and tubes that open to the outside of body
* Lining of digestive, respiratory, urinary, and reproductive tracts
* Epithelium + areolar connective tissue
* Goblet cells secrete mucus
61
Cutaneous membranes:
* Covers body surface
* Commonly called skin
* Part of integumentary system
62
Synovial membranes:
* Different from epithelial membranes
* Composed entirely of connective tissue
* Line joint cavities
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General Characteristics of Membranes:
* Excitable; respond to nervous stimulation
* Muscle cells are also called muscle fibers
* Contractile; can shorten and thicken
64
3 types of muscle tissue:
skeletal, cardiac, and smooth
65
Skeletal muscle tissue:
* Attached to bones
* Striated
* Voluntary
* Long, cylindrical, multinucleated cells
* Stimulated by nerve cells
66
Smooth muscle tissue:
* Non-striated
* Spindle-shaped fibers
* Walls of hollow organs and blood vessels
* Involuntary
67
Cardiac muscle tissue:
* Only in wall of heart
* Branching cells
* Involuntary
* Striated
* Intercalated discs, specialized intercellular junctions
68
Nervous tissues:
Found in brain, spinal cord, peripheral nerves
69
Neurons
* Main cells, which are specialized for communication, via
conduction of nerve impulses (sensory reception, motor
control)
* Coordinate, integrate, and regulate body functions
* Composed of cell body (soma), dendrites, and an axon
70
Neuroglia
Cells that support and nourish neurons
