Module 1: Basic Tissue Types Flashcards
What are the four basic tissue types?
Epithelium, connective tissue, muscle tissue, nervous tissue
What is the epitheliums function?
Protection
What is the connective tissues function?
Support
What is the muscle tissues function?
Movement
What is the nervous tissues function?
Control
Describe epithelium
Covering, lining, glands
Describe connective tissue
Connecting, supporting
Describe muscle tissue
Contractile
Describe nervous tissue
Generate and transmit waves of excitation/nerve impulses
Where is epithelium found?
Lining almost all body surfaces and cavities
When is epithelium called “endothelium”?
When lining blood or lymphatic vessels
When is epithelium called “mesothelium”?
When lining serous body cavities
What are the main functions of the epithelium?
Absorption, protection, secretion
What is basement membrane?
Supporting structure of the epithelium, separates epithelium from support tissue
What does muscle and nervous tissue have instead of basement membrane?
External laminae
What is the basal surface of the epithelium?
The part touching the basement membrane
What is the apical surface of the epithelium?
The side that faces outwards
What is an anchoring junctions function?
Provides mechanical strength
What is an occluding junctions function?
Links cells to form an impermeable barrier
What is a communication junctions function?
Allows communication between cells
How is epithelium classified? (3)
- Number of layers
- Cell shape
- Surface specialization
What is simple epithelium?
One layer of cells
What is stratified epithelium?
At least two layers of cells
What is pseudostratified epithelium?
One layer of cells appearing to be more
What are the three epithelial cell shapes?
- Squamous
- Cuboidal
- Columnar
What kinds of epithelium surface specializations may be present?
Keratin, cilia, microvilli, stereocilia
What is the function of simple epithelium?
Absorption, secretion, or selective diffusion
Little to no protection
What is simple squamous epithelium? What is its function?
Flattened irregular cells
Passive transport or gases or fluids
Where is simple squamous epithelium found?
Lungs (gas transport), capillaries (fluid transport)
Possibly pleural, pericardial, and peritoneal cavity linings
What is simple cuboidal epithelium? What is its function?
Square cells
Excretory, secretory, or absorptive
Where is simple cuboidal epithelium found?
Lining small ducts/tubules
Kidney collecting ducts, salivary glands, pancreas
What is simple columnar epithelium? What is its function?
Rectangular cells, nuclei at base, center, or apex
Highly absorptive or secretory
Where is simple columnar epithelium found?
Mucosa of small intestine, stomach, gallbladder
What is simple columnar ciliated epithelium? What is its function?
Rectangle cells with surface cilia
Propel fluid or minute particle across epithelial surface
Where is simple columnar ciliated epithelium found?
Fallopian tubes
What is pseudostratified columnar ciliated epithelium? What is another name for it?
Appear stratified but only one layer of rectangle cells with cilia
Respiratory epithelium
Where is pseudostratified columnar ciliated epithelium found?
Larger airways of respiratory system
What is the function of stratified epithelium?
Protection
Little to no secretion or absorption
What is stratified squamous epithelium? What is its function?
Layers of squamous cells from cuboidal basal layer
Withstands moderate abrasion
Where is stratified squamous epithelium found?
Oral cavity, pharynx, vagina
Esophagus, cervix, tonsils
Why is the basal layer of stratified squamous epithelium cuboidal and the upper layers are squamous?
Cuboidal cells undergo mitotic division and the cells moves upwards as it matures and degenerates until it is eventually sloughed
What is stratified squamous keratinizing epithelium?
Layers of squamous cells from cuboidal basal layer with apical layer of keratin
What is keratin?
Tough non-cellular layer of protein and degenerated epithelial cells
Where is stratified squamous keratinizing epithelium found?
Skin
What is stratified cuboidal epithelium? What is its function?
Layers of cuboidal cells
More robust lining that simple cuboidal epithelium
Where is stratified cuboidal epithelium found?
Lining larger excretory ducts
Salivary glands, sweat glands, pancreas
What is stratified columnar epithelium?
Two layers of columnar cells
Where is stratified columnar epithelium found?
RARE
Ocular conjunctiva, largest salivary gland ducts, parts of the urethra
What is transitional epithelium? What is its function?
Form of stratified squamous epithelium
Withstands large amount of stretching and toxicity of urine
What does transitional epithelium look like in its non-distended state?
Four to five layers
Basal cuboidal, polygonal, or dome shaped cells
What does transitional epithelium look like in its distended state?
Two to three extremely flat layers
Where is transitional epithelium found?
Urinary tract from renal pelvis to urethra
What is glandular epithelia’s main function?
Secretion
What are the two classifications of glands?
Exocrine and endocrine
What are exocrine glands? What do they do?
Glands composed of epithelial cells that are specialized for secretion
Secretes onto the surface of the epithelium
How are exocrine glands classified? (4)
- Duct arrangement
- Shape of secretory unit
- Type of secretion
- Discharge of products
What are the two types of exocrine duct arrangements?
Unbranched in simple glands
Branched in compound glands
What are unbranched exocrine glands?
Glands with a single unbranched duct
What might the secretory portion of an unbranched exocrine gland look like?
May be tubular or acinar
Maybe be coiled and/or branched
What are branched exocrine glands?
Glands with a branched duct
What might the secretory portion of a branched exocrine gland look like?
May be tubular and/or acinar draining into the same duct
May be coiled and/or branched
What are the possible shapes of exocrine gland secretory units? (3)
Tubular, acinar/alveolar, or tubuloacinar
What are acinar/alveolar exocrine secretory units?
Secretory units that appear grape like and are somewhat spherical
What are the types of secretions an exocrine gland may have? (3)
Serous, mucous, mixed
What is serous secretion of an exocrine gland?
Watery secretion, may contain enzymes
What is mucous secretion of an exocrine gland?
Mucous, viscous glycoproteins
How might an exocrine gland discharge its secretory products? (3)
Merocrine/eccrine, apocrine, holocrine
How do merocrine/eccrine exocrine glands secrete?
Secretory vessels fuse with cell membrane to discharge their products
Where are merocrine/eccrine exocrine glands found?
Most common
Exocrine pancreas, salivary glands, sweat glands
How do apocrine exocrine glands secrete?
Similar to merocrine/eccrine
Fuse with cell membrane to secrete but also lose part of the secretory cell
Where are apocrine exocrine glands found?
Axillae (armpit), breasts, pubic and perineal regions
Only secrete after puberty
How do holocrine exocrine glands secrete?
Whole secretory cells is discharged and disintegrates to release secretion
Where do holocrine exocrine glands secrete?
Primarily in sebaceous glands
Describe and give examples of simple tubular glands
Single straight tubular lumen
Large intestine and appendix glands
Describe and give examples of simple coiled tubular glands
Single tightly coiled lumen
Sweat glands
Describe and give examples of simple branched tubular glands
Several tubular portions drain into single unbranched duct
Pyloric stomach glands
Describe and give examples of simple acinar glands
Pockets in epithelial surface lined by secretory cells
Mucous glands in urethra
Describe and give examples of simple branched acinar glands
Several acini that empty into single excretory duct
Sebaceous glands
Describe and give examples of compound tubular glands
Tubular branched or coiled gland secrets into branched duct system
Brunner’s glands in duodenum
Describe and give examples of compound acinar glands
Secretory acini drain into branched duct system
Exocrine pancreas
Describe and give examples of compound tubuloacinar glands
Mixture of compound tubular and acinar glands
Salivary glands, prostate glands
What are endocrine glands?
Clumps of secretory cells surrounded by capillaries
No ducts
How do endocrine glands secrete?
Hormones secreted into intercellular spaces then it diffuses into capillaries
What are examples of endocrine glands?
Pituitary gland, adrenal gland Endocrine pancreas (Islets of Langerhans)
Name the 3 types of muscle
Smooth, skeletal, heart/cardiac
Describe skeletal muscle
Elongated, unbranched, cylindrical, striated
Numerous flattened peripheral nuclei
Arranged in bundles
What is skeletal muscles function?
Voluntary movement of skeleton and organs
Short forceful contractions
Describe smooth muscle
Elongated, spindle shaped, pointed ends, not striated
One elongated central nucleus
What is smooth muscles function?
Involuntary movement
Continuous rhythmic low force contractions
Where is smooth muscle found?
Gastrointestinal tract, uterus, bladder, blood vessels
Describe cardiac muscle
Long, branched, striated, intercalated discs at branches
One or two elongated central nuclei
What do intercalated discs of cardiac muscle do?
Have low electrical resistance to permit rapid spread of contractile force throughout the heart
What are contractile cells?
Muscle cells that function on their own
Name the 3 contractile cells and where to find them
Myoepithelial cells - secretory glands
Pericytes - smooth muscle cells surrounding blood vessels
Myofibroblasts - scar formation, secrete collagen
Name the 3 classifications of connective tissue
Collagen, elastic, adipose
What is connective tissues function?
Provide structural and metabolic support
Carry blood vessels and mediate material exchange
What is connective tissue composed of?
Extracellular matrix and specialized support cells
Name the six specialized support cells and their function
Fibroblasts - extracellular matrix (collagen, elastin)
Chondrocytes - extracellular matrix of cartilage
Osteocytes - extracellular matrix of bone
Myofibroblasts - contractile and secretory function
Adipocytes - fat storage, cushioning
Mast cells/macrophages - immunity
What is extracellular matrix?
Ground substance and fibers from support cells
What is ground substance?
Gel-like material of glycoproteins, fibronectin, and glycosaminoglycans (primarily hyaluronic acid)
Mostly combined with proteins to form proteoglycans
What are the two major types of collagen?
Collagen I
Collagen III - Reticulin
What is collagen I?
Collagen, 90% of all collagen
Dense or loose
Where is collagen I found?
Dermis, tendons, ligaments, in bone
What is collagen III?
Reticulin, collagin fibrils
Fine branching network
Where is collagen III found? What is its function?
Highly cellular tissues
Liver, lymph nodes
Provides support
Name 3 other significant collagens
Collagen II - hyaline cartilage
Collagen IV - basement membrane
Collagen VII - anchor fibrils to basement membrane
What is elastic made of?
Amorphous proteins, elastin, glycoprotein, microfibrils
Where is elastic found?
Artery walls, skin, bladder
Sheets of elastic laminae in some vessels
What is adipose tissue?
Fat, fat storage cells
Where is adipose found?
In most connective tissues
What is the function of adipose?
Energy reserve, insulation, cushioning/padding
Name the two types of adipose and where they are found
White fat - adults
Brown fat - newborns, small amount in adults
What are the two components of the nervous system and what do they consist of?
CNS - brain and spinal cord
PNS - brain and spinal cord extensions, cranial and spinal nerves, nodules of associated neuronal cell bodies (ganglia)
What is grey matter? What is white matter?
Grey matter - neuron cell bodies and associated fibers, neuroglia
White matter - tracts of nerve fibers, some neuroglia, mainly oligodendrocytes
What is the outer surface of the brain and spinal cord covered with?
Three layers of specialized connective tissue
Meninges
Where is the gray matter and white matter in the cerebrum?
Gray matter is on the outside (6 layers), white matter is on the inside (fiber tracts and central core)
Name the 2 layers of the cerebellum and how they stain
Gray matter/cortical covering - stains blue
White matter/medullary core - stains pink
Name the 3 layers of the gray matter
Molecular (outer)
Purkinje cells
Granular (inner)
What are Purkinje cells?
Large multipolar neurons
Describe the layers of the spinal cord
Center butterfly shaped gray matter
Outer white matter
What are the two parts of the PNS? What are their functions?
ANS - involuntary functions (circulatory, smooth and cardiac muscle, exocrine glands, other viscea)
SNS - voluntary functions (skeletal muscle)
What are the basic parts of a neuron?
Cell body containing nucleus and cytoplasm (perikaryon), axon/nerve fiber, axon hillock, dendrites, terminal boutons
Describe a multipolar neuron
Most common
Many dendrites at one pole or all parts of the cell body
Describe a bipolar neuron
Single dendrite from pole opposite to the axon
What are bipolar neurons used for?
Senses of smell, sight, and balance
Describe a pseudo-unipolar neuron
Single dendrite and axon from common stem of cell body
What is Nissl substance?
Clumps og basophilic cytoplasmic material in neurons
Represents the rough ER
Where is Nissl substance found?
In perikaryon and dendrites
What does the lack of Nissl substance suggest?
Nerve damage1
What is neuroglia?
Support cell masses that support neurons
Name the 4 types of neuroglia cells
Astrocytes
Oligodendrocytes
Microglia
Ependymal cells
What are astrocytes?
Star-shaped cells
Must numerous cells in gray matter
Long highly branched processes, many have perivascular feet at capillaries
What do astrocytes do?
Mediate some metabolic exchange between neurons and blood
What are oligodendrocytes?
Medium size, small amount of short branching processes
Predominant cell in white matter
What do oligodendrocytes do?
Myelination of axons in the CNS
Dendrites are short pedicles that connect the cell body to the myelin sheath
What are microglia?
Small phagocytic cells
Small irregular nuclei, little cytoplasm
Fine highly branched processes
What do microglia do?
CNS macrophages
In response to damage they become large amoeboid phagocytic cells
What are ependymal cells?
Simple cuboidal epithelial lining of brain and spinal canal ventricles
Cilated at luminal surface
Single branched process from base intermingles with astrocytes
What do ependymal cells do?
Cilia propels CSF in ventricles
The term mesothelium refers to the lining of which of the following?
a. blood vessel
b. serous body cavity
c. intestinal tract
d. lymphatic vessel
b. serous body cavity
Which statement is true regarding the basement membrane?
a. separates support tissue from muscle layers below it
b. penetrated by blood vessels
c. strength comes from occluding junctions
d. all epithelial tissues are attached to it
d. all epithelial tissues are attached to it
Which is not a characteristic used to classify epithelial tissue?
a. function
b. number of layers
c. cell shape
d. surface specialization
a. function
How would you classify an epithelial tissue that has cells three times as tall as they are wide, is one layer thick, and have cilia on its surface?
a. stratified columnar ciliated
b. simple columnar ciliated
c. simple cuboidal ciliated
d. stratified cuboidal ciliated
b. simple columnar ciliated epithelium
What is the basal surface of a cell?
a. surface opposite the basement membrane
b. surface that touches the cell beside it
c. surface that faces the basement membrane
d. surface that reaches the lumen
c. surface that faces the basement membrane
List the main functions of epithelial tissue
Protection
Absorption
Secretion
Describe the appearance of transitional epithelium in the distended and non-distended states
distended - appears to be 2-3 layers thick with extremely flattened layers
non-distended - appears 4-5 layers thick with cuboidal, polygonal, and dome shaped cells
Indicate whether the statement is true or false
- Villi and cilia are the same thing
- Pseudostratified epithelium is an example of simple epithelium because all cells reach the basement membrane
- Classification by cell shape is based on shape of the cells closest to the basement membrane
- The primary function of stratified epithelium is protection
- False
- True
- False
- True
Categorize each statement by describing it as either an endocrine or exocrine gland
- Secretes by means of a duct
- Maintains continuity with the epithelial surface
- Secretes directly into the circulatory system
- Consists of clumps of secretory cells
- Secretes to the surface
- Is ductless
- Surrounded by rich capillary network
- May be classified by secretory unit shape
- Exocrine
- Exocrine
- Endocrine
- Endocrine
- Exocrine
- Endocrine
- Endocrine
- Exocrine
Describe the 4 ways and exocrine glands may be classified
- Duct arrangement
- Shape of secretory unit
- Type of secretion
- Means of discharge
Which of the following is true of compound glands?
a. they may contain tubular or acinar forms but not both
b. have a branched duct
c. secrete directly into the blood stream
d. have a single unbranched duct
b. have a branched duct
Which of the following describes simple glands?
a. may have branched secretory portions
b. often have acinar and tubular forms draining into one duct
c. have a branched duct
d. secrete directly into the blood stream
a. may have branched secretory portions
What do serous glands secrete?
a. seromucous mixture
b. watery secretion containing glycoproteins
c. mucous secretion containing glycoproteins
d. watery secretion containing enzymes
d. watery secretion containing enzymes
What are glands that have secretory vessels which fuse with cell membrane to discharge their product called?
a. eccrine
b. apocrine
c. merocrine
d. all of the above
d. all of the above
Which type of glands only secrete after puberty?
a. eccrine
b. apocrine
c. merocrine
d. holocrine
b. apocrine
What type of gland has secretory cells which are discharged and disintegrate to allow release of the product?
a. eccrine
b. apocrine
c. merocrine
d. holocrine
d. holocrine
List and describe the 3 shapes of a secretory unit
- Tubular
- Acinar - grape/spherical
- Tubuloacinar
Indicate whether the following statement are true of false
- The pancreas is both and exocrine and endocrine gland
- Sweat glands are holocrine glands
- Eccrine and merocrine may be used interchangeably
- Holocrine glands are found in axillae, breat, pubic, and perineal regions
- Endocrine glands secrete hormones into intercellular space
- True
- False
- True
- False
- True
List the 3 types of muscle and 2 other names for each
- Skeletal, voluntary, striated
- Visceral, involuntary, smooth
- Cardiac, heart, myocardium
For each statement indicate which type of muscle it applies to
- Cross-striations are present
- Nuclei are numerous, flattened, and peripherally located
- Muscle fibers are spindle shaped
- Muscle fibers have branching cytoplasm
- Contraction is low force and rhythmic
- Nuclei are centrally located
- Intercalated discs are present at junctions
- Skeletal, cardiac
- Skeletal
- Visceral
- Cardiac
- Visceral
- Cardiac, visceral
- Cardiac
List and give the locations of 3 contractile cells that function on their own
Myoepithelial - secretory glands
Pericytes - surround blood vessels
Myofibrils - scar formation, secrete collagen
Connective tissue provides _______ and _______ support. It is composed of _______ _____ and _______ _____ _____ which produce the _______ _____. The extracellular matrix includes the _______ produced by the support cells and a gel-like material called _______ _______. This forms a medium for the transport of materials between _______ and the _______ _____.
structural metabolic extracellular matrix specialized support cells extracellular matrix fibers ground substance tissues circulatory system
What is ground substance made of?
a. proteoglycans
b. glycosaminoglycans
c. glycoproteins
d. all of the above
d. all of the above
How does ground substance appear microscopically after routine staining?
a. purple
b. unstained
c. pink
d. blue
b. unstained
What 2 broad categories are fibers classified into based on fiber type?
a. dense and loose
b. extracellular matrix and ground substance
c. collagenous and elastic
d. collagen and reticulin
c. collagenous and elastic
What type of collagen fiber is predominant and makes up about 90% of all collagen found in tissues?
a. Type I
b. Type III
c. Reticulin
d. Elastic
a. Type I
What was type III collagen formerly classified as?
a. collagen
b. elastic
c. reticulin
d. ground substance
c. reticulin
What are the sheets formed by elastic fibers called?
a. tonofibrils
b. elastic laminae
c. fibril aggregates
d. extracellular matrix
b. elastic laminae
Where are large amounts of elastic fiber found?
a. skin, bladder, liver
b. arteries, liver, bladder
c. liver, arteries, skin
d. bladder, skin, arteries
d. bladder, skin, arteries
What is the function of adipose tissue?
a. padding or cushion
b. insulation against heat loss
c. energy reserve
d. all of the above
d. all of the above
How do fat cells appear microscopically after routine processing and staining?
a. circle with pink center
b. jagged edge dark pink interior
c. signet-ring appearance
d. dark staining cytoplasm and nucleus
c. signet-ring appearance
What does white matter consist of?
a. nerve fibers
b. neuron cell bodies
c. vast number of neuroglia
d. all of the above
a. nerve fibers
In what part of the central nervous system are Purkinje cells found?
a. cerebral cortex
b. spinal cord
c. cerebellum
d. cerebral medulla
c. cerebellum
How is the peripheral nervous system divided functionally?
a. cranial and spinal nerves
b. autonomic and somatic
c. white and grey matter
d. cortex and medulla
b. autonomic and somatic
Neurons are ___ - _______ highly specialized cells that respond to _______. The cytoplasm is known as _______. Process of 2 types extend from the cell body; a single _____ and one or more _______. The axon arises from a cone-shaped portion of the cell body called the ____ _______. The axon terminates in small swellings called ______ ______. Axons are commonly referred to as _____ ______.
non-dividing stimuli perikaryon axon dendrites axon hillock terminal boutons nerve fibers
List the 3 main types of neurons and briefly describe their structure
- multipolar - most common, many dendrites from one pole or several places
- bipolar - single dendrite from pole opposite to axon
- pseudo-unipolar - single dendrite and axon from common stem
What does Nissl substance represent?
a. rough endoplasmic reticulum
b. Golgi apparatus
c. smooth endoplasmic reticulum
d. chromatin
a. rough endoplasmic reticulum
Where is Nissl substance found?
a. perikaryon
b. dendrites
c. axon
d. a and b
e. b and c
f. all of the above
d. a and b
Indicate which neuroglial cell each statement is referring to
- Analogous to the Schwann cell of the PBS
- Long highly branched processes give it a star-shaped appearance
- Small phagocytic cells, part of macrophage-monocyte defense
- Simple cuboidal ciliated epithelial lining, unsupported by a basement membrane
- Responsible for myelination
- Most numerous glial cell in gray matter
- Oligodendrocyte
- Astrocyte
- Microglia
- Ependymal cells
- Oligodendrocyte
- Astrocyte