Exam 1 Flashcards
(194 cards)
1
Q
Robert Hooke
A
Compound microscope (more than one lens), 20X, first person to use the term ‘cells’
2
Q
Antony Van Leeuwenhoek
A
First to describe bacteria found in plaque around teeth, simple microscopes, 200X, discover protozoans in lake water (‘animalcules’)
3
Q
Marie Francis Xavier Bichat
A
First to use the term ‘tissue’, identification of 21 tissues in the body, 4 major tissues: epithelial , connective, nerve, muscle.
4
Q
Matthias Schleiden and Theodor Schwann
A
Proposed cell theory, not applicable to nervous tissue (bc difficulty in staining them for examination)
5
Q
Giovanni Batista Amici
A
Introduced oil immersion, improved compound microscope
6
Q
Max Knoll and Ernst Ruska
A
Electron microscope, 100,000X with resolution distinguish two mechanisms next to each other
7
Q
Four basic tissues
A
Epithelial Tissue
Connective Tissue
Nerve Tissue
Muscle Tissue
8
Q
Preparation of Tissues for Microscopic Examination
A
Tissue Fixation (Preservation)
Embedding
Sectioning
Staining
9
Q
What is fixation?
A
Fixation stops cell metabolism and preserves the structure and composition of cells and tissues
10
Q
Fixatives are typically
A
Diluted Cross-linking agents
11
Q
Example of cross linking agents
A
Paraformaldehyde, formaldehyde (Formalin=37% aq. Sol of formaladehyde), glutaraldehyde
12
Q
How do crosslinking agents work?
A
Cross link amino groups of proteins in cells and tissues
Formaldehyde creates Ch2 cross links between proteins in tissues.
The cross links are formed between nitrogen residues in the side chains of lysines and the nitrogen atoms in peptide bonds
Formaldehyde Do not react with lipids: poor fixatives for membranes (membranes have a hard time being preserved)
13
Q
True or False: Formaldehyde must be in the polymeric form to function as a fixative
A
False: must be in monomeric form
14
Q
To prevent formaldehyde from creating polymers what must be added?
A
Water, the solution then becomes formalin, methanol stabilizes the formaldehyde to prevent polymerization
15
Q
After the tissue has been preserved via fixation, what must be done to the sample?
A
The tissue is washed and DEHYDRATED via alcohol which makes the tissue become transparent, paraffin is then added (wax) to harden the tissue sample for sectioning
16
Q
What can be used instead of paraffin for embedding and why?
A
Plastic resin- reduces tissue shrinkage and provides better morphological preservation than paraffin
17
Q
Organic solvent that removes alcohol from tissue sample making it clear
A
Xylene
18
Q
Slicing Machine
A
Microtome
19
Q
Eosin stains tissue
A
Pink/Red
Acidic (negatively charged)
General Cytoplasm
Extracellular Matrix
20
Q
Hematoxylin stains tissue
A
Blue
Basic (positively charged)
Nucleus:
Heterochromatin (condensed chromatin)
Nucleolus
21
Q
True or False: Euchromatin (uncondensed chromatin) appears unstained
A
True due to it having fewer positively charged histones
22
Q
Staining dyes react with the ___________ groups in tissue
A
Aldehyde
23
Q
Base loving
A
Cells that bind to basic stains: basophilic
Phosphate groups
Sulfate groups
Carboxyl groups
24
Q
Heterochromatin, nucleoli, Rough ER bind with basic dyes with their
A
Phosphate groups
25
Acid Loving
Cells that bind to acidic stains: acidophilic
Amino groups of proteins (positively charged) bind to negatively charged dyes
Eosin
26
Acidophilic Components of Cells/Tissues
Cytoskeletal filaments
Intracellular membranous components
Extracellular Fibers (amino groups)
27
Cytoplasm
Contents of a cell that are contained within its plasma membrane but, in the case of eukaryotes, outside the nucleus
Includes organelles
28
Organelles
Membrane-enclosed compartments in eukaryotes that have distinct structures and functions
29
Plasma membrane (plasmalemma) consists of what type of layer
Phospholipid bilayer that contains cholesterol and proteins which oligosacchardies (glycolipids and glycoproteins) can covalently link to
30
Functions of plasma membrane
Encloses the cell and defines its boundaries
Regulates the exchange of essential substances between cells contents and the external enviornment
Helps to maintain a constant intracellular enviornment that is different from extracellular fluid
Plays a critical role in cell-cell interactions and cell-signaling
31
How does cholesterol affect the bilayer of the plasma membrane?
Decreases the permeability of the bilayer to small water-soluble molecules and increases membrane rigidity
32
Major Classes of Membrane Proteins
Transport
Receptor
Recognition
33
Transport Proteins
Regulate the movement of water-soluble molecules through the plasma membrane (channel proteins)
34
Receptor Proteins
Trigger cellular responses when specific molecules in the extracellular fluid (hormones or nutrients) bind to them
35
Recognition Proteins
Identification tags (immune system) or mediate cell-cell adhesion
36
Liver cells can also be called
Hepatocytes
37
Periodic Acid-Schiff (PAS) Stain
Bleached basic fuchsin (ScHiff reagent) reacts with aldehyde groups to produce a distinctive magenta stain
Stains: carbs and carb rich macromolecules like GLYCOGEN, MUCUS, BASEMENT MEMBRANE, RETICULAR FIBERS in CT
38
True or False: Histochemical methods permit localization of specific molecules in cells and tissues
False, the localize general class (type) of molecule
39
True or False: Immunocytochemical methods do permit localization of specific molecules
True
40
Immunocytochemistry involves
Labeling cells or tissues with antibodies directed against specific antigens (Protiens, lipids, and carbs)
41
Immunocytochemistry Direct Method
Antibody against the specific molecule (the primary antibody) is tagged with a label
General: Antibodies are tagged with fluorescent compounds (fluorochromes) or enzymes (horseradish peroxidase) that convert substrates into colored precipitates. Question: How do they bind?
42
Indirect Method
Employs a tagged secondary antibody that binds to the primary antibody
Sensitive and easier to use
43
Germ Layer Derivative (Embryonic Ectoderm)
Central Nervous System (Brain and Spinal Chord)
Peripheral Nervous System
Sensory Epithelia of Eye, Ear, and Nose
Epidermis and its appendages (hair and nails)
44
Germ Layer Derivatives (Embryonic Mesoderm)
Connective Tissue Proper
Specialized Connective Tissues (adipose, cartilage, bone, blood)
Muscle
Blood/Lymph Vessels and Cells
Kidneys
Gonads (ovaries and testes) and genital ducts
45
Germ Layer Derivatives (Embryonic Endoderm)
Epithelial Lining of GI tract and respiratory tracts
Parenchyma of the tonsils, thyroid, parathyroids, thymus, liver, and pancreas
46
Mesenchyme
Origin of connective tissue
CT of early embryo
Formed via mesenchymal cells
cells migrate to various regions of the body to form CT
Forms mainly from the mesoderm (middle)
47
Mast Cell Secretion
IgE receptors on the plasma membrane, when plasma cells secrete IgE they bind to those receptors which release the cascade of events that lead to an allergic reaction
48
Chromatin
composition of chromosomes
complex of DNA, histones, and nonhistone proteins
49
Heterochromatin
highly condensed form of chromatin that describes INACTIVE GENES (not transcribed into mRNA)
50
Euchromatin
Less condensed chromatin (actively transcribed genes)
51
The orders of chromatin packing is believed to exist in
a metaphase chromosome
52
Nuclear Pores
Formed when the inner membrane (chromatin binding sites) and outer membrane (ER) fuse
53
True or False: Adhesins attach to the outer nuclear membrane
False: ribosomes attach not adhesins
54
True or False: Nucleolus are bound by a membrane
False: They are NOT bound by a membrane
55
Function of Nucleolus
site of processing rRNAs and their assembly into ribosomes
the size of the nucleolus varies with the number of ribosomes produced by the cell
56
Organization of the Endoplasmic Reticulum (ER)
The ER membrane encloses the ER lumen (space)
The ER membrane separates the ER lumen from the cytoplasm and REGULATES the transfer of molecules between the two
Proteins synthesized in the rER either remain in the ER membrane-> transmembrane proteins OR pass into the ER lumen
57
Functions of the Rough ER
rER membrane-> site of synthesis of ALL transmembrane proteins
proteins in the ER lumen-> secreted to cell exterior OR remain in the lumen of ER. OR transferred to golgi apparatus/lysosomes
rER-> proteins folded, disulfide bonds form, glycosylation occurs (first steps)
58
True or False: Proteins destined for the cytoplasm, nucleus, and mitochondria are synthesized in the rER
False: They are synthesized on the FREE RIBOSOMES in the the CYTOPLASM
59
What kind of cells contain the most rER
cells that produce secretory proteins
Ex: Plasma Cells and Pancreatic acinar Cells
60
So if proteins can be translated on free ribosomes and rER. What mechanism determines which they should choose?
Single Peptides (signal sequences of amino acids)-> rER
A signal recognition particle (SRP) binds to the signal sequence to direct them to rER
No signal sequence -> free ribosomes in the cytoplasm
61
True or False: sER lacks ribosomes
True
62
Function of sER
lipid biosynthesis and membrane sythesis and repair (cholesterol and phospholipids)
63
sER in liver cells are rich in
CYTOCHROME P450, function to detoxify drugs and alcohol
64
Golgi Apparatus Functions
Separates or sorts proteins and lipids received from the ER according to their final destination
Modifies proteins with glycosation, phosphorylation, sulfation
Packages materials in vesicles that are then transported to other parts of the cell or to the plasma membrane for secretion
65
Glycosylation
Addition of carbohydrate groups
66
Sulfation
Addition of sulfate
67
Phosphorylation
Addition of phosphate
68
Goblet Cells in Small Intestine
Specialized for secreting mucus produced in the ER and Golgi
POLARIZED CELL
69
What is mucus made out of
Glycoproteins and proteoglycans
70
Golgi Apparatus is made up of
Flattened membrane enclosed CISTERNAE OR SACS adjacent to the ER
71
Lysosomes
Vesicles that contain digestive enzymes to facilitate digestion and turnover of cellular components
72
Digestive Enzymes
Acid phosphatase
Ribonuclease
Deoxyribonuclease
Protease
Lipases
73
True or False: Lysosomal enzymes have optimal activity at a HIGH PH
False, low pH= 5.0
74
Endocytosis
Process where cells take up macromolecules by surrounding them by a small region of the plasma membrane to enter the cytoplasm
75
Phagocytosis
Cellular Eating, type of endocytosis, uptake of large molecules via large vesicles called PHAGOSOMES
76
Pinocytosis
Cellular drinking, type of endocytosis, ingestion of fluids and solutes in small vesicles
77
Receptor Mediated Endocytosis
Pinocytosis, macromolecules bind to transmembrane receptors on the cell surface in ‘coated pits’
Coats have CLATHRIN which assist in internalization of the bound materials in vesicles
78
Mitochondria
Acidophilic
Contain their own DNA
Convert chemical energy to ATP
79
True or False: Cardiac Muscle Cells have abundant mitochondria
TRUE bc they have high energy metabolism
80
Where do most mitochondrial proteins come from?
Cytoplasm
81
Inner Membrane folds in the Mitochondira
Cristae
82
Space between outer and inner membrane
Intermembrane space
83
Compartment enclosed by the inner membrane
Matrix
84
True or False: Most mitochondrial proteins are synthesized within the mitochondria
False, they are imported from the cytoplasm
85
Major types of proteins in the inner mitochondrial membrane
Electron transport system proteins
ATP synthase that generates ATP in the matrix
Transport proteins
86
Flow of Major Reactant in and out of the Mitochondrion
Intermembrane space has protons from the electron transport chain
Protons then pass through ATP synthase in inner membrane to generate ATP
87
Peroxisomes
Oxidize organic substrates producing hydrogen peroxide H2O2 which is very damaging to cells
But peroxisomes also have catalase which converts hydrogen peroxide to water and oxygen WHICH ALLOWS THE OXIDATION OF TOXIC MOLECULES (alcohol) in the liver and kidney
88
Cytoskeleton
System of protein filaments that gives the cells its SHAPE and capacity of DIRECTED MOVEMENT
89
Filaments of Cytoskeleton
Actin Filaments (microfilaments or thin filaments)
Microtubules
Intermediate Filaments
Each filaments have their own number of accessory proteins
90
Actin filaments
Flexible
Made up of actin
Dynamic
Functions:
Structural support of the plasma membrane
Cell motility
Muscle contracting (myosin)
Contractile ring in dividing cells
91
Microtubules
Composed of 13 PROTOFILAMENTS
PROTOFILAMENTS: composed of heterodoxies of alpha and beta tubulin
92
Functions of Microtubules
Provide railroad tracks for the movement of organelles throughout the cell
Core of cilia and flagella
Form centrioles
Form the mitotic spindle
93
True or False: in the formation of Microtubules, polymerization of tubulin heterodimers occurs rapidly at the minus end (-) than the plus end (+)
False: more rapidly at the plus end, depolymerization occurs rapidly at the minus end
94
To prevent depolymerization of Microtubules
The minus end is always embedded in a Microtubules organizing center
95
Microtubules Organizing Center
Centrosome
Within the center: centriole pair
96
Motor proteins involved with Microtubules
Kinesics and Dyneins
97
Intermediate Filaments
Heterogenous family of proteins (unlike the other filaments)
Tough and durable for mechanical strength
98
Examples of Intermediate Filaments Proteins
Keratin- epithelial
Desmin- Muscle Cells
GFAP- glial cells
Neurofilament proteins- neurons
99
Epithelium
Avascular sheet of cells
Forms the secretory portion of glands and their ducts (parenchyma)
Specialized epithelial cells act as receptors for our senses
100
Parenchyma
Formed by the epithelium
Composed of cells responses for the main function typical of an organ
101
Stroma
Formed by the connective tissues
Support tissues (connective tissues)
102
Cells adhere to one another through
Cell adhesion molecules (CAM) that form specialized cell junctions
103
Every epithelium is separated from the underlying connective tissue by a thin non cellular layer called
Basal lamina
104
Basal lamina is underlain by
Reticular fibers
105
Basal lamina are attached to underlying reticular fibers via
Anchoring fibrils
106
Basement membrane is comprised of
Basal lamina and layer of reticular fibers
107
Molecular composition of basal lamina
Type 4 collagen
Laminin, fibronectin, entactin (glycoproteins)
Proteoglycans (one or more GAG chains- amino sugars)
108
Reticular fibers consist of
Type 3 collagen fibers
109
Anchoring fibers are composed of
Type 7 collagen
110
Glycoproteins in the basement membrane are stained by
PAS technique
111
Functions of Basal Lamina
Attachment of cells to underlying CT
Filtration (to and from CT)- plasma filtrate in the glomulerlus of the kidney
Influence cell polarity- apical and basal cell domains
Regulate cell proliferation and differentiation by binding growth factors
Aid in tissue regeneration (use basal lamina as a scaffold to replace lost cells)
112
Apical domains structural modifications
Microvilli
Sterocillia
Cilia
113
Microvilli
Finger like cytoplasmic processes
Specialized for absorption
114
Stereocillia
Extremely long Microvilli
Found in male reproductive tract (epididymis)
Absorption
115
Cilia
Motile cytoplasmic processes
Found in epithelia lining the respiratory and female reproductive tracts
116
Intracellular Junctions
Within epithelial cells
Maintain cell-adhesion and permit cell communication
Marked especially within tissues that are subjected to stress (skin)
117
Hesmidesmosome
Mediates adhesive interaction between cells and the basal lamina NOT btw cells (anchoring cell junction)
118
Tight Junction (Zonula Occludens)
Zonula- band completely encircling cell
Most apical of junctions
Forms a seal around sells that prevents flow of material between epithelial cells
Restrict diffusion of cell membrane proteins bw apical and lateral compartments
119
Zonula Adherens (Adherens junction)
Transmembrane CAMs called E-cadherin mediate adhesion between apposing membranes
Cadherins require Ca2+ to bind to each other
Actin filaments bind to cytoplasmic tails of cadherins = imp. In folding of epithelial sheets into tubes and other structures
120
Desmosomes (Macula Adherens)
Disk-shaped
Hold adjacent epithelial cells together
Mediated by desmoglein and desmocollin (Cadeherin family)
Anchoring sites for intermediate filaments
121
Major adhesive protein for Hemidesmosomes
Integrin alpha6beta
122
Gap Junctions
Permit communication between cells (most cells use this method to communicate) except skeletal and blood cells
All passage of small water-soluble molecules to cells coupling cells both electrically and metabolically
123
How are epithelia classified?
The number of cell layers in the epithelium
The shape of the cells in the outermost layer
124
Simple epithelium
One cell layer thick
125
Stratified epithelium
Two or more cell layers thick
126
Squamous
Flat cells
127
Cuboidal
Nearly square
128
Columnar
Taller than wide
129
Pseudo-stratified Epithelia
Trachea, male reproductive tract
Appear stratified but is really simple
130
Transitional epithelia
Stratified epithelia that changes shape when stretched
Has dome shaped cells on its surface
Found in bladder and urinary tract
131
Lamina Propria
Layer of connective tissue that underlies the covering epithelia
Provides structural and metabolic support and bind it to neighboring structures
132
Stratified cuboidal (where are they found)
Sweat gland ducts, large duct of exocrine glands
133
Stratified columnar (where are they found)
Largest ducts of some exocrine glands (rare)
134
Important simple squamous epithelia
Endothelium- epithelia lining of vascular system
Mesothelium- lining of closed cavities of the body (abdominal, pericardial, pleural)
135
Stratified squamous KERATINIZED epithelia
Found on the skin mainly
Outer squamous cells are dead
136
Stratified squamous NON-KERATINIZED epithelium
Line moist cavities (mouth, vagina)
Surface cells are alive with their nuclei
137
Epithelium and lamina propria constitute the
Mucosa
138
Glandular epithelia
Tissues formed by cells specialized to produce secretions
Secretory granules: small vesicles that store molecules to be secreted
139
Example of unicellular glands
Goblet cells of small intestine
Consist of isolated glandular cells
140
Endocrine glands
Lack a duct system
Secrete products into CT where they enter the bloodstream
Secretory products are called HORMONES
141
Exocrine glands
Have a duct system
Secrete products onto the surface
Mechanisms of secretion
Merocine
Apocrine
Holocrine
142
Merocrine Secretion
Secretory granules take product to apical surface of cell
Secretory granules in cells that produce digestive enzymes: ZYMOGEN granules
Vesicles fuse with plasma membrane and release their contents by exocytosis
Most common mechanism for secretion
143
Example of cells that use merocrine secretion
Pancreatic acinar cell
144
Apocrine Secretion
Secretory product is surrounded by a thin layer of cytoplasm within an envelope of plasma membrane on the apical portion of the cell
Occurs in: lactating mammary gland, lipid droplets into milk
145
Holocrine Secretion
The product of secretion is shed with the whole cell= Secretory product and cell debris
Process involves the destruction of the secretion filled cells
Occurs in: sebaceous glands of skin (sebum)
146
Paracrine secretion
Short range cell-cell communication via secreted signal molecules that act on adjacent cells
Reaches target cells by diffusion through the Extracellular space
Occurs in: GI tract
147
Acini
Small rounded group of cells of the gland produced by secretory cells
148
Endocrine glands differentiation
Cells from branching (anastomosing) cords interspersed between dilated blood capillaries (adrenal gland)
Cells line a vesicles or follicle (thyroid gland)
149
Serous glands
Secretion is clear and watery
150
True or False: The cytoplasm of serous secretory units are acidophilic
False, they are basophils due to high content of ribosomes and rER
151
Functions of CT
Provide matrix that connects and binds cells and organs to give support to the body and maintains form
152
CT generally consists of
Cells and ECM (Extracellular matrix)
153
ECM is composed of
Fibers and ground substance
Major constituent of CT
154
Examples of Specialized CT
Bone
Cartilage
Adipose Tissue
Blood
Hematopoietic Tissue
155
Examples of Connective Tissue Proper
Loose (areolar) CT
Dense CT (irregular/regular)
156
Permanent residents of CT
Fibroblasts, adipocytes, macrophages, mast cells
157
Wandering/Transient Population in CT
Migrate into tissues from the blood in response to inflammation
Monocytes, plasma cells, neutrophils and eosinophils
158
Fibroblasts
Most common cells in CT
Active fibroblasts have:
Large ovoid nuclei
Well developed rER and Golgi
159
Functions of Fibroblasts
Synthesize ECM components (collagen, elastin, GAGs, and multi adhesive glycoproteins)
Synthesize growth factors
160
Fibroblasts function in wound healing
Form scars
Myofibroblasts participate in wound contraction
MFB rich in actin and myosin and behave in smooth muscle cells
MFB lack basal lamina
161
Macrophages
Derived from monocytes
Highly phagocytic cells
Visualized by injecting vital dyes (trypan blue or India ink) OR indented kidney shaped nucleus
162
Macrophage Function
Phagocytosis
Removal of cell debris
Cell-mediated resistance to tumor invasion
Secrete proteases and enzymes that degrade GAGs to facilitate migration of macrophages through CT
Antigen Presenting Cells
163
Antigen Presenting Cells
Macrophages phagocytose foreign cells-> present antigens called major histocompatibility complex II (MHC II)
Present antigen to helper T lymphocytes
If recognized by T cells-> immune response
164
Mononuclear Phagocytic System (MPS)
Monocytes differentiate into macrophages that differ depending on the tissue
Includes:
Kupfer Cells in liver
Osteoclasts in bone
Microglia in CNS
Langerhans cells of skin
165
Foreign body giant cells
Clusters of macrophages fused to form a large cell that engulfs the foreign body
166
Mast cells
Cytoplasm filled with basophillic secretory granules (blue)
Abundant in dermis of skin and digestive and respiratory tracts
167
Function of mast cells
Storage and release of chemical mediators of the inflammatory response
168
Constituents of Mast Cell Granules
Histamine (inc mucus production, contraction of smooth muscles, inc permeability of small blood vessels causing EDEMA-accumulation of fluid)
Eosinophil and neutrophil chemoattractant factors
Heparin (anticoagulant)
169
Anaphylactic shock
Hypersensitivity reaction to allergies, may be fatal
170
Plasma Cells
Derived from B lymphocytes
Synthesize antibodies
Transient CT
171
Neutrophils and Eosinophils
neutrophils- phagocytose and destroy invading bacteria
Eosinophils- destroy larger parasites and modulate allergic response
Transient CT cells
172
Four main groups of GAG
Hyaluronan
Chondroitin and Dermatan Sulfate
Heparin Sulfate
Keratan Sulfate
173
Swelling Pressure
Turgor, enables resistance to compressive forces
174
Proteoglycans
GAG chains covalently attached to a polypeptide chain (via serine residue)
175
True or False: All GAGs are attached to proteins to form proteoglycans
False, hyaluronan does not
176
True or False: proteoglycans have more carbohydrate composition than other glycoproteins
True
177
True or False: Collagen is the most abundant protein in the human body
True
178
Tropocollagen
Collagen molecules
Consist of 3 polypeptide alpha chains to form super helix
179
What amino acids are collagens rich in?
Proline (stabilizes the helical conformation) and glycine (allow helical chains pack together
180
Gly-X-Y
X- proline
Y- hydroxyproline
181
Stabilization of triple stranded helix of collagen
Hydroxyproline and hydroxylysine
Hydroxyl groups- hydrogen bonds
182
What cofactor is required for formation of hydroxyproline and hydroxylysine
Vitamin C
183
Enzymes that form hydroxyproline and hydroxylysine
Proline hydroxylase
Peptidyl lysine hydroxylase
184
What disease is caused with lack of Vitamin C
Scurvy
Collagen does not become helical structures-> skin lesion, loss of teeth
185
How many types of collagen are there
28
186
What is the type of college principle in skin and bone and most common
Type 1 collagen
187
Argyrophillic
Bind silver salts
188
Osteogenesis imperfecta
Caused my mutation in genes encoding alpha chains of type 1 collagen
Leads to reduced type 1 collagen or defective
Fragile teeth, hearing loss, loose joints
189
True or False: Elastin has little hydroxyproline and no hydroxylysine
True
190
Marfans syndrome
Mutations in fibrillin gene
Elastic arteries rupture (aorta)
191
Tendons
Attach muscle to bone
Dense regular CT
Collagen rich
192
Ligaments
Dense Reg CT
Attach bone to bone
Collagen and elastic filaments
193
Aponeuroses
Dense regular CT
Flattened tendons (abdominal muscles and the hand)
194
Loose CT are rich in collagen
False, they are rich in ground substance
Dense irregular CT are rich in collagen
