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SGU HISTOLOGY WEEK 1
Terms in this set (116)
Where is DNA sequestered?
What happens in the nucleolus?
Ribosome production. Three zones:
1. Fibrillar Center
2. Fibrillar material (transcription of rRNA genes)
3. Granular material (G)
(initial ribosome assembly)
Where is chromatin packaged in?
Nucleosomes, as histones
"beads on a string"
site of protein synthesis (translation), made in the nucleolus
Membrane bound ribosomes
(Seen on the rER)
Synthesize proteins that are being translocated into the ER lumen.
-plasma membrane proteins
Synthesize all other proteins:
Protein synthesis, consistent with the nuclear envelope
lipid synthesis/metabolism, detox in liver (CYP450), in muscle cells it sequesters Calcium
What does the golgi apparatus do?
Post-translational modification, packaging, sorting.
Especially well developed in secretory cells (plasma, pancreatic acinar)
2 membranes: outer and inner
2 compartments: intermembrane space/matrix
Anything moving from the rER to the Golgi or back uses specific proteins. What are these two proteins?
COP I: Retrogade (CGN->ER)
COP II: Anterograde (movement from the rER to the CGN)
CGN (cis-golgi network)
TGN (trans-golgi network)
Tay Sachs Disease
Lysosomal storage disease. Deficiency of HEXA (B-hexosaminidase A, a-subunit)
In chromosome 15q24) - Death of neurons in brain and spinal cord.
Major cellular pathway to degrade proteins and organelles in the lysosome - "Self eating"
Essential role in starvation, cellular differentiation, cell death and cell aging
Destroy proteins w/o lysosome. Polyubiquitination: Proteins targeted for destruction are covalently tagged with ubiquitin protein. Located in sER.
Important role in fat metabolism (b-oxidation enzymes, FA oxidation), degrade toxic reactive oxygen molecules. Important in hepatocytes.
Synthesized by free ribosomes. Involved in Zellweger syndrome
Defective import of peroxisomal proteins
Mitotic spindle poisons
1. Colchicine (anticancer) - also related to vinca alkaloids
2. Taxol (anticancer)
What are the microtubule motors?
1. Dynein - binding sit
The cytoskeleton contains what?
For structural support, track for motor proteins, organization
Actin filaments are found where?
Microvilli and stereocilia (elongated microvilli)
alpha and b-tublin protein subunits - for intracellular transport.
Found in cilia in a 9+2 doublet formation and a 9+0 triplet formation at the base of the cilia
Microtubule associated proteins (MAPs)
Tau proteins - abundant in neurons of CNS. Linked to alzheimers.
Dynein vs Kinesin
Dynein move along - end, Kinesin move along + end.
Both binding sites for vesicles. Dynein is faster!
Cilia and Flagella
Microtubules and axonemal dynein motors (movement produced by bending the core - axoneme)
Has a 9+2 configuration at the axoneme and a 9+0 configuration at its basal end
Function is for motility
Each doublet has dynein arms that uses ATP energy for movement
Very long microvilli
Therefore, they are made up of actin as well
What are the 6 classes of intermediate filaments?
1 & 2 Keratines
3. Vimentin & vimentin like
6. Beaded filaments
Found in all epithelial cells
Vimentin & VImentin like
Diverse, most widely distributed.
Vimentin: abundant in mesoderm derived cells
Vimentin like: found in variety of cells (desmin - mucle cells, glial cells, astrocytes)
Found primary in neurons
Found in nucleus of all nucleated cells (nuclear lamina), Lamin A&B proteins.
Eye lens-specific group
What is epithelium?
Avascular tissue composed of cells that cover the exterior body surfaces and line internal closed cavities (including vascular system) and body tubes that communicate with the exterior (alimentary, respiratory, genitourinary)
diffusion for gas and ion exchange
absorption and secretion
absorption and secretion
Keratinized: protection, mainly on skin
Non-keratinized: Protection, mainly in mouth, esophagus, vagina, rectum.
Function: absorption and secretion and protection
Found mainly in ducts of sweat glands
Function: absorption and secretion and protection
Found mainly in large secretory ducts
Function: absorption and secretion
Found mainly in trachea and male reproductive system
Not every cell reaches the lumen, but all cells touch the basement membrane
Function: protection and distension
Found mainly in bladder and urethra
Relaxed: most apical layer is dome shaped
Distended: most apical layer is flat
Apical domain of columnar cells contain ________, that increase surface area of absorption
microvilli - "brush border" that surface area of absorption
Zona Occludens (tight junctions)
1st part of junctional complex
Prevents anything from the lumen to enter or exit through the intercellular space
CAM: Occludins and Claudins
Goes all the way around the perimeter of the epithelial cell. Underneath occludens. Helps to attach adjacent cells using actin filaments.
Macula Adherens (desmosome)
When cells are 30nm apart
A dense plaque made of desmoplakins, with desmogleins and E-cadherins linking to each other and looping through it
Focal dense spots called the macula. Helps adhere cells in multiple cells.
Made up of connexins. Allows communication between adjacent cells
1 connexon = 6 connexins
Anchoring junctional complexes found in non-epithelial cells (ex. cardiac myocytes)
Help anchor epithelial cells to basement membrane (basal lamina). Contain keratin filaments attached to intracellular space.
Anchors the actin cytoskeleton to the extracellular matrix, detects and trans duces signals from outside the cell.
Fingerlike projections into the lumen
Made up of 25-30 actin filaments
Found between epithelial cells and connective tissue beneath
Composed of collagen, laminins, glycoproteins and proteoglycans. Produced by endothelial cells of capillary.
Exocrine glands (3 types)
Merocrine, apocrine and holocrine
Classifications of exocrine glands
Unicellular & Multicellular
Single secretory cell among non secretory cells
Multicellular glands can be ____________
Simple - not branched
compound - branched
Shape of multicellular glands can be
Acinar/Alveolar - sac like
Tubular - straight, coiled or branched
Secretions of multicellular glands are ________
Parotid Gland - only serous secretory units
Submandibular - pure serous and mucous w/ serous demilunes
Sublingual - pure mucous and mucous w/ serous demilunes
Watery, rich in protein secretions. Extensive RER
Slimy, rich in oligosaccharides. Flattened and compressed nuclei
serous and mucous cells
Secretion by exocytosis.
Membrane bound vesicles to the apical aspect. (pancreatic acinar cells)
Released in apical surface, a bit of cytoplasm leaves with it (lactating mammary glands)
secretion by cell death (sebaceous glands)
Ductless glands that release their content directly into bloodsteam
Parenchyma is the functional unit where you will find the secretory epithelial cells
What is connective tissue made up of?
Cells - permanent and transient
CT IS VASCULAR!!!
What is connective tissue's function?
Permanent cells of connective tissue
Transient cells of connective tissue
Excellence, Beauty and Power Never Last
Synthesize fibers and ground substance
Well developed ER
What are inactive fibroblasts called?
Nucleus and organelles are pushed to the periphery. Looks like a signet ring.
Rich Blood Supply
Adipocytes (brown fat)
Many lipid droplets. Central nucleus.
Common in neonates
Function: Heat production
Derived from monocytes that migrate to CT and differentiate into macrophages.
-Irregulat cell membrane, Cytoplasmic extensions, (pseudopodia)
Glycosaminoglycans are called _______ when bound to protein core
Function of macrophages?
They produce cytokines (phagocytic) and are antigen presenting.
In electron micrograph, there are:
Name of macrophages in different locations?
Liver - Kupffer cells
Brain - microglia
Bone - osteoclasts
Originate in the bone marrow. Once they are in the CT, they proliferate and acquire their granules.
Mast Cell granules
Are vasoactive mediators
Release histamine, heparin and chemotactic mediators
_________ are vasoactive mediators as well.
Not released from granules, rather released from cell membrane
What is collagen made up of?
_________ is formed inside of the cell, but _________ is assembled extracellularly
Ehler's Danlos Syndrome
Abnormal collagen production due to mutations in gene encoding alpha chain
Vitamin C deficiency
Type I collagen
Bone, Tendon and Skin - provides tensile strength
Type II collagen
Hyaline and Elastic cartilage
Type III collagen
Reticular Fibers, Lymph Organs - SHORT, THIN AND BRANCHING
Type IV collagen
Basal Lamina - binds to laminin
Type V collagen
Amnion and Chorion in fetus
Contain Type III collagen. Short, thin and branching. Found in organs w/ large volume changes, such as:
FIBRILLIN - the glycoprotein that acts as a scaffold for elastic fibers
Found in: Aorta, Elastic cartilage, Bronchi
Decreased elastic fibers due to a mutation in the fibrillin gene
glycoprotein and elastin
glycine, proline, desmosine, isodesmosine (lysine-like)
What does ground substance do?
-Holds the cells and fibers together
-Acts as a lubricant for cell migration
-Prevents invasion from bacteria or microorganisms
-General tissue tensile strength
What does ground substance contain?
Proteoglycans (GAG bound to protein core)
Mucous Connective Tissue
Mainly ground substance, few cells or fibers
Mucous CT is found in....
-Wharton's Jelly (Umbilical Cord) - prevents the blood vessels from collapsing
-Vitreous humor in the eye
Mesenchyme is __________
embryonic connective tissue
Loose Connective Tissue (areolar)
Fills spaces betwen other tissues. Flexible, rich blood supply, not resistant to stress.
Dense irregular connective tissue
more fibers than cells, withstands stress from different directions, no orientation of collagen fibers. No orientation of collagen fibers.
found in: Organ capsules, periosteum, dermis
Dense regular connective tissue
Specific orientation of collagen fibers. Imparts tensile strength. Found in tendons and ligaments.
Reticular connective tissue
Contain reticular cells (modified fibroblasts). Contains type III collagen in the reticular fibers. Use silver stain or PAS
Framework for myeloid (bone marrow) and lymphoid (lymph nodes, spleen) organs
Elastic connective tissue
Elastic fibers (yellow)
Found in ligamentum flavum, vocal ligament, suspensory ligament of the penis
Adipose connective tissue
What are the three specialized connective tissues?
Cartilage, bone and blood.
abnormal collagen production attributed to mutations in genes encoding the a-chains in the various collagens
Characterized by hyper mobility of joints, pale thin skin, early morbidity and mortaly due to rupture of vessels and internal organs.
Scar when raised than normal, but within original wound boundry.
Excess of the boundary, extending into the surrounding tissue
Ascorbate is essential for hydroxylation of amino acid proline which forms hydroxyproline - a major component of collagen.
Marfan's syndrome - more
Autosomal dominant disorder in deficiency of protein fibrillin-1.
Cardiovascular manifestations can include aortic aneurysm and mitral valve prolapse.
increased mast cell release of histamine.
increase tissue fluid
THIS SET IS OFTEN IN FOLDERS WITH...
SGU Term 1 Exam 1 Diseases
SGU Term 1 Exam 1 Drugs & Toxins
SGU Term 1 Exam 1 Genetic Disorders
SGU FTM Week 1
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