UNIT 1 Flashcards
Study of tissues of the body and how tissues are arranged to constitute organs
Histology
Other term for histology
microscopic anatomy or microanatomy
French word “tissue” means
Weave or texture
What year did tissue not refer to organic, cellular layers, but rather to anything woven or textured
1700s
Tissue was coined by French scientist
Bichat
First microscopes were constructed where
Netherlands
First microscopes were constructed when
Late 15000s
Images are poor under what magnification
3x-9x
4 basic types of tissues
Epithelial, connective, muscle, nervous
Different types and functions of cells
Epithelial, connective, muscle, nervous
Different types of characteristics of the matrix
Elastic, hard or gelatinous
Different relative amount of space occupied by cells versus matrix
Connective tissue vs muscle and epithelium
The embryo begins as what?
A single cell
What Divides into many cells that form layers (strata)?
Embryo
Three primary germ layers
Ectoderm, mesoderm, endoderm
Primary germ layer that is found in the epidermis and nervous system
Ectoderm
Primary germ layer that has mucous membranes and digestive glands
Endoderm
Primary germ layer that forms mesenchyme
Mesoderm
Primary germ layer that gives rise to muscle, bone, and blood
Mesoderm
Preparation of histological specimens
Fixation, sections, mounted on slides and stained
Reduces a 3-dimensional structure to a 2-dimensional
Sectioning (slicing) an organ or tissue
Types of tissue sections
Longitudinal, cross, oblique
Tissue cut along the longest direction of an organ
Longitudinal
Tissue cut perpendicular to the length of an organ
Cross
Tissue cut at an angle between a cross & longitudinal
Oblique
One or more layers of closely adhering cells
Epithelial tissue
What forms on the top of the epithelial tissue?
flat sheet with the upper surface exposed to the environment or an internal body cavity
the bottom of the epithelial tissue sits where?
Basement membrane
Types of arrangement of layers
Simple, stratified
Cell shapes
Squamous, cuboidal, columnar
Most abundant and variable tissue type
Connective tissue
Functions of connective tissue
- Binding of organs
- Support, protection, and movement
- Storage
- Transport
T/F Connective tissue has widely spaced cells
True
3 types of muscle tissue
Skeletal, cardiac, smooth
T/F the plasma membrane of the three muscle tissues cannot change their electrical states
False, it can
T/F the three muscle tissues can send an electrical wave called an action potential along the entire length of the membrane
True
T/F Nervous system can influence the excitability of cardiac and smooth muscle
True
T/F Skeletal muscle is completely independent from signaling from the nervous system
False, it is dependent
Both muscle types can respond to other stimuli
Hormones and local stimuli
What type of tissue is composed of nerve and glial cells?
Nervous tissue
Type of tissue that is responsible for the computation and computation that the nervous system provides
Nervous tissue
T/F Nervous tissue electrically active and release chemical signals to communicate between each other and with target cells
True
T/F nervous tissue are larger than neurons and play a supporting role for nervous tissue
False, they are smaller than neurons
Functions of glial cells
- Maintain the extracellular environment around neurons
- Improve signal conduction I neurons
- Protect them from pathogens
T/F Glial cell number matches neuron number and can send signals themselves
True
Description of cell
- Basic, structural, morphologic, developmental, functional unit of living organism
- Mass of protoplasm containing a nucleus
- Smallest biologic entity capable of independent existence
Cell constructed by imagination to include parts which can be found in other cells
Hypothetical cell
Organelles are formed by
Golgi apparatus
Organelles are secreted by
Exocytosis
Site of protein synthesis
Rough ER
T/F Golgi apparatus contains materials produced in the cell
False, organelle
Permeability barrier that allows the cell to maintain an interior composition far different from that of the extracellular fluid
Cellular membrane
2 proposed structures of the cellular membrane
Davson and Danielli
Fluid Mosaic Model
Proposed structure model that involves a Trilaminar structure
Davson and Danielli
Proposed structure model that was inspired by Singer and Nicholson
Fluid Mosaic Model
Creates kinks, prevents the close packing of the hydrophobic tails
Unsaturated fatty acids
Stabilize and regulate the fluidity of the phospholipid bilayer
Cholesterol
The dual properties of fluidity and flexibility of the cell membrane
- Decrease fluidity
- Decrease permeability to small water soluble molecules
Carbohydrate moieties – functions as receptors or antigens
Glycolipids
Three membrane proteins
Peripheral proteins, intrinsic/integral proteins, transmembrane proteins
Membrane protein found on the cytoplasmic side of the inner leaflet
Peripheral proteins
Membrane protein that may have just a segment embedded in one of the leaflets with a lipid anchor
Intrinsic/integral proteins
Membrane protein that span the lipid bilayer – functional on both sides of the bilayer
Transmembrane proteins
T/F cells are polarized
True
has an organized dimensional structure o Superior, inferior, lateral, distal
polarized cell
Superior side of the cell, faces the environment, faces a lumen, connects to the ducts and has channels
Apical region
Inferior side of the cell, Faces the capillary containing tissue – basement membrane
Basolateral region
T/F Epithelial cells are supported by basement membrane
True
Command center of the cell and contains the code for all of a cell’s enzymes and other proteins
Nucleus
DNA + Nucleoli = ?
RNA
T/F Nucleus is the site of ribosomes and messenger RNA synthesis
True
What biological concept is produced by the nucleus?
Transcription and Translation
Site of ribosomal RNA synthesis and ribosomal subunit assemble
Nucleolus
T/F mRNA is delivered to the ribosomes by nucleus
False, delivered by the nucleolus
Characteristics of Rough ER
- Granular appearance due to bound ribosomes
- Primary site of secretory protein synthesis
Characteristics of Smooth ER
- Appears smooth due to lack of bound ribosomes
- Site of lipid biosynthesis, steroid hormone synthesis, intracellular calcium storage, & detoxification of noxious metabolites
Consists of stacks of four to six stacked saucer-shaped cisternae
Golgi apparatus
Sites of intracellular digestion & turnover of cell components
Lysosomes
Type of lysosome that has small membrane bound vesicles containing hydrolytic enzymes
Primary lysosomes
Type of lysosome that is a composite structure formed by the fusion of a primary lysosome and a phagocytized foreign body
Secondary lysosomes
Mobile powerhouse of the cell
Mitochondria
Compartments of the mitochondria
Outer membrane, inner membrane, mitochondrial matrix, intramembranous space
Sites of protein synthesis
Ribosomes
Type of ribosomes that are found scattered in the cytosol
Attached ribosomes
Important in the proper management of metabolic waste products of the cell
Peroxisomes
What deposits do the peroxisomes produce?
Cytoplasmic
Three cytoskeletal components
Microfilaments, intermediate filaments, microtubules
Largest organelle within the cell, command center of the cell
Cell nucleus
Nuclear components of cell nucleus
Nuclear envelope, chromatin
Selectively permeable membrane separating the nuclear components from the cytoplasmic components
Nuclear envelope
An eightfold symmetrical structure made up of 30 different nuclear proteins
Nuclear pore complexes
Gate keeper of the nucleus
Nucleoporins
Assist in the translocation of proteins, RNAs and ribonuclear particles
Karyopherin
Also known as importins and exportins
karyopherin
Made of DNA and all associated proteins involved in the organization and function of DNA
Chromatin
Components of chromatin
DNA, Histones, DNA binding protein, RNA
Separate structures that forms when chromatin fibers coil up, Occurs when cell prepares to divide
Chromosome
Types of chromatin
Heterochromatin, euchromatin
Chromosomal segments which appear extremely condensed and dark in color in the interphase nucleus
Heterochromatin
Small, dense sex chromosome, One of the two large X chromosomes present in human females
Barr body
Structure that produces the initial organization of free double-stranded DNA into chromatin
Nucleosome
Phases of the cell cycle
G1, S, G2, M, G0
The cell cycle is regulated by what?
cyclins and cyclin dependent kinases (CDKs)
The time gap between mitosis and the beginning of DNA replication
G1 phase
Period of DNA synthesis
S Phase
Gap between DNA duplication and the next mitosis
G2 phase
Includes all phases of mitosis itself
M phase
Phase when cell activities are temporarily or permanently suspended
phase
Cell cycle checkpoints
G1 checkpoint, Intra S-phase checkpoint, G2/M Checkpoint, Mitotic Checkpoint
Cell cycle regulator that govern the transition between phases during cell cycle progression
Cyclin dependent kinases (CDKs)
Critical in chromosome segregation
Other kinases – Aurora, Mps1, and Bub
Frequently mutated in human cancer and deregulated CDK activity
Genes
3 classifications of cells
Permanent, labile, stable
Cells that will never reenter cell cycle
Permanent cells
Cells that keep on recycling/regenerating new cells
Labile cells
Cells that remain in the g0
Stable cells
A parent cell divides and each of the two daughter cells receives a chromosomal set identical to the parent cell
mitosis
Phases of mitosis
Prophase, metaphase, anaphase, telophase
Phase where nucleolus disappears and replicated chromatin condenses – discrete threadlike chromosomes
Prophase
Phase where microtubules move the chromosomes alignment at the equatorial plate
Metaphase
Phase where chromosomes condense further
Metaphase
Phase where two sets of chromosomes at the spindle poles begin to revert to their uncondensed state
Telophase
cycling serves to renew the differentiated cells of its tissues
stem cells
cells in transit along the path from the stem cell niche to a differentiated state
progenitor cells
Specialized process involving two unique and closely associated cell divisions – form sperm and egg cells
Meiosis
Two key features of meiosis
Synapsis, cells are haploid
reciprocal DNA exchanges
crossovers
new diploid cell from the union of haploid eggs and sperm at fertilization
zygote
Process of cell suicide
Apoptosis
Rapid, highly regulated cellular activity that shrinks and eliminates defective and unneeded cells
Apoptosis
