CELLS AND TISSUES Flashcards
basic structural and functional unit of living organism
Cell
so, when you define cell properties, you are in fact defining the
properties of life
the activity of an organism depends on the
collective activities of cells
according to this principle, the activities of cells are dictated by their structure, which determines function
Principles of Complementarity
basis for the continuity of life
cellular basis
double membrane barrier
Nuclear Envelope/Nuclear Membrane
jelly like fluid of the nucleus in which nuclear elements are suspended
Nucleoplasm
site where ribosomes are assembled
Nucleolus
scattered throughout the nucleus ( when cell is not dividing)
Chromatin
dense rodlike bodies (when cell is dividing)
Chromosomes
3 major components of the cytoplasm
Cytosol
Inclusions
Organelles
semitransparent fluid that suspends the other elements
Cytosol
stored nutrients or cell products floating in the cytosol; also known as Cellular Pantry
Inclusions
” little organs” are specialized cellular compartments that are metabolic machinery of the cell
Organelles
all cells exhibit irritability ( the ability to respond to stimuli)
digest foods, excrete wastes, and are able to reproduce, grow, move, and metabolize
Parts that can be found in nucleus(5)
• Nuclear Envelope / Nuclear Membrane
• Nucleoplasm
• Nucleolus
• Chromatin
• Chromosomes
Structure: rodlike, double membrane structures: inner membrane folded into projections called cristae
• Mitochondria
Function: Site of aerobic respiration ( the “burning” of glucose ) and ATP synthesis power of the cell
• Mitochondria
Structure: dense particles consisting of two subunits, each composed of RNA and protein. Free or attached to rough endoplasmic reticulum
Ribosomes
Function: the sites of protein synthesis
Ribosomes
Structure: Membranous system enclosing a cavity, the tunnel, and coiling through the cytoplasm. Externally studded with ribosomes.
• Rough Endoplasmic Reticulum
Function: Sugar groups are attached to proteins within the tunnels. Proteins are bound in vesicles for transport to the Golgi apparatus and other sites. External face synthesizes phospholipids
• Rough Endoplasmic Reticulum
Structure: membranous system of tunnels and sacs free of ribosomes
• Smooth Endoplasmic Reticulum
Function: site of lipid and steroid ( cholesterol ) synthesis, lipid metabolism, and drug detoxification
• Smooth Endoplasmic Reticulum
- Structure: consists of a stack of flattened cisternae and associated vesicles. Proteins and lipids from the ER enter this organelle at its cis face and exit at its trans face.
• Golgi Apparatus
Function: a factory in which proteins received from the ER are further processed and sorted for transport to their eventual destinations: lysosomes, the plasma membrane, or secretion
• Golgi Apparatus
Structure: single membrane-bound vesicles that are involved in energy metabolism and lipid biosynthesis
• Perixisome
Function: organelles that sequester diverse oxidative reactions and play important roles in metabolism, reactive oxygen species detoxification, and signaling. Oxidative pathways housed in peroxisomes include fatty acid β-oxidation, which contributes to embryogenesis, seedling growth, and stomatal opening
• Perixisome
Structure: membranous sacs containing acid hydrolases ( powerful digestive enzymes)
• Lysosomes
Function: sites of intracellular digestion. The “stomach” of the cell
• Lysosomes
Structure: Cyndrical structures made of tubulin proteins
• Microtubules
Function: support the cell and give it shape. Involved in intracellular and cellular movements form centrioles and cilia and flagella, if present
• Microtubules
Structure: fine filaments composed of the protein actin
• Microfilaments
Function: involved in muscle contraction and other types of intracellular movement help form the cell cytoskeleton and microvilli, it present
• Microfilaments
Structure: Protein fibers; composition varies
• Intermediate Filaments
Function: the stable cytoskeletal elements resist mechanical forces acting on the cell
• Intermediate Filaments
Structure: paired cylindrical bodies, each composed of nine triplets of microtubules
• Centrioles
Function: Organize a microtubule network during mitosis ( cell division) to form the spindle and asters. Form the bases of cilia and flagella
• Centrioles
Structure: Varied: include stored nutrients such as lipid droplets and glycogen granules, protein crystals, pigment granules
• Inclusions
Function: Storage for nutrients, wastes, and cell products
• Inclusions
what are the 2 main processes in membrane transport
A. Passive Processes
B. Active processes
the ability to respond to stimuli
irritability
Cell Physiology: All cells exhibit
irritability, digest foods, excrete wastes, and are able to reproduce, grow, move, and metabolize
The movement of a substance from an area of its lower concentration It occurs because of kinetic energy of the molecules themselves; no ATP required
Diffusion
The diffusion of dissolved solutes through the plasma membrane
simple diffusion
The diffusion of water across the plasma membrane
osmosis
Diffusion that requires a protein channel or carrier
facilitated diffusion
The movement of substances through a membrane from an area of high hydrostatic pressure to an area of lower fluid pressure
Filtration
In the body, the driving force of filtration is
Blood Pressure
use energy (ATP) provided by the cell
Active processes
Two types of ATP
Exocytosis and Endocytosis
2 types of active processes
active transport and vesicular transport
Substances are moved across the membrane against an electrical or a concentration gradient by proteins called solute pumps. This accounts for the transport of amino acids, some sugars, and most ions
Active Transport
Moves secretions and other substances out of a cells; a membrane-bounded vesicle fuses with the plasma membrane, rupture, and ejects its contents to the cell exterior
Exocytosis
In which particles are taken up by enclosure in a plasma membrane sac, includes phagocytosis, pinocytosis , and the highly selective receptor-mediated. In the latter membrane receptors bind with and internalize only selected target molecules.
Endocytosis
uptake of solid particles
phagocytosis
uptake of fluids
pinocytosis
the longer phase of the cell cycle; metabolic phase
Interphase
2 types of Cell Division
Mitosis and Cytokinesis
the process of dividing a nucleus into two daughter nuclei with exactly the same genes as the “mother” nucleus
• Mitosis
division of the cytoplasm, which begins when mitosis is nearly completed
Cytokinesis
Cytokinesis
Mitosis: Prophase
The centrioles separate from each other and begin to move toward opposite sides of the cell, directing the assembly of mitotic spindle ( composed of microtubules) between them as they move.
Mitosis: Prophase
By the end of phase, the nuclear envelope and the nucleoli have broken down and temporarily disappeared, and the chromosomes have attached randomly to the spindle fibers by their centromeres.
Mitosis: Prophase
The chromosome line up at the metaphase plate
Mitosis: Metaphase
The chromatids ( now called chromosomes again ) begin to move slowly apart, drawn toward opposite ends of the cell
Mitosis: Anaphase
This careful division of sister chromatids ensures that each daughter cell gets one copy of every chromosomes
Mitosis: Anaphase
The chromosomes at opposite ends of the cell uncoil to become threadlike chromatin again.
Mitosis: Telophase and Cytokinesis
The spindle breaks down and diasappears, a nuclear envelope forms around each chromatin mass, and nucleoli appear in each of the daughter nuclei
Mitosis: Telophase and Cytokinesis
Formation of cleavage furrow over the midline of the spindle
Mitosis: Telophase and Cytokinesis
usually begins during late anaphase and completes during telophase
Cytokinesis
Four Primary Tissue Types
- Epithelial Tissue
- Connective Tissue
- Nervous Tissue
- Muscle Tissue
Covering and lining epithelium covers all free body surfaces, both inside and out, and contains versatile cells
Epithelial Tissue
Function: Epithelial Tissue
- Protection
- Absorption
- Filtration
- Secretion
fit closely together to form continuous sheets with the help of cell junctions.
• Epithelial cells
The membranes always have one free ( unattached ) surface or edge, the Apical Surface
Characteristic of Epithelial Tissue
rests on a Basement Membrane
• Basal Surface
have no blood supply of their own
• Epithelial tissues
regenerated themselves easily
Epithelial cells
Classification of Epithelia: Based on number of cell layers
- Simple Epithelium
- Stratified Epithelium
Classification of Epithelia: Based on cell shape
- Squamous cells
- Cuboidal cells
- Columnar cells
Diffusion and Filtration and Secretion in serious membrane
Simple Squamous Epithelium
Secretion and absorption; ciliated types propel mucus or reproductive cells
Simple Cuboidal Epithelium
Secretion and absorption; ciliated types propel mucus or reproductive cells
Simple Columnar Epithelium
True or false: No simple transitional epithelium exists
True
Protection
Stratified Squamous Epithelium
Protection; these tissue types are rare in humans
- Stratified Cuboidal Epithelium
- Stratified Columnar Epithelium
Protection; stretching to accommodate distension of urinary structures
Stratified Transional Epithelium
It is the most abundant and widely distributed of the tissues types
Connective Tissue
Function of Connective Tissue
- Protection
- Supporting
- Binding together other body tissues
Characteristic of Connective Tissue (2)
• Variation in blood supply
• Extracellular Matrix
Produced by the connective tissue cells and the secreted to their exterior
• Extracellular Matrix
2 main elements of Extracellular Matrix
- 2 main elements: ground substance, fibers
Types of Connective Tissue (5)
• Bone
• Cartilage
• Dense Connective Tissue
• Loose Connective Tissue
• Blood
Three Types of Loose Connective Tissue
- Areolar Connective Tissue
- Adipose Connective Tissue
- Reticular Connective Tissue
Osseous Tissue
Bone
Composed of osteocytes sitting in cavities called lacunae
Bone
These pits are surrounded by layers of a very hard matrix that contains calcium salts in addition to large numbers of collagen fibers
Bone
Has an exceptional ability to protect and support other body organs
Bone
Less hard and more flexible than bone
Cartilage
major cell type of cartilage
chondrocytes
Types of Cartilage (3)
- Hyaline Cartilage
- Fibrocartilage
- Elastic Cartilage
has abundant collagen fibers hidden by a rubbery matrix with a glassy, blue-white appearance
- Hyaline Cartilage
highly compressible; collagen fibers are in thick bundles, tightly packed, and run in parallel
- Fibrocartilage
shares many similarities with hyaline cartilage; matrix is very light staining
- Elastic Cartilage
create a dark- staining network around the lacunae
Elastic fibers
Dense fibrous tissue other name
Dense Connective Tissue
the main element Dense Connective Tissue
Collagen fibers
Crowded between the collagen fibers are row of fibroblasts that manufacture the building blocks of the fibers
Dense Connective Tissue
Forms strong, ropelike structures such as Tendons and Ligaments
Dense Connective Tissue
attach skeletal muscle to bones at joints
Tendons
connect bones to bones at joints
Ligaments
Softer and have more cells and fewer fibers than any other connective tissue type except blood
Loose Connective Tissue
3 main types Loose Connective Tissue
• Areolar Connective Tissue
• Adipose Connective Tissue
• Reticular Connective Tissue
Fat; It is an areolar tissue in which adipose (fat) cells predominate
Adipose Connective Tissue
A glistening droplet of oil occupies most of a fat cell’s volume and compresses the nucleus, displacing it to one side
Adipose Connective Tissue
Insulates the body and protects it from bumps and extremes of both heat and cold
Adipose Connective Tissue
Insulates the body and protects it from bumps and extremes of both heat and cold
Adipose Connective Tissue
Vascular tissue
Blood
It is considered a connective tissue because it consist of blood cells surrounded by a nonliving, fluid matrix called blood plasma. The “ fibers” of blood are soluble proteins that become visible only during blood clotting
Blood
Transport vehicle for the cardiovascular system, carrying nutrients, wastes, respiratory gases, etc.
Blood
Highly specialized to contact, or shorten, which generates the force required to produce movement
Muscle Tissue
3 types of Muscle Tissues
• Skeletal Muscle Tissue
• Cardiac Muscle Tissue
• Smooth Muscle Tissue
Attached to skeleton; Can be controlled voluntarily
Skeletal Muscle
long, cylindrical and multinucleate, and they obvious striations
cells of skeletal muscle
consist of blood cells surrounded by a nonliving, fluid matrix called
blood plasma
soluble proteins that become visible only during blood clotting
The “ fibers” of blood
Is found only in the heart wall; As it contracts, the heart acts as pump to propel blood through the blood vessels
Cardiac Muscle
Involuntary control; Has striations, but cardiac cells have only a single nucleus and are relatively short, branching cells that fit tightly together ( like clasped fongers ) at junctions called intercalated discs
Cardiac Muscle
single nucleus and are relatively short, branching cells that fit tightly together ( like clasped fongers ) at junctions called
intercalated discs
Found in the walls of hollow organs such as the stomach, uterus, and blood vessel
Smooth Muscle
its walls contracts, the cavity of an organ alternately become smaller or enlarges so that substances are mixed and/or propelled through the organ along specific pathway
Smooth Muscle
For international communication and control
Nervous Tissue
Neurons and supporting cells form the brain, spinal cord, and nerves
Nervous Tissue
two major functional characteristic Nervous Tissue
Irritability and conductivity
Inflammation
Tissue Injury
Granulation tissue forms
Tissue Injury
Tissue repair: (2)
Regeneration and Fibrosis
replacement of destroyed tissue by the same kind cells
• Regeneration
involves repair by dense (fibrous) connective tissue, by the formation of scar tissue
• Fibrosis
osteocytes sitting in cavities called
lacunae
