Chapter 3: Cells and Tissues Flashcards
What are the 3 main regions of all cell structures?
Nucleus Cytoplasm Plasma membrane
•Control center of the cell
–Contains genetic material (DNA)
nucleus
What are the 3 regions of the nucelus?
Identify and find:
Nuclear envelop chromatin nucleolus nuclear pores rough ER nucleus
–Barrier of the nucleus
–Consists of a double membrane
–Contains nuclear pores that allow for exchange of material with the rest of the cell
nucelar envelope (membrane)
•Nucleoli
–
Nucleus contains one or more nucleoli
–Sites of ribosome assembly
–Ribosomes migrate into the cytoplasm through nuclear pores
•Chromatin
–Composed of DNA and protein
–Present when the cell is not dividing
–Scattered throughout the nucleus
–Condenses to form chromosomes when the cell divides
plasma membrane
•Barrier for cell contents
•Double phospholipid layer
–Hydrophilic heads
–Hydrophobic tails
•Also contains proteins, cholesterol, and glycoproteins
3 types of membrane junctions
–Tight junctions
–Desmosomes
–Gap junctions
–Tight junctions
- Impermeable junctions
- Bind cells together into leakproof sheets
–Desmosomes
•Anchoring junctions that prevent cells from being pulled apart
–Gap junctions
•Allow communication between cells
3 major elements of cytoplasm
–Cytosol
–Organelles
–Inclusions
–Cytosol
•Fluid that suspends other elements in a cell
–Organelles
- Metabolic machinery of the cell
- “Little organs” that perform functions for the cell
–Inclusions
•Chemical substances such as stored nutrients or cell products
Smooth endoplasmic reticulum cytosol lysosome mitochondrion centrioles microtubule intermediate filaments peroxisome nucleus chromatin nucleus
nuclear envelope plasma membrane rough endoplasmic reticulum ribosomes
golgi apparatus secretion being released from cell by exocytosis
•Mitochondria
–“Powerhouses” of the cell
–Change shape continuously
–Carry out reactions where oxygen is used to break down food
–Provides ATP for cellular energy
•Ribosomes
–Made of protein and RNA
–Sites of protein synthesis
–Found at two locations
•Free in the cytoplasm
•As part of the rough endoplasmic reticulum
•Endoplasmic reticulum (ER)
–Fluid-filled tubules for carrying substances
•Rough endoplasmic reticulum
–Fluid-filled tubules for carrying substances
–Studded with ribosomes
–Synthesizes proteins
•Smooth endoplasmic reticulum
–Functions in lipid metabolism and detoxification of drugs and pesticides
–Fluid-filled tubules for carrying substances
•Golgi apparatus
–Modifies and packages proteins
–Produces different types of packages
• Secretory vesicles
• Cell membrane components
• Lysosomes
•Lysosomes
–Contain enzymes produced by ribosomes
–Packaged by the Golgi apparatus
–Digest worn-out or nonusable materials within the cell
•Peroxisomes
–Membranous sacs of oxidase enzymes
• Detoxify harmful substances such as alcohol and formaldehyde
• Break down free radicals (highly reactive chemicals)
–Replicate by pinching in half
•Cytoskeleton
–Network of protein structures that extend throughout the cytoplasm
–Provides the cell with an internal framework
–Three different types of elements
• Microfilaments (largest)
• Intermediate filaments
• Microtubules (smallest)
•Centrioles
–Rod-shaped bodies made of microtubules
–Direct the formation of mitotic spindle during cell division
–Cilia
moves materials across the cell surface
•Located in the respiratory system to move mucus
built out of centriolles
–Flagella
propel the cell
•The only flagellated cell in the human body is sperm
built out of centriolles
–Microvilli
tiny, fingerlike extensions of the plasma membrane
•Increase surface area for absorption
What’s different about red blood cells?
they have no nucleus or organelles
A neuron has no centrioles.
True or false?
true
skeletal muscle cells have few mitochondria, and many nuclei.
True or Fasle
False. Skeletal muscle cells are multinucelated and have large numbers of mitochondria.
Cardia muscle has striated discs.
True or false?
Fasle. Cardia muscle has intercalated discs
sperm have flagella
true or false?
true
neutrophils/macrophages have large numbers of lysosomes
true or false?
true
pseudostratified ciliated columnar have cilia
true or false?
true
adipose cells store carbohydrates
true or false?
False. adipose cells store lipids.
•Diffusion
–Particles tend to distribute themselves evenly within a solution
–Movement is from high concentration to low concentration, or down a concentration gradient
–Osmosis
—simple diffusion of water
•Highly polar water molecules easily cross the plasma membrane through aquaporins
•Facilitated diffusion
- Substances require a protein carrier for passive transport
- Transports lipid-insoluble and large substances
•Active transport (solute pumping)
Amino acids, some sugars, and ions are transported by protein carriers called solute pumps
–ATP energizes protein carriers
–In most cases, substances are moved against concentration gradients
•Vesicular transport
–Exocytosis
Moves materials out of the cell
•Material is carried in a membranous vesicle
•Vesicle migrates to plasma membrane
•Vesicle combines with plasma membrane
•Material is emptied to the outside
•Vesicular transport
–Endocytosis
•Extracellular substances are engulfed by being enclosed in a membranous vescicle
–Types of endocytosis
•Phagocytosis—“cell eating”
•Pinocytosis—“cell drinking”
Stages of Mitosis: Prophase
–First part of cell division
–Centrioles migrate to the poles to direct assembly of mitotic spindle fibers
–DNA appears as double-stranded chromosomes
–Nuclear envelope breaks down and disappears
Stages of Mitosis: Metaphase
–Chromosomes are aligned in the center of the cell on the metaphase plate
Stages of Mitosis: Anaphase
–Chromosomes are pulled apart and toward the opposite ends of the cell
–Cell begins to elongate
Stages of Mitosis: Telophase
–Chromosomes uncoil to become chromatin
–Nuclear envelope reforms around chromatin
–Spindles break down and disappear
cytokinesis
–Begins during late anaphase and completes during telophase
–A cleavage furrow forms to pinch the cells into two parts
•Transfer RNA (tRNA)
–Transfers appropriate amino acids to the ribosome for building the protein
•Ribosomal RNA (rRNA)
–Helps form the ribosomes where proteins are built
•Messenger RNA (mRNA)
–Carries the instructions for building a protein from the nucleus to the ribosome
•Transcription
–Transfer of information from DNA’s base sequence to the complimentary base sequence of mRNA
–Three-base sequences on mRNA are called codons
occurs in nucleus where DNA is transcribe to mRNA
•Translation
–Base sequence of nucleic acid is translated to an amino acid sequence
–Amino acids are the building blocks of proteins
occurs in cytoplasm where mRNA is used to make proteins
Name the 4 primary types of tissue
•Epithelial tissue (epithelium)
•Connective tissue
•Muscle tissue
•Nervous tissue
•
Epithelial Tissues: Locations
–Body coverings
–Body linings
–Glandular tissue
Epithelial Tissues: Functions
–Protection
–Absorption
–Filtration
–Secretion
Epithelium Characteristics
- Cells fit closely together and often form sheets
- The apical surface is the free surface of the tissue
- The lower surface of the epithelium rests on a basement membrane
- Avascular (no blood supply)
- Regenerate easily if well nourished
Classification of Epithelia
Simple or stratified
AND
Squamous, cuboidal, or columnar
•Simple squamous
–Single layer of flat cells
–Location - usually forms membranes
•Lines body cavities
•Lines lungs and capillaries
–Functions in diffusion, filtration, or secretion in membranes
•Simple cuboidal
–Single layer of cube-like cells
–Locations
•Common in glands and their ducts
•Forms walls of kidney tubules
•Covers the ovaries
–Functions in secretion and absorption; ciliated types propel mucus or reproductive cells
–
•Simple columnar
–Single layer of tall cells
–Often includes mucus-producing goblet cells
–Location - lines digestive tract
–Functions in secretion and absorption; ciliated types propel mucus or reproductive cells
•Pseudostratified columnar
–Single layer, but some cells are shorter than others
–Often looks like a double layer of cells but all cells rest on the basement membrane
–Location - respiratory tract, where it is ciliated
–Functions in absorption or secretion
•Stratified squamous
–Cells at the apical surface are flattened
–Functions as a protective covering where friction is common
–Locations - lining of the Skin, Mouth & Esophagus
•Transitional epithelium
–Composed of modified stratified squamous epithelium
–Shape of cells depends upon the amount of stretching
–Functions in stretching and the ability to return to normal shape
–Location - lines organs of the urinary system
List 3 connective tissue functionings
–Binds body tissues together
–Supports the body
–Provides protection
•Bone (osseous tissue)
–Composed of
•Bone cells in lacunae (cavities)
•Hard matrix of calcium salts
•Large numbers of collagen fibers
–Functions to protect and support the body
•Hyaline cartilage
–Most common type of cartilage
–Composed of
•Abundant collagen fibers
•Rubbery matrix
–Locations
•Larynx
•Entire fetal skeleton prior to birth
–Functions as a more flexible skeletal element than bone
•Elastic cartilage
–Provides elasticity
–Location
•Supports the external ear
•Fibrocartilage
–Highly compressible
–Location
•Forms cushion-like discs between vertebrae
•Dense connective tissue (dense fibrous tissue)
–Main matrix element is collagen fiber
–Fibroblasts are cells that make fibers
–Locations
•Tendons—attach skeletal muscle to bone
•Ligaments—attach bone to bone at joints
•Dermis—lower layers of the skin
•Loose connective tissue types
–Areolar tissue
•Most widely distributed connective tissue
•Soft, pliable tissue like “cobwebs”
•Functions as a packing tissue
•Contains all fiber types
•Can soak up excess fluid (causes edema)
•Loose connective tissue types
–Adipose tissue
•Matrix is an areolar tissue in which fat globules predominate
•Many cells contain large lipid deposits
•Functions
–Insulates the body
–Protects some organs
–Serves as a site of fuel storage
•Loose connective tissue types
–Reticular connective tissue
•Delicate network of interwoven fibers
•Locations
–Forms stroma (internal supporting network) of lymphoid organs
»Lymph nodes
»Spleen
»Bone marrow
•Blood (vascular tissue)
–Blood cells surrounded by fluid matrix called blood plasma
–Fibers are visible during clotting
–Functions as the transport vehicle for materials
•Skeletal muscle
–Under voluntary control
–Contracts to pull on bones or skin
–Produces gross body movements or facial expressions
–Characteristics of skeletal muscle cells
•Striated
•Multinucleate (more than one nucleus)
•Long, cylindrical cells
•Cardiac muscle
–Under involuntary control
–Found only in the heart
–Function is to pump blood
–Characteristics of cardiac muscle cells
•Striated
•One nucleus per cell
•Cells are attached to other cardiac muscle cells at intercalated disks
•Smooth muscle
–Under involuntary muscle
–Found in walls of hollow organs such as stomach, uterus, and blood vessels
–Characteristics of smooth muscle cells
•No visible striations
•One nucleus per cell
•Spindle-shaped cells
•Composed of neurons and nerve support cells
•Function is to send impulses to other areas of the body
–Irritability
–Conductivity
•Support cells called neuroglia insulate, protect, and support neurons
exocytosis
the process by which the contents of a cell vacuole are released to the exterior thru fusion of teh vacuole membrane with the cell membrane
endocytosis
the taking in of matter by a living cell by the invagination of its membrane to form a vacuole
phagocytosis
the ingestion of bacteria or other material by phagocytes and amoeboid protozoans
