Week 2 - how do cells do what they do? Flashcards
intracellular
the space or fluid inside a cell, within the cell membrane
extracellular
the space or fluid outside a cell, outside the cell membrane
cytoplasm
the area and contents of a cell located within the membrane but outside the nucleus
organelle
a small, specialised intracellular unit with a specific function
nucleus
an organelle containing the cell’s DNA or genetic material
endoplasmic reticulum
a membranous organelle, rough if ribosomes, smooth if no ribosomes
epithelial cell
primary tissue type found lining ducts and tubes, and also lining the entire outside of the body
stratified
when epithelial cells are comprised of more than one layer
cuboidal
epithelial cells in a square shape, often with a round nucleus
columnar
epithelial cells in a tall rectangular shape, often with an oval shape nucleus
transitional
epithelial cells found only in the urinary system, allow for stretch depending on the volume of urine present
photomicrograph
a photo taken through a microscope, in order to visualise very small cells or tissues at high magnification
microvilli
small finger-like extensions off an epithelial cell membrane, increase surface area
adipose tissue
fatty tissue containing adipoctyes (fat cells)
What are the four functional characteristics of cells?
- energy use
- cell metabolism
- synthesis of molecules
- communication
- reproduction and inheritance
What are the functions of the plasma membrane?
controls the substances that move in and out of the cell membrane, it also supports cell flexibility
What are the components of the plasma membrane and their percentages?
phosopholipid bi-layer: hydrophilic phosphorous heads and hydrophobic lipid tails (45-55%), carbohydrates (4-8%) and proteins (45-55%)
What are the roles of proteins in the plasma membrane?
proteins act as receptors on the cell
What is the glycocalyx?
the glycocalyx consists of gylcoproteins and glycolipids. It forms the outer structure of the cell membrane.
What does the glycocalyx consist of?
Glycoproteins and glycolipids
What is the cytoplasm? What does it contain?
the cytoplasm is the cellular fluid material outside the nucleus but inside the plasma membrane. It includes organelles of the cell
What is cytosol? What are the two parts?
Cytosol consists of cytoplasmic inclusions (chemicals)_ and the cytoskeleton (supports the cell and is also involved in movement)
What is the role of cytoskeleton?
supports the cell and is involved in movement
What are the three parts of cytoskeleton?
microtubules, microfilaments, intermediate filaments
What is the function of the nucleus?
control centre of the cell, contains genetic material
What is the structure of the nucleus?
- nuclear envelope: bi-layer
- nucleoplasm
- nucleolus: produces ribosomes
Where are ribosomes found? What is their function?
ribosomes are found freely floating around in the cytoplasm of the cell, as well as attached to the rough ER
What is the function of ribosomes?
protein synthesis
What is the structure of ER?
flattened, interconnecting tubules and sacs
What is the difference between smooth and rough ER?
rough = ribosomes smooth = no ribosomes
What is the structure of the Golgi apparatus?
flattened membronous sacs with cisternae
What is the function of the Golgi apparatus?
modifies, packages and distributes proteins and lipids
What is the structure of lysosomes and where are they found?
lysosomes contain digestive enzymes which digest cell debris and microorganisms from inside the cell, form at the Golgi apparatus
What is the function of lysosomes?
digest molecules and debris that is no longer needed by the cell
What is the structure of mitochondria?
outer membrane, inner membrane space, inner membrane, with a matrix
What is the function of mitochondria?
synthesis of ATP (energy source of cells)
What is the structure of centrioles?
barrel-shaped organelles at right angles to each other.
What is the function of centrioles?
involved in cell division
What is the structure of cilia?
whip-like motile cellular extensions that project from th outer surface of cells
What is the function of cilia? Ie where are they found.
movement of substances across the surface of a cell: respiratory tract, fallopian tubes
What is the structure of flagella? Where are they found?
similar to cilia, but longer. Found on human sperm cells
What is the function of flagella?
motility of cell
What is the structure of microvilli? Where are they found?
extensions of the plasma membrane
What is the function of microvilli?
non-motile, increases the surface area of the cell
What is histology?
study of tissue and its micro anatomy
What is the difference between a biopsy and autopsy?
biopsy: performed on a living specimen
autopsy: performed on a dead specimen
What is the purpose of fixating a tissue sample?
to keep it in place on the microscope
What is haemotocylin and eosin? What are the different colours they stain?
Tissue stains. Haemotocylin stains the nucleus purple, whereas eosin stains the cytoplasm blue.
What are the four types of primary tissue and their basic functions?
epithelial: to cover
connective: to support
muscle: to move
nervous: to control
What are the characteristics of epithelial tissue?
- conducts and protects
- covers and lines
- avascular
- innvervated and can be regenerated
What are the cell surfaces of epithelial tissue?
free surface, lateral surface, basal surface
What are the classifications of epithelial tissue based on cell layers?
simple, stratified, pseudo stratified
What are the classifications of epithelial tissue based on cell shapes?
squamous , cuboidal, columnar, transitional
What is simple epithelial tissue?
one layer
What is stratified epithelial tissue?
more than one layer
What is psyeudostratified epithelial tissue?
looks like more than one layer, bit is only one layer
What is squamous epithelial tissue?
flat-shaped cells
What is cuboidal epithelial tissue?
cube-shaped cells, large round nucleus
What is columnar epithelial tissue?
tall, narrow cells with nucleus towards the bottom of the cell
What is transitional epithelial tissue?
can change shape depending on whether the tissue is stretched or loose (bladder)
What is the function and structure of simple squamous epithelium?
- single layer and flat
- diffusion: alveoli; filtration: kidney glomeruli
Where is simple squamous epithelium found?
alveoli and kidney glomeruli
What is the function and structure of simple cuboidal epithelium?
- single layer and tall
- absorption: kidney tubules; movement with cilia: terminal bronchioles
Where is simple cuboidal epithelium found?
kidney tubules, terminal bronchioles
What is the function and structure of simple columnar epithelium?
- single layers and tall with round nuclei
- absorption: small intestines; secretions: stomach; movement: lungs and fallopian tubes
Where is simple columnar epithelium found?
small intestines, stomach, lungs, fallopian tubes
What is the function and structure of transitional epithelium?
- resembles either stratified squamous or cuboidal
- accomdates the change in fluid volume: urinary bladder, ureter, upper urethra
Where is transitional epithelium found?
urinary bladder, ureter, upper urethra
What is the function and structure of stratified squamous epithelium?
- basal cells are cuboidal/columnar and become squamous towards the surface
- keratinised to protect and water-proof
- keratinised: sole of foot, palm of hands
- non-keratinised: mouth, oesophagus, anus, vagina
Where is stratified squamous epithelium found?
- keratinised: sole of foot, palm of hands
- non-keratinised: mouth, oesophagus, anus, vagina
What is the function and structure of stratified cuboidal epithelium?
- rare, limited distribution
- absorption, secretion, protection: ducts of sweat glands, ducts of salivary glands, developing ovum
Where is stratified cuboidal epithelium found?
ducts of sweat glands, ducts of salivary glands, developing ovum
What is the function and structure of stratified columnar epithelium?
- rare
- secretion and protection: ducts of mammary glands, larynx, part of male urethra
Where is stratified columnar epithelium found?
ducts of mammary glands, larynx, part of male urethra
What is the structure and function of pseudostratified columnar epithelium?
- single layer, differing heights, ciliated
- movement: pharynx, trachea; secretion: sperm-carrying ducts
Where is pseudostratified columnar epithelium found?
pharynx, trachae, sperm-carrying ducts
What is the function of connective tissue?
connects, binds, strengthens, protects, insulates, compartmentalizes, transports, provides energy
What is the composition of connective tissue?
cells produce ECM (adipose, mast cells, fibroblasts, white blood cells, macriphages), ground substances and fibres (extracellular matrix)
What is the ground substance of connective tissue?
fills the spaces between the cells of connective tissue , and is also the space where fibres are suspended
What are the fibres of connective tissue?
collagen, elastic, reticular
What are the classes of connective tissue?
CT proper, cartilage, bone, blood
What are the two types of connective tissue proper?
dense and loose
What are the classes of dense connective tissue proper?
- regular (attachments, ie tendons and ligaments)
- irregular (strength and stretching, dermis, fibrous coverings)
- elastic (high recoil and strength, artery walls, ligaments)
What are the classes of loose connective tissue proper?
- areolar (loose packing, support and binding, widely distributed in the skin)
- adipose (nutrient-storing, shock absorption, insulation)
- reticular (framework to support free blood cells, lymph nodes, spleen, bone marrow)
What are the functions and locations of areolar connective tissue?
loose packing, support, binding, widely distributed in skin
What are the functions and locations of adipose connective tissue?
nutrient-storing, shock absorption, insulation
What are the functions and locations of reticular connective tissue?
framework to support free blood cells, inlcudes lymph nodes, spleen, bone marrow
What are the functions and locations of regular connective tissue?
attachments, tendons and ligaments
What are the functions and locations of irregular connective tissue?
strength and stretching, dermis, fibrous coverings
What are the functions and locations of elastic connective tissue?
high recoil and strength, walls of arteries and ligaments
What are the characteristics of cartilage?
made of cartilage cells within a rigid matrix, avascular but not innvervated
What is function of cartilage?
protection, flexibility and rigidity, capable of withstanding pressure
What are the types of cartilage and their locations?
hyaline: rib cage, trachea, articulating surfaces of bones, nose
fibrocartilage: invertebral disc and pubic symphysis
elastic: ear and epiglottis
What are the functions of bone?
supports and protects body structures, composed of cells and matrix,
What are the two types of bone and their characteristics?
spongy bone: ends of long bones, sternum, vertebrae,, pelvis
compact: shaft of long bones, outer portion of all bones
What is the function of blood?
transports wastes, nutrients and gases around the body
What is blood comprised of?
red blood cells (erythrocytes), white blood cells (leucocytes) and platelets (involved in blood clotting)
What are the characteristics of muscle tissue?
highly cellular, well vascularised, responsible for body movement
What are the types of muscle tissue?
skeletal, smooth, cardiac
What are the characteristics and locations of skeletal muscle?
attach to bones, striated, multi-nucleated, mainly under voluntary control
What are the characteristics and locations of cardiac muscle?
walls of heart, responsible for pumping blood around the body, striated with intercalated discs, involuntary
What are the characteristics and locations of smooth muscle?
walls of hollow organs, no striations, one nucleus per cell, involuntary control
What does the nervous system comprise of?
brain, spinal cord, nerves
What are neuroglia?
support cells in the nervous system
What are the components of a neuron?
dendrite, axon, axon terminal, myelin sheath, cell body
What are the five cell types of connective tissue?
adipose, mast, white blood cells, fibroblasts, macrophages
