Cells Structures and their Functions Flashcards
basic structures/ units of living organisms.
Cell
Cell is a mass of __________ enclosed within a membrane and containing nucleus.
protoplasm
all cells arise only by ________ of pre- existing cell
division
Most Cells have a nucleus – a structure in their centre that contain genetic data, or _______________.
Deoxyribonucleic Acid. (DNA)
Cells rely on this _______ to build various molecules that are essential to life.
data
Organelles are held in the _________, the space between the nucleus and the cell membrane.
cytoplasm
Molecules are _________ the cell and others are ___________ just like in an efficient factory.
brought into
shipped out
This instructions are exported on long
molecules called messenger ribonucleic acid (mRNA). These molecules travel out o the nucleus and
into the cytoplasm.
Receiving Instructions (Nucleus)
The mRNA travels on an organelles attached
to the nucleus called the rough endoplasmic
reticulum. Protein molecule
Manufacture
The proteins travel in vesicles. They float to the cytoplasm to the golgi body.
Packaging
The mRNA travels on an organelles attached
to the nucleus called the rough endoplasmic
reticulum. Protein molecule
Shipping
is the cells command centre, containing
blueprints in the form of DNA
Nucleus
Produces and processes fats and some hormones.
Smooth Endoplasmic Reticulum
The organization points for microtubules. Structures that helps separate DNA during
cell division.
Centrosomes
containers that transport materials from the cell membrane to the interior and vise versa.
Vesicles
acts as a cell’s clean up crew. They contain chemicals used to get rid of unwanted molecules.
Lysosomes
the space between organelles- is filled with
microtubules.
Cytoplasm
powerhouses of the cells - where most of the cell’s supply of chemical
energy is generated
Mitochondria
Helps to make protein
Ribosome
a group of organism whose cells have defined a nucleus surrounded by nuclear membrane.
Eukaryotes
Eukaryotes is a primary component of multicellular organism.
Animal Cell
- Cells have no nuclear membrane and no distinct nucleus
- Mainly bacteria and blue-green algae
Prokaryotes
- Separates the cells from the external environment
- Regulates the transport materials in and out the cells.
-made of two layers of phospholipid (bilayer)
Cell Membrane
Cell Membrane has many ________ embedded in it.
protein
effective seal
between the cell or organelle’s
internal and external environment.
Selective Permeability
cells engulf extracellular
substances and bring them into the cytoplasm in membrane limited vesicles.
Endocytosis
“cell-eating”,engulfs insoluble extracellular substances.
Phagocytosis
“cell-drinking”, engulfs small amounts of intracellular fluid.
Pinocytosis
mediated endocytosis
Receptor
removes substance from
the cell; process used for both secretion and excretion of digestive materials.
Exocytosis
selective inhibit
the passage of the most water- soluble substances
Compartmentalization
Storage, transport and _________.
secretion
- control center
appears as rounded or elongated structures. The reservoir of DNA and carries most of if its genetic information. - controls cellular activity bt regulating RNA synthesis, which regulated proteins synthesis
Nucleus
Major nucleus component. Made of coiled DNA which is bound to basic
proteins called histones.
Chromatin
inactivated X-chromosome in the
nuclei of female cells.
Barr Body
Loosely packed and light staining
Represents active genetic materials
Euchromatin (dispersed)
Tightly packed
Dark staining because of unused genetic materials in storage
Heterochromatin (condensed)
- site for ribosomal RNA synthesis
- Deep staining basophilic area
- Composed of granules, fibrils and chromatin
Nucleolus
a semifluid, colloidal solution
in which the chromatin materials and the nucleolus are suspended.
Nucleoplasm
double membrane, maintains a separate milieu between the nucleoplasm and cytoplasm.
Nuclear envelope
vary in size, have a slit-like diaphragm that regulates what enters and leaves the nucleus.
Nuclear Pores
Nucleolus are what type of gatekeepers.
Protein gatekeepers
- Gel like substance enclosed within the cell
membrane - 70 to 90% water and usually colorless
Cytoplasm
- Little organs
- Usually membrane-bound
- Structures inside the cells that have specific
functions - Major organelles like mitochondria,
ribosomes, golgi bodies, etc.
Organlles
Non-Membrane Bound Organelles
- Ribosomes
- Microfilaments
- Microtubules
- Intermediate filaments
- Junctions
- Centrosomes
structures that are generally more transient than organelles and less actively involved in cell metabolism
CytoplasmicInclusions
Includes secretory inclusions (enzymes,
acids, proteins), nutritive inclusions (glycogen granules, lipid droplets), and pigment granule (melanin, lipofuscin, hemosiderin).
CytoplasmicInclusions
Provides structural stability for the maintenance of cell shape.
Cytoskeleton
- Network of flatted sacs and branching
tubules. - Involved in the synthesis, packaging, and processing of various cell subtances.
Endoplasmic Reticulum
- Granular, ribosomes are attached to the
other surface of the RER - Synthesis of protein
- Proteins are modified as they move through
RER
Rough Endoplasmic Reticulum
- Network of tubular membrane structures
- Continuous with RER
- No ribosomes attached to the surface
- Involved in lipid synthesis
- In muscle cells, the SER assist in the control
of muscle contraction - In liver cells, the SER detoxifies medications
and alcohol
Smooth Endoplasmic Reticulum
- is the microscopic study of the normal tissues of the body
- Study of the relationship of between cell structure and function
Histology
is the study of changes in the microscopic structures of tissues.
Histopathology
The organs in your body are composed of four basic types of tissue, including:
Epithelial
Connective
Muscular
Nervous
All substances that enter or leave an organ must cross the ___________ first.
epithelial tissue
Cover body surfaces and line the cavities of
hollow organs, tubes of the body, and cover
internal organs.
Epithelial Tissue
Epithelial Tissue May develop from?
ectoderm, mesoderm, or endoderm.
very cellular and compact
Epithelial cells
body substance in which the tissue cells are embedded; binds the epithelial cells together.
Intercellular cementing substance
True or False. One of the components of Epithelial tissues is it is large amount only.
False. Small amount only.
General Characteristics of Epithelial tissue.
- Most cellular tissue
- Form cheers or coverings
- Avascular- no blood vessels
- Wetormoist
- Form clumps or masses
- Attached to one another by cell junctions
Functions of Epithelium
- Protection
- Absorption
- Secretion
- Sensoryreception
- Excretion
- Lubrication
- all epithelial cells are attached to this
- Separates the epithelial tissue from
underlying connective tissue - Provides structural support for the epithelium
and binds it to neighboring structures
Basement membrane
The thin layer of loose connective tissue
immediately beneath the epithelium; underlying the basement membrane.
Lamina Propia
- Consist of multiprotein complexes
- Attachment on lateral surfaces of epithelial
cells - Epithelium forms continuous cohesive layer
Intercellular surfaces Cell junctions
(Membrane Specialization of) Epithelia
Functions:
- Holds together
- Cell junctions
(Membrane Specialization of) Consist of ___________ complexes
multi-protein
(Membrane Specialization of) Attachment on ________ of epithelial
cells
lateral surfaces
(Membrane Specialization of) Epithelium forms continuous ___________
cohesive layer
hemi desmosomes and desmosome (macula adherens); hold cell together to prevent lateral tearing of tissues and provide mechanical attachment
Adhering Junctions (zonula adherens)
impermeable junctions; most apical junction; principal function is to form seal that prevents the flow of materials between epithelial cells in either way.
Tight Junctions (zonulae occludens)
mediate intercellular communication, permit passage of substances between adjacent cells
Gap/Communicating Junctions
Gap/Communicating Junctions can occur almost anywhere along lateral membranes of most epithelial cells and present in?
nerves, heart muscles, smooth muscle (intestines), and epithelia
- minute finger-like extensions or
folds, about 0.5-1 micrometer high and 0.08 micrometer wide. - increase the cell surface area available for absorption.
- Brush border appearance
Luminal/Apical Surfaces
a. Microvilli
- elongated, motile structures, about 5- 10 micrometres long and 0.2 micrometres in diameter.
- have a rapid back and fort movement that is frequently coordinated propelling surface films of mucus and fluid.
Luminal/Apical Surfaces b. Cilia
- long, nonmotile process of cells of the epididymis and vas deferens, hair cells of the inner ear.
- Increase the cell surface area and facilitate the movement of molecules into the out of the cell.
Luminal/Apical Surfaces
c. Stereocilia
single layer
a. Lining/covering epithelium
Simple
single layer of flattened
cells with bulge where nucleus is located, cytoplasm is very thin and touch to see.
Simple Squamous
single layer of square or round cells, 3D are approximately equal, giving the cells a cube- like appearance
Simple Cuboidal
- Consists of cells whose length is several times their width.
- May vary tall and slender, standing upright like columns, all oval nuclei approximately at the same level.
- Can be found in your stomach
Simple Columnar
- ciliated with
goblet cell. - Can be found in respiratory track from nasal cavity to bronchi.
- The mucus secreted by the goblet cells traps the dust bacteria.
Pseudostratified columnar
Pseudostratified columnar - the cilia “sweep” the _________ up the respiratory tract towards the pharynx where it can be swallowed.
bacteria- laden mucus
two or more layers
Stratified
also called dry epithelium (Epidermis, palm skin, and soles of feet)- protection against mechanical abrasion water loss and pathogen entry.
Keratinized
also known as wet
epithelium ( Esophagus, lining of oral cavity, surface of the tongue, lining of esophagus, lining of vagina, and anal canal)- protects from mechanical abrasion
Non-Keratinized
Non-Keratinized due to?
eating food, swallowing, sexual intercourse, birth and defecation
Transitional Epithelium is also called as
Uroepithelium
lines in the urinary bladder, ureter and the upper part of urethra. Surface cells are rounder and often bulge above the surface (dome-shaped)
Transitional Epithelium
two or more layers
Neuroepithelium/ Sensory
each has long slender microvilli (taste hair) that protrude from the taste pore.
Taste buds
Auditory hair cells in the organ of?
corti-internal ear (for hearing)
Photoreceptors - ______
Olfactory epithelium
(olfactory sensory neurons) - __________
eye
nasal cavity
According to the number of secretory cells
Glandular/Pyramidal Epithelium
Unicellular - ___________ Multicellular glands
goblet cells
secretory products delivered thru a system ducts.
Exocrine
contains secretory cell
Secretory Portion
Secretory Portion that are thin, watery
Serous cells
Secretory Portion that are thick secretion
Mucous cells
ductless glands, release their products into the blood or lymph (hormones)
Endocrine
Examples of Exocirne
Sweat glands, salivary, mammary and sebaceous.
Example of Endocrine
Thyroid glands, adrenal, pituitary.
watery secretion (pancreas, parotid salivary gland)
Serous glands
intermediate
(submandibular salivary gland, sublingual gland)
Muco-serous/mixed glands
thick or viscid secretion
(goblet cells, sebaceous, deep esophageal and duodenal gland).
Mucous glands
Duct that is unbranched (tubular, branches tubular, coiled tubular and branched alveolar
Simple
Duct is branched (tubular or alveolar)
Compound
Secretory portion that is straight
Tubular
Secretory portion that is roughly spherical
Acinar
Secretory portion that is Intestinal gland
Simple tubular glands
Secretory portion that is sweat glands
Coiled- tubular glands
Secretory portion that is mammary gland
Compound acinar gland
Secretory portion that is salivary gland
Compound tubuloacinar gland
largest, pure serous, located nearaers and ascendingbranch of lower jaw.
Parotid glands
Duct is called ________ which opensin the rear of the mouth near the upper second molar.
Stensen’s duct
mixed secretion, but no more serous. Located along theside of the lower jaw bone.
Submaxillary/Submandibularglands
__________ opens into the floor of the mouth.
Wharton’s duct
mixedsecretion,mainly mucous
Sublingual glands
Located beneath the mucous membrane of the floor of the mouth bear the chin region. The duct is ___________ which consist of 8- 20smaller ducts called Rivinus’ Ducts
Bartholin’s duct
clear, lightly-stained , with the characteristics moth-eaten appearance or fine lace-like pattern
Cytoplasm
flattened towards against the base
Nucleus
darkly stained, it appears granular
Cytoplasm
rounded, located near the base
Nucleus
pure serous both exocrine and endocrine glands
Cells are pyramidal in shape.
Pancreas