Anatomy: Cytology and Microscopy

Anatomy and Histology

• Cytology pertains to how a cell is organized.
• Histology pertains to how cells are organized in tissues.
• Slide 8 contains 2 nuclei.
• Light DNA, which is loose and not compact, allows enzymes to produce proteins.
• Dark DNA, which is compact, prevents the cell from working.

Microscopes

• The optical microscope is used to observe the organization of tissues in organs.
• The electronic microscope is used to view the organization of the cell, including the nucleus, plasma membrane, and organelles.
• The use of fluorescent molecules that recognize proteins through antibodies is used in fluorescence microscopy.

Elements of a Microscope

• The stand is the body of the microscope.
• Oculars are eyepieces.
• Objectives contain the magnifying lenses.
• The mobile stage holds the slide on which the histological material is placed.
• Light is a component.
• The coarse focus knob moves the mobile stage, while the fine focus knob adjusts the clarity of the histological preparation.

Cytology

• Cytology studies the characteristics of cells, including morphology and function.
• Cells are mostly water, with ions, mineral salts, and organic molecules dissolved in the cytoplasm.

Organic Molecules

• Organic molecules are made up of O/N/H/C.
• Carbohydrates, proteins, lipids, and nucleic acids are examples.
• Carbohydrates, also known as sugars or glucides, have structural and energy functions, specifically within the plasma membrane.
• Simple carbohydrates are monosaccharides like glucose.
• Oligosaccharides contain only a few monosaccharides.
• Polysaccharides, like glycogen, are cleaved to produce energy.
• The monomer in glycogen contains glucose present in the cell.
• They associate in chains within cell membranes to stabilize them or impart a specific function.

Lipids

• Lipids are made up of chains of fatty acids, forming polymers of fatty acids.
• They have structural and energetic functions, with adipocytes storing and releasing lipids in large quantities as triglycerides.
• Triglycerides consist of 3 fatty acid chains and one glycerol chain.
• Phospholipids consist of 2 fatty acid chains, a phosphate group, glycerol, and a variable molecule, with a hydrophobic tail formed by fatty acids and a hydrophilic head.

Amino Acids

• Amino acids are monomers of proteins which constitute complex molecules.
• They are acquired through diet and assembled within the organism.
• They consist of an amino group (NH2), a carboxyl group, and a variable molecule determining whether the amino acid is polar or nonpolar.
• Peptide bonds link amino acids, leading to protein polymerization.
• Peptide bonds happen through a reaction between the carboxyl group of one amino acid and the amino group of another,.
• It forms a covalent bond; a condensation reaction occurs, releasing water and requiring energy.

Protein Structure

• The primary structure does not have a mature conformation and is simply the amino acid sequence.
• The secondary structure involves bonds between distant amino acids in the chain.
• The tertiary structure is three-dimensional, mature, and functional, with bonds between distant amino acids.
• The quaternary structure involves multiple proteins.

Nucleic Acids

• Nucleic acids are made up of nucleotides or monomers.
• Nucleotides consist of a pentose sugar, a nitrogenous base, and a phosphate group.
• Nitrogenous bases are either purines (A/G) or pyrimidines (C/T/U).
• DNA is a double helix of nucleotides with deoxyribonucleic sugar.
• A-T/G-C alterations can lead to genetic mutations.
• DNA production occurs when the cell duplicates, creating the possibility of continuous errors.
• RNA is produced from a strand of DNA using ribose sugar and nitrogenous bases like A-U/G-C.

Vitamins

• Vitamins are biological macromolecules acquired through diet.
• They act as cofactors for intracellular chemical reactions.
• Vitamin A, found in red/orange fruits and vegetables, is transported to ITO cells in the liver, modified into retinal, released into the bloodstream, and converted into a chemical signal in the retinal epithelium that is composed of cones and rods.

Eukaryotic Cells

• Eukaryotic cells are confined by the plasma membrane, which connecting them to the extracellular environment.
• The cytoplasm contains all cellular organelles.
• The cell duplicates, nourishes itself, respires, grows, can move, and responds to external stimuli.

Organelles

• Membranous organelles have membranes similar to that of the cell, including the endoplasmic reticulum.
• They preside over protein production and lipid metabolism, the Golgi apparatus presides over protein modifications, lysosomes degrade macromolecules and particles from the exterior, peroxisomes degrade lipids, mitochondria produce energy, and the nucleus stores genetic material.
• Non-membranous organelles include ribosomes that preside over protein production, the cytoskeleton composed of various proteins that form scaffolding for cells, and proteasomes that degrade proteins.

Plasma Membrane

• Plasma membrane is a semipermeable barrier with selective permeability, allowing only certain substances to pass based on size, chemical characteristics, and concentration gradients.
• This ensures optimal working conditions for the cell, maintains equilibrium (homeostasis), connects cells via molecules or junctions and is guaranteed by molecule-mediated junctions.

Membrane Structure

• Lipid components are made of phospholipids in a bilayer formation that is hydrophobic in the core and hydrophilic externally towards the cytoplasm.
• Protein components include integral/intrinsic and extrinsic membrane proteins.
• Integrals, when incorporated within the phospholipid bilayer, span from one side to the other.
• Extrinsic proteins are positioned above the layer or towards the cytoplasm.
• Glucidic components bind to membrane proteins or lipids on the external to form glycoproteins or glycolipids, respectively. They create a trilaminar structure with two external electron-dense and hydrophilic layers, and one internal electron-transparent and hydrophobic layer.
• Integral membrane proteins share lipid priority, featuring a hydrophobic interior and hydrophilic exterior, traversing the membrane multiple times.
• Extrinsic proteins do not traverse the membrane.
• Transmembrane proteins exchange ions, like ionic pumps.
• Amino acids use channel proteins to pass down the gradient without energy, and carrier proteins to travel against the gradient.

Membrane Proteins

• Membrane proteins can also be linker proteins that ensure cell attachment to the extracellular environment and create junctions that maintain contact and facilitate substance passage.
• Transport across the membrane is selective, which occurs according to chemical properties, size, and electrical charge, and is defined by an electrochemical gradient.

Gradient-based Transport

• Down the gradient, from high to low concentration, includes diffusion and requires no energy.
• Simple diffusion facilitates small molecules and/or hydrophobic substances like lipids, as well as ions.
• Facilitated diffusion is for larger, non-hydrophobic molecules and involves integral membrane proteins as channels or carriers.
• Channels span the entire membrane, and carriers open a gap for molecules to enter.
• Against the electrochemical gradient, from low to high, requires energy and complex transporters with an ATP binding site to transport molecules.
• Uniport transports 1 molecule at a time.
• Simport transports + molecules from inside to outside, or vice versa.
• Antiport transports one molecule outside and one inside.

Vesicle-mediated Transport

• Transport of large substances that cannot pass through transporters: mediated by vesicles.
• In exocytosis, a substance stored in a membrane-coated vesicle moves towards the plasma membrane, fuses with it, and releases the substance outside, stimulated by hormones or nerve stimuli.
• In endocytosis, substances move from the exterior to the interior; immune cells eliminate pathogens through invaginations that form vesicles, which then fuse with digestive enzyme-coated organelles to digest exogenous particles ingested by macrophages.
• Membrane specializations are structures on the plasma membrane that characterize specific cell functions and are distinguished based on their position: apical, lateral or basal.
• Apical specializations face the extracellular environment and include microvilli, cilia, flagella, and the glycocalyx.
• Lateral specializations are on the contact surface between cells and are junctions.
• Basal specializations connect epithelial cells with underlying tissues.

Apical Specializations

• Microvilli are short extensions of the plasma membrane that show an internal skeleton of actin-cytoskeletal protein-actin anchored to other actin filaments and filamentous thicker-intermediate/plus microvilli/absorbs nutrients.
• Glycocalyx includes sugars binding to proteins/ lipids in the membrane that is helpful in assisting in the process of absorbing nutrients with enterocytes

Cilia and Flagella

• Cilia = protusion and 2x longer than microvilli.
• Cilia are mobile undulating motion, ex trachae help push muco to oral cavity.
• Uterine tubes move ovulated egg to w uterus
• Display internal skeleton of filaments in microtubules & assonema
• If dyein is missing it can lead to issues in breathing and other health concerns

Stereocilia

• Located in the inner ear/epididymis
• Consisting of immobility actin
• Laterali (junctions): structure with protein in plasma membrane
• occluding mediano = cells unite in the cell beneath apical surfaces -maintaining the polarity of a cell

Cell Nucleus

• Has patterns of genetic
• Replication
• Production of RNA
• Some have + of 1 nucleus- striate muscle (skeletal muscke) sincizi
• Other = cell will dup DNA withtout splitting (Megacariociti)
• Cell without nuclei the eritrociti = lose the nucleus during maturation.

Organule

• Membrane has double membrane liscia internal, rugged ext
• Nucleoskeleton matrix help impalcatora du nucleus- influencing compattarsi
• Cromatina : structure that help find DNA in manera

Nucleolus Structure

• Nucleoli that help find RNA in DNA and ribosomial
• Ribosomi in cytoplasm that has to do w sintesi protein= mRNA
• Libero: to velocate protein del citocell, cytoskell or mitochondria

Protein Sintesis

• Comincel nucleso transcrita --> synthesis mRNA partir dna
• Errore durante questo = alterazzione gene.
• Endoplasmic reticulum vicinanzo del nuclueso
• REL : metabolizzare dei lipidis and conserve ioni calcion ( + sviluppate nei cellule musculares

Modification Post

• Glicosillazine = sugar that modify proprie chemicale
• Abboldate by RER : tanto proteina - to be segregator

Golgi

• From sistrerna membrane to nuovo maturazione
• Diverse modificattion e
• Concentrazione to vesicles and golgi to differente postazione

Lisosoi

• Decompose de molecule ( degrader macromole cole) like macromolecules tumrover organuli substance esterm
• Enzyme = idrolitiche that attack molecule like glucidi lipi proteins
• Activia solo in acid ph

Per ossisomi

• Memb organuli coinvoti del metallum
• De compostine lipidi e riduce radicali libri ossidenon acido grassi lunga per produrred energi and catalisis
• The peroxided in attivo because of catalasi H in H2O and O2
• Mitoconder
  • Organlu de forma allungata due membrane internal e sterna
  • Matrice mitochondria codificare protein

Cytoschelletro

• Organulo constituete impalatura- sustain

• Actina

• Dimension - 7mm

• Mantiene form

• Microtubules

• 25nm - alpha e beta

• Filiamento INTERMEDi

• 10 NM

The Cell Membrane and Transport Mechanisms

• The plasma membrane is made up of a double layer of lipids.
• Proteins float within the lipid later and allows for the transport of water and inorganic molecules and some large water soluble organic molecules.
• These channel proteins allows certain molecules to flow in/out of the cell without any outside energy.

Key Cell Structures and Function

• Cilia: Minute hairlike structures that help to move mucous secretions and trapped dust.
• Microvilli: Aid in absorbing substances into the cell
• Tight junctions: Forms a leakproof seal bringing cells close together.
• Gap Junctions: Allows cells to directly communicate by allowing molecules to flow from cell to cell.

Tissues

• Epitelial cell are 3 1: Cell with not lots of mater 2: Cell that are polari and different funzioni 3: Capable cell dividere but with cell to stamminalita I: Epithelium di revestimento (stratified) II epillio glandulate I: Epitellal sensori

Membrane basale

• Support with epitelio 1: Fornisce support fisico to eptelilie 2: Regola pasagio de substanzi 3: supporto ALL RIGENERATIONS

Type of Layer of Epitelio

Cells in layer contatto of membrane basale I. PAVIMENTOOS IS Ii. Cibica (same alto con ampio) = with forma circolare nucleus III EPITheliate II . Pseudo stratificato III . Stratificate of cell of Superfice and some like cabatine = protegee epiteli

Test Connettive

with Lots of martx

• 3 componente

1. Matrix esternal that compostie from component fiberous
2. The SOSTENZA fonda mentale that composte aqua

3. The sell che carataterizzo Testo Connello

Tipes De Cellule With The Connection

1.Fibblast (procluce subtasnza nel test) 2. Cell MIGIRante or reclutatte (che richarmate ) Cell residente popolano Fiboblast

• Sintesti da tutte le proteina

Test connettive prop I test Conello Lasso

The Adoptions

The testo connettito to Sotto that prottege and epillileo is + fragile invinzzioni rughe collagen that familia. 1 al xviii

1. Iregollan

• I/ the lamina basale

2. Fibrilla regolate 4/ abondan te testo cono connettive fil oblasto

• Fibbricolati a tipi iiii tanteez +zuccheri nel interna deorgani linfordi I) Fiber ellastiche e test of tensile

2. Test cooel lasso with FIB Scar ce II" ( test connettivoso lasso) cavita orageni cavo prevde ce sial eilline in questo connel l

II) TEst CO Connettiva Dense = colozazione

• intense III, Tessutto Adiposa: che trasforami le lipi sotto stimolazione nell interno dei circilo sanguine E . Testo Adspodr Bumo= tantis mitochondria che fa

Test to cartilagine With 3 i. IAlina 2. Elastica piu elastica sin trova

Tessoo osseo

to consituisc le ossa I: Proezonieorganide

• Cellulle dei Test o Oseo *

a. Depositano matrice che dirivano messichinale b. che riiasorbano atrici o e del a e

Osteocasti

cell capacita muoversi nell superficie dell osseo er asorbire matrice il e eriva al saguee 1- I OSEBLASTI INvecchiao Diveno Osteociti (sono capaci di MANTENERE CONTATTO FRA Loro,

per via de microcanalli with protesione del cell.a di 2) regolate dal ormone

Osteo ClaSTti

• 1 . Celllle gorse capacita di movesi

I) Peria Ostea (support esterno ) ED endo ostea (il support inteerno)

Testo OSSEO a) E organizate con lamelle

• ORGANIZZATO CON LAMelle *

1. OSSEO COMPATTO NEI REG Superf. del OSSEO with Parte estera RIvesto dal perioteiio 2- OSSSO sputnose internee all osseoooo

COMPATTO

a sist HAversiana CON osteomiii a-) fibrocati sostena fundamentale CHE

• LANANETTI SONO ORIENTAT IN DIVVERSAE ZDIEE *

B) TRA oste e E AlTO CANNelli

a- TESTO MII E con sistema

• 2. CANNelli 3} TEST OSSE A FORAM CA CON MIDODO (

4. with gelatinoso 5,) with il Midddolo Ossreo Gialllos -adiptocidi

Testuto Sangue

Testo CONNETTIVOS Specizzaito a- Componenze cell e extre B . cell sono liti Tocoiti Troombociitiy e +

COMP Cellule

iiii, Eritrovti = volume de cellulle iii, Ematocritoo = al quantita cell in sanghe

iv,, Componesni de globuli bianchii with plasma

• 2.1 PLASMA PROTEine

Testo Cell stamili Empitoetiche

Cell

1: Steminalte to e in cell emattooo petikei

2. Linfocitive = perde steminalita

I TEsso musu larr

I.

1, Mussa colari che e volontrra ii1: With conrtrazione intensa ii: Test con colume with cell con + cell = sincizi

• Con proteine muscolare che fascomeee
• 2 mitocondori per proctilire atp

II: Cardico

A. Cellula one ucentrale with Certa bandee B Non ha cell Satelliiti

III,Liscio con

CELL AFFUSAOT CON CELL O Oganlli A. With cell conttati = proteime contratto

• With sinpasi e
• NEURONS WITH PROLUNGATTI
• NEURO GLIA COM NON CONGUCIBIS

Cell supporto neruono"

1: Astroo teti (proteina con capillares) barriento 2> CELL MINOGILIA 3 . (0) PANGUIMA 1I L1U1OR 6 Cell di schan

NEI nerii i NEivvo che with guaiiina connettivie II Guaine Connette va I ASSOIN ii AMIELLINTEO WITH SHA iii a) Cell die Sh ii) cell a