Module 1 Flashcards
Recall the basics of cell structure and function
There is a cell plasma membrane that acts as a barrier, inside is the cytoskeleton that holds things in place, there is cytoplasma (fluid inside cell) there are different organelles that function to keep things working, nucleus that holds DNA.
Describe the plasma membrane in detail
Maintain cell shape, protects, contain receptors that activate the cell, plays a role in transport in and out of the cell, and defines cell boundaries. There is a phospholipid belayer that prevents most water-soluble molecules from entering the cells. Allows oxygen and carbon dioxide to diffuse into the cell.
What role do proteins play in the cell membrane?
Proteins serve as cell receptors, enzymes, transporters, and transport channels. Membrane function is largely determined by proteins. Proteins can serve as cell surface markers that identify the cell to other cells.
Describe cell to cell adhesions:
Cell to cell adhesions is how groups of cells are held together to form tissues and organs
Extracellular matrix- mesh and fibers that fill the spaces between cells. Substances such as collagen, elastin, and fibronectin can form the matrix.
Cell adhesions molecules- proteins that help cells stick to each other
Specialized cell junctions- structures that occur at points of contact between neighboring cells, allowing them o shear to each other
Describe the primary mode of cellular communication and signal transduction
Cellular communication-remote, contact by plasma membrane, and gap junction
Chemical Signal transduction:
Contact dependent- membrane signal molecules
Paracrine- secreting cell targets a different kind of cell
Autocrine- secreting cell targets itself
Hormonal- hormone is release goes into the blood and targets a different kind of cell
Neurohormone secretion- secreting cell is a neuron goes into the blood and neurohormone targets a different cell
Neurotransmitter- nerve releases neurotransmitter and receptors on target cell receive
Describe passive transport
No energy transport of uncharged molecules through any semipermeable barrier. Different methods include- diffusion, hydrostatic pressure (filtration), and osmosis.
Diffusion- movement off a solute molecule from an area of greater solute concentration to an area of less solute concentration.
Hydrostatic Pressure-the mechanical force of water pushing against cellular membranes. Blood pressure at the capillaries is 25-30 mmmHG, sufficient to “filter” or push the water across the capillary membrane
Osmosis- movement of water down the concentration gradient
Active transport
Simultaneous movement of a single solute molecule in one direction (uniport ); of two different solute molecules in one direction (symport); and of two different solute molecules in opposite direction (antiport)
Passive medicated transport- also called facilitated diffusion (uses a carrier protein)- moving molecules through membranes without expending energy. Moving down a concentration gradiant
Active medicated transport- “active transport” the protein transporter moves molecules against or up the concentration gradient. Requires the used if energy (ATP).
Basics of cellular metabolism for ATP production
There are three phases of catabolism (energy releasing process) to produce ATP:
Phase 1 Digestion- large molecules are broken down into smaller subunits (proteins->amino acids->polysaccharides->simple sugar, fats->fatty acid and glycerol)
Phase 2 Glycolysis and oxidation- small molecules are further broken down (sugars become private while enters the mitochondria and becomes acetylene CoA; glycolysis occurs splitting of glucose to pyruvate which yeilds 2 atp per glucose + 2 pyruvate. Occurs through process of oxidation, or the removal and transfer of a pair of electrons.
Lack of oxygen leads to anaerobic metabolism and oxygen lead to aerobic metabolism.
Phase 3 Kreb’s Cycle- starts with Krebs cycle and ends with oxidative phosphorylation where 36 atp are formed
Discuss resting membrane potential
The major determination of the resting membrane potential is the ratio of intracellular K+ and extracellular Na+. The cell becomes more permeable and Ana cation potential is trigged by the rush of sodium ions into the cells.
What are the 4 major types of tissue?
Epithelial, connective, muscle, and neural
How is epithelial tissue formed?
Covers most internal and external surfaces of the body; formed from ectoderm, mesodermal, and endoderm
How is connective tissue formed?
Connective tissue is found in blood vessels, tendons, ligaments, organ structure; developed from the mesoderm layer of an embryo
How is muscle tissue formed?
Muscle tissue can be found in the (smooth) GI tract, uterus, bladder and other muscle tissue cardiac and skeletal; it is formed from the mesoderm
How is the neural tissue formed?
Neural tissue composes the neurons, receives and transmit electrical impulses across synapses. It is formed from the ectoderm following and inductive signal from the mesoderm.
Describe normal distribution of body fluid
Body fluids are distributed among functional compartments are classified as ICF or ECF. ECF includes intravascular fluid (plasma), interstitial fluid (think blood) and transcellular fluid. They body is 55-60% fluid, 2/3 being ICF and 1/3 being ECF
How does edema develop?
4 causes: increased capillary hydrostatic pressure, decreased plasma oncotic pressure, increased capillary membrane permeability, lymphatic obstruction
Capillary hydrostatic pressure isn’t eh same as blood pressure. Fluids goes out depending on hydrostatic pressure and is taken back in depending on oncotic pressure.
Filtration done by capillary hydrostatic pressure and interstitial oncotic pressure
Pulling fluid back into cells done through capillary oncotic pressure and interstitial hydrostatic pressure.
What is the function of normal sodium?
The body uses sodium to regulate fluid balance, maintain blood pressure, also vital in muscle and nerve work. Sodium balance is regulated by aldosterone, which increases reabsorption of sodium by the distal tubule of the kidney.
What is the function of Chloride and where is it found?
Chloride helps keep proper balance of fluids in the body. It is the most abundant extracellular ion and is primarily associated with sodium in the extracellular fluid. Cl-
What regulates water balance?
It is regulated by the sensation of thirst and antidiuretic hormone, which is initiated by an increase in plasma osmolality or a decrease in circulating blood volume.
Describe the RAAS system
Angiontensinogin is released from the liver and is in blood vessels, the kidney (juxtaglomerular cells) release reinin and this turns angiotensinogin into angiotensin I, lungs release ACE and turns into angiotensin II and causes vasoconstriction.
The RAAS is a negative feedback system that started with the release of renin by the juxtaglomerular cells in response to hypovolemia or hypotension. The end result is blood volume and increased blood pressure.
Acid-Base buffer balance
The renal and respiratory systems, carbonic-acid bicarbonate, protein and phosphate.
CO2+H20<—> H2CO3 <—> HCO3 +H
Respiratory Kidneys
Clinical manifestations of hypernatremia
Cerebral signs of hypernatremia include confusion, coma, and cerebral hemorrhage which is caused by water being pulled from within the cells in an attempt to balance out the high sodium in the extracellular space.
Describe the thirst drive in maintain water balance
A decrease in water stimulates the thirst drive and symptoms of thirst (dry mouth), osmoreceptors to then notify the hypothalamus. When the hypothalamus is aware of the low fluid in the body it will produce the thirst sensation. Hypothalamus then notifies the posterior pituitary to produce anti-diuretic hormone (ADH). This hormone allows the body to preserve the water in the body by decreasing urination and reabsorbing water in the body.
Distinguish endocytosis and exocytosis
Endocytosis- the enfolding or engulfing of substances outside the cell, that lead to that substance moving into the cell. Example: phagocytosis
Exocytosis- is the discharge of substances from vesicles on the cell surface (substances are coming form inside the cells). Example: the release of insulin
Discuss fluids, isotonic, hypertonic, hypotonic
isotonic- normal, no change in cell or fluid balance
Hypertonic (enter vessels)- to decrease intercellular volume and increase vascular volume, water particles will move out of the cell D10W, Albumin, 3% NS
Hypotonic (out of vessel)-water will move into the cells, to treat or prevent cellular dehydration1/2 NS
What is apoptosis?
Programmed cell death, involves an active process of cellular self-destruction that has a a role in normal and pathological tissue.
Autosomal Dominant trait
Disease is usually present in a parent, both sexes exhibit trait in equal proportions, no skipping generations, 50% chance
Autosomal Recessivie Disorder
Include most inborn errors of metabolism, onset is early in life, seen in siblings but not parents
25% chance
What is a codon?
Is a triplet of base pair of RNA (like UAG, GGG) that are necessary to code for a specific amino acid
Genes
Basic units of inhertiance
Gene Regulation
The process of turning genes on and off
Gene Variant (Mutation)
An alteration (permanent change) in the normal DNA sequence
New mutation-happens when neither parent has a particular gene and the child is affected
Mutagen- is a substance that increases the frequency of mutations
Gene Screenings
Noninvasive prenatal testing (NIPT)- determines the risk that a fetus will be born with certain genetic abnormalities
Newborn Screening- performed on all newborns in the USA shortly after birth to assess risk for genetic conditions
Direct-to-consumer genetic testing- provides people access to their genetic information without involving a healthcare provider. Send out DNA testing etc.
Genomic Imprinting
The process of gene silencing
Genotype
Is the genetic makeup
Referred to as:
Homozygous dominant TT
Heterozygous tt
Homozygous Resistant Tt
Phenotype
What is observed, the expression of traits
Incidence Rate
The number of NEW cases of a disease reported during a specific time period divided by the number of individuals in the population
Prevalence rate
The proportion of the population affected by a disease at a specific point in time
What are multi factorial disease caused by?
Caused by both genetics and environmental factors. Examples- cancer, diabetes, migraine, and blood pressure.
What is penetrance?
The frequency the genotype will result in the phenotype.
100% penetrance menas that the gene will always be expressed
Reduced penetrance means that the gene is not always expressed phenotypically.
What is translation?
The process of where protein assembly occurs from the interaction of messenger RNA (mRNA) and transfer RNA (tRNA)
What is transcription?
Is the process by which genetic information is transferred from DNA to RNA for protein synthesis
What are the 3 types of epigenetics?
DNA Methylation- causes a gene to become transcription ally inactive or silent. Works in x-inactivation which is random transcriptional silencing of genes on one of the two females X chromosomes.
Histone modification- histones are proteins that condense and structure the DNA of eukaryotic cell nuclei into units called nucleosomes
Micro-ribonucleic acids (miRNAs)- key role in regulation of gene expression. MiRNAs usually produce gee silencing by binding to target sites found within the targeted messenger RNA.
Expressivity
To what degree a gene is expressed
Variable expressivity refers to variations in the effect caused by a particular mutation.
Anticipation
Is a phenomenon in which the signs and symptoms of genetic conditions tend to become more severe, or expressed at an earlier age as it is passed from one generation to the next. 1
Describe the cytoplasm
Fluid within cells that surrounds organelles
Describe the endoplasmic reticulum
Helps process molecules created by the cell. Also transports these molecules to their specific destinations either inside or outside of the cell
Describe the Golgi apparatus
Packages molecules processed by the endoplasmic reticulum to be transported outside of the cell.
Describe the Mitochondria
Complex organelles that convert energy from food into a form that the cell can use. They have their own genetic material separate from the DNA in the nucleus, can make copies of themselves.
What are ribosomes
Process the cells genetic instructions to create proteins. Float freely in the cytoplasm or can connect to the endoplasmic reticulum.
What is DNA?
DNA is the hereditary material in humans, located in the cell nucleus
What is a chromosome?
DNA that is packaged in a thread like structure. Each chromosome is made up of DNA tightly coiled many times around proteins called histones that support its structure.
Each cell normally contains 23 pairs of chromosomes, for a total of 46.
