Molecules, Cells, and Tissues Exam 1

Health

a state of complete physical, mental, and social well-being. not merely the absence of disease or illness

Disease

the interruption, cessation, or disorder of a body system or organ resulting in abnormal physiology

Acute Disease

disease characterized by rapid onset, short duration, and is generally severe in nature

Chronic Disease

disease characterized by relatively slow onset, long duration, and generally not as severe as acute disease

Disease states: Remission

period when clinical manifestations disappear, diminish significantly

Disease states: Exacerbation

periods when clinical manifestations become worse, moer severe

Disease states: Sequelae

any abnormal conditions that follow/result from a disease (after initial disease has ended), treatment, injury.

Mortality

deaths associated with a particular disease

Morbidity

state of being symptomatic for a disease or condition, expressed through prevalence or incidence (state of having disease)

Comorbidity

medical conditions that coexist alongside a primary diagnosis that affect health

Disease type: Congenital

conditions present at birth, which may be due to genetic factors or environmental influences. (ex. fetal alcohol syndrome)

Disease type: Inherited/genetic

disorders caused by alterations in genes or chromosomes, passed from parent to offspring

not all genetic diseases are inherited (some occur spontaneously)

Disease type: Metabolic

disorders resulting from abnormal chemical processes in the body, often involving enzyme deficiencies or hormonal imbalances

Disease type: Degenerative

progressive deterioration of tissues or organs over time, leading to impaired function

Disease type: Neoplastic

relating to abnormal tissue growth (tumors), which can be benign or malignant

Disease type: Immunologic

disorders involving dysfunction of the immune system, including autoimmune diseases and immunodeficiencies

Disease type: Infectious

diseases caused by pathogenic microorganisms such as bacteria, viruses, fungi, or parasites

ex. nosocomial: infection from being in a hospital/care facility (healthcare associated infection)

Disease type: Physical/chemical agent induced

conditions resulting from exposure to harmful physical forces (ex. radiation) or chemical substances

Disease type: Nutritional deficiencies

disorders caused by inadequate intake or absorption of essential nutrients

Disease type: Psychogenic

physical symptoms or disorders that originate from or are influenced by psychological factors

Disease type: Iatrogenic

adverse effects or complications resulting from medical treatment or interventions

Disease type: Idiopathic

conditions with no known cause or where the underlying mechanism is not fully understood

Epidemiology

study of disease occurance in human populations

how disease is spread

how to control disease

how to prevent disease

how to eliminate disease

Etiology

cause/origin of disease

intrinsic: coming from within

extrinsic: originating from external factors

idiopathic: cause unknown

Incidence

measures new cases of a disease or condition and is calculated over a specific time period.

expressed as a rate (ex. 8 in 10 women get breast cancer)

useful for assessing risk and identifying causative factors

Prevalence

measures existing cases of a disease or condition

represents a proportion at a specific point in time or over a period

expressed as a percentage or ratio of cases to total population (ex. autoimmune diseases are 2x more likely to affect females)

useful for assessing disease burden and healthcare planning

Wilson’s Disease (WD)

AR, M=W, late childhood to 40 yo

accumulation of body copper (Cu) in blood, excess Cu storage in liver & brain

presents as cirrhosis, neurological symptoms (parkinsonism, dementia, and Kayser-Fleischer ring)

progresses from acute hepatitis to cirrhosis and portal hypertension

increased risk of hepatocellular carcinoma

Neoplasm (cancer cell)

new tissue growth that is unregulated, irreversible, and monoclonal from a single progenital cell → replicative immortality

Normal cell vs Cancer cell

normal cell: large cytoplasm, single nucleus, fine chromatin

cancer cell: smaller cytoplasm, multiple nuclei, coarse chromatin. state of genetic instability

Benign vs Malignant

benign: stays in one place, easy to treat

malignant: grow through original organ, metastasize

Sarcoma

connective tissue (ex. blood)

spread via blood stream

prevalent in children

Carcinoma

epithelial tissue

spread via lymph vessels

prevalent in adults

what organelle is present in all normal body cells?

plasma membrane

Organ

tissues that are organized into discrete multicellular entities

Organ system

group of organs organized from a common purpose

Biological hierarchy (structure → function)

cells → tissues → organs → organ system → organism

Cell theory

1. cells are the basic working unit of life

2. all living things are made up of one or more cells

3. new cells arise only from pre-existing cells

Homeostasis

maintain a stable (internal) environment. maintains life in the face of change via positive/negative feedback

physiologic cause & effect

(ex. increase in body temp → sweating

increase in O2 → constriction of arterioles

decrease in blood pressure → increase in thirst)

Cell differentiation

process by which cells adopt a specialized structure and function

Cell differentiation - Functions

1. movement

2. conductivity

3. metabolic absorption

4. secretion

5. excretion

6. respiration

7. reproduction

8. communication

Cancer cell differentiation

well differentiated: less aggressive cancer, looks similar to healthy cells

poorly differentiated: more aggressive cancer, has a distinguishable shape & structure

Prokaryote

cell lacking organelles, complexity, organization

(ex. bacteria)

Eukaryote

cell with characteristic set of membrane-bound intracellular compartments (ex. plants, fungi, animals)

Cell composition

water: 70-85%

proteins: 10-20%

lipids: 2-3%

ions/small molecules: 1-2%

carbohydrates: 0.2-0.5%

Plasma membrane/plasmalemma

apical surface covered by microvilli

lateral surfaces form invaginations with adjacent cells

basal surface rests on the basal lamina

selective barrier involved in cell communication, import/export of molecules, and cell growth/motility

composed of a lipid bilayer and associated proteins

Nucleus

site of DNA replication, translation to RNA

largest organelle in the cell

present in all cells except RBCs

Nucleolus

site of rRNA synthesis and ribosome assembly

control of cell cycle and response

not membrane-bound

Nuclear envelope

contains many nuclear pores

Golgi apparatus

composed of multiple flattened cisternae responsible for modifying, processing, sorting, & packaging proteins and lipids for intracellular/extracellular transport

post-translational modifications: glycosylation, sulfation, phosphorylation

Mitochondria

site of aerobic respiration

provide most of the energy to cell by producing ATP (90%) in the process of oxidative phosphorylation

enclosed by double membrane

contain their own DNA (mtDNA), enzymes for citric acid cycle and electron transport chain

Rough endoplasmic reticulum

bound ribosomes synthesize proteins mostly for exocytosis

region associated with ribosomes and site of protein synthesis and modification

Smooth endoplasmic reticulum

synthesizes steroids/lipids

serves in detoxification of many substances (particularly hydrophobic ones)

contains the enzyme glucose-6-phosphatase (necessary for glucose export & gluconeogenesis)

in muscle, regulates Ca2+ concentrations, essential for contraction

abundant in steroid-secreting cells, endocrine tissues

Lysosomes

contain digestive enzymes that are formed from endosomes by targeted delivery of unique lysosomal membrane proteins and lysosomal enzymes

Centrioles

non-membranous

mitotic spindles for cell division

short, paired cylindrical structures found in the center of the centrosome, gives rise to basal bodies of cilia

organize microtubules to maintain cell shape

Proteosome

site of intracellular protein breakdown

protein complexes that enzymatically degrade damaged and unnecessary proteins into small polypeptides & amino acids

Cytoplasm

everything outside of the nucleus

Cytosol

semi-liquid gel that fills the space in cell

stores triglycerides, glycogen, cations, inclusions

40% of body weight

chemical composition of the cytosol differs from the extracellular fluid ECF (ex. blood plasma) extremely crowded environment!

Peroxisomes

involved in production and degradation of H2O2 and fatty acids

contain oxidase enzymes for detox

catalase enzymes turns into H2O & O2

digests long fatty acids, filter drugs

abundant in metabolically active cells, hepatocytes, kidney tubules

as you age, peroxisomes stop working

Central dogma

DNA is transcribed to RNA which is translated to proteins

Chromatin

DNA bound to histones and other proteins, exists in 2 forms

Heterochromatin

condensed chromatin that is transcriptionally inactive

Euchromatin

dispersed regions of unpacked chromatin that is often actively transcribed

Barr body

condensed, inactive X chromosome

biological female (XX): 1 barr body/somatic cell

during interphase the barr body is visible as a dark stained body within the nucleus

Lipofuscin

forms if lysosome cannot degrade material

Lysosomal storage disorders

deficiency in lysosomal degradative enzymes → accumulation of abnormal metabolic products

Lysosomal storage disorders: Fabry disease

deficiency in a-galactosidase A

Lysosomal storage disorders: Gaucher disease

most common, deficiency in b-glucosidase

Lysosomal storage disorders: Niemann-Pick disease

deficiency in sphingomyelinase

Lysosomal storage disorders: Tay-Sachs disease

deficiency in hexosaminidase A

Lysosomal storage disorders: Pompe disease

deficiency of acid alpha-glucosidase

Lysosomal storage disorders: I cell disease

deficiency in lysosome tag mannose-6-phosphate

swollen cells

Mycobacterium lysosomal evasion

hide from lysosomes (ex. TB)

Mitochondrial disorders

mtDNA is inherited only from the mother

disorders caused by mutations in mtDNA and tissues with the greatest demands for ATP are often most seriously affected (ex. muscle, CNS)

examples of mitochondrial disorders: myopathies and leber hereditary optic neuropathy

Microtubules

non-membranous

form cytoskeleton with actin and intermediate filaments, provide dynamic instability (addition/subtraction of tubulin dimers)

Ribosomes

essential for protein synthesis and composed of ribosomal RNA and ribosomal proteins

Cytoskeleton

structural: provides structural support to cell; stabilizes junctions between cells

movement: assists with cytosol streaming/cell motility; moves organelles, vesicles, other materials throughout cell; helps move chromosomes during cell division

Cytoskeleton structure

microfilaments: composed of F-actin (5-7 nm, continuous remodeling)

intermediate filaments: composed of cytokeratins (10-15 nm)

microtubules: composed of tubulin (24 nm, continuous remodeling)

Centrioles structure

barrel shaped, 2 form centrosome composed of microtubule

in non-dividing cell turn into basal bodies

which of the following are cytoskeleton functions?

a) movement of lysosome to phagocytosed foreign body

b) projection of pseudopod toward foreign body

c) positioning of mitochondria within cell

d) b & c

e) a, b, c

e) a, b, c

Extracellular matrix (ECM)

stuff between cells (non-living)

fibers & ground substance

complex network proteins and carbohydrates that surround, support, give structure to cells/tissues (collagen, elastin, proteoglycans, adhesive glycoproteins)

Osmosis

water moving from high to low concentrations

Diffusion

solutes moving from low to high concentrations

Glucose

glucose provides energy needed by cells

glucose is maintained in blood (blood sugar/blood glucose levels) as sole energy source for brain & available energy source for all other tissues

Hypoglycemia

low sugar

Hyperglycemia

high sugar

Fructose

food sources of fructose: fruits, veggies, honey, high fructose corn syrup

Galactose

food sources of galactose: milk, dairy products made from milk

Disaccharides: maltose

maltose = glucose + glucose; sprouted grains (starch)

Disaccharides: sucrose

sucrose = glucose + fructose; refined table sugar

Disaccharides: lactose

lactose = glucose + galactose; “milk sugar” dairy products

Polysaccharides: starch

complex carbohydrate

storage form of carbs in plants; human digestive enzymes.

straight chains = amylose

branched chains = amylopectin

Polysaccharides: glycogen

complex carbohydrate

long, branching chains of glucose radiating around central protein storage form of carbohydrates in animals (liver, muscles)

not from diet, synthesized

Polysaccharides: fiber

complex carbohydrate

indigestible plant carbs (cellulose cell wall)

no digestive enzymes to break down, microbiota ferment in colon

Carbohydrate digestion: 1. oral cavity

mechanical digestion teeth; salivary glands enzymatic digestion (salivary amylase of starch)

Carbohydrate digestion: 2. stomach

low pH inactivates salivary amylase, more mechanical digestion

Carbohydrate digestion: 3. small intestine

pancreatic amylase & enterocyte digestion enzymes (maltase, lactase, sucrase) = glucose, fructose, galactose absorbed across enterocytes → blood → liver

Carbohydrate digestion: 4. colon

mostly fiber, gut microbiota ferment into short-chain fatty acids

Blood glucose regulation

blood glucose regulation maintained by insulin & glucagon

Insulin

blood glucose is too high, body cells take up glucose

Glucagon

blood glucose is too low

liver → glycogenolysis & gluconeogenesis