Biology Flashcards
what happens in the nucleolus?
what does an endosome do?
rRNA is synthesized
endosomes transport/package/sort cell material traveling to/from the membrane
- involved in endocytosis
what is the function of the endoplasmic reticulum?
compare smooth vs rough ER
what about the golgi?
what about peroxisomes?
ER function is synthesis/transport of biomolecules
Smooth does lipid synthesis, Rough does protein synthesis
The golgi modifies then packages/transports cellular products to their correct destination
peroxisomes do B-oxidation, synthesis of phospholipids, have enzymes for PPP
describe the 3 components of the cytoskeleton
- microfilaments
- MTs
- intermediate filaments
- Microfilaments are made of actin, and give the cell protection; also form a ring during cytokinesis of mitosis
- MTs are made of tubulin, providing pathways for kinesin/dynein (motor proteins) to carry vesicles; also cilia and flagella
- Intermediate filaments do cell-cell adhesion and maintain integrity of cytoskeleton
explain types of epithelial cells:
- simple
- stratified
- pseudostratified
- cuboidal
- columnar
- squamous
- simple - one layer of cells
- stratified - multiple layers of cells
- pseudostratified - one layer but appear as multiple
- cuboidal - cube shaped
- columnar - long and thin
- squamous - flat/scalelike
gram-positive vs. gram-negative cell walls
- gram-positive has a thick layer of peptidoglycan (protection from host’s immune system) and also contains lipoteichoic acid
- gram-negative contain small amount of peptidoglycan and also outer membranes containing lipopolysaccharides
what is binary fission?
what are virulence factors?
asexual reproduction in prokaryotes
they’re traits that increase pathogenicity (toxin production/projections/evasion)
transformation vs. conjugation vs. transduction for bacteria
Transformation is integration of foreign material into the host genome. Conjugation is bacterial form of mating (forming conjugation bridge, donor male + to recipient female - . Transduction genetic recombination process that requires a vector
what is a transposon
what are the phases of bacteria growth?
- lag phase
- exponential/log phase
- stationary phase
- death phase
genetic elements capable of inserting and removing themselves from the genome
- lag phase is when bacteria first adapt to the new local conditions
- exponential/log phase is when rate of division increases
- stationary phase is when reduction of resources slows reproduction
- death phase is when environment cant support bacteria and they die
what is a capsid? what are virions? what are bacteriophages? describe functions of tail sheath vs tail fibers
capsid is the protein coat of a virus. virions are viral progeny used to infect other cells. bacteriophages are viruses that target other bacteria. tail sheath acts like a syringe, tail fibers recognize/connect to correct host cell
what is a retrovirus? describe positive vs. negative sense genomes
retroviruses are ssRNA viruses that carry reverse transcriptase, synthesizing DNA from RNA and integrating that DNA into the host cell’s genome
- positive means the genome may be directly translated from to functional proteins by the ribosomes like mRNA
- negative carry RNA replicase to synthesize proteins from the RNA
lytic vs lysogenic cycles
prions vs. viroids
lytic cycle is when bacteriophage maximizes use of cell’s machinery w/ little regard for survival of host cell (virus is VIRULENT), lysogenic phase is when virus replicates as bacterium reproduces because it is part of host’s genome
- prions are nonliving infectious proteins, causing misfolding of other proteins, viroids are small pathogens consistent of a very short circular ssRNA, they bind to large # of RNA seq. and silence genes in plant genome
the stages of the cell cycle:
G0
Interphase - G1, S, G2
M stage - Mitosis
- G0 - cell is simply living / carrying out functions
- G1 - cells create organelles for energy/protein production (RESTRICTION POINT)
- S - cell replicates genetic material so daughter cells have identical copies (PLOIDY DOESNT CHANGE)
- G2 - cell passes through another quality control
- M - cells separate into identical daughter cells
explain p53’s role
explain role of cyclins and CDKs
p53 controls if cell needs to arrest to repair DNA or if it is ready for synthesis
- CDKs are activated by the right cyclins, and this complex phosphorylates TFs that promote transcription of genes for next stage of cell cycle
explain 4 steps of mitosis and cytokinesis
- prophase
- metaphase
- anaphase
- telophase
- cytokinesis
- prophase - chromosomes condense, centrioles separate to poles and spindle fibers form
- metaphase - chromosomes align at metaphase plate b/c of spindle apparatus
- anaphase - sister chromatids are pulled apart by shortening kinetochore fibers
- telophase - new nuclear membrane forms around each set of chromosomes, spindles disappear
- cytokinesis - separation of cytoplasm and organelles to each daughter cell
Meiosis I and then Meiosis II
when does crossing over occur in meiosis?
Meiosis I results in homologous chromosomes being separated generating HAPLOID daughter cells (reductional division)
Meiosis II is similar to mitosis, resulting in separation of sister chromatids W/O change in ploidy (equational division)
Prophase I
what are the functions of seminiferous tubules and interstitial cells of Leydig
what do cowper’s glands do?
seminiferous tubules (secrete testosterone) and interstitial cells of Leydig (produce sperm)
produce clear/viscous fluid that cleans remnants of urine and lubricates urethra during arousal
define terms:
- spermatogonia
- primary spermatocyte
- secondary spermatocyte
- spermatid
- spermatozoa
- spermatogonia - diploid stem cells in males
- primary spermatocyte - diploid sperm after S stage
- secondary spermatocyte - haploid sperm after Meiosis I
- spermatid - haploid sperm after meiosis II
- spermatozoa - mature sperm
where is an egg ovulated into? and then what does it travel through? what is its destination?
peritoneal sac; fallopian tubes, uterus
define terms:
- primary oocyte
- secondary oocyte
- zone pellucida
- corona radiata
- primary oocyte - created and stored until menarche, when one is released per month
- secondary oocyte - primary oocyte after meiosis I
- zone pellucida - surrounds oocyte, is an acellular mixture that protects oocyte
- corona radiata - layer of cells that adhere to oocyte during ovulation
when does GnRH get released? what happens after that?
at the start of puberty the hypothalamus releases pulses of GnRH
- triggers anterior pituitary to release FSH and LH
describe menstrual cycle
- follicular phase
- ovulation
- luteal phase
- menstruation
- pregnancy
- menopause
- follicular phase - begins w/ menstrual flow, GnRH increases which increases FSH and LH and produce follicles, which have negative feedback on hormones; estrogen spikes late
- ovulation - high estrogen levels cause GnRH, FSH, LH to spike. LH surge induces ovulation
- luteal phase - LH causes ruptured follicle to form corpus luteum which secretes more and more progesterone. negative feedback on GnRH, FSH, LH.
- menstruation - w/o implantation, corpus luteum loses stimulation from LH, progesterone decreases, uterine lining is shed. GnRH block is removed
- pregnancy - if implantation occurred, zygote forms into blastocyst which implants into uterine wall and secretes hCG, which maintains corpus luteum.
- menopause - w/ age, ovarian atrophy occurs. estrogen/progesterone drop, endometrium atrophies, menstruation stops. blood levels of FSH and LH rise b/c negative feedback stops
determinate vs indeterminate cleavage
describe blastulation
determinate is when cells’ fates are already determined, indeterminate is when cells can still develop into complete organisms
- blastulation is when morula (ball of cells) forms into a blastula (hollow ball of cells w/ fluid inside called blastocoel). mammalian blastula is a blastocyst
- outer layer trophoblast cells become placenta, inner cell mass becomes organism
what is gastrulation? deuterostomes vs protostomes; describe the 3 primary germ layers
- ectoderm
- mesoderm
- endoderm
gastrulation is generation of three distinct cell layers
- deuterostomes develops into anus, protostomes develops into mouth
- ectoderm - outermost layer, gives rise to hair/skin/nails/eye lens/NS
- mesoderm - middle layer, gives rise to musculoskeletal, circulatory, excretory systems
- endoderm - innermost layer, forms epithelial linings of organs, lungs, liver, pancreas
how do cells differentiate into distinct cell types during development? also talk about induction
explain neurulation
- notochord
- neural folds
- neural groove
- neural tube
- neural crest cells
selective transcription of genome
- induction is one group of cells influencing fate of nearby cells
- chemical substances (inducers) diffuse from organizing cells to responsive cells
- notochord - rod of mesodermal cells that forms long axis of organism (spine)
- neural folds - notochord induces cells to slide inward forming folds, which surround neural GROOVE
- neural tube - folds grow towards each other and fuse to form neural tube, becoming CNS
- neural crest cells - at tip of each fold, these cells move outward to form PNS
rank the potency of a cell
autocrine vs paracrine vs juxtacrine vs endocrine
- totipotent is greatest potency (stem cells) and can differentiate into anything
- pluripotent can differentiate into any type except for placental structures
- multipoint can differentiate into multiple cell types within a particular group
autocrine is to itself, paracrine is to cells that are close, juxtacrine is stimulating receptors of adjacent, endocrine is to cells far away
how are the umbilical arteries/vein different?
describe the 3 shunts in a fetus
- foramen ovale
- ductus arteriosus
- ductus venosus
umbilical artery carries deoxygenated blood away from from fetus to placenta, and umbilical vein carries oxygenated blood and nutrients to fetus from placenta
- foramen oval is one way valve connecting R atrium to L atrium, avoiding ventricles and driving blood in circulation
- ductus arteriosus - shunts leftover blood from pulmonary artery to aorta
- ductus venosus - shunts blood returning from placenta directly into inferior vena cava
what happens in first trimester? second trimester? third trimester?
talk about birth
- parturition
- prostaglandins
- oxytocin
- afterbirth
1st trimester is when major organs begin to develop, skeleton begins to form into bone, brain fairly developed
2nd trimester fetus undergoes tremendous growth, begins to move, face becomes human, toes/fingers elongate
3rd trimester is more growth and brain development, antibodies transferred from mother,
- parturition - vaginal childbirth
- prostaglandins - coordinates rhythmic contractions of uterine muscle
- oxytocin - peptide hormone in pos. feedback for contractions
- afterbirth - placenta and umbilical cord are expelled
what cells produce myelin? (in PNS and CNS)
- difference b/w tracts and nerves?
temporal vs. spatial summation
oligodendrocytes in CNS and schwann cells in PNS
- nerves carry more than one type of info, tracts only carry one
temporal is multiple signals integrated during a short period of time, spatial is additive effects based on # and location of incoming signals
define the function of each:
- glial cells
- astrocytes
- ependymal cells
- microglia
- oligodendrocytes (CNS) / schwann cells (PNS)
what is saltatory conduction?
- glial cells - myelinate neurons
- astrocytes - form BBB
- ependymal cells - line ventricles of brain, produce CSF
- microglia - ingest/break down waste products in CNS
- oligodendrocytes (CNS) / schwann cells (PNS) - produce myelin for axons
the signals hops from node to node
what part of the spinal cord are sensory neurons found?
what is the first neuron in ANS called? second neuron?
dorsal root ganglia
preganglionic neuron; postganglionic neuron
difference in function b/w peptide hormones and steroid hormones
- what do peptide hormones end in? steroid hormones?
peptide hormones can’t pass membrane so they use second messenger, steroid hormones diffuse thru membrane so they bind to intracellular receptors (slower effect)
-in or -ine; -one or -oid
direct vs. tropic hormones
products of anterior pituitary mnemonic? which are tropic and which are direct?
direct hormones act directly on target tissue, tropic hormones require an intermediary to act
F - FSH L - LH A - ACTH T - TSH Prolactin Endorphins G - GH FLAT is tropic and PEG is direct
where does the hypothalamus secrete compounds? what does being hormones to?
what is the HPA axis? how does negative feedback work for it?
hypophyseal portal system; anterior pituitary
hypothalamus->CRF->anterior pituitary->ACTH->adrenal cortex->cortisol
- cortisol inhibits ACTH and CRF when too high
define the function of the following:
- ADH (vasopressin)
- oxytocin
- prolactin
contrast anterior vs posterior pituitary
- ADH (vasopressin) - increases reabsorption of H2O in ducts of kidneys
- oxytocin - stimulates uterine contractions
- prolactin - stimulates milk production in mammary glands
anterior produces/secretes its own hormones, posterior is projection of hypothalamus and stores/secretes those hormones
what are the 2 functions of the thyroid?
how does it mediate both effects?
- setting BMR
- promoting Ca2+ homeostasis
- releases T3 & T4, which increases cell. resp.
- release of calcitonin, which decreases plasma Ca2+ levels
what does parathyroid hormone (PTH) do?
what is the 3 functions of corticosteroids mnemonic?
serves as an antagonistic hormone that raises blood Ca2+ levels
- also activates vit.D which is required for Ca2+ absorption
3 S’s
- Sugar (glucocorticoids)
- Salt (mineralocorticoids)
- Sex (cortical sex hormones)
define functions of each corticosteroid, which are released by the _____
- Glucocorticoids
- Mineralocorticoids (describe how low BP is regulated)
- cortical sex hormones
adrenal cortex
- Glucocorticoids - regulate BGL, affect protein metabolism; Cortisol and Cortisone decrease inflammation
- Mineralocorticoids - used in salt/water homeostasis (aldosterone)
- low BP causes juxtaglomerular cells to secrete renin, which cleaves angiotensinogen to angiotensin I, then to angiotensin II by ACE. angiotensin II bring BP up - cortical sex hormones release androgens/estrogens
what are the 3 types of Islets of Langerhans in the pancreas? what does each one secrete?
compare Type I vs Type II diabetes
what does somatostatin do?
- alpha - glucagon
- beta - insulin
- delta - somatostatin
Type I is caused by destruction of B-cells, so low/no insulin production. Type II is result of receptor resistance to effects of insulin
inhibits glucagon and insulin secretion, also GH secretion
what does erythropoietin do and where is it secreted from?
talk about atrial natriuretic peptide (ANP)
also thymosin
what secretes melatonin?
from the kidneys
- stimulates bone marrow to increase production of erythrocytes in response to low blood O2 levels
released from heart to regulate salt/water balance
thymosin is released from thymus which is important for T-cell development/differentiation
pineal gland
order that air goes from mouth to lungs
define the following terms:
- total lung capacity (TLC)
- residual volume (RV)
- vital capacity (VC)
- TV
- expiratory reserve volume (ERV)
- inspiratory reserve volume (IRV)
mouth to pharynx to larynx to trachea to bronchi to bronchioles to alveoli
- total lung capacity (TLC) - max lung volume when inhaling completely
- residual volume (RV) - volume remaining after exhalation
- vital capacity (VC) - TLC-RV
- TV - volume inhaled/exhaled during normal breaths
- expiratory reserve volume (ERV) - volume of additional air that can be exhaled
- inspiratory reserve volume (IRV) - volume of additional air that can be inhaled
what enzyme is in the nasal cavity? describe mucociliary escalator
what 3 immune cells are in the lungs?
what is the bicarbonate buffer system equation?
lysozyme; mucus catches particles/large matter, then cilia propel mucus up respiratory tract to be expelled/swallowed
- macrophages
- IgA antibodies
- Mast cells
CO2 + H2O -> H2CO3 -> H+ + HCO3-
what do each of these hormones cause to release form the anterior pituitary?
- GnRH
- GHRH
- TRH
- CRF
- GnRH -> FSH and LH
- GHRH -> GH
- TRH -> TSH
- CRF -> ACTH
hypothyroidism vs. hyperthyroidism
what 3 hormones affect water homeostasis?
hypo is when thyroid hormones are secreted in insufficient amounts or not at all, hyper is when there is overstimulation of thyroid hormones
- ADH released from posterior pituitary increases blood volume and decreases blood osmolarity
- Aldosterone from adrenal cortex increases blood volume but no effect on osmolarity
- ANP released from heart decreases blood volume but no affect on osmolarity
which side is the bicuspid (mitral) valve? tricuspid?
what do semilunar valves separate?
what nerve provides parasympathetic signals?
bicuspid is with L atrium/ventricle; tricuspid is with R atrium/ventricle
they separate ventricles from vasculature
vagus nerve
systole vs. diastole
do arteries or veins have more smooth muscle?
describe structure of arteries vs. veins
systole is ventricular contraction & closure of AV valves; diastole is ventricle relaxation and refilling, semilunar valves are closed
ARTERIES
arteries are highly muscular and elastic and have tremendous resistance to flow, veins are thin-walled and inelastic and can accommodate larger quantities of blood
- VEINS HAVE VALVES
order blood travels in the body
describe the 3 portal systems blood passes through
- hepatic portal system
- hypophyseal portal system
- renal portal system
R atrium, tricuspid value, R ventricle, pulmonary valve, pulmonary artery, lungs, pulmonary venules, pulmonary veins, L atrium, mitral valve, L ventricle, aortic valve aorta, arterioles, capillaries, venules, veins, IVC/SVC, R atrium
- hepatic portal system - blood leaving capillary beds of gut passes through hepatic portal vein before liver
- hypophyseal portal system - blood leaving capillary beds in hypothalamus travel to anterior pituitary to allow for PARACRINE SECRETION
- renal portal system - blood leaving glomerulus travels through efferent arteriole before nephron
explain functions of 3 cells in blood
- erythrocytes
- leukocytes
- platelets
what is hematocrit?
what is hematopoiesis and the 2 main hormones?
- erythrocytes - O2 transport by hemoglobin, DONT DO oxid. phosph. for ATP, only rely on glycolysis
- only live for 120 days until phagocytized - leukocytes - WBCs, crucial part of immune system
- platelets (thrombocytes) - assist in clotting, made from megakaryocytes in bone marrow
hematocrit is measure of how much of blood sample consists of RBCs
hematopoiesis is blood cell production
- erythropoietin is secreted by kidney and stimulates RBC development
- thrombopoietin is secreted by liver/kidney and stimulates platelet development
what are the 5 types of leukocytes? function? Granulocytes: 1. neutrophils 2. eosinophils 3. basophils Agranulocytes: 1. lymphocytes 2. monocytes (macrophages)
- Granulocytes: contain cytoplasmic granules that are toxic for microbes and can be released during inflammatory rxns and allergies, etc.
1. neutrophils
2. eosinophils
3. basophils - Agranulocytes: help in specific immune response, like particular pathogens (virus/bacteria). contain a memory bank of pathogen recognition
1. lymphocytes
2. monocytes
ABO vs. Rh factor antigens
what are the 4 blood types? and what are the 2 ways to express A blood? B blood?
ABO antigens is composed of 3 alleles for blood type
- A (or Ia) and B (Ib) alleles are CODOMINANT, if they’re both present they’ll both be expressed
- Type O (or i) blood don’t express either, RECESSIVE to A and B
Rh factor is a surface protein expressed on erythrocytes, can be Rh+, Rh- (presence/absence of D)
A, B, AB, O
Ia Ia, Ia i, Ib Ib, Ib i
who is a universal donor? universal recipient?
explain erythroblastosis fetalis
what is CO equation? BP equation?
type O is universal donor, type AB is universal recipient
if fetus is Rh+ and mother is Rh-, mother is sensitized to Rh factor and makes antibodies, and next child could die because mother’s immune system fights fetal blood cells if Rh+ again
CO = SV x HR BP = TPR x CO
hydrostatic pressure vs. oncotic (osmotic) pressure (in blood) (STARLING FORCES)
explain coagulation; what does prothrombin form? then converted to what?
what breaks down a clot?
- hydrostatic pressure is force the blood exerts against vessel walls
- osmotic (oncotic) pressure is sucking pressure generated by solutes as they attempt to draw water into bloodstream
when endothelium of blood vessel is damaged, connective tissue containing TISSUE FACTOR is exposed, platelets detect tissue factor and it’s sensed as injury. Platelets aggregate, and coagulation factors (secreted by liver) initiate cascade.
- prothrombin is activated and forms thrombin by thromboplastin, then convert fibrinogen into fibrin, which forms net over injury
plasmin, generated by plasminogen, breaks down a clot
innate (nonspecific) immunity vs. adaptive (specific) immunity
- innate immunity is defenses that are always active against infection, but lack ability to target specific invaders
- adaptive immunity is defenses that target specific pathogens (slower to act)
The ____ is the location of blood storage
- what do plasma cells produce?
what is humoral immunity?
what are T cells? where are they matured? what immunity are they part of?
bone marrow
- antibodies (adaptive immunity)
part of adaptive immunity where antibodies dissolve in blood
T-cells are a class of adaptive immune cells, mature in thymus, agents of CELL-MEDIATED IMMUNITY (coordinate immune system and kill viral cells)
what do lymph nodes do?
what are adenoids, tonsils, peyer’s patches, and lymphoid aggregates examples of?
produce/filter lymph, activate B-cells,
gut-associated lymphoid tissue (GALT)
function of lymphocytes? monocytes?
- lymphocytes produce antibodies, modulate immune system, target killing of infected cells
- monocytes are phagocytic cells in bloodstream, become MACROPHAGES (microglia, langerhans, osteoclasts)
what is complement system? classical vs. alternate pathway
what is an interferon? when is it produced?
complement system consists of # of proteins in blood that act as NONSPECIFIC defense against bacteria
- can be activated through classical pathway (requires BINDING OF ANTIBODY to pathogen)
- or activated through alternate pathway (DOES NOT REQUIRE ANTIBODY)
produced when a cell has been infected with viruses, it is a protein that prevents viral replication/dispersion
- increased antigen representation
- decreased permeability
what does a macrophage do when it detects a bacterial invader? talk about cytokines too
describe MHC
it is activated
- phagocytizes invader thru endocytosis
- digests invader using enzymes
- presents little pieces of invader to cells using MHC
- macrophages can release cytokines which stimulate inflammation and recruit other immune cells
MHC binds to antigen which carries it to cell surface to be recognized by adaptive immune system
MHC-I vs. MHC-II
what is a pattern recognition receptor (PRR)?
- MHC-I is in all nucleated cells in body and presents ENDOGENOUS PATHWAY b/c binds antigens from inside cell
- MHC-II is in antigen-presenting cells (macrophages) and presents EXOGENOUS PATHWAY b/c antigens originate outside of cell
PRRs are able to recognize category of invader and allows for appropriate cytokines and then appropriate immune cells
explain each kind of cell
- natural killer cells (NK)
- neutrophils
- eosinophils
- basophils / mast cells
- natural killer cells (NK) - nonspecific lymphocyte, destroys body’s own cells that are infected (goes after cancer cells)
- neutrophils - short lived leukocytes, phagocytic, opsonize bacteria
- eosinophils - red/orange granules, ALLERGIC RXNS, release histamine (vasodilation & leakiness of blood vessels), causing inflammation, PARASITES
- basophils / mast cells - purple granules, allergic responses, release histamine in response to allergens
what is degranulation?
describe structure of antibodies
- what is variable region?
- what is constant region?
occurs when antigen binds to antibody on surface of mast cell, exocytosis of granule contents, releasing HISTAMINE
2 heavy chains and 2 light chains, held together by disulfide/noncovalent linkages
- antigen-binding region contains variable region (domain) at tips of Y, BINDS 1 AND ONLY 1 SPECIFIC ANTIGEN
- constant region is remaining part of Y, where macrophages/NKs/etc. bind for complement cascade
where do naive B-cells wait? what happens when that antigen is detected? (what 2 cells are produced?
primary vs. secondary response
lymph nodes, waiting for their antigen to come
- upon exposure to right antigen, B-cells proliferate producing 2 types of cells: plasma cells & memory-B cells
- plasma cells produce large amount of antibodies
- memory-B cells stat in lymph node, awaiting reexposure
primary response is initial activated, 7-10 days, plasma cells die but memory cells live; secondary response is if reexposure ever occurs
positive vs. negative selection of T-cells
explain killer T-cells (CD8+)
- MHC-I or MHC-II?
Positive selection is allowing only maturation of cells that can respond to presentation of antigen on MHC. Negative selection is causing apoptosis in cells that are self-reactive
killer T-cells (CD8+) are capable of directly killing virally infected by injecting toxic chemicals that promote apoptosis into infected cells
- MHC-I b/c better for extracellular infections (8x1=8)
explain helper T-cells (CD4+)
- what does loss of these cells do?
- MHC-I or MHC-II?
helper T-cells (CD4+) coordinate immune response by secreting chemicals known as lymphokines, which recruit other immune cells and increase their activity
- loss of them (occurs in HIV) prevents immune system from mounting adequate response to infection
- MHC-II b/c better for intracellular infections (4x2=8)
explain suppressor T-cells
explain memory T-cells
suppressor T-cells express CD4, but also Foxp3.
- these cells keep immune response in sweet spot
- turn off self-reactive lymphocytes
memory T-cells can be generated to await reexposure
what happens with self-antigens and autoimmunity?
active vs. passive immunity
what is hypermutation?
self-antigens are attacked by immune systems for people with autoimmune diseases
active immunity is when your immune system does the job of making you immune (vaccines) longer lived, passive immunity is when someone else’s immune system does the work (maternal), short lived
hypermutation is what gives an antibody specificity to an antigen
how do lymphatic vessels provide a secondary system for circulation?
where are lacteals located? what travels through them?
what are geminal centers?
what structure is responsible for returning material from lymphatic circulation back to cardiovascular system?
they drain tissues to push little remaining liquid back into bloodstream
located at center of each villus in small intestine, carry chylomicrons filled w/ fat (chyle)
germinal centers are collections in lymph nodes where B-cells proliferate/mature
thoracic duct!
what are the 2 types of helper T-cells
- T h1 cells release interferon gamma, activating macrophages and helping to kill bacteria
- T h2 cells activate B-cells
what does the enteric nervous system do?
what 2 enzymes are released in saliva?
what are the 3 parts of the pharynx?
governs function of GI system (e.g. peristalsis)
salivary amylase (hydrolyzes starch into sugars) and lipase (catalyzes lipid hydrolysis)
oropharynx, nasopharynx, laryngopharynx
what are the 2 esophageal sphincters? which one is associated w/ GERD?
explain the 4 divisions of the stomach
- fundus
- body
- antrum
- pylorus
lesser curvature vs. greater curvature
- what are rugae?
upper esophageal sphincter (muscles of oropharynx) and lower esophageal sphincter (entrance to stomach), LES is complicated w/ GERD
- fundus - very top section, contains mostly gastric glands
- body - middle part, contains mostly gastric glands
- antrum - second lowest part, contains mostly pyloric glands
- pylorus - closest to small intestine, contains mostly pyloric glands
lesser curvature is inner curve, greater curvature is outer curve
- rugae are the folds that make up lining of stomach
what do gastric glands do? define the 3 types
- mucous cells
- chief cells
- parietal cells
what about pyloric glands? (what do G-cells secrete?)
- what does gastrin do?
respond to signals from vagus nerve of PNS in response to sight, taste, smell of food
- mucous cells - produce bicarbonate rich mucus that protects muscular wall from acid (pH=2)
- chief cells - part of gastric juice; secrete pepsinogen (zymogen form of pepsin), which cleaves peptide bonds near aromatic AAs
- parietal cells - part of gastric juice; secrete HCl, cleave pepsinogen into pepsin
- also secretes INTRINSIC FACTOR, glycoprotein involved in absorption of B12
contain G-cells that secrete gastrin, a peptide hormone
- Gastrin induces parietal cells to secrete more HCl and signals stomach to contract
what are the 3 parts of the small intestine?
what are brush border enzymes and when are they secreted?
what are the 3 other things does duodenum secrete?
- duodenum (majority of chemical digestion)
- jejunum (absorption)
- ileum (absorption)
secreted by duodenum in the presence of chyme, they break down dimers/trimers of biomolecules into absorbable monomers
enteropeptidase which activates other digestive enzymes from accessory organs of digestion, and secretes secretin/CCK into blood
what happens when there are undigested disaccharides in intestines?
what is the role of aminopeptidase? dipeptidase?
what does enteropeptidase activate? into what? what else does it activate?
it creates an osmotic effect and pulls water into stool causing diarrhea
aminopeptidase removes N-terminal AA from peptide; dipeptidase cleaves peptide bond of dipeptides to release free AAs
activates trypsinogen into trypsin; activates procarboxypeptidases A and B into active forms
what 2 things does secretin do?
what is the role of cholecystokinin (CCK)
- causes pancreatic enzymes to be released into duodenum
- regulates pH of digestive tract by reducing HCl secretion from parietal cells and increasing bicarbonate secretion from pancreas
CCK is secreted in response to chyme in duodenum. It is a peptide hormone which causes release of bile & pancreatic juices
- promotes SATIETY
what are acinar cells?
- pancreatic amylase, trypsinogen, chymotrypsinogen, carboxypeptidases A & B are all enzymes in what? activated by what?
what is the role of pancreatic lipase?
how do pancreatic ducts empty into duodenum?
pancreatic exocrine cells that produce bicarbonate rich pancreatic juices
- all in pancreatic juices; enteropeptidase
breaks down fats into free FAs and glycerol
major and minor duodenal papillae
explain bile ducts in liver
explain hepatic portal vein
bile is produced in liver and travels down bile ducts where it is stored in gallbladder and secreted into duodenum
liver receives/processes all blood draining from abdominal portion of GI tract through hepatic portal vein, then vena cava
- takes up excess sugar for glycogen, excess fat for triacylglycerols, etc.
what is major components of bile?
what happens if liver cannot process/excrete bilirubin?
what 2 proteins does the liver synthesize?
bile salts, pigments (bilirubin) from breakdown of hemoglobin, and cholesterol
jaundice
- albumin - protein that maintains plasma oncotic pressure; also a carrier for drugs/hormones
- clotting factor - used during blood coagulation
what is the role of the gallbladder? release of CCK?
what germ layer do accessory organs of digestion originate?
where do fat-soluble vitamins (A D E K) go during digestion?
stores/concentrates bile thru bile ducts
- upon CCK release, gallbladder contract and pushes bile into biliary tree
ENDODERM
right into chylomicrons to enter lymphatic circulation
explain trancellular and paracellular movement of water during digestion
describe the 3 parts of large intestine
- cecum (and name valve and what organ attaches)
- colon
- rectum (and 2 sphincters)
water moves transcellularly (across cell membrane) and paracellularly (squeeze b/w cells)
- cecum - an out pocketing that accepts fluids exiting the small intestine through ILEOCECAL VALVE; site of attachment for appendix
- colon - main function is to absorb water/salts from undigested material left over from small intestine and concentrates rest into feces
- rectum - storage/expulsion site for feces
- internal (involuntary) and external (voluntary) sphincters
what are the 2 circulatory vessels in villus?
what does ghrelin do?
capillaries and lacteals
promotes a sensation of hungry, increasing feeding behavior
what are the outer and inner layers of the kidney called? what exits through the renal hilum?
what is the order of structures starting from afferent arterioles?
what is the vasa recta?
outermost is cortex and innermost is medulla; renal artery, vein, and ureter exit through hilum
afferent arterioles, glomeruli (bowman’s capsule), proximal convoluted tube, descending/ascending loop of henle, distal convoluted tube, collecting duct
capillary bed surrounding loop of henle that is part of efferent arterioles
for the bladder, what is:
- detrusor muscle
- internal urethral sphincter
- external urethral sphincter
what is micturition reflex?
- detrusor muscle - muscular lining of bladder
- internal urethral sphincter - smooth muscle, contracted in normal state (involuntary)
- external urethral sphincter - skeletal muscle (voluntary)
when bladder is full, PNS tells detrusor muscle to contract and internal sphincter to relax, then individual chooses to relax external sphincter to pee
where does blood flow during filtration in nephron?
what does the glomerulus filter out? where does that go?
when/where is urea produced?
is secretion moving solutes into blood in bowman’s capsule or not?
blood flows from glomerulus into bowman’s capsule because of higher hydrostatic pressure in glomerulus being higher than osmotic pressure in opp. direction
filters out large molecules like cells/proteins; goes through efferent arterioles to vasa recta
urea is produced in the liver from large amount of NH3 (sometimes from meat heavy diets), then transported to kidney for exertion
NO, anywhere besides bowman’s capsule
what is absorbed at the proximal convoluted tube (PCT)? what waste products (mnemonic)
what happens to filtrate at descending loop of henle? ascending?
what is the diluting segment of loop of henle? why are cells bigger?
is there a net increase or decrease of dilution in loop of henle? of volume?
AAs, glucose, vitamins, salts are reabsorbed into interstitium then vasa recta
- DUMP the HUNK (H+, Urea, NH3, K+)
descending is permeable ONLY TO WATER; ascending is permeable ONLY to SALTS
transition from inner to outer medulla, loop of Henle becomes thicker b/c cells are bigger b/c more mitochondria to move salts by active transport
slight increase in dilution, and large decrease of volume
what does the distal convoluted tube (DCT) respond to? function? is there waste secretion or no?
what happens in collecting duct? what is it responsive to?
DCT responds to aldosterone, which promotes Na+ reabsorption, causing water to reabsorb w/ it and decreasing urine volume but increasing concentration
- YES waste secretion
responsive to aldosterone and ADH
- it is where water is reabsorbed, but reabsorption is dependent on permeability of duct (depending on hydration level)
where are aldosterone and ADH secreted from? why?what effect do ADH and aldosterone have?
oncotic vs. osmotic pressure
Aldosterone:
- aldosterone is secreted by adrenal cortex in response to low BP
- aldosterone acts to increase Na+/K+ reabsorption by adding Na+/K+ pumps at DCT, which pulls in more water and excretes more K+, increasing BP
ADH:
- ADH (vasopressin) is released from posterior pituitary in response to high blood osmolarity
- allows more water to be reabsorbed at collecting duct (inhibited by alcohol and caffeine)
osmotic pressure is sucking pressure that draws water into vasculature by dissolved particles, oncotic pressure is osmotic pressure from dissolved proteins specifically
layers of skin starting from outermost to innermost
what are strata? name layers from outermost to innermost (mnemonic?)
epidermis, dermis, hypodermic
layers of epidermis; stratum corneum, lucidum, granulosum, spinosum, basale
Come Lets Get SunBurned
what happens in each layer of the epidermis? (
- stratum corneum -
- stratum lucidum
- stratum granulosum
- stratum spinosum -
- stratum basale -
what does excessive keratin deposition and friction form?
- stratum corneum - contains many layers of flattened keratinocytes forming barrier from pathogens
- stratum lucidum - only present in thick hairless skin
- stratum granulosum - site where keratinocytes die and lose their nuclei
- stratum spinosum - site of langerhans cells, which are macrophages that present antigens to T-cells
- stratum basale - contains stem cells and responsible for proliferation of keratinocytes (produce keratin)
CALLUSES
what do melanocytes derive from? where are they found? what do they form?
what is function of melanin?
derive from neural crest cells, found in Basale, form melanin
melanin protects skin from DNA damage caused by UV radiation
what are the two layers of the dermis? what is in each?
define functions of:
- merkel cells
- meisner corpuscles
- ruffini endings
- pacinian corpuscles
what is in the hypodermis?
- papillary layer - loose connective tissue
- reticular layer - dense
- merkel cells - sensory receptors responsible for deep pressure and texture sensation
- meisner corpuscles - respond to light touch
- ruffini endings - respond to stretch
- pacinian corpuscles - respond to deep pressure and vibration
fat and fibrous tissue
what happens during sweating?
what happens during shivering/goosebumps?
body temp rises, postganglionic sympathetic neurons that use ACh innervate sweat glands which secrete water and ions. vasodilation occurs to maximize heat loss, and heat is absorbed from body by environment when sweat evaporates
body temp decreases, arrestor pili muscles contract causing piloerection (hairs stand up). this traps layer of heated air near skin, vasoconstriction occurs, and skeletal muscles contract rapidly causing ATP to be used but released as thermal energy
what portion of nephron is sodium NOT ACTIVELY TRANSPORTED out?
primary function of nephron is to create that is ______ to the blood
thin portion of ascending limb of loop of henle
HYPERTONIC
difference between red and white fibers
which types of muscles exhibit myogenic activity? explain
what do intercalated discs do? which type of CAM hold them together?
red fibers (slow-twitch) fibers have HIGH MYOGLOBIN content and derive energy aerobically, and contain many mitochondria. white fibers (fast-twitch) contain less myoglobin and fatigue quickly
smooth and cardiac muscle; muscle cells respond to nervous input but don’t require external signals to undergo contraction
intercalated discs hold cardiac muscle cells together, and contain many gap junctions
how does the # of nuclei per cell vary b/w muscle types?
skeletal has many nuclei per cell, smooth has 1 nuclei per cell, cardiac has 1-2
what does each letter represent in sarcomere? (mnemonic)?
- Z
- M
- I
- A
define myofibril, muscle fiber, muscle
- Z - defines boundaries of sarcomere (end of alphabet/end of sarcomere)
- M - MIDDLE of MYOSIN
- I - only thin (actin) filaments (I is thin, only thin)
- A - ALL of thick filament (myosin)
myofibrils are repeating sarcomere units, muscle fiber is many myofibrils, a muscle is many muscle fibers
define the following:
- sarcoplasmic reticulum
- sarcoplasm
- sarcolemma
- T-tubules
- titin
- sarcoplasmic reticulum - covering that surrounds myofibrils, contains A LOT OF Ca2+
- sarcoplasm - modified cytoplasm located just outside SR
- sarcolemma - cell membrane of myocyte
- T-tubules - perpendicular to myofibrils, they distribute AP’s to all sarcomeres
- titin - anchors actin/myosin and prevents excessive stretching
explain a muscle contraction from contraction to relaxation
Of I, H, Z, A, what changes and what stays the same during muscle contraction?
NS sends efferent signal to synaptic button, releases ACh into synapse and binds to sarcolemma, causing DEPOLARIZATION which triggers AP which spreads down sarcolemma and T-tubules to SR. SR releases Ca2+ which bind to TROPONIN, triggering conformational change of TROPOMYOSIN, exposing myosin binding sites on ACTIN. The free globular heads of MYOSIN bind to sites and pull, drawing thin filaments toward M-line, shortening sarcomere, which releases Pi and ADP. Then, ATP binds myosin head again, releasing it from actin and is hydrolyzed
I and H shorten while A and Z stay the same
what happens w/ ACh and Ca2+ during relaxation?
what is latent period in muscle contraction?
what is tetanus?
ACh is degraded in synapse by AChase, allowing sarcolemma to repolarize, and Ca2+ release ceases and Ca2+ is taken up by SR.
latent period is time b/w reaching threshold and onset of contraction, when AP spreads along muscle allowing Ca2+ to be released
when muscle contractions become so frequent that muscle is unable to relax and becomes fatigued
what are two supplemental energy reserves in muscle?
what does the axial skeleton consist of?
what tissue does bone derive from?
- creatine phosphate can be created during times of rest
- myoglobin reserves can be used for muscles during activity
skull, spinal cord, ribcage, hyoid bone
embryonic mesoderm
what are trabeculae?
where is marrow produced? red vs. yellow marrow
diaphysis vs. metaphysis vs. epiphysis
tendons vs. ligaments
the bony points in spongy bone?
produced in the cavities b/w trabeculae
- red is filled w/ hematopoietic stem cells (generate cells in blood)
- yellow composed of fate and is inactive
diaphysis are cylindrical shafts of bones, metaphysis are the wider parts of bones, and epiphysis is the ends of each bone
tendons connect muscle to bone, ligaments hold bones together at joints
what are the organic and inorganic components of bone matrix?
describe the following:
- osteons
- lamellae
- haversian vs volkmann’s canals, what do they contain?
- lacunae
- canaliculi
- organic - collagen, glycoproteins, other peptides
- inorganic - Calcium, phosphate, hydroxide
- osteons (haversian systems) - structural units of matrix
- lamellae - concentric circles of bony matrix in osteons
- haversian vs volkmann’s canals - haversian are longitudinal, volkmann’s are transverse; contain vessels, fibers
- lacunae - small spaces b/w lamellar rings that house osteocytes (mature bone cells)
- canaliculi - tiny channels that connect lacunae that allow for exchange of nutrients/wastes
what are the functions of osteoblasts and osteoclasts?
how does PTH affect bones? vit. D?
how does calcitonin affect bone growth?
- osteoblasts build bone
- osteoclasts (macrophages) resorb bone
PTH released by parathyroid glands in response to LOW Ca2+, promotes resorption of bone and increases Ca2+ and phosphate in blood
- vit.D is activated by PTH, causes resorption and thus encourages bone growth.
calcitonin is released by parafollicular cells of thyroid in response to HIGH Ca2+, promotes bone formation and lowers Ca2+ levels
what is chondrin?
endochondral ossificaiton vs intramembraneous ossification (where does it happen?
T or F the periosteum can differentiate into osteoblasts?
chondrin is firm/elastic matrix of cartilage
endochondral is process of cartilage hardening into bone, the cause of formation of long bones. intramembraneous is when undifferentiated embryonic connective tissue is transformed into/replaced by bone
- IN SKULL
TRUE
define the following about joints:
- synovial capsule -
- synovium -
- articular cartilage -
origin vs. insertion of bones
flexor vs. extensor
abductor vs adductor
medial vs lateral
- synovial capsule - encloses joint cavity
- synovium - layer of soft tissue which secretes synovial fluid (lubricates)
- articular cartilage - coats articular surfaces of bone so impact is restricted to lubricated joint cartilage, not bones
origin is end with larger muscle attachment, insertion is end with smaller attachment
- flexor vs. extensor - flexor decreases angle, extensor increases angle
- abductor vs adductor - abductor moves part of body away from midline, adductor moves it closer
- medial vs lateral rotation - medial rotates axis of limb toward midline, lateral rotates away
what is hemizygous?
complete dominance vs. codominance vs. incomplete dominance
penetrance vs. expressivity (constant and variable)
when only one allele is present for a given gene (parts of X chromosome for males)
complete dominance is one dominant and one recessive, codominance is when both are dominant (AB blood type), and incomplete dominance is when heterozygote expresses phenotype b/w both (pink flower)
penetrance is proportion of pop. w/ given genotype who actually express the phenotype; expressivity is diff. manifestations of same genotype across pop.
- constant expressivity is when all individuals w/ genotype express same phenotype, variable is same genotype but diff. phenotype
segregation and independent assortment allow for greater _________ in offspring
the centromere is where the ________ and ________ are held together
what is recombination in chromosomes?
genetic diversity
daughter strand and parent strand
small segments of genetic material are swapped b/w chromatids in homologous chromosomes
what is transforming principle?
mutation vs. wild type?
what is a transposon?
live, nonvirulent bacteria must have acquired the ability to form smooth capsules from dead virulent bacteria
mutation is change in DNA sequence of allele, while WT is normal/natural allele
an element that can insert/remove itself from DNA, causing mutation if in coding region
define the diff. point mutations (1 nucleotide swapped for another)
- silent
- missense
- nonsense
what is a frameshift mutation?
what does it mean if a mutation is deleterious? what are inborn errors of metabolism?
- silent - when change in nucleotide has no effect on final protein synthesized because of degeneracy
- missense - change in nucleotide result sin substituting 1 AA for another
- nonsense - when change in nucleotide results in substitution of STOP codon for AA
frameshift is when codon is inserted/deleted into genome
the mutation is detrimental to the organism
- inborn errors of metabolism are a type of deleterious mutation where there are defects in genes required for metabolism
what is genetic leakage?
define the following:
- genetic drift
- founder effect
- bottlenecks
what is inbreeding depression? outbreeding/outcrossing?
leakage is a flow of genes b/w species, sometimes producing hybrid offspring
- genetic drift - changes in composition of gene pool due to chance (more pronounced in small populations)
- founder effect - extreme case of genetic drift, small pop. finds itself in reproductive isolation from other populations as a result of natural barriers (or other bottlenecks)
- bottlenecks - drastically/suddenly reduce size of pop. available for breeding
inbreeding depression is the loss of genetic variation and a reduce in fitness of pop. outbreeding is introduction of unrelated individuals to group to increase variation
what is a test cross?
sex linked traits apply to X or Y?
what is the relationship b/w recomb. freq. and distance b/w genes
what is chiasma?
organism w/ unknown genotype is crossed w/ known homozygous recessive
- if all offspring are dominant, other is homozygous dominant
- if 1:1, heterozygous
- if all recessive, other is recessive too
X
they are proportional
point where 2 genes cross over
if 2 genes are 29 map units apart, what does that say about recombination?
what are 5 criteria for HW equilibrium?
29% of total gametes examined would show recombination somewhere b/w these two genes
- pop is very large (no drift)
- no mutations
- mating is random (no sexual selection)
- no migration in or out
- genes are all equally successful
T or F individuals evolve
what is inclusive fitness?
what does punctuated equilibrium suggest?
FALSE populations evolve
measure of organism’s succession pop. based on # offspring, success in supporting offspring, etc.
changes in some species occur in rapid bursts rather than evenly over time (opposes darwin)
stabilizing vs. directional vs. disruptive selection
what are polymorphisms?
- stabilizing keeps phenotypes within a specificities range by selecting against extremes (e.g. human birth weight)
- directional is when adaptive pressure leads to dominance of initially extreme phenotype (e.g. bacteria that are resistant to antibiotics)
- disruptive is when 2 extreme phenotypes are selected over the norm (e.g. finch beak size)
naturally occurring differences in form b/w members of same pop. (e.g. light&dark coloration of same butterfly)
what is adaptive radiation in the context of species? what is its benefit?
what is a niche?
describes rapid rise of a # of diff. species from a common ancestor
- benefit is that it allows for various species to occupy diff. niches
niche is specific environment (habitat, available resources, predators) for which a species is specifically adapted
prezygotic vs. postzygotic mechanisms
what happens if isolation occurs?
prezygotic prevent formation of zygote completely (e.g. breeding at diff times, diff niches, lack of attraction), postzygotic allow for gamete fusion BUT yield nonviable OR sterile offspring (offspring that can’t reproduce, infertile second generation)
the progeny of these populations could no longer freely interbreed. (separate species now)
divergent vs. parallel. vs convergent evolution
what is the molecular clock model?
- divergent is independent dev. of dissimilar characteristics in 2 or more lineages sharing a common ancestor (e.g. seals and cats are both mammals, yet differ in general appearance)
- parallel is process that related species evolve in similar ways for a long period of time in response to analogous environmental pressures
- convergent is independent dev. of similar characteristics in 2 or more lineages not sharing a common ancestor (e.g. fish and dolphins)
more similar genomes b/w two species, more recent they separated from one another
