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bio Flashcards

1
Q

where are the checkstops in cell cycle? what are each checkstop for and what proteins mediate it/

A

restriction point - G1 and S - sees if cells condition is good enough for replication, fixes damaged DNA. mediated by p53

between G2 and M - sees if size/organelles are adequate for replication, p53 also plays role

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2
Q

what are centrioles, centrosome, spindle fibers, asters, kinetochore/fibers

A

centrioles - where the spindle fibers will move outward from
centrosome- location at opposite end of cell where centrioles will travel to
spindle fibers - microtubules from centrosome which will either anchor or move toward the chromosomes
asters - spindle fiber microtubules which are anchored to cell wall
kinetochores - specific protein in centromeres where spindle fiber apparatus will attach to during metaphase

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3
Q

what are the two stages of meoisis?

A

I - reductional - diploid to haploid: homologous chromosomes are separated

II - equational: sister chromatids are separated

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4
Q

when does crossing over happen?

A

prophase

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5
Q

spermatogenesis? starting at the diploid sperm stem cell to spermatazoa

A

diploid sperm stem cell - spermatagonia
S phase - primary spermatocytes
1st division - secondary spermatocytes
2nd division - spermatids

spermatids mature into spermatozoa

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6
Q

what happens during oogenesis?

what stage is primary oocyte paused at?
what stage is secondary oocyte paused at until fertilization?

A

at birth, all oocytes are completed S phase so they are primary oocytes in prophase I

  • each month, one egg will undergo first meiotic division to become a secondary oocyte + polar body
    • stalled at metaphase II
  • will remain at metaphase II until fertilization
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7
Q

male sexual development - what does LH/FSH at puberty accomplish?

A

FSH - works on sertoli cells to cause maturation of sperm

LH - works on leydig cells to produce testosterone

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8
Q

what is progesterone secreted by in the female reproductive system? in response to?

A

corpus luteum in response to LH

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9
Q

which hormone forms corpus luteum from ruptured follicle?

A

LH

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10
Q

mendels 1st and 2nd law?

A

1st - law of independent assortment

2nd - law of segregation

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11
Q

what are the two hardy- weinberg principles?

what is equal to homozygous dominant?
heterozygous?
homozygous recessive?

A
  1. p + q = 1 (frequency of alleles)
  2. p^2 + pq + q^2 (frequency of genotypes and phenotypes)

homo dom - p^2
hetero - pq
homo rec - q^2

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12
Q

what is inclusive fitness?

A

it is part of the modern day neo-darwinism theory that reproductive success also depends on the ability of the parents to care for offspring, offspring to care for offspring, etc.

  • altruistic behavior promotes reproduction in a species
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13
Q

difference between darwin, neodarwin and punctuated equilibrium?

A

darwin - natural selection promotes evolution based on favorable traits that promote reproductive fitness

neo-darwin - modern - genetic recombination and mutation causes reproductive success, change is more likely to pass on to next generation - includes inclusive fitness (altruistic behavior)
-evolution happens evenly throughout time

punctuated equilibrium - that lineages stay the same for a long period of time, then there is a sudden burst of evolutionary change

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14
Q

three natural selection patterns?

A
  1. stabilizing - gets rid of extremes
  2. directional - pushes to one extreme
  3. divergent - pushes to both sides of extremes - can introduce speciation
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15
Q

patterns of evolution?

A

convergent, divergent, parallel

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16
Q

what path does sperm take ?

A

SEVEN UP

seminoferous tubule
epididymis
vas deferens
ejaculatory duct 
urethra 
penis
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17
Q

what is each cell’s function?
glial cells

astrocytes –
ependymal –
microglia –

A

glial cells – support cells such as astrocytes, ependymal cells, microglia, and oligodendrocytes

astrocytes – nourish neurons and forms BBB
ependymal – lines the ventricles and produce CSF
microglia – phagocytic cells in CNS

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18
Q

what ion is responsible for setting resting membrane potential?

what does the Na/K pump do?

A

potassium

restores resting membrane potential - Na/K pump pumps 3 Na+ out and 2 K+ in

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19
Q

sodium channels three states and their membrane potentials?

A

closed – before reaching threshold (-70 mV) and after inactivation has been reset
open – after reaching threshold (-50 mV)
inactivated – above +35 mV until back to resting

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20
Q

saltatory conduction –

A

ion movement only allowed at nodes of Ranvier; thus, the signal jumps node to node

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21
Q

white matter vs gray matter

A

white matter - axons

gray matter - cell bodies and dendrites

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22
Q

where in the spinal cord do sensory neurons enter?
where do motor neurons leave?
white matter is located inside/outside of spinal cord?

A

periphery, dorsal (back) of spinal cord - cell bodies of sensory neurons found in dorsal root ganglia

ventrally (near front of spinal cord)

white matter (axons) found outside area of spinal cord - grey matter (ganglia) found inside the spinal cord

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23
Q

difference between somatic and autonomic neurons:

A
  • motor neurons will go directly from the spinal cord to the muscle without synapsing
  • autonomic neurons will work in series to transmit messages from spinal cord (preganglionic and postganglionic)
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24
Q

differences between peptide/steroid hormones:

what are they made of/from?
can they cross membrane?
water/lipid soluble?
transient or long lasting?
quick or slow onset?
how do they modulate transcription?
carrier protein or no?
where are the receptors?
A

peptide hormones – made of amino acids
- are charged so they cannot cross membrane – must bind to extracellular receptor as first messenger  activates secondary messengers to activate signaling cascade

possibility for amplification – one hormone molecule can bind multiple receptors

  • since peptide hormones work strictly through secondary messengers, they are transient and quickly turned on and off
  • water-soluble  does not carrier proteins

steroid hormones – derived from cholesterol (produced by gonads and adrenal cortex)
- lipid-soluble  requires carrier proteins
o often inactive while in carrier protein

carrier proteins can be specific or nonspecific

  • receptors are INTRACELLULAR/INTRANUCLEAR
  • hormone-receptor complex will bind DNA to increase/decrease transcription
  • slower process, but will last longer
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25
Q

amino-acid derivative hormones: what receptors do catecholamines bind to?
thyroid hormones?

A

cat - g-coupled receptors

thyroid - intracellularly

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26
Q

how are anterior pituitary and hypothalamus connected?

A

hypophyseal portal system

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27
Q

homrones released from hypothalamus that stimulate release of hormones from anterior pituitary?

GnRH 
GHRH 
TRH 
CRF 
dopamine (PIF)
A 
 FSH and LH 
 GH
 TSH
 ACTH
- inhibits prolactin release
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28
Q

what is the hypothalamus’ interaction with the posterior pituitary?

A
  • hypothalamus sends axons down the pituitary stalk directly into posterior pituitary
  • releases oxytocin and ADH
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29
Q

what hormones are secreted by the anterior pituitary? are they tropic or direct?

A 
F- FSH
L- LH
A- ACTH
T- TSH
(tropic)

P-PROLACTIN
E- ENDORPHINS
G- GH
(direct)

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30
Q

how does GH promote growth of bones and muscle?

A

growth hormone – promotes growth of muscle and bone
- will inhibit uptake of glucose in cells that are not growing
- will breakdown FA to produce acetylcoA and stimulate gluconeogenesis
o both will increase levels of glucose overall for other cell’s growth

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31
Q

what are two functions of the thyroid?

A
  • controlled by thyroid stimulating hormone from anterior pituitary
  • two major functions:
    o setting metabolic rate via T3 and T4
    o promotes calcium homeostasis via calcitonin
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32
Q 
hypothyroidism vs hyperthyroidism:
activity level?
body temp?
respiration/heart rate?
weight?
A

hypothyroidism – lethargy, decreased body temp, slowed respiratory/heart rate, weight gain
hyperthyroidism – heightened activity level, increased body temp, high respiration/heart rate, weight loss

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33
Q

what kind of cells produce T3/T4? calcitonin?

A

follicular

parafollicular

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34
Q

what is parathyroid hormones job?

A
  • secretes parathyroid hormone – opposite function of calcitonin (will increase calcium levels in blood )
    o also activates vitamin D
    o increases reabsorption of phosphorus
35
Q

adrenal cortex :
what three steroids are secreted from here?

glucocorticoid steroids do what?

cortisol is considered a SLOW stress hormone why?

A

mineralcorticoid (aldosterone), sex cortisol (androgens) and glucocorticoids

glucocorticoid steroids – regulate glucose levels

  • include cortisol and cortisone – which increase blood glucose levels via gluconeogenesis and decreasing protein synthesis
  • cortisol is thought of as a stress hormone – because increase glucose levels in times of stress for utilization
36
Q

ADRENAL MEDULLA - what does it secrete and what do the hormones do?

A

responsible for production of epinephrine and norepinephrine (catecholamines)

  • both act as sympathetic nervous sytem stimulators
  • will dilate bronchi, increase heart rate and shunt blood to important organs that need blood in time of panic (heart, lungs, brain, muscle) and will divert blood away from skin, gut, kidneys
37
Q

why is the pancreas both exocrine and endocrine?

what is islet of langerhans?
what kind of hormone cells does the pancreas have and what do they secrete?

A

PANCREAS
both endocrine and exocrine functions

exocrine – secretes digestive enzymes
endocrine – secretes hormones

islet of Langerhans – clusters of hormone producing cells containing three distinct cell types; a-, B-, and G- cells

a- cells – secrete glucagon
B-cells – insulin
gamma cells – somatostatin

38
Q

what does somatostatin do? what is it stimulated by?

A
  • inhibitor of both glucagon and insulin

- stimulated by high glucose and amino acid concentration

39
Q

OTHER ORGANS that produce hormones and their functions?
kidneys –
heart –
thymus –

A

OTHER ORGANS
kidneys – produce erythropoietin: increases production of RBC in bone marrow
heart – ANP: regulates salt and water balance (will lower blood volume when atria is stretched)
thymus – thymosin: important for proper T cell differentiation

40
Q

what is the micturition reflex ?

A

micturition reflex – when the bladder is full, stretch receptors will cause parasympathetic neurons to fire and contract detrusor muscle and relax internal urethral sphincter

41
Q

Relative hydrostatic and oncotic pressure of glomerulus vs bowmans capsule: net flow??

A

Relative hydrostatic and oncotic pressure of glomerulus vs bowmans capsule: net flow
hydrostatic – much higher in GC compared to bowmans capsule (which causes blood to flow into bowmans capsule)
oncotic – blood osmolality is higher than bowmans capsule (which draws blood out of bowmans capsule)

since hydrostatic pressure difference is much higher than oncotic pressure, net flow is usually out of glomerulus into bowmans space

42
Q

osmotic pressure vs oncotic pressure ?

A

osmotic pressure – ‘sucking’ pressure that draws water into the vasculature caused by dissolved particles
oncotic pressure – osmotic pressure attributable to dissolved proteins

43
Q

what are the layers of the epidermis? what layer is only present in hairless skin (palm/sole of foot)?

which layer holds langerhan cells?

A

epidermis – divided into layers called strata (superficial to deep): COME, LETS GET SUN BURNED

  1. stratum corneum – contains flattened keratinocytes that forms barrier to prevent pathogen invasion/prevents loss of fluids and salts
  2. stratum lucidum – present only in thick, hairless skin (palm, sole of foot)
  3. stratum granulosum – keratinocytes die and lose their nuclei
  4. stratum spinosum – keratinocytes connect to each other, and contains langerhan cells
  5. stratum basale – contains stem cells and proliferate keratinocytes
44
Q

what layers does the dermis layer contain?
what kind of cells predominate in this layer?

merkel cells
meissners corpuscles
ruffini endings
Pacinian

A

dermis – contains two layers (superficial to deep):

  1. papillary – loose connective tissue
  2. reticular layer – sweat glands, blood vessels and hair follicles

most sensory information is in this layer:

  • merkel cells – deep pressure and texture
  • meissners corpuscles – light touch
  • ruffini endings – stretch
  • Pacinian – deep pressure and vibration
45
Q

cooling mechanisms?
sweating –
vasodilation

retaining heat mechanisms?
piloerection
vasoconstriction
shivering

A

cooling:
sweating – cooling mechanism
- controlled by the hypothalamus
- postganglionic sympathetic neurons  ACh to secrete water
- evaporation of sweat using body heat is the cooling mechanism

vasodilation – for heat loss because brings large volume of blood to the skin

retaining heat:
piloerection – arrector pili contract to cause the hairs of the skin to stand up on end

vasoconstriction – to decrease heat loss because not as much blood is brought to skin

shivering – skeletal muscle contracts rapidly
- requires a lot of ATP

46
Q

HUMORAL IMMUNITY – ___ cells, why?

CELL-MEDIATED IMMUNITY – ___ cells, why?

place for housing and activating B-cells, filters blood and lymph?
T cells mature here?
B cells mature where?

A

HUMORAL IMMUNITY – B cells will enter plasma to release antigens which will be dissolved in the blood

CELL-MEDIATED IMMUNITY – T cells directly kill virally infected cells

spleen – place for housing and activating B-cells
thymus – T cells mature here
bone marrow - where B cells mature

47
Q

GALT (gut associated lymphoid tissue) – immune tissue proximal to digestive system
- includes what 4 tissues?

function of lymph nodes?

A

GALT (gut associated lymphoid tissue) – immune tissue proximal to digestive system
- includes tonsils and adenoids, peyers patch in small intestine and appendix

filters lymph and is a site where immune response can be mounted

48
Q

what type of cells originate from hematopoietic stem cells ?

A

leukocytes (includes both agranulocytes and granulocytes)

RBC, platelets

lymphocytes - NK cells, B cells and T cells

49
Q

granulocytes have granules which secrete toxic enzymes and chemicals which can kill pathogens, bacteria, fungal infections
- includes what cells?

agranulocytes include?

A

granulocytes have granules which secrete toxic enzymes and chemicals which can kill pathogens, bacteria, fungal infections
- includes neutrophils, eosinophils, basophils

agranulocytes include:
lymphocytes – responsible for antibody production, immune system modulation
monocytes – phagocytic cells that become macrophages

50
Q

is complement innate or adaptive? what is it?

A

complement – proteins in the blood which act as nonspecific defense against bacteria
- can be activated by classical or alternative pathway

51
Q

cells of the innate immune system
macrophages:
- includes what three cells for example?

3 steps of an activated macrophage

MHC I –what type of cells, what type of proteins are presented?
- _________ pathway

MHC II – what type of cells? 4 examples?
- _______ pathway:

A

cells of the innate immune system
macrophages – agranulocyte, reside in tissue
- includes osteoclasts, microglia in NS, Langerhans cells in the skin

  1. phagocytizes invader
  2. digests using enzyme
  3. presents little piece of invader to other cells using MHC (which will be recognized by other cells of adaptive immunity)

MHC I – all nucleated cells, any protein produced within a cell can be presented with MHC I
- endogenous pathway: will present unfamiliar antigens from within cell when invaded and will be killed by T cells

MHC II – professional antigen-presenting cells (like macrophages, dendritic cells, B cells, epithelial cells)
- exogenous pathway: will pick up pathogens from environment and will eat them and the show protein (antigen) on surface

52
Q

what type of cell can recognize when MHC is being downregulated by a pathogen and induce apoptosis

A

NK

53
Q

what type of cell is the most popular leukocyte in blood and are very short lived
- target bacteria via opsonization

opsonization – ?

A
  • most popular leukocyte in blood and are very short lived
  • target bacteria via opsonization

opsonization – when bacteria is marked with antibody

54
Q

??

  • allergic reactions and invasive parasitic infections
  • release histamine  inflammatory response

??

  • allergic reactions
  • mast cells are closely related
  • release histamine  inflammatory response
A
  1. Eosinophils (granulocyte)
    - allergic reactions and invasive parasitic infections
    - release histamine  inflammatory response
  2. basophils (granulocyte)
    - allergic reactions
    - mast cells are closely related
    - release histamine  inflammatory response
55
Q

when Ab bind to antigen in body fluid, three main possibilities:
???

when antigen binds to Ab on B cell:

when antigen binds to Ab on mast cell:

A

when Ab bind to antigen in body fluid, three main possibilities:

  1. Ab attracts leukocytes via opsonization to phagocytose
  2. Ab may cause antigens to clump together or agglutinate forming large insoluble aggregates
  3. Ab may block ability of pathogen to invade tissue

when antigen binds to Ab on B cell:
1. will cause activation of B cell which results in its proliferation and memory of that antigen

when antigen binds to Ab on mast cell:
1. causes degranulation, releasing histamine

56
Q

variable region of Ab is for?

clonal selection ?

constant region of Ab is for?

5 different isotypes –?

A

variable region – at the end of Ab, antigen-binding region

  • will bind one, and only one, specific antigen
  • will undergo hypermutation, in order to find best match for antigen

clonal selection – all other B cells that don’t have specific antigen with high affinity will die

constant region – activates complement and phagocytosis during innate immunity

5 different isotypes – IgA, IgG, IgE, IgM, IgD (GAMED)

57
Q

naïve B cells will wait in lymph until activated by ____
- when activated, they will proliferate into two types of daughter cells, what are they and what do they do?

primary response vs secondary response

A

naïve B cells will wait in lymph until activated by antigen
- when activated, they will proliferate into two types of daughter cells: plasma B cells and memory B- cells

plasma B cells – produce large amount of antibodies
memory B cells – say in lymph awaiting re-exposure

primary response: initial activation – 7 days
secondary response: memory B- cells will live (whereas plasma will die) and will produce Ab against repeated pathogens

58
Q

helper T cells (CD__+) – ?

  • recruits what kind of cells?
  • respond what MHC? intra/extracellular?

cytotoxic T cells (CD__+) – ?
- mostly respond to MHC?

suppressor T cells – ?

A

helper T cells (CD4+) – coordinate immune response by secreting chemicals

  • recruits plasma B cells, cytotoxic T cells, and macrophages
  • respond to MHC II – target EXTRACELLULAR pathogens

cytotoxic T cells (CD8+) – directly kill cells by injecting them with toxic chemicals
- mostly respond to MHC I antigens, meaning they are better at targeting intracellular infections

suppressor T cells – contain protein Foxp3 which tones down immune system once infection is contained

59
Q

Bacterial (extracellular) infections events? (what class of MHC? what is attracted to site of infection?

what cells are responsible for bringing antigen from infection to lymph nodes to activate B cells?

A

Bacterial (extracellular) infections

  1. macrophages will phagocytose bacteria and MHC II will present antigen on cell surface
  2. will attract inflammatory cells such as neutrophils and more macrophages
  3. mast cells will release histamine to dilate vessels and allow more immune cells to localize
  4. dendritic cells then leave infection and travel toward lymph nodes to present antigen to B-cells
  5. B- cells produce Ab through clonal selection to create plasma and memory cells
  6. Ab will travel to site of infection and tag bacteria for destruction
  7. dendritic cells will also present antigen to T cells
    - CD4+ cells activated which recruits more macrophages
  8. plasma B cells die after infection is gone, but memory B and T cells remain
60
Q

viral (intracellular) infection events? (what does cell produce during viral infection? what class of MHC? what is attracted to site of infection?)

A

viral (intracellular) infections

  1. infected cell will produce interferons (decreasing ability of transcription/translation and causing flu like symptoms in host)
  2. MHC I presents proteins on surface (including viral ones)
  3. CD8+ recognizes foreign endogenous protein and will form complex, directly killing the cell
  4. in the case where a virus downregulates MHC, NK cells will cause apoptosis
61
Q 
immunization 
active immunity (natural vs artificial) vs passive immunity
A

immunization
active immunity – immune system stimulated to produce Ab against specific pathogen
- natural: Ab generated by B-cells after individual becomes infected
- artificial: (vaccines) results in generation of Ab by B-cells without ever experiencing infection

passive immunity – transfer of Ab to an individual

62
Q

lacteals – ?

A

lacteals – small lymphatic vessels are located at the center of villi in small intestine
- lymphatic fluid carrying many chylomicrons takes on a milky white appearance called chyle

63
Q

what are the three functions of the lymphatic system?

A
  1. equalization of fluid distribution
    - hydrostatic pressure pushing fluid out of the vessel at arteriole end is higher than oncotic pressure which draws fluid back into vessel
    o this leaves fluid in the tissue – which is drained by lymphatic vessels

edema will only occur if lymphatic vessels are overwhelmed or blocked

  1. transportation of biomolecules
    - transports fats from digestive system into the bloodstream
  2. immunity
    - place for maturation of B-cells and antigen-presenting cells
64
Q

vessels carry lymphatic fluid and joins ____ duct in the chest which delivers fluid to ______ vein

A
  • vessels carry lymphatic fluid and joins thoracic duct in the chest which delivers fluid to subclavian vein
65
Q

atria separated from ventricles by atrioventricular valves

  • left atrium: ?
  • right atrium: ?

ventricles are separated from vasculature by _____ valves

A

atria separated from ventricles by atrioventricular valves

  • left atrium: bicuspid (LAB)
  • right atrium: tricuspid (RAT)

ventricles are separated from vasculature by semilunar valves

66
Q

muscle cells of ventricles contain ______ discs with many ________ for a cohesive contraction

A

muscle cells of ventricles contain intercalated discs with many gap junctions for a cohesive contraction

67
Q

THREE PORTAL SYSTEMS?

A

THREE PORTAL SYSTEMS:

  1. hepatic portal system: blood leaving capillary beds of the gut will pass though hepatic portal vein before reaching capillary bed in the liver
  2. hypophyseal portal system: blood leaving capillary beds of the hypothalamus travels to capillary bed in anterior pituitary to allow for paracrine secretion of releasing hormones
  3. renal portal system: blood leaving glomerulus travels through efferent arterioles into vasa recta
68
Q

composition of blood:
plasma –?
serum – ?

cellular portion of blood includes ?

A

composition of blood:
plasma – liquid portion of blood (nutrients, gases, salts, hormones, blood proteins)
serum – plasma without clotting factors

cellular portion of blood includes erythrocytes, leukocytes and platelets

69
Q

ERYTHROCYTES – RBC

how many hemoglobin per cell?
how many oxygen molecules per hemoglobin?

  • biconcave:why?
  • when mature, what do they lose? what does this imply?
A

ERYTHROCYTES – RBC

  • specialized cells for oxygen delivery
  • each cell contains around 250 million molecules of hemoglobin, each that can bind 4 molecules of oxygen
  • biconcave: increases surface area and allows them to fit through capillaries
  • when mature, nuclei, mitochondria, and other membrane-bound organelles are lost
    o meaning they do not perform oxidative phosphorylation to generate ATP!
70
Q
  • erythropoietin from _____ will induce RBC formation

- thrombopoietin from ______will induce platelet formation

A
  • erythropoietin from kidney will induce RBC formation

- thrombopoietin from kidney and liver will induce platelet formation

71
Q

megakaryocytes

A

thrombocytes – platelets

- cell fragments released from cells in bone marrow called megakaryocytes

72
Q

where is the largest pressure drop in circulation?

A

from the arterioles to capillaries (because capillaries cannot withstand that much pressure)

73
Q

cooperative binding of oxygen to hemoglobin?

A

cooperative binding:
as first oxygen binds to hemoglobin, it changes conformation from taut to relaxed
- this makes it easier for subsequent oxygen to bind
as first oxygen leaves, it changes conformation resulting in subsequent release of oxygen

74
Q

Underneath the endothelial cells connective tissue containing collagen and tissue factor

  • When platelets touch _____ they will be activated and will aggregate
  • Coagulation factors (released from ____) will be activated by __________

Know that prothrombin is made into thrombin by ________
_________ then converts fibrin to fibrinogen (net-like structure)

A

Underneath the endothelial cells connective tissue containing collagen and tissue factor

  • When platelets touch collagen they will be activated and will aggregate
  • Coagulation factors (released from liver) will be activated by tissue factor

Know that prothrombin is made into thrombin by thromboplastin
Thrombin then converts fibrin to fibrinogen (net-like structure)

75
Q 
Z- line: ?
M- line: ?
I-band: ? 
H-zone: ? 
A-band: ?
A 
Z- line: length of sarcomere
M- line: center of sarcomere
I-band: thin filaments only 
H-zone: thick filaments only 
A-band: thick and thin
76
Q

what causes the powerstroke in cross bridge cycling?

what causes the dissociation between myosin and actin?

A

The dissociation of ADP and Pi causes the power-stroke, not the hydrolysis of ATP

ATP binding

77
Q

Creatine phosphate is created when???? and for what

A

Creatine phosphate is created DURING TIMES OF REST in order to make energy reservoirs for when energy is needed by the muscle

78
Q

Long bones:

diaphyses,?
metaphyses?
epiphyses?

epiphyseal plate?

A

Long bones: typically characterized by cylindrical shafts called diaphyses, that swell at each end to form metaphyses and terminate in epiphyses

at the epiphyses of long bones are mitotic cells that contribute to longitudinal growth (Growth plate)

79
Q

what is a periosteum

A

surrounds long bone to protect it and also serves as a site for muscle attachment

80
Q

Organic components of bone?

Inorganic components of bone?

A

Organic components include collagen, glycoproteins, peptides

Inorganic components include calcium, phosphate, hydroxide anions to form hydroxyapatite crystals

81
Q

BONY MATRIX ORDERED IN STRUCTURAL UNITS CALLED ??

harversian canals?
Volkmanns canals ?

Why does it hurt when you break a bone?

A

BONY MATRIX ORDERED IN STRUCTURAL UNITS CALLED haversian systems
Longitudinal – harversian canals
Transverse (to bone) – Volkmanns canals

these canals have blood vessels, lymph vessels and nerves in them!!!

82
Q

Reabsorption of bone means what?
what two things will activate reabsorption??

how is reabsorption good for bone growth?

what will cause bone formation in response to high calcium?

A

Reabsorption of bone will release calcium and phosphate into bloodstream!!

  • PTH activates vitamin D, which will also cause reabsorption of bone

REABSORPTION OF BONE PROMOTES BONE GROWTH BECAUSE IT RESULTS IN COMPENSATION OF OSTEOBLASTS AND FORMATION OF NEW STRONGER BONE

  • Calcitonin (from thyroid) will cause bone formation in response to high calcium
83
Q

Cartilage

  • Secreted by _____ and is made up of _______
  • Allows for flexibility
  • innervated? vascularized?
A

Cartilage

  • Secreted by chondrocytes and is made up of chondrin
  • Allows for flexibility
  • Is not innervated and is avascular
84
Q

Endochondral ossification – _______ to bone

Intramembranous ossification – _______ to bone

A

Endochondral ossification – cartilage to bone

Intramembranous ossification – undifferentiated embryonic connective tissue transformed into bone

MCAT (6 decks)

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