biology Flashcards
1
Q
four tenets of cell theory
A
- all living things are made of cells
- the cell is the basic functional unit of life
- cells arise from preexisting cells
- cells carry genes in DNA that is passed onto daughter cells
2
Q
viruses violate which two tenets of cell theory?
A
3 - do not reproduce on their own
4 - use RNA, not DNA
3
Q
prokaryotic cells are always ____________.
A
unicellular
4
Q
what do membrane-bound organelles allow for?
A
compartmentalization of function
5
Q
eukaryotic cells have a membrane-bound ________ that contains ______ in the form of chromosomes. they reproduce via __________.
A
nucleus
DNA
mitosis
6
Q
what surrounds the nucleus?
A
nuclear membrane/envelope, double-layered with nuclear pores to allow exchange
7
Q
what is the dark spot on a nucleus? what does it do?
A
nucleolus
it synthesizes rRNA
8
Q
cytoplasmic/extranuclear inheritance
A
transmission of genetic material independent of the nucleus
9
Q
serial endosymbiosis theory
A
some organelles (mitochondria) arose when an anaerobic prokaryote ate an aerobic prokaryote and formed a symbiotic relationship
10
Q
autolysis
A
lysosomes release catalytic enzymes, leading to apoptosis by direct breakdown of cellular components
11
Q
peroxisome functions
A
- breakdown long chain FA by beta-oxidation
- synthesize phospholipids
- role in pentose phosphate pathway
12
Q
microfilaments are made up of
A
solid polymerized rods of actin
13
Q
roles of microfilaments (3)
A
- protection, resistant to compression/fracture
- contraction, interact with myosin
- cytokinesis, forms cleavage furrow
14
Q
microtubules are made up of
A
hollow polymers of tubulin
15
Q
roles of microtubules (3)
A
- pathway for proteins, i.e., kinesin and dynein
- motility, make up flagella and cilia
- mitosis, attach to kinetochores and pull apart sister chromatids
16
Q
cilia
A
projections from cell involved in movement of material along the surface
17
Q
flagella
A
involved in movement of the cell itself
18
Q
eukaryotic flagella/cilia structure
A
9 + 2
nine pairs of MT in outer ring
two MT in center
19
Q
centrioles
A
located in centrosome, organize microtubules for mitotic spindle
20
Q
intermediate filaments are made up of
A
filamentous proteins (i.e., keratin, desmin, vimentin, lamin)
21
Q
roles of intermediate filaments
A
cell-cell adhesion
integrity of cytoskeleton
22
Q
formation of epithelial tissue
A
epithelial cells connect together & to the basement membrane below them (connective tissue)
23
Q
epithelial cells constitute the
A
parenchyma (functional unit of organ)
24
Q
epithelial tissue by layer classifications (3)
A
- simple - one layer of cells
- stratified - multiple layers of cells
- pseudostratified - one layer but look like multiple due to heights
25
epithelial tissue by shape classifications (3)
1. cuboidal - cubed
2. columnar - long and thing
3. squamous - flat and scale-like
26
connective tissue constitute the
stroma (support of organ)
27
bone, cartilage, tendons, ligaments, fat, and blood are examples of
connective tissue
28
cells in connective tissue produce/secrete collagen and elastin to form
the extracellular matrix
29
prokaryotes do not contain ______________ and they have a single ________ DNA in an area called the __________
membrane-bound organelles
circular
nucleoid
30
eukaryotes are most similar to which prokaryote?
archaea
31
shapes of bacteria (3)
1. cocci - spherical
2. bacilli - rod
3. spirilli - spiral
32
what three structures do bacteria share with eukaryotic cells?
1. cell membrane
2. cytoplasm
3. flagella/cilia
33
obligate aerobes
require oxygen for survival
34
anaerobes
do not require oxygen for survival
35
obligate anaerobe
die in oxygen
36
facultative anaerobe
can use oxygen if present, but switch if not
37
aerotolerant anaerobe
don't use oxygen but don't die if its there
38
what do prokaryotes have for protection that eukaryotes dont?
cell wall
39
envelope of prokaryote
contains external cell wall + internal cell membrane
40
gram positive cell wall
absorbs crystal violet and appears purple with safranin
41
gram negative cell wall
does not absorb crystal violet and appears pink/red with safranin
42
what do gram positive cell walls contain
1. peptidoglycan - protection
| 2. lipoteichoic acid - trigger human immune response
43
what do gram negative cell walls contain
outer membranes of phospholipids/lipopolysaccharides - produce a strong human immune response
44
periplasmic space
space between cell wall and peptidoglycan cells
45
structure of bacterial flagella
1. filament - helix of flagellin
2. basal body - anchors flagellum to membrane, rotates up to 300 Hz
3. hook - connects filament to body to allow propulsion when basal body rotates
46
true histones are in
archaea and eukaryotes
47
how do prokaryotes reproduce
binary fission
48
steps of binary fission
1. circular DNA attaches to cell wall
2. DNA replicates
3. cell grows
4. plasma membrane and cell wall grow inward
5. pinch off and produce two cells
this occurs very rapidly
49
virulence factors
traits that increase pathogenicity
50
episomes
type of plasmid that can integrate into the genome of the bacteria
51
types of genetic recombination in prokaryotes
1. transformation
2. transduction
3. conjugation
52
transformation
integration of foreign genetic material into the host genome
53
conjugation
donor male (+) transfers genetic information to recipient female (-) across a conjugation bridge
54
what forms the conjugation bridge
sex pili, found in donor male
55
how are sex pili formed?
donor male has sex factor plasmids that contain genes needed (ex: F factor)
56
transduction
requires a vector (virus), the bacteriophage accidentally picks up DNA from a bacteria and shares it when it infects another
57
bacteriophage
virus that infects bacteria
58
transposons
can insert and remove themselves from genome
59
phases of bacterial growth
1. lag - adjust to new environment
2. exponential - exponential increase in # of bacteria with division
3. stationary - reduction in resources slows reproduction
4. death - depletion of resources leads to death
60
a straight line on a semiolog plot indicates
exponential growth
61
virus composition
1. genetic material (RNA/DNA)
2. protein coat (capsid)
3. lipid envelope (phospholipids/proteins)
62
which viruses are easier to kill? why?
enveloped, the envelope is sensitive to heat and detergents
63
why are viruses obligate intracellular parasites?
they lack ribosomes to carry out protein synthesis
64
what other structures do bacteriophages have?
1. tail sheath - syringe to inject bacteria
| 2. tail fibers - help recognize the correct host
65
types of single-stranded RNA viruses
positive
| negative
66
positive sense ssRNA virus
genome can be translated by ribosomes of the host cell (mRNA -> protein)
67
negative sense ssRNA virus
RNA acts as a template for synthesis of a complementary strand, which then can be used to make a protein (RNA -> mRNA -> protein)
68
what do negative sense RNA viruses require?
RNA replicase to make the complementary strand
69
retroviruses
example of enveloped ssRNA, DNA inserted into host and integrated into the genome
RNA --> DNA --> RNA --> proteins by reverse transcriptase
70
infection of virus
must bind to receptors
if enveloped, it fuses with membrane and enters the cell
if bacteriophage, it injects material
71
translation of virus
- DNA -> nucleus -> mRNA -> cytoplasm -> proteins
- + ssRNA -> cytoplasm -> protein
- - ssRNA -> mRNA by replicase -> protein
- > ssRNA -> DNA in retrovirus -> genome of bacteria -> protein
72
progeny release of virus
1. cell death - releases contents
2. lysis - cell gets too big and bursts, not advantageous because it kills cell
3. extrusion - fuses with membrane, productive
73
bacteriophage cycles
lytic and lysogenic
74
lytic cycle
virulent! maximize cell, don't care about its survival. once it reproduces, cell lyses
75
lysogenic cycle
provirus/prophage! virus replicated in bacterium genome
76
prions
infectious proteins, trigger misfolding
77
viroids
small pathogens of ssRNA that infect plants
78
what form is DNA in during interphase? why?
chromatin, must be less condensed to allow RNA polymerase to bind
79
what must be met to pass the G1/S checkpoint?
aka restriction point, is DNA good enough for synthesis?
80
of chromatids ______ entering G2. # of chromosomes _______.
double, stay the same
81
what must be met to pass the G2/M checkpoint?
there must be enough organelles and cytoplasm for two cells & there must be no errors in DNA replication
82
what protein controls the G1/S and G2/M checkpoints?
p53
83
cyclin-CDK role in checkpoints
CDK require the right cyclins
cyclins increase/decrease during stages
CDK-cyclin form complex that phosphorylates TF
TF promote transcription of genes for the next stage of the cycle
84
TP53
mutation of p53 gene, cell cycle is not stopped to repair DNA damage
85
meiosis I
reductional, results in haploid daughter cells with 1/2 ploidy
separation of homologous chromosomes
86
meiosis II
equational, generates haploid daughter cells with same ploidy
separates sister chromatids
87
synapsis
intertwining of homologous chromosomes
88
synaptonemal complex
holds together the homologous chromosomes
89
chiasma
point of contact between homologous chromosomes
90
Mendel's second law of independent assortment
inheritance of an allele (genes of trait) are independent of inheritance of other alleles
91
homologous chromosomes are lined up at the metaphase plate & held by
one spindle fiber
92
Mendel's first law of segregation
distribution of homologous chromosomes is random with respect to parental origin (can get all moms in one cell, or one mom and two dad)
93
SRY gene
Y-linked gene, codes for a TF that initiates testes formation
94
seminiferous tubules
produce sperm
95
what cells nourish the seminiferous tubules
sertoli
96
what cells produce testosterone/androgens
Leydig
97
why is the scrotum below the penis
allows it to maintain a temperature 2-4 Celsius below body temperature
98
pathway of sperm
SEVEN UP
| seminiferous tubules, epididymis, vas deferens, ejaculatory duct, nothing, urethra, penis
99
where does sperm gain motility
in the epididymis
100
where is sperm stored
epididymis
101
what produces seminal fluid
seminal vesicles, prostate gland, and bulbourethral gland
102
what do the seminal vesicles add to the seminal fluid
fructose to nourish sperm & alkalinity for survival in the female tract
103
what does the prostate add to the seminal fluid
it makes it milky & alkaline to survive in the female
104
what do the bulbourethral (Cowper's) glands give to the seminal fluid
clear viscous fluid that cleans urine & lubricates the urethra
105
sperm + seminal fluid =
semen
106
steps of spermatogenesis (4)
1. S = spermatogonia -> primary spermatocytes
2. MI = primary spermatocytes -> secondary spermatocytes (n)
3. MII = secondary spermatocytes -> spermatids
4. maturation = spermatids -> spermatozoa
107
how many spermatozoa does one spermatogonium produce
4
108
midpiece of sperm
filled with mitochondria, generate energy to swim
109
head of sperm
covered by acrosome, penetrates ovum
110
what produces estrogen and progesterone
ovaries
111
what structure contains, nourishes, and protects ova
follicles
112
pathway of ovum each month
FPFUCV
1. follicle
2. peritoneal sac, lines abdominal cavity
3. Fallopian tube/oviduct, cilia propels egg forward
4. uterus
5. cervix, end of uterus
6. vaginal canal
113
steps of oogenesis (3)
1. S = primary oocytes, occurs by the time you are born
2. M1 = primary oocyte -> secondary oocyte + polar body
3. M2 = secondary oocyte -> mature ovum + polar body
114
primary oocytes are arrested in
prophase I
115
secondary oocytes are arrested in
metaphase II
116
when do primary oocytes complete meiosis I
when menarche occurs
117
when do secondary oocytes complete meiosis II
when fertilization occurs
118
zone pellucida
surrounds oocyte for protection
contains compounds needed for sperm to bind
mixture of glycoproteins
119
corona radiata
outside Zona pellucida
layer of cells that adhere during ovulation
triggers meiosis II when a sperm penetrates them
120
ovum contributes what to the zygote?
half DNA
all organelles
all RNA
121
gonadotropin-releasing hormone
secreted by hypothalamus
| triggers anterior pituitary gland to secrete LH and FSH
122
FSH acts on
Sertoli cells - sperm production
| ovaries - release of estrogens
123
LH acts on
interstitial leydig cells - release testosterone
| ovaries (CL) - release progesterone
124
testosterone levels throughout life
low, increases at puberty, remains high in adulthood, decreases when old
125
functions of estrogens (3)
1. develop/maintain female reproductive system and secondary characteristics
2. in embryo - stimulate development of reproductive tract
3. in adult - thicken the endometrium to prepare for implantation
126
what secretes progesterone
corpus luteum (remains of follicle after ovulation)
127
function of progesterone
development and maintenance of endometrium, not thickening
128
follicular phase
with period, estrogen/progesterone decrease
increases GnRH, FSH, and LH
follicle grows
estrogen increases
- negative feedback = GnRH, LH, and FSH decrease
- endometrium lining regrows
129
ovulation
```
follicle really big
estrogen reaches peak
- positive feedback = GnRH, LH, and FSH spike
LH spike induces ovulation
follicle ruptures and releases egg
```
130
luteal phase
ruptured follicle forms corpus luteum
progesterone increases
- negative feedback = decrease GnRH, LH, TSH
- prevents ovulation of more eggs
131
menstruation
```
without fertilization, corpus luteum dies
decrease progesterone
- no maintenance of endometrium
- endometrium sheds
decrease estrogen and progesterone
- GnRH increases, cycle repeats
```
132
pregnancy
if fertilization occurs, zygote -> blastocyst that implants in lining
blastocyst releases hCG which mimics LH
LH maintains corpus luteum
by second trimester, hCG decreases
progesterone and estrogen remain high by placenta
133
menopause
ovaries less sensitive to LH and FSH
ovaries die off
estrogen and progesterone decrease
endometrium dies and menstruation stops
negative feedback removed so LH and FSH increase
- causes the bad symptoms like hot flashes
134
what part of the Fallopian tube does fertilization occur?
ampulla
135
what occurs immediately after penetration?
cortical reaction
136
cortical reaction
release of calcium ions
137
what is the purpose of cortical reaction depolarization
prevents fertilization by other sperm
| increases metabolic rate of zygote
138
what ratios does cleavage increase
nuclear:cytoplasmic
surface area: volume
increases exchange
139
two types of cleavage
indeterminate - cells that can develop into complete organisms
determinate - cells determined to become a certain cell type
140
morula
solid mass of cells
141
blastula
hollow ball of cells
142
trophoblast cells
surround blastocoel and give rise to chorion/placenta
143
inner cell mass
protrudes into blastocoel and gives rise to the organism
144
what embryonic stage implants in the endometrium
blastula
145
chorion
extraembryonic membrane that becomes the placenta
146
trophoblast cells become
chorionic villi
147
chorionic villi
projections that penetrate the endometrium & support maternal-fetal gas exchange in placenta
148
what connects the embryo to the placenta
umbilical cord
149
what makes up the umbilical cord
two arteries - deoxygenated blood/waste to placenta
| one vein - oxygenated blood/nutrients to embryo
150
allantois
involved in early fluid exchange between embryo and yolk sac
151
amnion
surrounds allantois, filled with amniotic fluid to acts as a shock absorber
152
archenteron
membrane invagination into blastocoel
153
what does the archenteron become
gut
154
blastopore
opening of the archenteron
155
in deuterostomes (humans), what does the blastopore become
anus
156
in protostomes, what does the blastopore become
mouth
157
what does the ectoderm develop into
"attractroderm"
| cosmetic features, integumentary system, and nervous system
158
what does the mesoderm develop into
"meansoderm"
means of getting around
MS, circulatory, excretory
gonads, adrenal cortex
159
what does the endoderm develop into
"endernal"
lingings of digestive and respiratory tracts
pancreas, thyroid, bladder, liver
160
what forms to notochord
mesodermal cells
161
what does formation of the notochord do
induces ectoderm cells to slide inward and form neural folds
162
what forms the central nervous system
neural tube
163
what forms the peripheral nervous system
nerve crest cells
164
spina bifida
parts of NS are exposed or covered with a thin membrane
| often from folic acid deficiency
165
anencephaly
brain fails to develop
166
first stage of cell specialization
specification
167
specification
reversibly designated as a specific cell type
168
determination
commitment of a cell to a particular function, irreversibly committed
169
morphogens
molecules that cause neighboring cells to follow a particular developmental pathway
170
differentiation
assuming the structure, function, and biochemistry of the designated cell type
171
stem cells
cells that have not differentiated and can give rise to others cells that will differentiate
172
totipotent
stem cells that can differentiate into any cell type
| cells before the three germ layers
173
pluripotent
cells can differentiate into any cell type, except placental types
cells are primary germ layer
174
multipotent
cells can differentiate into multiple types of cells within a tissue group
ex: hematopoietic can become all cells in blood but not neurons
175
autocrine signaling
signaling the cell that releases the signal
176
paracrine signaling
signals act on cells in the vicinity
177
juxtracrine signaling
signals by directly stimulating the adjacent cell
178
endocrine signaling
signaling through hormones to a distant target
179
cell --> apoptotic blebs ---> apoptotic _______
bodies
180
what is the purpose of apoptotic blebs
to maintain harmful substances inside a membrane
181
necrosis vs apoptosis
necrosis - cell death by injury, internal substances are released
apoptosis - programmed cell death, internal substances maintained in membrane and eaten by phagocyte
182
complete regeneration
lost/damaged tissue is replaced with identical tissue
183
incomplete regeneration
new tissue is not identical in structure or function to the tissue that was lost/damaged
184
how do nutrients and gas exchange between mother and fetus
diffusion, mother must have a higher partial pressure of oxygen
185
other than diffusion, how do fetuses receive oxygen from mother?
HbF, higher affinity for oxygen than HbA in the mother
186
do fetus and mother blood mix?
NO
187
umbilical arteries cary blood ________ the fetus _____ the placenta
from the fetus
| to the placenta
188
umbilical vein carries blood _________ the fetus _______ from the placenta
to the fetus
| away from the placenta
189
what do the umbilical arteries carry
deoxygenated blood and waste
190
what does the umbilical vein carry
oxygenated blood
191
where does gas exchange occur in a fetus
placenta, lungs do not function until birth
192
where does detoxification and metabolism occur in a fetus
placenta, liver does not function until birth
193
why do fetuses have shunts to carry blood away from the liver/lungs
they are still developing and are sensitive to high blood pressure
194
what shunts move blood from the lungs
foreamen ovale and ductus arteriosus
195
foreamen ovale
one-way valve connecting right atrium to left atrium, bypasses lungs
blood bypasses the right ventricle and is pumped into circulation directly
196
which side of the heart has higher pressure in fetuses
right side
197
which side of the heart has a higher pressure when born
left, closes foreman ovale
198
ductus arteriosus
pumps oxygen-rich blood from pulmonary artery to the aorta, bypasses lungs
199
ductus venosus
connects umbilical vein to the inferior vena cava, bypasses liver
oxygenated blood mixes with deoxygenated blood
enters right side of heart into atrium
200
what trimester does the embryo become a fetus
first
201
what trimester does organogenesis occur
first
202
what trimester does the most growth occur
second
203
what trimester does the fetus resemble a human
second
204
what month of pregnancy is antibody transfer the highest
ninth month
205
what hormones coordinate parturition
prostaglandins and oxytocin
206
what trimester does fetal movement begin
second
207
what is a structural difference between the autonomic and somatic NS?
autonomic NS has preganglionic and postganglionic neurons
208
the knee-jerk reflex is a _________________ reflex arc
monosynaptic, sensory neuron synapses on motor neuron
209
the withdrawal reflex is a _________________ reflex arc
polysynaptic
| the sensory neuron synapses on an interneuron that synapses on a motor neuron
210
types of hormones by chemical structure
peptides
steroids
AA derivatives
211
what are peptide hormones derived from
polypeptides that are cleaved during post translational modification
212
where are hormones activated
Golgi apparatus
213
how do peptide hormones activate second messenger
they bind to a receptor on the cell, do not enter the cell because they are charged
214
peptide hormones are ________-soluble
water
215
peptide hormone effects are _________ and _____________
rapid and short-lived
216
what are steroid hormones derived from
cholesterol
217
steroid hormones are _________-soluble
lipid, they easily cross the membrane
218
steroid hormone effects are __________ and ___________
slow and longer-lived
219
why are steroid hormones longer-lived?
they directly participate in gene regulation
220
what receptors do steroid hormones bind to
intracellular, form a complex that binds to DNA to alter transcription
221
what can change the levels of active steroid hormones?
carrier proteins, more protein bound = less blood levels
222
insulin is a type of __________ hormone
peptide
223
estrogen and testosterone are types of __________ hormones
steroid
224
epinephrine and thyroxine are types of __________ hormones
AA derivative
225
what are AA derivative hormones derived from
one or two AA
226
what type of receptor do AA derivative hormones bind
all kinds
catecholamines bind to GPCR
thyroid bind to intracellular
227
mnemonic for hormone type
- in/-ine tend to be peptide and AA derivative
| - one/-oid tend to be steroid
228
tropic vs direct hormone
direct hormone acts directly on tissue (ex: insulin acts on muscle to secrete glucose)
tropic hormone has an intermediary (ex: LH acts on ovary to release another hormone progesterone)
229
how does the hypothalamus control the pituitary gland
paracrine, it releases hormones into a portal system that connects them
230
what portal system does the hypothalamus secrete its hormones into
hypophyseal portal system
231
what part of the pituitary gland does the hypophyseal portal system connect to
anterior
232
GnRH by hypothalamus --> _________ by pituitary
LH and FSH
233
GHRH by hypothalamus --> _________ by pituitary
growth hormone
234
TRH by hypothalamus --> _________ by pituitary
thyroid-stimulating hormone (TSH)
235
CRF by hypothalamus --> _________ by pituitary
adrenocorticotropic hormone (ACTH)
236
PIF/dopamine by hypothalamus --> _________ by pituitary
DECREASE in prolactin release
237
how does the posterior pituitary respond to the hypothalamus
it receives axons
238
what does the posterior pituitary secrete
oxytocin and antidiuretic hormone (ADH)
239
what does the anterior pituitary secrete
FLAT PEG
indirect: FSH, LH, ACTH, TSH
direct: prolactin, endorphins, GH
240
prolactin
stimulates lactation in the mammary glands
241
steps of lactation
1. nipple stimulation activates hypothalamus
2. posterior pituitary releases oxytocin
contracts nipple to release milk
3. anterior pituitary stops receiving dopamine/PIF
prolactin release, production of milk
242
endorphins
decrease perception of pain
243
growth hormone
promotes growth of bone and muscle, needs glucose
prevents glucose uptake in tissues not growing
stimulates breakdown of fatty acids
244
what causes gigantism
excess GH in childhood
245
what causes dwarfism
deficits in GH in childhood
246
what causes acromegaly
GH acts on small bones in adults, long bones are sealed
247
ADH
secreted in response to low blood volume or increased blood osmolarity
increases permeability of collecting duct to water, reabsorbs water
increased BP and blood volume
248
where are oxytocin and ADH synthesized
hypothalamus
249
where are oxytocin and ADH stored
posterior pituitary
250
two major functions of the thyroid
1. setting basal metabolic rate
| 2. promoting calcium homeostasis
251
how does the thyroid set the basal metabolic rate
releasing triiodothyronine (T3) and thyroxine (T4)
252
how does the thyroid promote calcium homeostasis
releasing calcitonin
253
what do the numbers mean in T3 and T4
number of iodine added to tyrosine from the follicular cells
254
what does T3 and T4 increase
cellular respiration
| increases protein and FA turnover
255
what does T3 and T4 decrease
TSH and TRH synthesis
256
cretinism
intellectual disability and developmental delay caused by deficiency in thyroid levels
257
what produces thyroid hormones
follicular cells
258
what produces calcitonin
parafollicular (C) cells
259
what does calcitonin decrease
calcium
260
how does calcitonin decrease calcium
increasing excretion from kidneys
decrease absorption from gut
increasing storage in bone
261
what does parathyroid hormone do
increase calcium
maintain phosphorous homeostasis
activates vitamin D
262
how does parathyroid hormone increase calcium
decreases excretion by kidneys
increases absorption in gut (using vitamin D)
increases bone resorption
263
how does parathyroid hormone alter phosphorous
increases resorption from bone
| reduces reabsorption in kidney, excretes it
264
what is parathyroid hormone effect on phosphorous
minimal, just keeps it stable
265
what does the adrenal cortex secrete
corticosteroids
266
what are the types of corticosteroids
glucocorticosteroids
mineralocorticoids
cortical sex hormones
267
what type of steroid are glucocorticosteroids
steroid
268
what do cortisol and cortisone do
1. raise blood glucose - increase gluconeogenesis, decrease protein synthesis
2. decrease inflammation
269
pathway before glucocorticoid release
CRF from hypothalamus -> ACTH from anterior pituitary -> glucocorticoids from adrenal cortex
270
function of mineralocorticoids
salt and water homeostasis
271
aldosterone function
1. increases sodium reabsorption - water follows, increases BV/BP
2. decreases K+/H+ reabsorption
272
aldosterone __________ osmolarity
does not change
273
ADH ___________ osmolarity
decreases, only reabsorbs water
274
pathway to aldosterone secretion
decrease BP activates juxtaglomerular cells of kidney --> renin secretion
angiotensin -> angiotensin I by renin
angiotensin I -> angiotensin II by angiotensin-converting enzyme (ACE)
angiotensin II acts on adrenal cortex -> aldosterone
275
what are the cortical sex hormones
estrogens and androgens
276
an excess of cortical sex hormones could cause
ambiguous or masculinized genitalia in women
277
what does the adrenal medulla produce
epinephrine and norepinephrine
278
what part of the pancreas produces hormones
islets of langerhans
279
what do the alpha islet secrete
glucagon
280
what do the beta islet secrete
insulin
281
what do the delta islet secrete
somatostatin
282
what does glucagon do
increase blood glucose
| triggers glycogenolysis, gluconeogenesis, and breakdown of FA/proteins
283
what triggers glucagon release
low blood glucose
cholecystokinin
gastrin
284
what does insulin do
decrease blood glucose
| triggers uptake of glucose my muscle/liver and FA/protein synthesis
285
what causes type I diabetes
autoimmune destruction of beta islet cells, low/absent insulin production
286
what causes type II diabetes
receptor-level resistance to insulin effects
287
somatostatin
inhibits insulin and glucagon secretion
| decreases GH secretion
288
what triggers somatostatin secretion
high blood glucose and AA concentration
289
what does the pineal gland secrete
melatonin
290
erythropoietin
stimulates bone marrow to increase production of RBC
291
what stimulates secretion of erythropoietin by the kidneys
low oxygen
292
what releases ANP
the heart
293
ANP
promotes exertion of sodium, opposite of aldosterone
294
what releases thymosin
thymus
295
thymosin
important for propter T-cell development and differentiation
296
what passes through the pharynx
food and air, at the back of your mouth
297
what passes through the larynx
air, below the pharynx
298
the glottis (opening of larynx) is covered by the _________ during swallowing
epiglottis
299
visceral pleura
surface adjacent to the lung
300
parietal pleura
outer part of the pleura covering the lung
301
what divides the thoracic cavity from the abdominal cavity
diaphragm
302
what NS controls the diaphragm
somatic
303
what kind of muscle is the diaphragm
skeletal
304
external intercostal muscles
layer of muscles between the ribs
305
stages of negative-pressure breathing
1. diaphragm contacts
2. chest wall expands
3. intrathoracic volume increases
4. intrapleural space volume increases
5. intrapleural pressure decreases
6. lungs give air to intrapleural space
7. lung pressure decreases
8. outside air comes in to restore
306
what muscles are used during inhalation
diaphragm and external intercostal muscles
307
what muscles does passive exhalation use
external intercostal and diaphragm, just relaxes them
308
what muscles does active exhalation use
internal intercostal muscles and abdominal muscles
309
total lung capacity
maximum volume when you inhale
310
residual volume
leftover volume when you exhale completely
311
vital capacity
difference between minimum and maximum air
312
tidal volume
volume inhaled or exhaled with a normal breath
313
expiratory reserve volume
volume of extra air you can exhale after a normal exhale
314
inspiratory reserve volume
volume of extra air you can inhale after a normal inhale
315
hypercarbia/hypercapnia results in
increase in respiratory rate
316
hypoxemia must be severe to
decrease respiratory rate
317
where do pulmonary arteries come form
the right ventricle of the heart
318
what do pulmonary arteries carry
deoxygenated blood
319
where does the pulmonary vein go
to the left atrium of the heart
320
what do the pulmonary veins carry
oxygenated blood
321
lungs play a role in pH by
adjusting carbon dioxide levels
322
the right side of the heart pumps
deoxygenated blood to the lungs
323
where does oxygenated blood return to the heart
left side
324
pulmonary circulation
blood from body -> right heart -> lungs
| via vena cava and pulmonary arteries
325
systemic circulation
blood from lungs -> left side of heart -> body
| via pulmonary vein and aorta
326
what blood enters the right side of the heart
deoxygenated
327
what blood enters the left side of the heart
oxygenated
328
what valves separate the ventricles from the vasculature
semilunar valves
329
what valve separates the right atrium and ventricle
tricupsid
330
what valve separates the left atrium and ventricle
mitral/bicupsid
331
what are the two atrioventricular valves
tricuspid and bicupsid
332
what are the two semilunar valves
pulmonary valve and aortic valve
333
how many leaflets do the semilunar valves have
3
334
which side of the heart is more muscular? why?
left, it must push blood to the whole body
335
pathway of cardiac electrical impulse
SABP - sam always bugs people
| SA, AV, bundle of His, Purkinje
336
how many signals does the SA node generate? how?
60-100 per minutes, it does this without NS input (myogenic)
337
where is the SA node
wall of the right atrium
338
atrial systole
contraction of both atriums due to SA node impulse, results in an increase in pressure that pushes more blood into the ventricles
339
atrial kick
extra blood that flows into ventricle during asystole
340
where is the AV node
between atria and ventricles
341
what happens at the AV node
signal is delayed to allow ventricles to fill completely
342
where is the bundle of His
interventricular septum
343
what do the Purkinje fibers do
distribute the electrical impulse through the ventricular muscle
344
what allows for coordinated ventricular contraction
intercalated discs of muscle cells, gap junctions connect cytoplasm
345
how does the sympathetic system alter the heart
speeds up HR and increases contractility
346
how does the parasympathetic system alter heart
slow down HR, through the vagus nerve
347
systole
```
ventricles contract, blood pumped out
AV valves (bicupsid/tricupsid) close
```
348
diastole
ventricles relax, blood filling from atria
AV (bicupsid/tricupsid) valves open
semilunar (aortic/pulmonary) valves closed
349
what allows arteries to maintain pressure when ventricles are not contracting
elasticity
350
cardiac output
total volume of blood pumped by a ventricle in one minute
| CO = HR (bpm) x SV (stroke volume = volume pumped per beat)
351
arteries --> _____________ --> capillaries
arterioles
352
capillaries --> venues --> _______
veins
353
what lines blood vessels
endothelial cells
354
how do endothelial cells maintain the vessel (3)
release chemicals for vasodilation and vasoconstriction
allows WBC to pass through during inflammation
release chemicals when damaged to form blood clots
355
which has more smooth muscle? veins or arteries.
arteries
356
arterioles
smaller, muscular arteries
357
arteries move blood away _________ to ___________
away from the heart
| to the lungs and body
358
which arteries contain deoxygenated blood
pulmonary arteries
| umbilical arteries
359
which arteries contain oxygenated blood
most of them
360
why must the left side of heart generate such high pressurebod
to overcome the resistance of arteries
361
veins carry blood from __________ to __________
from the body
| to the heart
362
veins are thin-walled and ________
inelastic
363
which veins carry oxygenated blood
pulmonary vein
| umbilical vein
364
which veins carry deoxygenated blood
most of them
365
venules
smaller venous structures that connect capillaries to larger veins
366
what makes veins less elastic than arteries
less smooth muscle
367
how do veins work against gravity
have valves that prevent backflow and push blood forward
| surrounded by skeletal muscle that contract and push blood up
368
hepatic portal system
blood leaving capillaries in gut pass through the hepatic portal vein before reaching capillary beds in the liver
369
hypophyseal portal system
blood leaving capillaries in hypothalamus travel to capillaries in anterior pituitary
370
renal portal system
blood leaving glomerulus travels through arteriole before surrounding the nephron in a capillary network
371
what forms all blood cells? where do they originate?
hematopoietic stem cells
| from the bone marrow
372
three cellular components of blood
1. erythrocytes
2. leukocytes
3. platelets
373
erythrocyte function
binding oxygen
| each RBC has 250 molecules of hemoglobin that can bind 4 O2
374
why are RBC concave?
1. travel through small capillaries
| 2. increases surface area for gas exchange
375
how do RBC generate ATP
glycolysis
do not have mitochondria for oxidative phosphorylation
dont consume the O2 in it
376
when RBC mature...
they lose all organelles to make room for HgB
377
WBC function
immune response
378
two classes of WBC
1. granulocytes
| 2. agranulocytes
379
types of granulocytes
neutrophils, eosinophils, basophils
380
granulocytes
contain granules that release compounds by exocytosis
381
what are granulocytes involved in
inflammation, allergies, pus, and destruction
382
agranulocytes
do not contain granules of compounds
383
types of agranulocytes
monocytes and lymphocytes
384
what are lymphocytes involved in
specific immune response
385
B-cells
lymphocytes that originate in the bone marrow
386
T-cells
lymphocytes that originate in the thymus
387
B-cells are responsible for
antibody generation
388
T-cells are responsible for
killing virus infected cells and activating other immune cells
389
what are monocytes responsible for
phagocytosis
390
monocytes become macrophages when
they enter an organ
391
what do thrombocytes originate from
fragments of megakaryocytes
392
function of thrombocytes/platelets
assist in blood clotting
393
erythropoietin released by ___________ to __________
kidney
| stimulate RBC development
394
thrombopoietin released by _________ to ____________
liver and kidney
| stimulate platelet development
395
antigens are surface proteins on
RBC
396
why are blood type O universal donors
blood does not have A or B antigens, so don't initiate an immune response
397
why can't type O receive from A or B
they produce anti-A and anti-B antigens that will induce an immune response if A or B are present
398
why are type AB universal recipients
they can receive blood from all blood types
| A or B can be received, ii doesn't produce antigens
399
difference between Rh+ and Rh-
expression of allele D
400
Rh+ is autosomal _________
dominant, you only need one allele
401
where does the largest drop in blood pressure occur
from arteries to arterioles
402
why does a drop in blood pressure occur at the arterioles
capillaries are so thin that they cannot withstand high pressure
403
what acts as resistors in the cardiac system
arterioles and capillaries
404
longer a blood vessel = __________ resistance
more
405
larger the cross-sectional area of a vessel = _________ resistance
smaller
406
oxygen saturationg
% of hemoglobin carrying oxygen
407
write the CO2 bicarbonate equation
CO2 + H20 H2CO3 H+ + HCO3- by carbonic anhydrase
408
extra protons can bind to Hgb and ________ its affinity for oxygen
decrease
409
Bohr effect
decrease in Hgb oxygen affinity (shift to right) due to a lower pH
410
what causes the Bohr effect
more oxygen demand, increase metabolism, increase CO2
| more CO2 and lactic acid, more H+, decrease pH
411
the decrease in affinity for O2 during the Bohr effect allows
oxygen to be unloaded at the tissues
412
what three things causes a shift to the right of a oxyHgb dissociation curve
1. exercise - increase CO2, increased H+, decreased pH
2. temperature increase
3. increase 2,3-BPG from glycolysis
413
fetal hemoglobin has a _______-shift curve compared to adults
left, higher affinity for oxygen
414
respiratory alkalosis
1. hyperventilation
2. less CO2
3. less H+, more pH
4. shift in curve to the left
415
how can the kidneys compensate for respiratory alkalosis
increase excretion of bicarbonate
416
how are carbs and AA absorbed
into intestine, enter circulation via hepatic portal system
417
how are fats absorbed
into lacteals of intestine, enter circulation via thoracic duct
418
hydrostatic pressure
F/area against vessel walls
419
what generates hydrostatic pressure
contraction of heart and elasticity of arteries
420
hydrostatic pressures pushes fluid ______ of the bloodstream
out
421
what generates osmotic pressure
solutes/plasma proteins
422
osmotic pressure pushes fluid _______ the bloodstream
into
423
when arteriole meets capillary, which pressure is greatest?
hydrostatic, water pushes out of circulation
424
as fluid moves out of vessels, which pressure is greatest?
osmotic stays the same, hydrostatic decreases
425
at venue end of capillary, which pressure is greatest?
osmotic, influx of water into circulation
426
starling forces
balance of hydrostatic and osmotic pressures
427
tissue factor
protein that is exposed when blood vessel is damaged
428
how is injury sensed by platelets
they come into contact with exposed collagen
429
what secretes coagulation factors
liver
430
what do coagulation factors do
sense tissue factor and initiate an activated cascade
431
what does the activation cascade of clotting end with
activation of prothrombin -> thrombin
432
prothrombin -> thrombin by __________
thromboplastin
433
fibrinogen -> fibrin by ___________-
thrombin
434
what does fibrin do
forms fibers that cross link into a net to capture RBC/platelets and form a clot
435
what breaks down a clot
plasmin
436
what is plasmin generated from
plasminogen
437
innate/nonspecific immunity
always active against infection, does not target specific invaders
438
adaptive/specific immunity
targets a specific pathogen
439
spleen
function of storage and activation of B-cells
440
what do B-cells turn into
plasma cells
441
B-cells = ___________ immunity
humoral, antibodies act in the blood
442
T-cells = __________ immunity
cell-mediated, directly kill infected cells
443
defensins
antibacterial enzymes on our skin
444
lysozymes
bacterial enzyme in tears and saliva
445
complement system
proteins in blood that give nonspecific defense
| punch holes in the wall of bacteria
446
classical pathway
binding of an antibody to pathogen
447
alternative pathway
does not require antibodies
448
interferons
proteins that prevent viral replication and dispersion
449
what specific things do interferons do (3)
1. decrease production of viral proteins in nearby cells
2. decrease permeability of cells, less able to bind virus
3. upregulate MHC I and iI, better detection by immune system
450
macrophage process (4)
1. eats invader through endocytosis
2. digests invader with enzymes
3. presents pieces of the invader to other cells using MHC
4. release cytokines to stimulate inflammation and recruit cells
451
major histocompatibility complex
protein that binds to a peptide (antigen) and carries it to the cell surface to be recognized by the immune system
452
all ____________ in the body present MHC class I
nucleated cells
453
why is MHC I called the endogenous pathway
it binds antigens (proteins from invader) that come from within the cell
454
____________ in the body present MHC II
antigen-presenting cells (macrophages)
455
if MHC I are on all cells, how it is recognized
T-cells recognize foreign proteins on the surface
456
why are MHC II called exogenous pathway
they pick up pathogens from the environment and then present the protein on their surface
457
pattern recognition receptors
recognize category of invader (ex: bacteria, fungus, etc.)
458
natural killer cells
nonspecific lymphocyte, detect down regulation of MHC and induce apoptosis
459
neutrophils
phagocytes that eat bacteria
460
how do neutrophils target bacteria (2)
1. chemotaxis - sense products given off by the bacteria
| 2. opsonized (marked by B-cell)
461
what is responsible for the formation of pus
dead neutrophils
462
eosinophils
orange granules involved in allergic reactions and parasitic infection
463
what do histamines do
release histamine
| cause vasodilation to allow more immune cells to move into the tissue
464
basophils/mast cells
purple granules involves in allergic responses
| mast cells smaller, exist in mucosa/epithelium
465
what do basophils/mast cells do
release histamine in response to allergens
466
where are B-cells activated
spleen and lymph nodes
467
B-cells produce
antibodies
468
what do antibodies secreted in fluids do (3)
1. opsonization - attack other leukocytes to eat the antigen
2. agglutinate - form insoluble complexes of antigen that can be eaten
3. neutralize - block ability of the pathogen to invade tissue
469
what do antibodies on the surface of a cell do
activates the B-cell, results in proliferation and formation of plasma & memory cells
470
when do antibodies on a mast cell do
degranulation - release histamine
471
what are the daughter cells of B-cells
plasma
| memory
472
plasma cells
produce antibodies
473
memory B-cells
stay in lymph node, wait for another antigen
474
primary response
B-cells making plasma and memory B-cells
475
secondary response
memory cells activated and produce antibodies specific to pathogen
476
where does T-cell selection occur
thymus
477
positive selection
kill cells that don't respond to MHC
478
negative selection
kill cells that are self-reactive (activated by proteins they produce)
479
what hormone facilitates maturation of T-cells
thymosin
480
clonal selection
choosing B/T-cells with the highest affinity for the antigen
481
helper/CD4+ T-cells
secrete lymphokines
482
lymphokines
recruit other immune cells and increase their activity
483
what cells are lost in HIV
helper T-cells
484
what do helper T-cells respond to
antigens on MHC-II molecules
485
what are CD4+ cells most effective against
bacteria, fungi, parasites; because they respond to exogenous antigens
486
cytotoxic/CD8+ T-cells
directly kill virally infected cells by injecting toxic chemicals
487
what do CD8+ T-cells respond to
antigens on MHC-I molecules
488
what are CD8+ cells most effective against
viruses; respond to endogenous antigens
489
suppressor/regulatory T-cells
tone down the immune response, express Foxp3
490
suppressor T-cells also express
CD4
491
self-tolerance
turning off self-reactive lymphocytes to prevent autoimmunity
492
memory T-cells
wait until subsequent exposure
493
IgX = _______ cell
plasmaa
494
which pathogen does not have an immediate defense
prions
495
autoimmunity
attacking the self-antigens expressed on a cell
496
active immunity
immune system stimulated to attack a specific antigen
497
passive immunity
transfer of antibodies to an individual
498
what part of the lymph node do B-cells mature
germinal centers
499
intracellular digestion
oxidation of glucose and FA for energy
500
extracellular digestion
extraction of nutrients from food
501
where does extracellular digestion occur
alimentary canal
502
what is the alimentary canal
pathway from mouth to anus, sectioned by sphincters
503
enteric nervous system
collection of neurons in the walls of the digestive tract governing the GI system
504
what does the enteric system trigger
peristalsis, rhythmic contractions of gut
505
parasympathetic system innervates all glands except
sweat
506
parasympathetic ________ digestion
stimulates
507
what hormones make you thirsty
ADH and aldosterone
508
what hormones make you hungry
glucagon and ghrelin
509
what secretes ghrelin
stomach and pancreas
510
what hormones make you feel full
leptin and cholecystokinin
511
salivary amylase
breaks down carbs
512
lipase
breaks down lipids
513
what two enzymes does saliva contain
salivary amylase and lipase
514
what is broken down in the mouth
lipids and carbs
515
the top third of the esophagus is __________ muscle and the bottom third is _____________ muscle
skeletal, smooth
516
the top third of the esophagus is under __________ control
somatic
517
gastric glands
respond to vagus nerve of parasympathetic NS
518
where are gastric glands in the stomach
fundus and body (top)
519
three different cell types of gastric glands
1. mucous
2. chief
3. parietal
520
mucous cells
produce bicarbonate-rich mucus that protects the walls from acidic stomach
521
gastric juice
combination of pepsinogen and HCl
522
chief cells
secrete pepsinogen
523
parietal cells
secrete HCl and intrinsic factor
524
what cleaves pepsinogen into pepsin
H+
525
pepsin
digests proteins by cleaving peptide bonds near aromatic AA
526
intrinsic factor
glycoprotein involved in absorbing vitamin B12
527
what do the pyloric glands contain
G-cells
528
G-cells
secrete gastrin
529
gastrin
peptide hormone, induces parietal cells to secrete more HCl and signals the stomach to contract
530
three parts of the small intestine
duodenum, jejunum, ileum
531
which part of the small intestine does most chemical digestion
duodenum
532
which parts of the small intestine do more absorption
jejunum and ileum
533
what sphincter separates the stomach and small intestine
pyloric
534
presence of chyme in the duodenum signals
release of brush-border enzymes
release of enteropeptidase
release of secretin and CCK
535
brush-border enzymes
break down dimers/trimers of biomolecules into monomers
536
enteropeptidase
activates other enzymes from accessory organs
537
malate, lactase, sucrase, etc. are types of
brush-border enzymes
538
carbohydrates are absorbed as
monomers
539
proteins are absorbed as
di/tri/monomers
540
enteropeptidase activates _________ to __________
trypsinogen to trypsin
541
enteropeptidase also activates ___________ into their active form
procarboxypeptidases A and B
542
secretin
peptide hormone, causes pancreatic enzymes to be released
543
what reduces HCl secretion and increases bicarbonate secretion
secretin
544
enterogasatrone
hormone that slows GI motility
545
give an example of an enterogastrone
secretin
546
cholecystokinin
peptide hormone, stimulates release of bile/pancreatic juices and promotes satiety
547
bile
fluid of bile salts, pigments, and cholesterol
548
do bile salts perform chemical digestion
no, they are not enzymes
549
what do bile salts do
emulsify fats and cholesterol into micelles so that pancreatic lipase can act on them
550
what do pancreatic juices do
neutralize acidic chyme
551
what cells of the pancreas release pancreatic juices
acinar
552
bile ducts
connect the liver to the gallbladder and small intestine
553
where is bile produced
liver
554
where is bile stored
gallbladder
555
how does the liver receive blood from the GI tract
through the hepatic portal vein, processes it and then drains into inferior VC
556
how does the liver store glucose and fats
glucose as glycogen
| fats as triacyglycerols
557
how does the liver produce glucose and fats
glycogenolysis and gluconeogenesis
| mobilizes fat in lipoproteins
558
the breakdown of HgB will produce what byproduct
bilirubin
559
bilirubin travels to the liver where it is ___________ and secreted into bile
conjugated, added to a protein
560
albumin
protein maintaining osmotic pressure
| serves as a carrier for drugs/hormones
561
what organ produces albumin
liver
562
what organ produces clotting factors
liver
563
what triggers release of bile from the gallbladder
CCK
564
how are simple sugars and AA absorbed
1. secondary active transport & facilitated diffusion
2. cross to blood
3. carried away to portal vein
565
how are long chain FA/cholesterol absorbed
1. simple diffusion
2. packed into chylomicrons
3. enter lacteals
4. enter thoracic duct into heart
566
how are short-chain FA absorbed
1. simple diffusion
2. cross to blood
3. carried away
567
how are bile salts absorbed
1. active transport
2. cross to blood
3. carried away
568
how is water absorbed
transcellularly and paracellularly
569
function of large intestine
water absorption
570
three parts of large intestine
cecum, colon, rectum
571
what is the valve between the small and large intestine
ileocecal valve
572
colon
absorbs water and salts, concentrates material into feces
573
rectum
stores feces
574
which sphincter of the rectum is voluntary
external
575
which sphincter of the rectum is involuntary
internal
576
afferent arterioles
arteries entering the glomerulus
577
capillaries of the afferent arterioles
glomeruli
578
efferent arterioles
arteries leaving the glomerulus
579
detrusor muscle
lining of the bladder
580
internal urethral sphincter is made up of ____________ muscle and is ____________ at rest.
smooth
| contracted
581
external urethral sphincter is made up of ____________ muscle and is ____________ at rest.
skeletal
| relaxed
582
micturition reflex
stretch receptors in the body signal the parasympathetic system to contract the detrusor muscle and the internal sphincter to relax. to actually urinate, you must relax your external sphincter.
583
what causes urination
contraction of the abdomen, which increases compression on the bladder
584
blood passing through the glomerulus is filtered as filtrate into
Bowman's space
585
hydrostatic pressure in glomerulus is __________ than Bowman's
higher, fluid moves into BS (nephron)
586
osmotic pressure of glomerulus is _________ than Bowman's
lower, pushes water out
587
hydrostatic pressure is ________ then osmotic pressure in nephron
greater, net flux of fluid is into the nephron (from blood/glomerulus)
588
secretion
movement of solutes from blood to filtrate at any other point than BS
589
reabsorption
movement of solutes from filtrate to blood
590
major products of urine
HUNK
| H+, urea, NH3, K+
591
what does the proximal convoluted tubule absorb
Na+, Cl- water, AA, glucose, vitamins
592
what is the descending loop of Henle permeable to
water only! changing permeability or changing concentration of interstitium will alter flow of water
593
what is the ascending loop of Henle permeable to
solutes only, no water
| maximizes salt reaabsorption
594
diluting segment
area of ascending loop where there is a large amount of mitochondria for active transport of NaCl
the filtrate can become hypotonic to blopod
595
a net reabsorption of water occurs in
the loop of Henle
596
the distal convoluted tubule responds to
aldosterone
597
in the DCT, ____ and _____ are reabsorbed
sodium and water
598
what does the collecting duct respond to
ADH and aldosterone
599
when well hydrated, the collecting duct is ___________
impermeable
600
when dehydrated, aldosterone and ADH will cause the collecting duct to become
permeable
601
net aldosterone effects
increase blood volume and BP
| increase potassium and H+ excretion
602
when pH is low, what do the kidneys do
excrete H+ and reabsorb bicarbonate
603
stratum basale
stem cells, proliferates keratin cells
604
stratum spinosum
site of langerhans cells
605
stratum granulosum
keratin cells die
606
tatum lucidum
thick, hairless skin
607
stratum corneum
flattened keratin cells, prevent invasion and help prevent loss of fluids/salt
608
langerhans cells
present antigens to T-cells
609
skeletal muscle appears
striated, due to sarcomeres
610
skeletal muscle is ________-nucleated
multi
611
slow-twitch fibers
high myoglobin and mitochondria content
carry out oxidative phosphorylation
appear red
612
fast-twitch fibers
less myoglobin
613
muscles that sustain activity by contracting slowly are primarily _____ fibers
red
614
muscles that contract fast but fatigue quickly are _______ fibers
white
615
smooth muscle is ______-nucleated
uni
616
smooth muscles do not appear striated, why?
they do not have well-organized myosin and actin
617
tonus
constant state of low-level contraction, seen in smooth muscle
618
which muscles have myogenic activity
smooth and cardiac
619
cardiac muscle appears
striated
620
thick filament of a sarcomere
bundles of myosin
621
thin filament of sarcomere
actin + troponin + tropomyosin
622
titin
protein that anchors actin and myosin together, prevents excessive stretching of the skeletal muscle
623
Z-lines
bounds of sarcomere
624
M-line
middle of sarcomere, through middle of myosin
625
I-band
only thin filaments
626
H-zone
only thick filaments
627
A-band
all of thick filaments, even if thin is overlapping
628
during contraction, what band remains constant
A-band, thick filaments
629
myofibrils
sarcomeres attached end to end
630
what surrounds myofibrils
sarcoplasmic reticulum, full of calcium
631
what surrounds the SR
sarcoplasm, cytoplasm
632
what surrounds the SR and sarcoplasm
sarcolemma, membrane
633
how does the sarcolemma give an AP to all the sarcomeres
transverse tubules, oriented perpendicular to myofibril
634
myocyte/muscle fiber contains ____________ in parallel
myofibrils
635
muscle contains many ________
myocytes
636
sarcomere --> _________ --> muscle fiber ---> __________
myofibril
| muscle
637
what do efferent neurons release onto sarcolemma
ACh
638
motor unit
a nerve terminal + all its muscle fibers
639
depolarization --> AP --> travels down the _________ --> SR
T-tubules
640
when the AP reaches the SR, ______ is released
calcium
641
steps of contraction initiation
1. AcH released from motor neuron
2. AP travels down to SR
3. SR releases calcium
4. calcium binds troponin's regulatory subunit
5. tropomyosin changes shape
6. myosin-binding site exposed on actin
642
steps of sarcomere shortening
1. myosin binds to free sites on actin
| 2. myosin pulls on actin, drawing thin filaments towards middle
643
actin-myosin cross-bridge cycle
1. myosin + ADP/P chilling out
2. calcium binds to troponin
3. myosin binds to site on actin
4. ADP + P leave myosin. powerstroke! gives energy for sliding of actin over myosin
5. ATP binds to myosin, releasing from actin
6. ATP hydrolyzed to ADP + P
644
what bands shorten during contraction
H - thick filaments only
| I - thin filaments only
645
what stops the signal at the NMJ
acetylcholinesterase
646
muscle fibers contract in __________ fashion
all-or-none
647
how do nerves control muscle force
recruitment of motor units
648
simple twitch
response of one muscle fiber to a stimulus at or above threshold
649
latent period
time between reaching threshold and onset of contraction, AP spreading down muscle
650
frequency summation
muscle fiber receives a prolonged stimulus, cant relax in enough time for the next
contractions combine and become stronger/longer
651
tetanus
muscles cannot relax at all
652
what two things will your muscles use if they dont have oxygen
creatine and myoglobin
653
creatine phosphate equation
creatine + ATP creatine phosphate + ADP
654
how does creatine give you energy
it quickly makes ATP by giving a phosphate to ADP
655
with extreme exercise, we produce
lactic acid
656
why is amount of oxygen to recover = amount of oxygen debt
to recover, you have to convert lactic acid to pyruvate
| which requires the same amount of oxygen you owed
657
axial skeleton
framework of body (i.e., skull, vertebrate, ribs)
658
appendicular skeleton
bones of the limbs, pectoral girdle, and pelvis
659
what makes up the skeleton
bone and cartilage
660
what embryonic layer does bone derive
mesoderm
661
compact bone
dense and strong bone
662
spongy/cancellous bone
lattice structure of bone
663
diaphyses and metaphases are filled with
bone marrow
664
epiphyses are made up of
spongy core, disperse force and pressure at joints
665
prior to adulthood, the epiphyseal plate contains
mitotic cells, contributing to growth
666
at puberty, ___________ close
epiphyseal plates
667
periosteum
surrounds bone to protect and serve as a site for muscle attachment
668
ligaments hold
bone to bone
669
tendons hold
bone to muscle
670
osteoclasts
resorb bone, macrophages
671
osteoblasts
build bone
672
vitamin D promotes
resorption of bone
673
calcitonin promotes ________ of bone
formation
674
parathyroid hormone promotes _________ of bone
resorption
675
how is cartilage different than bone other than its strength
avascular and not innervated
676
endochondral ossification
hardening of cartilage into bone
677
intramembranous ossification
undifferentiated mesenchymal tissue into bone
678
where does intramembranous ossification occur
skull
679
codominance
more than one dominant allele
680
incomplete dominance
phenotype intermediate between the two homozygous genotypes
681
penetrance
probability a genotype will express the phenotype
682
expressivity
different phenotypes of a single genotype
683
point mutation
one nucleotide is swapped
684
silent mutation
new nucleotide has no effect on the final protein
685
missense mutation
new nucleotide results in a different AA in the final protein
686
nonsense mutation
new nucleotide results in a new stop codon
687
frameshift mutations
nucleotides inserted or deleted
688
deletion mutation
large segment of DNA is lost from chomosome
689
small deletion mutation
a nucleotide is deleted
690
duplication mutation
segment of DNA is copied
691
inversion mutation
segment of DNA is reversed
692
insertion mutation
segment of DNA is moved from one chromosome to aanother
693
translocation mutation
segment of DNA from one chromosome is swapped with segment of DNA from another chromosome
694
hardy weinberg
p + q = 1
| p2 + 2pq + q2 = 1
695
stabilizing selection
keeps phenotypes within a range, selects against extremes
696
directional selection
dominance of an extreme phenotype
697
disruptive selection
two extreme phenotypes favored over the norm
