Biology Flashcards
(155 cards)
1
Q
A sodium influx would make the cell more ___ whereas a potassium influx would make the cell more __.
A
Positive; Negative
2
Q
Na+ channels open during an action potential leading to ___
A
Depolarization
3
Q
During depolarization (~+35) what voltage gated channels open to restore balance?
A
K+ / Potassium
4
Q
When the action potential reaches “hyperpolarization” what does this mean and what channels (if any) are open at this stage?
A
-70 ; Na+ and K+ Leak Channels
5
Q
The HPA axis is comprised of the Hypothalamus that secretes __ to activate the anterior pituitary and __ to activate the adrenal cortex.
A
CRF ; ACTH
6
Q
Cortisol levels are part of the important __ feedback loop that regulates the HPA axis.
A
Negative
7
Q
The HPG axis is comprised of the hypothalamus, pituitary and gonads. Some hormones are __.
A
GnRH, FSH and LH
8
Q
On day 0 of the cycle GnRH levels rise this first results in ___ increasing through its release from the anterior pituitary and later __ levels rising.
A
FSH ; LH
9
Q
On days 5-9 of the cycle estrogen uses __ feedback to prevent multiple ovulation.
A
negative
10
Q
On days 10-13 of the cycle estrogen uses __ feedback to induce ovulation.
A
Positive
11
Q
FSH is secreted by the anterior pituitary and its effect on the ovaries is ___.
A
follicle maturation of primary oocytes which can be detected by a rise in estrogen. estrogen als stops other follicles from maturing to prevent multiple ovulation.
12
Q
LH is secreted by the anterior pituitary and it surges in preparation for __.
A
ovulation where the secondary oocyte ruptures.
13
Q
In terms of myelin producing cells the CNS has __ and the PNS has __ cells.
A
oligodendrocytes ; schwann
14
Q
The soma is the part where we can find __.
A
ribosomes
15
Q
The dendrites are the part where they can receive __
A
messages
16
Q
The axon hillock is the portion where we __
A
sum / integrate
17
Q
A nerve is in the __ nervous system and consists of multiple neurons bound together. If clustered, it is referred to as a __
A
Peripheral ; Ganglia
18
Q
A tract is in the __ nervous system and consists of multiple axons bound together. If clustered, it is referred to as a __
A
Central ; Nuclei
19
Q
Astrocytes serve what purposes?
A
1) nourishment 2) blood brain barrier
20
Q
Ependymal cells serve what purposes?
A
1) lining brain ventricles 2) producing cerebrospinal fluid
21
Q
Microglia cells have a phagocytic effect in the __ nervous system,
A
central
22
Q
The resting membrane potential is maintained by__
A
1) distribution of ions across the membrane 2) active transport
23
Q
Excitatory neurons cause __
A
depolarization
24
Q
Inhibitory neurons cause __
A
hyperpolarization
25
Temporal summation means that __
many in a small time leads to action potential
26
Spatial summation means that __
the number and location matters i.e. many inhibitory in one space --> inhibiton
27
The absolute refractory period is when no action potential can occur whereas a relative refractory period is __
greater than normal stimulation can lead to an action potential
28
The CNS is composed of __
brain, spinal cord
29
The PNS is composed of __
cranial, spinal, sensory
30
Afferent neurons are considered __ and follow the following signaling mode : sensor --> CNS.
Sensory
31
Efferent neurons are considered __ and follow the following signaling mode : CNS --> Effector.
Motor
32
The somatic nervous system is considered __ i.e. muscles whereas the autonomic is considered __ i.e. heart rate.
voluntary ; involuntary
33
A monosynaptic system consists of the following flow:
afferent presynaptic --> sensory --> motor --> efferent postsynaptic
34
A polysynaptic system consists of the following flow:
sensory --> INTERNEURON --> motor
35
Peptide hormones work indirectly and require a ___. They are __ acting and require __ carrier through the blood.
second messenger like cAMP ; short and transiently ; no
36
Steroid hormones work directly and require ___. They are __ acting and require __ carrier through the blood.
no secondary messengers as they can bind and make a conformational change like dimerization ; slow and longer lived ; a lipid soluble like albumin
37
Amino acid derivative hormones include T3, T4 which function like steroid hormones and __
catecholamines (epinephrine, norepinephrine) which function like peptide hormones
38
Catecholamines like epinephrine act like peptide hormones in that they are __ acting and require __.
faster, transient ; GPCR
39
Direct acting implies a hormone directly acts on a target tissue such as __
insulin
40
Tropic acting implies that a hormone requires __ and must secrete __. An example of this is GnRH and LH.
an intermediate ; another hormone
41
GnRH is secreted by the hypothalamus and does the following:
1) releases __ and __ from the anterior pituitary
2) targets __ (organ)
3) ultimately releasing __
FSH, LH ; gonads ; testosterone OR estrogen, progesterone
42
CRF is secreted by the hypothalamus and does the following:
1) releases __ from the anterior pituitary
2) targets __ (organ)
3) ultimately releasing __
ACTH ; adrenal cortex ; glucocorticoids
43
TRH is secreted by the hypothalamus and does the following:
1) releases __ from the anterior pituitary
2) targets __ (organ)
3) ultimately releasing __
TSH ; thyroid ; T3 & T4
44
Low dopamine levels in the hypothalamus does the following:
1) releases __ from the anterior pituitary
2) targets __ (organ)
3) ultimately releasing __
prolactin ; breast tissue ; n/a
45
GnRH is secreted by the hypothalamus and does the following:
1) releases __ from the anterior pituitary
2) targets __ (organ)
3) ultimately releasing __
growth hormone ; bone, muscle ; n/a
46
Recalling the FLAT PEG mnemonic where FLAT hormones are tropic and PEG hormones are direct acting what are the hormones in the mnemonic?
F: FSH ; L: LH ; A: ACTH ; T= TSH & P: Prolactin ; E: Endorphins ; G: Growth Hormones
47
The posterior pituitary secretes __ when there is high blood osmolarity. The immediate effect is increased water reabsorption in the collecting duct resulting in decreased plasma osmolarity.
ADH/ vasopressin (peptide hormone)
48
The adrenal glands secrete __ when there is low blood volume. The immediate effect is increased activity of the Na+/K+ pump in the nephron which results in increased blood volume.
Aldosterone (steroid hormones)
49
Somatostatin, in the pancreas, inhibits which two hormones __ and __
insulin ; glucagon
50
The adrenal medulla secretes catecholamines which increase __ and __ by bronchial dilation.
glycogenolysis ; metabolic rate
51
Increased blood sugar triggers __ release and glucose uptake by tissues. The sugar is then absorbed by cells, converted to glycogen and used for fatty acids or proteins.
insulin
52
Low blood sugar triggers __ release and glycogenolysis to increase blood sugar levels. The pancreatic alpha cells produce this hormone.
glucagon
53
Cortisol antagonizes insulin and is produced by the __ and stimulated by __.
adrenal cortex ; adrenal cortex
54
Parathyroid hormone increases plasma Ca2+ levels which thereby inhibit levels of PTH in a __ feedback mechanism.
negative
55
Calcitonin differs from PTH since it __ blood calcium levels.
lowers
56
The Hypothalamus - Pituitary - Gonadal Axis is important. __ release leads to progesterone (F), testosterone (M) and __ release leads to estrogen (f) and spermatogenesis (m)
LH ; FSH
57
The HPA axis consists of CRH which stimulates __ release in the anterior pituitary .
ACTH
58
The HPT axis consists of TRH which stimulates release of __ and eventually __ and __.
TSH ; T3 & T4
59
Endocrine signaling is a form of cell to cell communication where hormones are secreted __.
directly into the bloodstream
60
Paracrine signaling is a form of cell to cell communication where hormones are secreted __.
alongside/ adjacent through extracellular fluid
61
Juxtacrine signaling is a form of cell to cell communication where hormones are secreted __.
because of docking / touching
62
The Renin- Angiotensin- Aldosterone system is an example of __ feedback. Angiotensinogen --> renin leads to Angiotensin I and ACE leads to Angiotensin II which stimulates the release of aldosterone and increases blood pressure. The blood pressure inhibits angiotensinogen.
negative
63
The kidney uses three different process 1) filtration 2) secretion 3) reabsorption.
Filtration: moves solutes from blood into filtrate ; Secretion: move solutes blood to filtrate NOT Bowman ; Reabsorption: move solutes from filtrate to blood
64
The renal corpuscle of the nephron generates __.
filtrate
65
The PCT reabsorbs __ and secretes ammonium and creatinine.
Na+, Cl-, K+, Water, Glucose, Amino Acids, Bicarbonate, Ca+, Phosphate
66
The descending loop of henle reabsorbs __.
water
67
The thin ascending loop of henle reabsorbs __
sodium and chloride
68
The thick ascending loop of henle reabsorbs __
ammonium, sodium, chloride
69
The distal convoluted tubule (DCT) reabsorbs __ and __.
sodium, chloride
70
The collecting duct responds to ADH and aldosterone. It reabsorbs __ and __. It secretes ammonium, hydrogen ions and potassium.
sodium chloride ; water
71
The blood passage goes from renal __ to renal __.
artery; vein
72
Skin can exhibit cooling effects through __ and __
vasodilation and sweating
73
Skin can exhibit warming effects through __ , piloerection, fat insulation and shivering.
vasoconstriction
74
The stratum basale of the epidermis contains __
keratinocytes
75
The dermis contains sensory endings such as nerve ends for pain Meissener for __ and Ruffini __ and Pacinian __.
light touch ; stretch ; vibration and pressure
76
The hypodermis comprises fat and connective tissues and has an important role of __
connecting the skin to the rest of the body
77
There is pH regulation with bicarbonate. If blood pH is high then the levels of bicarbonate in the urine are __.
high
78
Fertilization occurs with the help of __ enzymes. The __ reaction then prevents additional sperm from fertilizing an egg.
acrosomal ; cortical
79
Indeterminate cleavage means that a cell can become __ whereas determinate cleavage means that a cell can become __.
any cell ; specific cell
80
Morula
Mass of cells (early)
81
Blastula
forms the placenta
82
Chorion
mom and fetal blood
83
Allantois
fluid exchange
84
Amnion
amniotic fluid
85
Germ Layer (Ectoderm)
integument ; epidermis, hair , nails, mouth, nervous system and lens of eye
86
Germ Layer (Mesoderm)
musculoskeletal, circulator, excretory systems, gonads, muscular + connective tissues, adrenal cortex.
87
Germ Layer (Endoderm)
epithelial lining in respiratory and digestive system, thyroid, bladder, distal urinary
88
Neurulation occurs in three main steps. 1) the notochord induces __ to form neural folds 2) the neural folds fuse to form __ (CNS) 3) tip of neural fold has neural crest which becomes the __, melanocytes , and calcitonin producing cells.
ectodermal cells; neural tube ; PNS
89
Teratogens can cause defects or the death of the embryo. What are examples of teratogens?
alcohol, drugs, environmental chemicals, viruses, bacteria
90
Determination of cells means that cells commit to __. Differentiation indicates changes due to __.
a cell lineage ; transcription
91
Totipotent stem cells
all cell types including germ layer, placenta
92
Pluripotent stem cells
all germ layers and derivatives
93
Multipotent stem cells
only a subset of cell types
94
Signaling: Paracrine
local cells not physically / directly
95
Signaling : Juxtacrine
directly simulates adjacent cells
96
Inducers release __ to promote __ of a competent responder.
factors ; differentiation
97
The Milestones of embryogenesis
morula --> blastula --> gastrula
98
The umbilical ARTERY carries __ blood from fetus to placenta. Fetal hemoglobin has a higher affinity for oxygen than adult hemoglobin.
deoxygenated
99
The umbilical VEIN carries __ blood from the placenta to the fetus. Fetal hemoglobin has a higher affinity for oxygen than adult hemoglobin.
oxygenated
100
Three Shunts of Fetal Circulation : Foramen Ovale , Ductus Arteriosus, Ductus Venosus
1) Foramen Ovale- right atrium to left atrium bypassing lungs
2) Ductus Arteriosus- pulmonary artery to aorta bypassing lungs
3) Ductus Venosus - umbilical vein to inferior vena cava ; bypassing liver
101
During the first trimester __ occurs
organogenesis
102
During the second trimester __ occurs
tremendous growth, movement begins, face of human and digits elongate
103
During the third trimester __ occurs
rapid growth, brain development, transfer of antibodies to fetus
104
During birth __ occurs
cervix thins, amniotic sac ruptures, uterine contractions due to oxytocin and prolactin
105
The mitochondria is unique in that it is semi-autonomous. Therefore it is able to replicate via __ __ and is an example of extracellular inheritance.
binary fission
106
The proton-motive force is established by the mitochondria. Specifically, the __ __ to the intermembrane space.
mitochondrial matrix
107
Red blood cells are unique in that they contain no __
organelles
108
Microfilaments
actin, cytokinesis
109
Microtubules
tubulin, kinesin and dynein
110
Intermediate Filaments
filamentous ; keratin, desmin, lamin
111
Epithelial
underlying connective tissue (basement membrane) ; kidney nephron, liver hepatocytes etc.
112
Obligate anaerobes are only anaerobic and have no way to use O2, but facultative anaerobes can function __
with or without oxygen
113
Aerotolerant anaerobes
tolerate the presence of oxygen in the environment , but cannot use oxygen for metabolism.
114
Gram Positive Bacteria
turn purple ; thick cell wall
115
Prokaryotic ribosomes are __ and __ but eukaryotic ribosomes are 40s and 60s.
30s and 50s
116
Episomes are plasmids that __
integrate into the genome
117
Bacterial Genetic Recombination (conjugation):
transfer of genetic material from one bacterium to another
118
Bacterial Genetic Recombination (transduction):
transfer via a bacteriophage vector
119
Bacterial Genetic Recombination (transposons):
insert or remove themselves from genome
120
Viroids are plant pathogens which are comprised of __. Prions trigger protein misfolding.
small circles of complementary DNA
121
The lytic life cycle of a bacteriophage is when it is __ and new virions will continue until the cell lyses.
virulent
122
The lysogenic cycle is when it is in a __.
provirus
123
Penetrance
proportion of population with genotype who express the phenotype
124
Expressivity
varying phenotypic manifestations of the same genotype
125
Founder effect leads to __
homozygous genotypes incr.
126
Genetic leakage is the flow of genes between _
species thru hybrid offspring
127
Missense Mutation
substitution of one amino acid for another
128
Nonsense Mutation
substitutes a stop codon for amino acid
129
Recombination Frequency
likelihood of two alleles sep. crossing over in mitosis
1 map unit = 1% recombination frequency
determine % of genes furthest
130
Hardy Weinberg must meet the following conditions
1) large population
2) no mutations
3) mating is random
4) no migration into/out of
5) genes equally successful at being reproduced
131
p2+ 2pq+1^2=1
p^2=TT
2pq= Tt
q^2=tt
p^2+2pq = frequency dominant
132
Punctuated Equilibrium
slow with bursts of evolutionary activity
133
G1: Pre Synthetic Gap
incr. size, create organelles
| proper complement of DNA to progress to S stage
134
S: Synthesis of DNA
replicate genetic material so each daughter cell has identical copies
2 identical chromatids per chromosome per chromosome . Ploidy 2x
135
G2: Postsynthetic Gap
checkpt. of enough organelles and cytoplasm for 2 cells ; checks for any errors to avoid passing to progeny
136
M: Mitosis
PMAT
137
cyclins bind __ to phosphorylate transcription factors thus transcription of genes for the next stage occurs
CDKs
138
Prophase
chromosomes condense, form spindle
139
Metaphase
gather at metaphase plate
140
Anaphase
sister chromatids separate and migrate
141
Telophase
chromosome decondenses , spindle breaks, nucleoli reappear, nuclear membrane reforms, 2 daughter cells
142
Meiosis occurs in gametocytes with __ round of replication and __ rounds of division (reductional and equatorial).
1 ; 2
143
Meiosis I: Prophase
```
homologs intertwine (synapsis)
4 chromatids (tetrade) and cross over
accounts for law of independent assortment
```
144
Meiosis I: Metaphase
homologous chromosomes line up on opposite sides of metaphase plate
145
Meiosis I: Anaphase I
pulled to opposite poles - accounts for Mendel's Law of Segregation
146
Meiosis I: Telophase I
chromosomes may or may not fully decondense and cell may enter interkinesis
2 haploid daughter cells by end
147
Meiosis II
sister chromatids separated functionally similar to mitosis
| 4 haploid gametes by end
148
Pathways of Sperm (SEVEN UP)
```
seminiferous tubules
epididymis
vas deferens
ejaculatory duct
nothing
urethra
penis
```
(cowper glands clean out urine)
149
Spermatogenesis
spermatogonia (diploid) --> 1 spermatocyte --> 2 spermatocyte (haploid) --> spermatids --> spermatozoa (4 total)
150
Female Reproductive Pathway
ovaries --> peritoneal sac --> fallopian --> uterus
151
Oogenesis
oogonia --> 1 oocyte arrested at prophase 1 --> 2 oocyte + polar body
after menstruation 1 primary oocyte to 2 oocyte monthly. The 2 oocyte stays at Metaphase II unless fertilized
152
Steps of the Menstrual Cycle
1) Follicles mature (FSH, LH)
2) LH surge triggers ovulation
3) LH + FSH inhibition by estrogen secreted by corpus luteum
4) if no fertilization menses occurs (FSH + LH up and estrogen down)
153
Menopause
ovaries stop producing estrogen and progesterone
| FSH and LH levels rise
154
hCG
an LH analog to maintain the corpus levels drop at the end of the first trimester
155
nondisjunction
45, x instead of 46 xx
