REPRODUCTION and immunity Flashcards
(303 cards)
0
Q
scrotum
A
sac that houses the testes outside the abdomen
1
Q
asexual
A
process in which a single cell or set of cells produces offspring that inherit all of their genetic material from one parent
2
Q
sexual
A
process in which genetic material from two parents combines and produces offspring that differ genetically from either parent
3
Q
spermatozoa (sperm)
A
the mature motile male sex cell of an animal, by which the ovum is fertilized, typically having a compact head and one or more long flagella for swimming
4
Q
epididymis
A
Long, thin coiled tube where sperm mature and are stored
5
Q
prostate gland
A
I gland surrounding the neck of the bladder in male mammals and releasing prostatic fluid
6
Q
testosterone
A
A steroid hormone that stimulates development of male secondary sexual characteristics, produced mainly in the testes, but also in the ovaries and adrenal cortex
7
Q
steroid
A
any of a large class of organic compounds with a characteristic molecular structure containing four rings of carbon
8
Q
acrosome
A
holds enzymes in a sperm
9
Q
urethra
A
the tube in the penis for both semen and urine
10
Q
three glands that make semen
A
seminal vesicle
cowpers
prostate
11
Q
the structure in testes that makes sperm
A
seminiferous tubule
12
Q
where is the egg typically fertilized?
A
in the fallopian tube
13
Q
what closes off the uterus and dilates when a woman is in labor
A
cervix
14
Q
which cells nurture the egg?
A
follicle
15
Q
what does FSH tell the ovary to make
A
follicle
16
Q
layer that becomes muscle and bones
A
mesoderm
17
Q
A neurological gland that releases growth hormone
A
pituitary gland
18
Q
outer layer of blastocyst
A
trophoblast
19
Q
endometrium
A
where blastocyst embeds
20
Q
types of pathogens
A
fungus, virus, bacteria, Protozoa
21
Q
pathogen fungus examples
A
athletes foot, yeast infection
22
Q
virus pathogen examples
A
HIV, herpes, chickenpox, swine flu
23
Q
bacteria pathogen examples
A
tuberculosis, E. Coli, strep throat, leprosy
24
protazoa
malaria, amoebic dysentery
25
prions
infectious proteins
26
a "big eater" that works by phagocytosis
macrophage
27
lymphatic system
A part of the circulatory system that collects fluids and blood
28
what starts puberty
release of hormones
29
how oftem do eggs mature?
every 28 days
| one at a time in alternate ovaries
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menstrual cycle
rhythmic and maturation of eggs and other chemical and physical events that accompany the process
31
how is the menstrual cycle controlled
by chemical messengers (hormones) that move via the bloodstream
32
hormones
chemical messengers that move via the bloodstream
33
follicle stimulating hormone (FSH)
hormone that when high enough in levels start the maturing process of the eggs in a woman's ovary
34
where does each egg mature?
inside of a follicle
35
follicle
cluster of protect cells, near the surface f one of the eggs
36
when the egg is fully mature, which hormone reaches its peak?
LH (Luteinizing Hormone)
37
when does the follicle burst open and release the egg?
when LH and FSH reach high levels
38
ovulation
when the follicle bursts open and releases the egg
39
what sweeps the egg into the tube which leads to the uterus
cilia
40
as a reaction to increasing levels of what hormone, the lining of the uterus (also called the endometrium) has been prepared to receive a fertilized egg by building it's lining with nurturing tissues and blood vessels
estrogen
41
when does the remaining follicle tissue become a hormone secreting gland (corpus luteum)
after the egg is released from the follicle in the ovary
42
which glad releases the hormone progesterone?
corpus luteum
43
high levels of which hormones help maintain the uterus wall lining as it is built up and thickened
progesterone and estrogen
44
what happens if the released egg remains unfertilized?
it does not implant in the uterus lining. This triggers further hormonal changes. Both estrogen levels and progesterone levels drop. This causes the lining of the uterus (also called the endometrium) to deteriorate. As a result, both unfertilized egg and uterus lining shed and are passed out of the body
45
periodic loss of tissues and fluid from the uterus
menstruation
46
why do females often break out in pimples before menstruation?
because the skin and estrogen are responding to estrogen
47
why don't bones respond to estrogen?
only target cells with the right receptors respond to the hormone estrogen. You do not have receptor for estrogen on bone cells
48
pituitary gland
located at the base of the brain. Secretes the two hormones that trigger the growth and development of the the egg in the Overy (FSH and LH)
in response, the ovary then secretes the two sex hormones that control development of the egg in the uterus lining (estrogen and progesterone) when ovarian hormones reach low levels, this stimulates the pituitary gland to once again secrete it's hormones to trigger the next cycle
49
the female gamete
ova/egg
50
group of cells that protect the egg
follicle
51
female gonad
ovary
52
leftover follicle that makes progesterone
corpus luteum
53
causes the formation of the corpus luteum
leutenizing hormone
54
works with estrogen to thicken the endometrium
progesterone
55
on what day does the FSH reach its peak in concentration
13-14
56
what day does LH reach its peak in concentration?
14
57
what happens to the egg on day 14 after LH reaches its peak
The follicle bursts open and releases a fully developed egg and during a process known as ovulation
58
what gland secretes estrogen?
ovary
59
on what day does estrogen reach its peak in concentration?
12-13
60
why does the female need a steak uterus lining if fertilization does occur?
thick lining will catch and support the developing embryo
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what makes menstruation cycle?
hypothalamus restarts process when hormones are low
62
first line of nonspecific chemical body defenses
sweat
oil
mucus
acid
63
first line of nonspecific physical body defenses
shedding epidermis
| cell membrane
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"moat"
sweat
oil
mucus
65
"wall"
physical barriers
66
second line of nonspecific body defenses
Macrophage (guard)
| Swelling) Histamine (alarm
67
humoral response
b cells that attack using antibodies (CIA)
68
cell mediated response
cytotoxic t cells that attack by popping
69
first trimester time period
1-12 weeks
70
at what week will the srY gene either turn on or stay off?
8 weeks
71
which hormone stars contractions?
oxytocin
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parasite
uses host organelles for energy and to make offspring
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retro viral infection
insert genetic information which embeds with in the host genes, eventually destroying host
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gamates
human sex cells
75
how are human sex cells made?
meiosis
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purpose of semen
fluid that raises the pH to above seven to neutralize the vagina, produces sugar first sperm to eat, lubricant, for sperm to swim
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muscular tube that propels the spermatozoa towards the urethra
vas deferense
78
three glands that make semen
seminal vesicle
cowpers
prostate
79
monthly steps for females
one. The pituitary hormones LH and FSH are released into the blood
two. An ovum starts to develop a follicle which produces estrogen so the uterine lining gets thick
three. at day 14 ovulation occurs
four. follicle becomes the corpus luteum, which makes progesterone
five. the corpus luteum dies so the uterine lining is uneeded and us shed in a process called menstruation
six. the egg doest meet a soerm in the fallopian, so it dissolves
seven. another ovum starts to develop in one of the ovaries and the process begins again
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hypothalamus
detects low hormone levels triggers master gland
81
gastrulation
infolding of blastocyst forming germ layers
1. endoderm
2. mesoderm
3. ectoderm
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functions of blood
transporting oxygen, water and nutrients to cells.
distributes hormones throughout body
removes waste products
fight infection and heal wounds
83
leukocytes
white blood cells
have a nuclei and mitochondria
responsible for fighting infection/ preventing growth of cancer
84
pathogens
disease causing organisms or viruses
85
types of pathogens
```
certain bacteria
protozoans
fungi
worms
viruses
```
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infectious diseases
diseases that are caused by pathogens
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disease
I just order of structure or function in a human, animal or plant especially one that produces specific signs are sometimes
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germ theory of disease
infectious disease is caused by pathogens that can spread the disease from one organism to another organism
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how pathogens are transmitted
```
inhaling
physical contact
contaminated food or water
sexual contact
animals
```
90
ideal location for the virus to invade cells and multiply
mucous membrane
91
nonspecific defenses
does not distinguish one invader from another
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epidermis
outer layer of skin that is comprised of tough, dead cells that most bacteria and other organisms cannot penetrate. constantly shedding so bacteria cannot embed and grow
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lysozome
found in saliva and tears. an enzyme that breaks down the cell walls of many bacteria
94
digestive and respiratory system
lined with mucous membranes (barrier)
mucus in the trachea creates a sticky barrier the traps microorganisms. Silly on movies trapped particles up to the pharynx where there swallowed. Then, stomach acids and enzymes help to destroy the pathogens, as well as many other of microorganisms and your food and drink
95
what happens if pathogen evade the first line of body defenses
met with second line: internal nonspecific defenses
includes certain pathogen destroying white blood cells, the inflammatory response, and certain specialized proteins. Since they do not single out specific pathogen, these defenses are also said to be nonspecific, like the first line of differences
96
macrophage
destroys microorganisms through phagocytosis
| when it encounters invading pathogen, it engulfs it. enzymes like lysozymes kill the pathogen
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neutrophils
smaller and more numerous than macrophages.
| kill by phagocytosis.
98
at three weeks the embryo has three layers that make up the embryonic disk. Which layer will become the muscles and bones?
mesoderm
99
what hormone causes the egg and follicle to mature?
FSH
| Follicle Stimulating Hormone
100
what hormone is produced by the corpus luteum?
progesterone
101
FSH in the male causes the production of...
spermatozoa
102
which hormone is responsible for fraternal twins?
FSH
| follicle stimulating hormone
103
what hormone will an embryo send to the corpus luteum to ensure that it continues progesterone production?
LH
104
at eight weeks, testosterone floods the fetus and turns it into a
male
| xy
105
after implantation, the developing human is called an
embryo
106
the lungs, and the digestive and reproductive systems result from the...
endoderm
107
mitosis stages after interphase:
prophase
metaphase
anaphase
telephase
108
The stage of mitosis where the chromosomes appear in the nuclear membrane breaks down
prophase
109
where must sperm pass when going from the vagina to the uterus
cervix
110
contains the eggs
| produce estrogen and testosterone
ovary
111
crater like structure that produces progesterone and estrogen
corpus luteum
112
a membrane found at the opening of the vagina
hymen
113
This part of the sperm contains an enzyme that can dissolve the egg coating
acrosome
114
this gland provides a protective coating that counteracts vaginal acids
prostate
115
provides food (fructose) for the sperm
seminal vesicle
116
this is where sperm is manufactured in the testicles
seminiferous tubules
117
where sperm is stored. It is attached directly to the testes
epididymis
118
The bursting of the follicle and the formation of the corpus luteum is controlled by
LH
119
what does luteinizing hormone from the pituitary gland cause to bd produced in males
testosterone
120
what does follicle-stimulating hormone from the pituitary gland caused be produced in the male body
sperm
121
a mature egg cell
ovum
122
endometrium
inner uterine lining
123
difference between fallopian tube and oviduct
no difference
| oviduct is the medical term
124
what do male pituitary glands release?
LH and FSH
testes release testosterone after puberty
never release progesterone
125
pituitary releases..
LH and FSH
triggers the ovary to release estrogen
after day 14 the corpus luteum releases the estrogen
126
what triggers the white blood cells response to attack
recognizing foreign molecules
127
Natural Killer (NK)
type of white blood cell
they recognized body cells that have become infected by a virus and kill them by releasing chemicals that poke holes in the infected cells membrane. Natural killer cells also recognize and attack abnormal body cells such as cancer cells. They played a key role in defending against cancer by killing abnormal cells before they can form a tumor
128
inflammatory response
A nonspecific defense characterized by redness, heat, swelling, and pain.
129
mast cells
cells that release a type of chemical alarm called histamine at the site of pathogen invasion
130
histamine
A chemical secreted by mast cells which causes nearby blood vessels to dilate. The expanded blood vessels increase the volume of blood flowing to the injured tissue. In addition, the vessels become more porous, allowing more blood plasma to leak into the interstitial fluid.
131
dilate
expand
132
interstitial fluid
A solution that famous and surrounds the cell of multicellular animals. It is the main component of the extracellular fluid, which also includes plasma entry and cellular fluid.
133
what happens during an inflammatory response
during an inflammatory response, chemical signals trigger changes in blood vessels and attract white blood cells that help destroy the invaders
134
phagocyte
A type of cell within the body capable of engulfing and absorbing bacteria another small cells and particles
135
what produces the redness, heat, swelling and pain you may experience around the injured area
The local increase of bloodflow, fluid, and white blood cells
136
what is the major function of the inflammatory response
removing pathogens and cleaning injured tissues. Inflammation may occur in a tiny area, such as the site of a mosquito bite. Or, if pathogens get into the body or release toxins that are carried throughout the body by the circulatory system, the whole body may react with an inflammatory response. In such a response white blood cells increased and a fever may occur
137
why is a high fever dangerous
because it can destroy proteins and cause other damage. But a moderate fever may contribute to the defense by stimulating phagocytosis and stopping the growth of many kinds of microorganisms
138
interferon
A family of proteins produced by cells in response to becoming infected by a virus. the infected cell may die, but it's interferon reaches healthy cells in the area, stimulating them to produce proteins that interfere with virus reproduction. affected against many viruses so it is nonspecific. affective against flu and common cold
139
antiviral proteins
proteins that are introduced about human or animal cells to interfere with viral replication
140
name two major functions of the immune system
sdestroy pathogens and detect and kill abnormal cells
141
which type of pathogen is always intracellular
viruses
142
examples of surface barriers
skin, mucus membranes
143
examples of innate internal defenses
cells and chemicals in body fluids
144
adaptive defenses (specific)
t and b cells
145
after the surface barriers a.k.a. any external defenses are penetrated, what is the next line of defense?
me (nonspecific) internal defenses
146
name the four keyways adaptive defenses differ from innate defenses
are specific, they involve BNT lymphocytes, they have memory, and they can act anywhere in the body
147
specific b cells called plasma cells secrete antibodies which bind to the
antigens
148
what is the first line of defense in lungs?
mucus in the nasal cavity traps foreign particles before they can enter the lungs
149
scribe how macrophages protect the human body
macrophages engulfed any pathogens that have passed the physical barriers. engulfing process is called phagocytosis
150
how do B cells recognize a specific virus? What do they do with the virus after they recognize it?
each of these cells have a different receptor protein on the surface of the used to attach to a particular virus. When he sounds fine to the virus than golfing and then break it into pieces to display pieces on the outside to alert helper T cells. Eventually these cells become antibody producing factories
151
b cells produce y shaped proteins called
antobodies
152
Albertise cells will use chemical signals called
cytokines
| trigger infected b cells to multiply
153
what is the purpose of a memory cell
The memory cell will rapidly produce the virus/antigen when they encounter the virus during the second infection. This is why you never get really sick with that virus again
154
The kind of blood cells that play a role in the body's immune system
white
155
A substance for into the body, such as disease causing organisms, that stimulates the body's immune system
antigen
156
A protein substance produced by the body to fight and invading foreign substance such as a disease causing organisms
antibody
157
immune system T cells developed in this gland
thymus
158
a chemical produced by the body that protects against viruses
interferon
159
The immune system can cause this response following an organ transplant
rejection
160
lymphocyte
A specific white blood cell that is involved in antibody production
161
The process by which a white blood cell ingests a disease causing organisms
phagocytosis
162
what does AIDS stand for
acquired Immune Deficiency Syndrome
163
what does HIV stand for?
human immunodeficiency virus
164
disease characterized by a breakdown of the body's immune system
AIDS
165
A substance injected into the body that helps protect against disease
vaccine
166
The type of immunization that is long-lasting
active
167
the type of immunity that is short term
passive
168
the type of disease in which the immune system itself attacks the body
autoimmune
169
lymphocyte that alerts when the body is invaded
helper t cell
170
cells that release ntobodies
plasma cells
171
turn into plasma cells
B lymphocytes
172
they poke holes in infected cells
Cytotoxic or killer T cells
173
third line of defense
immune system
174
The immune system
third line of defense. this system recognizes and defense against specific pathogens, cancer cells, and certain chemicals. specific/targeted defense.
175
immunity
when the body is resistant to the pathogenx that causes a specific disease.
176
how is immunity acquired
by becoming infected by the pathogen
177
antigen
A large molecule, usually a protein, that provokes an immune response.
antibody generating
178
antobodies
proteins found on the surface of certain white blood cells, or in blood plasma, that attach to particular antigens
179
most common antibody shape
y shape
180
what is at the tip of each arm of the Y
antigen binding site, or antigen receptor
181
what does the shape of the binding site make it possible for the antibody to do
for the anti-body to recognize a specific antigen with a complementary shape. each antigen sits on the surface of the invading particle and has a particular shape but knobs that protrudes from the surface
182
markers
unique to each antigen
183
explain how a specific antibody can bind to a specific antigen
just as a particular key is shaping able to fit into a specific lock, the antigen marker fits into a specific antibody. There is a huge variety in the three-dimensional shapes of antigen binding sites. This variety gives antibodies the ability to recognize an equally large variety of antigens
184
how are antigens neutralized
an anti-body tags the invader by binding to the antigen molecule. This triggers mechanisms that neutralize or destroy the invader
185
what does binding to an antigen do
The binding of antibodies stops and viruses from attaching to a host cell. This disables the virus and halts further infection.
186
antigens cause pathogens to clump together. What does this clumping do
this clumping makes the cells easy targets for phagocytes to capture and destroy
187
complement ptoteins
antibodies me also activates immune system chemicals called complement proteins that can attach to viral services or bacterial membranes. These proteins help to call viruses for fish is a Texas by white blood cells are puncture holes in bacterial outer membranes, causing the pathogen to break open. All of these antibiotic mechanisms involving specific recognition and attack phase, followed by nonspecific destruction phase
188
lymphocytes
The white blood cells that recognize specific invaders
189
where do lymphocytes originate
in bone marrow from stem cells
190
b cells (b lymphocytes)
A white blood cell that continues their development in bone marrow.
191
T Cells or T Lymphocytes
transported to the thymus gland where they mature
192
where do both B cells and T cells eventually travel to
in the blood to the lymph nodes and other parts of the lymphatic system
193
what enables things to target particular antigens
The ability to target particular antigen is due to the specific shapes of the antigen receptors on the lymphocyte surface
194
B cells play a key role in
humoral immunity
195
he sells played a major role in
cell mediated immunity
196
helper t cell mission
to coordinate immune system attacked by a recruiter sheeting and activating other immune system cells
197
when ejaculation occurs during sexual intercourse, the sperm enters where
the vas deferens
198
what do B cells defend primarily against
bacteria and viruses that are found outside of cells in body fluids
199
what activates a B cell
when fighting a pathogen, a B cell containing the matching androgen receptor binds to the antigenic the pathogen. activation means that the B cell grows and clones itself, forming millions of identical cells. Each of the cells is capable of developing into a plasma cell
200
plasma cell
A cell that produces and secretes antibodies specific to the antigen that activated the original b cell
201
humoral immunity
Community that originates from the cells
202
how do t cells work
T cells work by directly attacking hosts that contain multiplying bacteria or viruses. these host cells are actually body cells that have become infected
203
how do T cells recognize infected cells?
each T-cell has receptors for a specific antigen. When a pathogen infects a body cell, the pathogens antigens are displayed on the surface of the body cell
204
cytotoxic T cells
T cell clones which is then attack cells infected with the pathogen that triggered the response. Cytotoxic T cells binding to an infected cells membrane and poke holes in it by secreting a protein called perforin
The infected so leaks fluid, breaks open, and dies
205
what happens during the humoral response
b cells produce antibodies after being activated by free antigens present in body fluids
206
what happens during a cell mediated response
cytotoxic t cells attack infected cells that display the antigens of pathogens on their surface
207
helper t cell
both you moral and cell mediated immunity gets a boost from a particular type of lymphocyte called helper T cells. Like all lymphocytes, helper T cells are present in many versions, each with surface receptors that recognizes specific antigen. Like cytotoxic T cells, the helper T cells activated by finding to sells the display antigens of a pathogen. But the antigen displaying sell that helper T cells recognize her macrophages, the white blood cell that you pathogens bifacial sentences.
208
how do helper T cells respond to this announcement
by secreting chemicals that activate both cytotoxic T cells and B cells
209
cell mediated immunity
attack on infected cells
210
humoral immunity
secretion of antibodies by plasma cells
211
long lasting lymphocytes
memory cells
212
primary immune response
The first formation of B and T cells to battle new invading pathogen. this first response is relatively slow and we can because time is needed for enough specific lymphocytes to form to detect the pathogen
213
secondary immune response
A second exposure to the same pathogen triggers a much quicker and stronger response
214
The second exposure stimulates the memory B cells to rapidly produce plasma cells double secrete antibodies specific to that antigen. Meanwhile memories cells a.k.a. T cells rapidly produce large numbers of cytotoxic T cells that attack cells infected with the pathogen. The process is so quick but you don't develop symptoms of the disease. Your body destroys the invader before you feel sick
swaq
215
Dr. Jonas Salk
polio vaccine
216
vaccine
A dose of a pathogen or part of a pathogen that is been disabled or destroyed so it is no longer harmful
217
booster shot
this shot is an additional dose of an antigen that boosts antibody production and extends the memory for that antigen
218
why are booster shots important
because some of the initial memory cells that were produced after the first shot died
219
active immunity
whenever your body produces antibodies against infection. can develop from catching a disease such as chickenpox or from receiving a vaccine, such as that for polio.
220
passive immunity
when your body receives antibodies for a particular disease from another source
221
allergy
an abnormal oversensitivity to an otherwise non-harmful antigen which is called an allergen
222
antihistamine
A drug that blocks the action of histamine, minimizing symptoms of an allergic reaction
223
anaphylactic shock
dangerous type of allergic reaction
224
autoimmune disease
The immune system turns against some of the bodies own molecules
225
what happens when HIV destroys the body's helper T cells
The immune system cannot activate other T cells or B cells. Both the Hume oral and cell mediated immune responses are impaired, and the body cannot fight pathogens.
226
an organism that causes an infectious disease is called
pathogen
227
where are eggs produced
ovary
228
uterus
hollow, muscular organ with thick walls, roughly the size and shape of a pear
229
neck of the uterus
cervix
230
connects the uterus to the vagina
cervix
231
vagina
flexible, thin walled organ about 9 cm long
232
functions of the vagina
receives the penis and spermatozoa during intercourse
birth canal through which the baby exits
passage way for menstrual flow
233
the main male reproductive structures
```
testes
scrotum
epididymis
vas deferens
penis
```
234
where do sperm begin development
testes
235
singular of testes
testis
236
function of the scrotum
house the testes outside the main body cavity to keep them cool
237
semen
The substance that is emitted during the process called ejaculation
238
ejaculation
muscular contractions propel spermatozoa from the epididymis through the connecting ducts called the vas deferens and finally through the urethra
239
ejaculation takes place muscles at the base of the urethra contract and close off the outlet from the
bladder
240
penis
and organ consisting mainly of specialized tissues called erectile tissue. filling of this tissue with blood causes an erection
241
through what process are sex cells generated
meiosis
242
when does the development of the egg cells begin
before a female is born
243
primary oocyte
a diploid cell that is in the prophase stage of meiosis 1. at this stage the process pauses
244
secondary oocyte
egg/ova
245
ovum
mature egg cell with a haploid nucleus that is capable of fusing with a spermatozoa
246
primary spermatocyte
the beginning process of spermatozoa synthesis
247
where do spermatozoa complete development
epididymis
248
ovarian cycle
refers to the cyclic changes that occur in the ovaries
249
menstrual cycle
refers to the cyclic changes that take place in the uterus
250
first part of the ovarian cycle
follicular phase
251
what triggers the hypothalamus to secrete a releasing hormone, which causes the anterior pituitary to secrete follicle-stimulating hormone and lutenizing hormone
low estrogen levels
252
as the follicle matures, what does it secrete
estrogen
253
hypothalamus
A region of the forebrain below that Salamis that cord needs both the autonomic nervous system and the activity of the pituitary
254
what do rising levels of LH signal in males
signal the testes to produce and secrete testosterone
255
what stimulates spermatozoa production
the combination of FSH and testosterone
256
the master control center of that endocrine system
hypothalamus
257
prolactin
stimulates milk production
| anterior lobe
258
Fertilization
occurs when the egg and sperm cells fuse
259
zygote
fertilized sex cell
260
what does successful fertilization require
living sperm in the oviduct on the day of, or shortly after, ovulation.
261
function of the acrosome
contains enzymes that help the spermatozoa cells penetrate the protective coats of the oocyte
262
50/50 chance
chance of entering the wrong oviduct the one that doesn't contain the egg
263
what prevents more than one sperm from entering
once one sperm successfully contracts the plasma membrane of the oversight, a barrier forms on the oocytes surface that prevents other sperm from entering. This ensures that just one sperm nucleus will be present to fuse with the ovums nucleus
264
mid piece
contains mitochondria
265
developing human (after 9 weeks)
embryo
266
implantation
The embedding of the blastocyst in the second endometrium that lines the uterus
267
The function of a trophoblast
The trophoblast grows, extending into the endometrium and anchoring the blastocyst in place. The trophoblast contributes to the development of the membranes that will nourish and protect the embryo. The intercell mass will eventually form the organism itself
268
The result of more than one egg being fertilized during an ovarian cycle. For this to happen, both ovaries must release an egg, or one ovary must release two eggs
fraternal twins
269
why are fraternal twins genetically different
each zygote fraternal twins is formed from a different egg and sperm. As a result, the genetic information for fraternal twins is different for each individual, and the same way that brothers and sisters born at different times have different genetic material.
270
The result of one early stage embryos splitting into two
identical twins
271
what does the embryo consist of at implantation
The trophoblast and an inner cell mass
272
where do stems cells come from
The intercell mass gradually gives rise to the organs and tissues of the embryo. Cells of this inner mass are also called stem cells
273
gastrulation
approximately three weeks after fertilization, a process called gastrulation takes place. Gastrulation forms three cell layers: ectoderm, endoderm and mesoderm
274
three layers of gastrulation
ectoderm, endoderm and mesoderm
275
ectoderm
outer layer
| forms the outer part of the embryo skin and the central nervous system
276
endoderm
inner layer
| forms the digestive track and lungs
277
mesdoderm
middle layer
| forms most of the other organs
278
amnion
A membrane that forms a fluid filled sac
| protects the embryo from physical impact
279
yolk sac membrane
produces the first blood cells and is the source of cells that eventually form gametes
280
chorion
A third membrane that becomes the embryos portion of the placenta
281
what forms part of the umbilical cord that connects the embryo to the placenta
allantois
282
placenta
soon after implantation, trophoblast cells and cells from the uterus form an important structure called the placenta. The placenta develops inside the uterus and surrounds the embryo. This structure enables nutrients and waste products to be transferred between the mother and developing baby
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by when is the placenta fully formed and functional
the third month
284
fetus
from week 9 to birth
| name of developing human
285
fetal position
when the fetus is filling up much of the space in the uterus and it curls forward
286
24 until birth
third trimester
287
why is it important for pregnant mothers to be nutritious
during pregnancy, substances and the mothers bloodstream are transferred to the fetus is bloodstream, this is how the fetus is nourished for nine months. But this transfer process can pose a serious health risk for the fetus is the mother doesn't have a healthy lifestyle.
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labor
A series of strong arrhythmic contractions of the muscles of the mother's uterus
289
lymphocyte
eventually become B cells (bone marrow) go to blood stream slash lymphatic system
or T cells (thymus)
white blood cells
290
nonspecific defense mechanism
first line of defense
| second line of defense
291
spleen
part of lymphatic system that helps filter waste that the lymph finds. located mid abdomen area
292
amniotic sac
sac in which the fetus develops
293
tonsils
part of the lymphatic system in the throat
294
HCG
human chorionic gonadotropin
produced in the pituitary gland
levels raise when pregnant
295
t cell vs helper t cell
helper t cell would activate the cytotoxic t cells
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capsid
outer layer that incloses the virus
| protein coat
297
cleavage
when a cell pinches to split into two
298
gonads
ovary and testes
299
lytic
make more viral protein
300
trophoblast becomes...
placenta
umbilical chord
amniotic sac
301
blastocyst becomes..
embryo
| endo meso ecto
302
lytic vs lyso
lytic - virus attaches, inserts, tricks to make new, continues to make new in body
lyso - attaches, inserts, hides in nucleus, comes out, hides again
