11 animal physiology Flashcards
1
Q
when do muscles exert force
A
when they contract and not when they relax and lengthen
2
Q
how many directions can muscles cause movement in
A
only one
3
Q
what does there need to be for opposite movements
A
a pair of muscles that exert muscles in opposite directions - an antagonistic pair of muscles
4
Q
what is the anchorage
A
one end of the muscle which is the firm point of attachment that does not move when the muscle contracts
5
Q
what shape are typical muscles
A
elongated
6
Q
examples of anchorages and insertions in humans
A
bones
7
Q
examples of anchorages and insertions in arthropods
A
the exoskeleton
8
Q
what is the opposite end of the muscle from the anchorage
A
insertion
9
Q
how do bones and exoskeletons act as levers
A
they can change the size and direction of the force exerted by a muscle.
10
Q
what are the junctions between bones called
A
joints
11
Q
give the two general overall types of joints
A
fixed joints
joints that allow movement (articulation0
12
Q
what are the three main parts of synovial joints
A
cartilage covering the surface of the bones to reduce friction where they could rub against each other
synovial fluid between the cartilage covered surfaces to lubricate the joint and further reduce friction.
joint capsule that seals the joint and holds in the synovial fluid
13
Q
what are ligaments
A
tough cords of tissue connecting the bones on opposite sides of a joint.
14
Q
ligaments attach
A
bone to bone
15
Q
tendons attach
A
muscle to bone
16
Q
function of ligaments
A
they restrict movement and help to prevent dislocation. they also ensure that certain movements can occur at a synovial joint but not at others. e.g. the elbow allows a lot of movement in one plane of bending or straightening, but little in the other planes
17
Q
biceps…
A
the flexor muscle, used to bend the arm at the elbow
18
Q
humerus bone…
A
provides a firm anchorage for the muscles
19
Q
triceps…
A
the extensor muscles, used to straighten the arm
20
Q
joint capsule…
A
seals the joint
21
Q
synovial fluid…
A
lubricates the joint to reduce friction
22
Q
cartilidge
A
a layer of smooth and tough tissue that covers the ends of the bones where they meet to reduce friction
23
Q
ulna…
A
bone that is the insertion for the triceps and acts as a lever transmitting forces from the triceps through the forearm
24
Q
radius…
A
bone that is the insertion for the biceps and acts as a lever transmitting forces from the biceps through the forearm
25
tendon...
attaches muscle to bone
26
distal
furtherst away e.g. for the thigh bone, it is the end by th knee.
27
proximal
closest e.g. for the thigh bone, it is the end by the torso.
28
dorsal
upper
29
ventral
underside
30
explain how the tendons work in the leg of an insect
the tendons at the distal end are attached to the opposite sides of the exoskeleton of the tibia, so one of them is a flexor of the joint between the femur and tibia and the other is an extensor.
31
what are synovial joints
joints that allow movement or articulation. they mostly consist of the same three parts.
32
synovial joints usually consist of
cartilige
synovial fluid
joint capsule
33
upper part of an insect leg
femur
34
lower part of an insect leg
tibia
35
ankles of a insect leg
spur (the pointy thing towards its head and tarsus, the whole ankle.
36
what term refers to the number of nuclei skeletal muscle fibres have
multinucleate
37
what do skeletal muscle fibres contain
specialised endoplasmic reticulum
38
why are muscles that are used to move the body called skeletal muscles
because they are attatched to bones
39
types of muscle
straited (stripes)
smooth
cardiac
40
what is sarcolemma
a single plasma membrane surrounding a muscle fibre
41
why are muscle fibres longer than usual cells
embryonic muscle cells fuse together to form muscle fibres
42
what is the sarcoplasmic reticulum
a modified version of the endoplasmic reticulum.
43
function of the sarcoplasmic reticululm
it wraps around every myofibril, conveying the signal to contract to all parts of the muscle fibre at once. it stores calcium.
44
what are inbetween the myofibrils
large numbers of mitochondria, providing the ATP needed for contractions
45
what are myofibirils
the many parallel, elongated structures within each muscle fibre. they have alternating light an dark bands, the stripes of the straited muscle, going across each myofibril
46
what is in the centre of the light myofibrils
a disc shaped structure, referred to as the z line
47
what is each myofibril made up of
contractile sarcomeres
48
what is the part of the myofibril between one z line and the next called
sarcomere, the functional unit of the myofibril
49
what are the two types of protein filament
thin actin filaments
| thick myosin filaments
50
where are actin filaments attatched
to a z line at one end
51
where are mysosin filaments attatched
theyre interdigiated with actin filaments at both ends and occupy the centre of the sarcomere.
52
how many actin filaments surround an actin filament
six, and they from cross bridges during muscle contraction
53
what area of the myofibri does the thick myosin filaments relate to
the dark areas
54
what is the z line on the myofibril
the light band, whilst the thin actin filaments continue and the thick myosin filaments stop.
55
within each muscle fibre are cylindrical structures called
myofibrils
56
around myofibrils there is
a specialised type of endoplasmic reticulum. there are also mitochondria between the myofibrils
57
what do myofibrils consist of
repeating units called sarcomeres
58
describe the bands in sarcomeres
light and dark
59
what do skeletal muscle consist of
large multinucleate cells called muscle fibres
60
a sarcomere contains thin
actin filaments
61
a sarcomere contains thick
myosin filaments
62
what is at either end of a sarcomere
a z line
63
describe the heads of myosin
they have heads that form cross bridges by binding to the actin
64
what part of the sarcomere is dark
the part containing myosin
65
what part of the sarcomere is light
the part containing actin
66
what goes down the middle of the sarcomere
the m line
67
what band is the middle of the sarcomere
A band
68
what band is inbetween the z line and m line
I band
69
what zone is the middle of the sarocmere
H zone
70
what is skeletal muscle contraction
the sliding of actin and myosin filaments sliding over eachother. this pulls the end of the muscles together, making the muscle shorter
71
what is required for sliding filaments and muscle contraction
ATP.
72
describe the hydolosis of ATP
3 adenanine moelcules and 3 phosphate groups. one phosphate group is broken down into energy for aerobic respiration to become ADP
73
types of muscle
cardiac
smooth
skeletal
74
what causes muscles to contract
action potential
75
how do muscles know to contract ?delete?
an electrical signal of action potental opens calcium channels.
ca2+ ions flood in the fibre, triggering neurotransmitters to move onto the next cell across the synapse
the neurotransmitters attatch to the sodium pathway which allow sodium ions to pass through.
these sodium ions depolarise the sarcoplasmic reticulum which can then release stored ca2+ ions into the cell cytoplasm which cause muscle cells to contract
76
the mechanism of muscle contraction
myosin filaments have heads which form cross bridges when they are attatched to binding sites on actin filaments.
ATP binds to the myosin heads and causes them to break the cross bridges by detatching from the binding sites.
ATP is hydrolysed to ADP and phosphate, causing the myosin heads to change their angle. the heads are now 'cocked' in position, as they store potential energy from ATP.
the heads attatch onto binding sites on actin that are further from the centre of the sarcomere than the previous sites.
the ADP is released and the heads push the actin filaments inwards towards the centre of the sarcomere. this is called the powerstroke.
77
how do muscles know to contract
an electrical action potential causes an influx of Ca2+ ions.
the influx of Ca2+ triggers the synaptic vesicles full of neurotransmitters to move across the synaptic cleft (synapse)
the synaptic vesicles bind to sodium channels and they open. (as they couldn't previously.)
now soidum can travel through the channels to the sarcoplasmic reticulum. (this is aided by a concentration gradient)
the positive Na+ ions means the membrane (which was positive on the outside and negative on the inside) has flipped, this is called depolarisation.
this means the sarcoplasmic reticulum releases loads of Ca2+. this becomes the stored ca2+ ions.
78
skeletal muscle fibres are ...
multinucleate
79
what is the sliding filament theory of muscle contraction
when a muscle contracts, the actin is pulled along myosin toward the centre of the sarcomere.
the actin and myosin filaments become completely overlapping.
there is no pale area in the centre.
the muscle shortens.
80
what do catalytic converters do
remove CO, NOx, and unburned hydrocarbons from exhaust gases, making them CO2, N2 and H2O
81
what do catalytic convertes have to make them have a large surface area
a ceramic honeycomb coated with a thin layer of catalyst metals (Pt, Pd, Rh)
82
why is blood in the glomerulus under high pressure
because the diameter of the afferent ateriole is wider than the effering ateriole
83
what is the entering ateriole called
afferent
84
what is the leaving ateriole called
efferent
85
what is the filtration membrane made of
glycoproteins, surrounding the endothelium of the capillaries
86
what does the inner layer of the bowmans capsule consist of
highly adaptive podocytes
87
what prevents proteins an cells passing through the bowmans capsule
largegaps between podocytes
88
what passes through bowmans capsule
glucose, ions, water, urea etc
89
stages of the nephron
```
renal artery
glomerulus
bowmans capsule
proximal convoluted tubule
loop of henle
distal convoluted tubule
collecting duct
```
90
what does the liver do
cleans the blood
91
glucose present in the filtrate is...
actively transported out of the proximal convoluted tubule into the tissue fluid surrounding the nephron, using energy from mitochondria
92
how much of the sodium and chlorine ions are actively transported out of the proximal convoluted tubule, using a Na pump in the basal membrane
90%
93
what do cotransporter proteins do
bring in glucose and amino acids
94
contransporters bring in glucose and amino acids, establishing a conc gradient between...
the filtrate and the tissue fluid outside.
95
contransporters bring in glucose and amino acids, establishing a conc gradient between the filtrate and the tissue fluid outside. this causes...
water to move out of the filtrate down a water potential gradient by osmosis
96
what are the most permable (freely permable) to water parts of the nephron
the proximal convoluted tubule and descending limb of the loop of henle
97
which part of the nephron is impermeable to water
the ascending limb
98
which parts of the nephron have variable permability to water
the distal convoluted tubule
99
what do metabolic processes produce
waste
100
what type of waste is nitrogenous
protein waste
101
what are osmoregualtors
the organisms that are able to keep or regulate the solute concentration of their body fluids above or below that of their external environment.
they control the osmolarity of their tissues within very narrow limits.
102
when you become dehydrated...
urine darkens
skin becomes less elastic
heart rate and breathing rate increase
blood pressure decreases.
103
is the renal artery or renal vein nearer the top of the kidney
the renal artery, then renal vein
104
endothelial cells are
the inner layer of cells
105
epitherial cells are
the outer layer of cells
106
function of loop of henle
create a high concentration of sodium ions and chlroide ions in the tissue fluid of the medulla
107
why does the loop of henle perform its function
so that water can be reabsorbed from the contents of the nephron as they pass through collecting duct
108
survival advantage of the loop of henle
very concentrated urine can be produced
| conserves water and prevents dehydration
109
the descending limb of the loop of henle is
water permable
110
the ascending limb of the loop of henle is
more permeable to salts/less permeable to water
111
which part of the loop of henle is the descending limb
the thick part
112
why is the glucose conc in the renal vein slightly lower than that of the renal artery
some of the glucose is reabsorbed for metabolic processes
113
why is the oxygen concentration lower in the renal vein than in the renal artery
some of the oxygen is used in the metabolic processes
114
why is the carbon dioxide concentration higher in the renal vein than in the renal artery
due to the production of carbon dioxide during respiration in the cells of the kidney
115
each kidney has around
1 000 000 nephrons
116
bowmans capsule function
Highly porous wall which collects the filtrate
117
glomerulus function
Knot-like capillary bed where high-pressure filtration takes place
118
proximal convoluted tubule function
Twisted section of the nephron where water, nutrients and salts are reabsorbed back into the blood; contains many mitochondria and microvilli
119
loop of henle function
Hairpin shaped tube with a descending and ascending limb; water and salt reabsorption takes place here
120
distal convoluted tubule function
Another twisted section of the nephron, where water and salts are reabsorbed back into the blood; also contains many mitochondria and microvilli
121
collecting duct
A slightly wider tube that carries the filtrate to the renal pelvis
122
afferent ateriole
Brings blood from the renal artery
123
efferent ateriolle
A narrow blood vessel that restricts blood flow, which helps to generate the pressure needed for filtration
124
vasa recta
An unbranched capillary shaped like the loop of Henle, with the descending limb bringing blood deep into the medulla
125
what are podocytes
the cells of the inner walls of the bowmans capsule. They have many extensions which fold around the blood capillary forming a network of filtration slits that hold back the blood cells during ultrafiltration with the help of the glomerular basement membrane.
126
what is the basement membrane made of
glycoproteins
127
what are the small window like openings called in capillaries
fenestrations
128
wwhere does ultrafiltration take place
fenestrations
129
the fenestrations in the capillary wall allow WHAT to flow out and WHAT to come in
The fenestrations in the capillary wall allow blood to flow out, however, the basement membrane acts like a sieve during the ultrafiltration process and stops the blood cells and large proteins. Thus, white and red blood cells cannot pass through, but small proteins, salts and nutrients can.
130
what do cells of the proximal convluted tubule have
lots of mitochondria to provide energy for active transport
131
does the tissue fluid deep in the medull have a high or low water potential/salt concentration
low water potential
| high salt concentration
132
where is blood taken away from the kidneys
via the renal vein connecting to the inferior vena cava
133
what does the ureters connect
urine from the kidney to bladder
134
where does a nephron begin and end
in the cortex and the looop of henle moved down into the medulla
135
where is the basement membrane
inbetween the glomrulus and the bowmans capsule
136
what type of pressure is there inside the glomerulus capillaries
hydrostatic build up
137
what substances travel from blood plasma to glomerulur filtrate
```
water
inorganic ions
urea
uric acid
glucose
amino acids
```
138
what substances travel from blood plasma to glomerular filtrate
```
water
inorganic ions
urea
uric acid
glucose
amino acids
```
139
what si ficls law
rate of diffusion = surface area x conc gradient
| / length of diffusion pathway
140
what is ficks law
rate of diffusion = surface area x conc gradient
| / length of diffusion pathway
141
what substances are reabsorbed back into the blood during selective reabsorbtion
all glucose, amino acids, vitamins, and many Na and Cl ions are reabsorbed out of the PCT and back into the blood
142
what do outer membranes of cells actively transport (kidneys) out of cytoplasm and where does this substnace go
```
sodium ions (sodium potassium pump)
down a conc gradient back into the cytoplasm, passing through co-transporter proteins that transport glucose or amino acids
```
143
what does selective reabsorbtion of salts, glucose and amino acids do
reduce the water potential of cells
increase water potential in tubules
keep water via osmosis
144
outline the function of the proximal convoluted tubule
selective reabsorbtion of water, glucose, minerals, useful substances
absorption by active transport
145
what is the medulla (hyper...)
tonic
146
what does the cortex do
ultrafiltration
147
explain the process of ultrafiltration
blood in the glomerulus is under high pressure caused by the difference in diameter of afferent and efferent arterioles.
fluid plasma and small molecules forced into bowmans capsule
which prevents larger molecules or blood cells from passing through
148
where is the loop of henle
in the medulla
149
where is the nephron (except LOH)
in the cortex
150
if molecules are left behind after ultrafiltration they they exit through
the efferent ateriole
151
podocyte function
helps support structure of glomerulus
152
what does fennestrated mean
has holes in it
153
what do the endothelial fenestrationd in the glomerulsus do
allow all small molecules to pass through (water, urea, ions etc, NOT large proteins)
154
what does the different sizing of aterioles in the glomerulus do
create blood pressure theat gives hydrostatic pressure that brings about filtration
155
what is the basement membrane
the filtration membrane
156
in the lumen of the PCT, what happens to Na+
it is actively transported back using atp energy from mitochondria.
157
in the lumen of the PCT, what happens to all glucose and AA
reabsorbed by co transporter proteins (Na diffuses in providing energy for the exchange.
158
in the lumen of the PCT, what happens to water
absorbed by osmosis
159
what is in the glomerular filtrate
H2O
salt urea
glucose
AA
160
what do the microvilli around the lumen of the PCT do
increase SA
161
what is the purpose of the LOH
to make the surrounding tissues (or medulla) more salty, this helps to concentrate urine and reabsorb water via osmosis (higher conc grad).
162
the descending limb is impermeable to...
| and permeable to..
impermeable to Na+
| permeable to H2O
163
the ascending limb is impermeable to...
| and permeable to..
impermeable to H2O
| permeable to Na+
164
why is the descending limb first
so that we dont get rid of too much water, and so it can concentrate the filtrate before the ascending limb
165
what is an aquaporin
small protein pores in the collecting duct that make it permeable to water. adh constructs these temporarily, as the collecting duct is usually impermeable to water.
166
chemical formula for ammonia
NH3
167
chemical formula for urea
(NH2)2CO
168
chemical formula for uric acid
C5H4N4O3
169
ammonia toxicity
high
170
urea toxicity
moderate
171
uric acid toxicity
low
172
animals that produce ammonia
aquatic animals (because ammonia is very soluble and can dissolve in the water)
173
animals that prouce urea
terrestrial animals (most land animals convert ammonia to urea or uric acid which require less water for excretion and they are less toxic than ammonia)
174
animals that produce uric acid
reptiles and birds
175
how to make more effective kindeys
maybe lengthen loop of henle
| saltier medulla tissue
176
what is osmoregualtion
the process by which organisms regulate the water content of the body
177
what do osmoreceptors do
montior water potential of the blood and vary the amount of ADH released into the bloodstream. the kidneys respond to a change in ADH conc by adjusting the vol and conc of the urine
178
mammals are osmoregulators. what do they need to do
ensure the volume of blood plasma and concentration of dissolved substances in the blood and tissue fluid stay relatively constant.
179
what do osmoconformers do
keep the osmotic potential of their bodies the same as their sea water environment.
180
how do marine invertebrates keep the osmotic potential of their bodies the same as their sea water environment
they take in ions and salts but (sharks) also accumulate high levels of urea which increases the concentration of solutes in their body.
181
how do amoeba osmoregualte
they use contractile vacuole which contracts and expels water out of the cell.
182
how do insects osmoregualte
they have malphigian tubes that control water balance and excrete nitrogenous waste.
183
how do mammals osmoregualte
the kidney:
excretes urea
controls the balance of water and salt
184
how do fish osmoregualte in a freshwater environment
drinks little water, actively takes up ions through gills, absorbs water through skin and excretes dilute urine.
185
how do fish osmoregulate in a saltwater environment
drinks ample water excretes ions through gills, loses water through skin
186
give 4 examples of organisms that are osmoconformeres
sharks
jelly fish
sea cucumbers
sea fish
187
how do contractile vaculoes help osmoregualte
it uses active transport to pump ions into the CV. water then enters by inward osmosis and then is released into the surrounding environment by exocytosis.
188
how do malphigian tubes help osmoregualte
MT collect excess water from blood in the insect's abdomen and pass it onto the hind gut of the digestie system. more water can be absorbed here.
189
how do kidneys help osmoregualte
kidney nephrons collect excess water from the blood through ultrafiltration. this water collects in the kidney pelvis and is stored in the bladder for urine.
190
where does ADH act
in the DCT and CD
191
where is ADH secreted from
pituitary glandf
192
what monitors solute concentration in the blood
osmoreceptors in the hypothalamus
193
what is an aquaporin
Aquaporins are membrane proteins. They initiate a series of events which causes vesicles with aquaporins to fuse with the surface membrane. The aquaporin then allows water molecules to pass through
194
what does the binding of ADH to the receptors in the cell membranes in the collecting tubules cause
increased water permabiliy by causing aquarporin to move to the surface membrane. the aquaporin then allows water molecules to pass through,
195
primary causes of kidney failure
diabetes and hypertension or high blood pressure
196
what is dialysis
Hemodialysis is a process that uses an artificial membrane known as dialysis tubing (found within the dialyser) to remove wastes, such as urea, from the blood as well as to restore the proper balance of electrolytes in the blood and eliminate extra fluid from the body.
197
how does dialysis work
The dialyser is made up of two parts, one for your blood and one for a washing fluid called dialysate. The dialysis tube is a thin membrane that separates these two parts. During hemodialysis, blood cells, protein and other important molecules remain in your blood because they are too big to pass through the membrane. Smaller waste products in the blood, such as urea, creatinine, potassium and extra fluid, pass through the membrane and are washed away in the dialysate.
198
alternative to dialysis
kidney transplant
199
what would too much glucose in the urine indicate
diabetes
200
what would too much protein in the urine indicate
ultrafiltration process failing
201
waht does erythrocytes in urine indicate
severe infection or tumour
202
what would blood or leuocyctes inurine indicate
infection or kidney tumour
203
why do insectes exrete uric acid
This molecule has very low solubility in water and is excreted as a semisolid form in insect faeces. This allows water conservation.
204
where does spermatogenesis take place
semi inferous tubules in testes.
205
in the geminal epithelium of the semi inferous tubules, there are
stem cells which form spermatogonia.
206
what does spermatogonia divide by mitosis to produce
```
additional spermatogonia (2n)
and
primary spermocytes (2n)
```
207
waht do primary spermocytes divide by meiosis I to produce
two lots of secondary spermocytes (n)
208
what do secondary spermocytes divide by meiosis II to produce
spermatids (n)
209
what do spermatids divide to produce
sperm with the nursing of sertolli cells
210
what is multiplication phase in spermatogenesis
spermatogonia --> primary spermocytes
211
what is growth phase in spermatogenesis
primary spermocytes --> secondary spermocytes
212
what is maturation phase in spermatogenesis
secondary spermocytes --> spermatids
213
what is spermiogensis in spermatogenesis
spermatids --> sperm
214
where does oogenesis occur
ovaries, in the primary follicle, where there is a primaru oocyte surrounded by a single layer of follicle cells
215
what does the oogonium from germinal epithelium diide by mitosis to produce
oogonium (2n)
216
what does the oogonium (2n) divide by mitosis to produce
primary oocyte (2n)
217
what does the primary oocyte divide by mitosis to produce
```
polar body (n)
and
secondary oocyte (n)
```
218
what does the secondary oocyte produce involving ovulation
```
2nd polar body
fertilised egg (2n)
```
219
stages of fertilisation of a human egg
```
arrival of sperm
binding
acrosome reaction
fusion
cortical reaction
mitosis
```
220
arrival of sperm in fertilisation
sperm attracted by a chemical signal and swim up the oviduct to reach the egg. fertilization is only successful if many sperm reach the egg.
221
binding in fertilization
the first sperm to break through the layers of the follice cells binds to the zona pellucida. this triggers the acrosome reaction.
222
acrosome reaction in fertlization
the contents of the acrosome are released by the separation of the acrosomal cap from the sperm. enzymes from the acrosome digest a route for the sperm through the zona pellucida, allowing the sperm to reach the plasma membrane of the egg.
223
fusion in fertlization
the plasma membranes of the sperm and egg fuse and the sperm nucleus enters the egg and joins the egg nucleus. fusion causes the cortical reaction.
224
cortical reaction in fertilzation
small vesicles called cortical granules move to the plasma membrane of the egg and fuse with it, releasing their contents by exocytosis. enzymes from the cortical granules cause cross linking of glycoproteins in the zona pellucida, making it hard and preventing polyspermy.
225
mitosis in stages of fertilzation
the nuclei from the sperm and egg do not fuse together. instead, both nuclei carry out mitosis, using the same centrioles and spindle of microtubules. a two cell embryo is produced.
226
what happens after the mitosis stage in fertilization
a hollow ball of cells called a blastocyst is formed and cells begin to differentiate.
the zygote has become an embryo and next implants into the uterus lining
if the embryo successfully implants it will keep growing and produce hCG hormone.
hCG hormone causes the ovary to continue producing progesterone - pausing the menstrual cycle
227
what basic stages are in both spermatogenesis and oogenesis
mitosis generates large numbers of male gametes in the testes
cells grow so that the cells have enough resources to undergo two divisions of meiosis.
meiosis to undergo haploid cells.
differentiation so the haploid cells develop into gametes with structures needed for fertilization.
228
which part of the seminiferous tubule divide endlessly by mitosis to produce more diploid cells
the outer layer called germinal epithelium cells
229
the diploid cells formed by the endless mitotic divisions of the germinal epithelium become
primary spermocytes.
230
what does each primary spermocyte form (via meiosis I)
two secondary spermocytes
231
what does each secondary spermocyte form (via meiosis II)
two spermatids
232
what do spermatids form
spermatozoa
233
what happens once spermatozoa become sperm
the sperm detatch from sertolli cells and are eventually carried out of the testis by the fluid in the centre of the semiinferous tubule
234
what does the acrosome contain
enzymes that digest the zona pellucida around the egg
235
where is the haploid nucleus
underneath the acrosome.
236
what is the haploid nucleus
contains the 23 chromosomes that are passed from father to offspring.
237
what does the tail of the sperm do
provide propulsion that allows the sperm to swim up the vagina, uterus and oviduct until it reaches the egg.
238
where is the centriole in the sperm
between th head and midpiece
239
what do the helical mitochondrion do in sperm
produce ATP by aerobic respiration to supply energy for swimming and other processes in the sperm.
240
what do the microtubules do in the sperm
make the sperm tail beat from side to side and generate the force that propel the sperm
241
what do the protein fibres do in the sperm
strengthen the tail
242
which cells in the womans ovaries divide by mitosis to form more diploid cells
the germinal epithelium cells
243
what do the diploid cells formed by the germinal epithelium cells in the ovaries do
grow into larger cells called primary oocytes
244
what do primary oocytes do
start the first division of meiosis but stop during prophrase I. the primary oocyte and a single layer of follicle cells around it form a primary follicle.
245
how many primary follicles are there in a newborn girl
400, 000
246
what does the primary oocyte complete and form
the first division of meiosis, forming two haploid nuclei. the cytoplasm of the primary oocyte is divided unequally, forming a large secondary oocyte and a small polar cell.
247
what does the secondary oocyte start
the second division of meiosis but stops in prophase II. the follicle cells meanwhile are proliferating and follicular fluid is forming.
248
what happens when the mature follicle burts at the time of ovulation
the egg that is released is still the secondary oocyte.
249
what happens after fertilisation in the ovaries
the secondary oocyte completes the second division of meiosis to form an ovum (with a haploid nucleus inside) and a second polar cell or body. the first and second polar bodies do not develop and eventually degenerate.
250
PAGE 140 PHOTO
STAGES IN SPERMATOGENESIS
251
PAGE 141 PHOTO
STAGES IN OOGENESIS
252
what is the cytoplams/yolk in a mature human egg used for
droplets of fat and other nutrients needed during early stages of embryo development.
253
what do the cortical granules do in the mature egg
harden the zona pellucida to prevent multiple fertlization
254
what does the zona pellucida do in the mature egg
protects the egg cell and restricts entry of sperm.
255
what are the layer of follicle cells in a mature egg called
corona radiata
256
significant differences between spermatogenesis and oogenesis
millions of sperm produced by men every day from puberty.
only one egg produced each 28 days for women.
nearly all the cytoplasm is removed during the latter stages of spermatogenesis so sperm contain very little.
egg cells contain more cytoplasm than any other human cell.
257
species that partake in internal fertilisation
humans + mammals
pythons + reptiles
albatrosses + birds
258
species that partake in external fertilisation
salmon + fish
| frogs + amphibians
259
what is polyspermy
fusion of two or more sperm with an egg cell results in a cell that has three of each chromosome or more. this is called polyspermy. cells produced in this way often die and those that survive are often sterile.
260
where do sperm swim
```
vagina
cervix
uterus
oviducts
if there is an egg in the oviduct, the sperm can fuse with it to produce a zygote
```
261
describe zygote to blastocyst
divides by mitosis to form a 2 cell embryo, then a 4 cell embryo until it becomes a blastocyst
262
where is the blastocyst transported
down oviducts to uterus. at 7 days, the embryo implants itself into the endometrium. if implantation doesnt occur then the embryo is not supplied with enough food and dies.
263
how and where does the ovum divide after fertilisation
by mitosis in the oviduct
264
what happens whilst he embryo migrates down the oviduct to the uteurs
it divides even more
265
what is a blastocyst
an embryo with about 125 cells
266
what is the outside of the blastocyst
zona pellucida
267
what is the trophoblast
the outer layer of cells
268
what is the blastocoel
a fluid filled blastocyst cavity
269
what is the embryoblast
inner cell mass
270
where does the blastocyst implant
the endometrium (lining) of the uterus
271
BLASTOCYST
DIAGRAM
272
after the egg cell reserves are used up what happens
the zona pellucida breaks down allowing the balstocyst to implant into the uterine wall. Finger like projections grow into the uterine wall and will develop into the placenta, allowing the embryo to access external supplies of the required nutrients.
273
how does the endometrium not shed during pregnancy
continued production of progesterone and estrogen. early in pregnancy, the embryo's outer cells that will develop into the placenta starts to produce hCG stimulating the corpuus luteum to continue the production of progesterone and estrogen. hCG remains until the placenta is fully established and can take over the role of progesterone an estrogen secretion.
274
what connect the embryo to the endometrium (?)
fingerlike projections, chorionic villi. they produce max imum surface area for contact with the maternal blood.
275
placenta diagram
!
276
where do the chorionic villi project to
the intervillous space, where maternal blood collects. he fetal blood circulates in capillaries which lie very close to the surface of the villus, with only a few micrometres separating them from the maternal blood pools. This short distance facilitates diffusion between the maternal blood and the fetal blood.
277
functions of the placenta
Exchange of material to keep the fetus alive during pregnancy (see Table 1 ).
Production of progesterone and estrogen. At the beginning of the pregnancy, this task is performed by the corpus luteum. However, the activity of the corpus luteum progressively decreases from the beginning of the eighth week. Its role is entirely replaced by the placenta at the end of the first trimester (about 12 weeks).
278
what passes from mother to fetus via diffusion
oxygen
drugs
alcohol
279
what passes from mother to fetus via facilitated diffusion
glucose
amino acids
vitamins
minerals
280
what passes from mother to fetus via osmosis
water (and back from fetus to mother)
281
what passes from mother to fetus via endocytosis
hormones (and back from fetus to mother via exocytosis)
282
what passes from mother to fetus via receptors
some viruses like HIV
283
what passes from fetus to mother via diffusion
carbon dioxide
284
waht passes from fetus to mother via facilitated diffusion
urea
285
what do the two fetal arteries (or umbilical arteries) bring from fetus to placenta
deoxygenated blood
286
what does the fetal or umbilical vein bring
oxygenated blood back from the placenta to fetus
287
describe the correlation between size or mass of animal and gestation period
positive
288
how is birth signalled to happen
the fetus signals to the placenta to stop producing progesterone, triggering the secretion of oxytocin, produced by the posterior lobe of the pituitary gland and by the fetus. the estrogen continues to rise, inducing the development of oxytocin receptors on the muscles of the uterine wall, increasing the responsiveness of the uterus to oxytocin
289
what starts uterine contraction
the endometrium secretes prostaglandins
290
what happens as more and more oxytocin is released
contractions become stronger and stronger
291
what is prolactin
the hormone ahat is produced by the anterior pituitary gland, stimulating milk production
292
causes of estrogen pollution
widespread use of contraceptives like estradiol
293
consequences of estrogen pollution
lowering sperm count in maels
294
when does the embryo implant into the endometrium
after about 7 days
295
as body mass increases,
so does gestation period
296
what secretes hCG
human embryos
297
what does hCG do
stimulates the ovary to maintain the secretion of progesterone during the first 3 months of preganancy
298
what does progesterone do
cause the uterus lining to thicken
ensure that the uterus develops and sustains the growing fetus
prevents uterine contractions and so spontatneous abortions
299
in the last third of pregnancy, progesterone falls and allows the mothers body to secrete what
oxytocin
300
in the last third of pregnancy, progesterone falls and there is a rise in...
estrogen, which causes an increase in the number of oxytocin receptors on the muscle in the uterus wall. when oxytocin binds to these receptors it causes the muscle to contract, stimulating the release of more oxytocin, contractions becoming stronger and stronger. this is positive feedback loop.
301
stages in fertilisation
```
arrival of sperm
binding
acrosome reaction
fusion
cortical reaction
mitosis
```
302
what do human embryos secrete in the early stages of pregnancy
hcg, which stimulates the ovary to maintain the secretiion of progesterone so the uterus lining doesnt shed. this stops after about 12 weeks, by which point the placenta has developed and now secretes the progesterone needed to sustain the preganancy until labour. the placenta also secretes estrogen
303
what can th eplacenta secrete
estrogen and progesterone and hcg
304
when does an embryo beome a fetus
when it is 8 weeks old
305
what does a new fetus develop
placenta
| umbilical cord
306
give the layers from fetus to outside
```
aminotic fluid
placneta
aminiotic sac
endometrium
myometrium
```
307
myometrium is
muscular wall of uterus, used during childbirth
308
intervillous spaces in placenta
maternal blood flows through these spaces, brought by uterine arteries and carried away by uterine veins
309
where does oxygenated blood flow
back to the fetus from the placenta along the umbilical vein
310
where does deoxygentaed blood flow
from the fetus from the placenta along the umbilical veins
311
what are the placental villi
small projections that give a large surface area for gas exchange and exchange of other materials. fetal blood flows through capillaries in the villi.
312
endometrium
lining of uterus
313
what exchanges across placenta to the fetus
```
oxygen
glucose
lipids
water
minerals
vitamins
antibodies
hormones
```
314
what exchanges across placenta to the mother
co2
urea
hormones
water
315
what is in the inter villus space
maternal blood
316
what is chorion
forms the placental barrier, controlling what passes
317
what is the basement membrane's permability
freely
318
adaptations of placenta capillaries carrying fetal blood
close to villus surface and has a very thin wall of single cells
319
what is there inside the villus
connective tissue
320
the nervous system consists of
thymus
spleen
transport network of lymoh nodes
321
describe the first line of defence
inital cells not destroyed in injury send out a chemical signal to attract attention.
large macrophages enter danger zone and kill bacteria by digesting them mercilessly.
neutrophils enter from the blood, kill everything and then themselves.
inflammation.
dendritic cell activates the specific helper t cell
322
neutrophils
enter from blood
kill everything and then themselves for safety a few days later
vomit deadly chemicals or eat the bacteria.
can explode and eject a toxic net of dna that trap and kill bacteria
323
what is inflammation
fluid from blood (dense with complement proteins) being released into the danger zone
324
describe (the actions of a) dendritic cell
collects samples of bacteria by ripping it into tiny parts and covering itself in it.
enters lymph nodes.
looking for a specific helper t cell that can help with this type of bacteria.
dendritic cell rubs itself against every possible t cell until it finds the one that can recognise the bacteria's antigens
325
describe the second line of defence
helper t cell clones itself again and again
group1 go to the danger zone to rejuvinate macrophages.
group2 go to activate b cells. eventually making 2000 antibodies a second.
antibodies flood danger zone.
they clump bacteria together to be killed
326
what are b cells
protein super weapons that can make antiboies for every single type of bacteria.
327
end of the primary immune response
all soldier cells kill themselves to save resources except a few helper t cells which turn into memory cells.
328
b cell
a type of lymphocyte that, when stimulated by a particular antigen, differentiates into plasma cells that synthesize the antibodies that circulate in the blood and react with the specific antigens.
329
clones of plasma cells
differentiated plasma cells that secrete a specific antibody and a clone of memory cells that make the antibody on subsequent encounters.
330
histamine
a physiologically active amine found in plant and aminal tissue and released from mast cells as part of an allergic reaction in humans, it causes the dilation of capillaries, constriction of bronchial smooth muscle and decreased blood pressure
331
hybridoma
a cell hybrid produced in vitro by the fusion of a lymphocyte that produces antibodies and a myeloma tumour cell in order to produce a continuous supply of a specific antibody.
332
memory cell
a type of lymphocyte that is released as a specific immune response and is stored in case of a second exposure to the same antigen.
333
monocolonal antibodies
any of the highly specific antibodies produced in large quantities by the clones of a single hybrid cell that has been formed in the laboratory by the fusion of a b cell with a tumour cell.
334
t lymphocyte
a type of white blood cell that completes maturation in the thymus and that has various roles in the immune sysem, including the identification of specific foreign antigens in the body and the activation and deactivation of other immune cells.
335
what are antigens constructully
proteins, polysaccharides or glycoproteins
336
where are antigens found
on the cell wall of a bacterium, protein coat of a virus on the cell membrane of a tissue or organ transplant
as a free molecule as a toxin
337
where does cell mediated immunity occur
within cells
338
where are t lymphocytes produced
stem cells in the bone marrow
339
explain cell mediated immunity
t lymphocytes produced in bone marrow and then go on to the thymus gland where they are activated
each t lymphocyte has a protein receptor embedded in its membrane that has a specific shape that will bind to one type of antigen (your body will produce millions of different types of t lymphocyte)
if the t lymphocyte binds to its specific antigen it will clone itself by mitosis
some of these cells differentiate into cytotoxic t lymphocytes
these destroy host cells infected with viruses (by releasing a cytotoxin that makes holes in the membrane) because antigens from the virus are left in the host cell membrane after infection.
340
what is humoral immunity
physiological mechanism protects the body from pathogens and foreign substances in extracellular fluids and is part of both the innate and adaptive immune systems ( not within a cell)
341
explain humoral immunity
after infection by a pathogen, a macrophage engulfs the microbe and antigens from the pathogen become embedded in the cell membrane of the macrophage
a b lymphocyte is activated due to the embedded antibody binding to a complementary shaped antigen
the activated b lymphocyte then divides by mitosis forming many clones
some of these clones differentiate to become plasma cells which produce antibodies. each type of plasma cell produces one type of antibody
342
how many sites does each antibody have that can bind to specific seperate antigens
two sites. this allows a number of antibodies to bind many microbes to form a lattice like structure called an antibody antigen complex.
343
what do antibodies do
bind antigens together (agglutination forming an antibody-antigen complex)
cause the precipitation of soluble toxins rendering it harmless
bind to receptors on the surface of pathogens preventing them from binding to the cell membranes of host cells.
activate proteins which stimulate phagocytes to engulf the antibody antigen complex.
344
what is the latent period
the 3-14days required for the person to produce the relevant antibody.
345
what happens after the latent period
the concentration of antibody in the blood rises rapidly and then begins to fall when the pathogen has been killed
346
benefits of memory cells
the secondary immune response has a much shorter latent period and produces a much higher concentration of antibodies
347
do phagocytes or lymphocytes produce antibodies
lymphocytes
348
what process of phagocytes engulf bacteria by
endocytosis
349
how many antigens to antibodies bind to
only one specific antigen
350
where are lymphocytes stored
lymphnodes and thyroid
351
what are polyclonal antibodies
the production of many different antibodies from many different lymphocytes stimualted by the many antigens on a microbes surface
352
what does the MHC protein do
cover the antigen so the body doesnt view the macrophage as a pathogen
353
stages of antibody reprodution, primary response
antigen production
activation of helper t cell
activation of b lymphocytes
proliferation
354
what is the surface of a virus
protein coat/capsid
355
what is the capsid of some viruses sometimes covered by
membane taken from the plasma membrane of the host cell
356
how are unique surface molecules used
viruses recognize and bind to their host using molecules on the surface of the hosts cell
living organisms recognize theri own cells and cell types using surface molecules
living organisms recognize cells that are not part of the organism and also viruses by surface molecules that are not present in the organism. these moelcuels trigger the production of antibodies.
357
what is the ABO blood groups system based on
the presence or absence of a group of glycoproteins in the membranes of red blood cells.
358
what is the ABO blood group system
three different version of the glycoprotein. the O antigen is always present.
359
how is the A antigen made in blood groups
adding an N-acetyl-galactosamine molecule to the O antigen
360
how is the B antigen made in blood groups
adding galactose
361
what antigens are present in an o blood group
o
362
what antigens are present in a A blood group
O and A
363
what antigens are present in a B blood group
O and B
364
what antigens are present in a AB blood group
O, A and B
365
what are basophils
a type of white blood cell
366
what are mast cells
similar to basophils but are found in connective tissue
367
what is histamine secreted in response to
local infection
368
what does histamine do
cause the dilation of the small blood vessels in the infected area. the vessels become leaky, increasing the flow of fluid containing immune components to leave the blood vessel, resulting in both specific and non specific immune responses
369
what are allergies
reactions by the immune system to substances in the environment that are normally harmless, such as pollen, bee stings or specific food.
370
how are allergies caused
when substances in the allergens cause over production of basophils and mast cells, and therefore excrete excessive secretion of histamine.
371
stages in antibody production
activation of helper t cells
activation of b cells
production of plasma cells
production of memory cells
372
activation of t helper cells
helper t cells have antibody like receptor proteins in their plasma membrane to which one specific antigen can bind. then the helper t cell is activated, and the antigen is brought to the helper t cell by a macrophage, a type of phagocytic white blood.
373
activation of b cells
inactive b cells have antibodies in their plasma membrane. if these antibodies match an antigen, then the antigen binds to the antibody. an activated helper t cell with receptors for the same antigen can then bind to the b cell. the activated helper t cell sends a signal to the b cell, activating it
374
production of plasma cells
activated b cells start to divide by mitosis to form a clone of cells. these become very active, with a much greater volume of cytoplasm. they are then known as plasma cells. they have an extensive network of rER, used for the synthesis of large amounts of antibody which is then secreted by exocytosis.
375
production of memory cells
memory cells are b cells and t cells that are formed at the same time as activated helper t cells and b cells, when a disease challenges the immune system. after the activated cells adn the antibodies produced have disappeared, the memory cells persist and allow a rapid response in case the disease is encountered again, allowing long term immunity.
376
what is on the tips of the antibody molecule
the antigen binding sites
377
what is the base of the y of the antibody molecule
constant region
378
uses of the constant region
making a pathogen more recognizeable
preventing viruses from docking to host cells
neutralizing toxins produced by pathogens
binding to the surface of a pathogen cell an dbirsting it by causing the formation of pores.
sticking pathogens together (agglutination) so they cant enter host cells and phagocytes ingest them more easily.
379
what does a vaccine contain
weakened or killed forms of the pathogen. or the chemical that acts as the pathogen
380
describe the first test/use of a vaccine
edward jenner deliberately infected an 8 year old boy with cowpox using pus from a blister of a milkmaid with this disease. he then tried to infect the boy but he was now immune. he then tested it on 23 others including himself
381
what was wrong with jenner's vaccineexperiment
the child was too young to give informed consent, and he had not done tests to find out if it had harmful side effects.
382
epidemiological data
study of the distribution, patterns and causes of disease in a population. can be used to help plan vaccination programmes, and prevent further spread.
383
what are plasma cells fused with to form hybridoma cells
tumour cells
384
describe pregnancy tests
urine of pregnant women contains hcg, a protein secreted by the developing embryo and later by the placenta. pregnancy tests contain monoclonal antibodies to which hcg binds. this causes a coloured band to appear, indicating that hcg was present.
385
what are the extracted and purified antibodies called that are produced by cultured hybridoma cells (produced by clones of the hybridoma cell)
monoclonal
386
how long is ther between fertilisation and a four cell embryo
about 48 hours
387
when the four cell embryo is fomred where is it and where is it travelling
still in the oviduct so now migrates down to the uterus (7 day journey)
388
when does the zona pellucida break down
once the egg cell uses up its reserves for the early embryo to grow after implantation of the blastocyst intot he endometrium lining
389
what does hcg do
stimulate the corpus leuteum to continue the production of progesterone and estrogen, which maintain the endometrium. it also ensures that the corpus leutum remiains until the placenta is flly established and can take over the role of progesterone and estrogen
390
where does fertilsiation take place
oviduct
391
what travels by facilitted diffusion between the mother and baby
glucose, amino acids, vitamins, minerals
urea from baby to mother
392
how do hormones travelf rom mother to baby
endocytosis
| (and exocytosis from baby to mother
393
how do viruses travel from mother to baby
via receptors
394
What does the fetal vein carry?
oxygenated fetal blood away from the placenta
395
what is estrogen pollution
increasing levels of estrogne in the environemnt
396
what is hemolyiss
the rupture of the red blood cells membrane, leading to the release of the hemoglobin and other internal components into the surrounding fluids
397
the receptors on b cells bind to
antigens
398
what are complement proteins
a group of more than 20 proteins that are present in blood and tissue fluid. These are normally in an inactive form. Some of the complement proteins become activated when they are presented with antigens, this function is fulfilled by antibodies. When an antigen bound to an antibody is presented to a complement protein, the complement is activated and binds to the pathogen. This is called opsonisation . This then causes the pathogens to lyse or encourages phagocytosis.
399
what is opsonisation
the coating of a pathogen with antbodies to promote and enhance phagocytosis
400
what is zoonosis
transmission of a disease from animals to humans
401
what is histamine produced by
basophils and mast cells (wbc)
402
functions of histamine
dilate and increase the permeability of capillaries
403
what is the role of LH in spermatogenesis
stimulates the interstitial cells to release testosterone
404
what is the role of FSH in spermatogenesis
Stimulates meiosis I – stimulates the primary spermatocytes (2n) to produce haploid secondary spermatocytes (n).
405
what is the role of testosterone in spermatogenesis
Stimulates:
1. Meiosis II: the formation of spermatids from secondary spermatocytes.
2. Differentiation of spermatids to spermatozoa.
406
where is the medulla on the kindey
inbetween the outsie part (cortex) and pelvis
407
where is the cortex on the kidney
on the outside
408
just before birth, which hormonal levels change and in what order
Progesterone levels decrease, oxytocin increases, uterine contractions increase, oxytocin increases further.
409
list 3 features of the bowmans capsule and glmerulus that promote rapid removal of filtrate
podocytes
fenestrations
high hydrostatic pressure
410
explain why proteins would not be present in the filtrate in the PCT
large molecules incapable of passing the basement membrane of the capillary
411
two features of the PCT cells are microvilli and numerous mitcohodnria. explain why
microvilli increase surface area for reabsorption
| mitochondria allow for more active transport by supplying ATP/energy
412
A diabetic has elevated levels of blood glucose. Suggest, using your knowledge of nephron function, why a common symptom of diabetes is the production of a larger than normal volume of urine
glucose conc of filtrate is elevated, and cannot all be reabsorbed in the PCT. water can be reabsorbed by osmosis. osmosis is less efficent and less water is absorbeddue to high solute potential.
413
joint cavity function
cavity contains the fluid and prevents shock damage to joint and bones
414
joint capsule function
produces synovial fluid
415
cartilidge function
reduce friction and absorb shock
416
explain how a pari of muscles causes movement
```
limbs are moved by antagonisitic pairs of muscle, as they can only provide force when contracting
the extensor (tricep) muscle straightens the limb, and the antagonist flexes the limb. when one muscle contracts, the antagonist is extended to its orginal length.
```
417
how do joints limit movement
they are desiigned to allow movement to a certain extent and in certain places. the elbow is a hinge joint that allows 180 movement in one plane only
418
how are monoclonal antibodies used in pregannacy kits
the urine of pregnant women contains hcg, a protein secreted by the embryo and later by the placenta. preganancy test kits contain monoclonal antibodeis to which hcg binds. this causes a coloured band to appear, indicating that hcg was presen tin the urine sample, and consequently the woman is pregant.
419
monoclonal antibdoies are...
specific. they give an accurate/precise diagnosis.
420
immune response
1. A macrophage engulfs the pathogen with the antigen by phagocytosis.
2. The pathogen is partially digested in the lysosome.
3. Macrophage presents these antigens on their membranes.
4. Helper T-cells bind to the antigen on the macrophage, become activated, and then bind to the specific B cell type.
5. The specific B cell type becomes activated.
6. Activated B cells multiply to form clones of plasma cells and memory cells.
421
By the end of the proximal convoluted tubule, approximately ______ of all the water, glucose and mineral ions have been reabsorbed.
80%
422
immune response
A macrophage engulfs the pathogen with the antigen by phagocytosis, partially digests them and presents them on their membranes.
Helper T-cells bind to the antigen on the macrophage, become activated, and then bind to the specific B cell type.
The specific B cell type becomes activated.
Activated B cells multiply to form clones of plasma cells and memory cells.
Plasma cells secrete specific antibodies. Antibodies aid the destruction of pathogens.
Memory cells provide long-term immunity as they remain circulating in the bloodstream waiting for a secondary infection to produce more antibodies and cause a faster response.
423
what is the role of lh in spermatogenesis
stimulates the intertesital cells to release testosterone
424
FSH source
Pituitary gland
425
FSH role in spermatogenesis
Stimulates meiosis I – stimulates the primary spermatocytes (2n) to produce haploid secondary spermatocytes (n).
426
testosterone role in spermatogenesis
Stimulates:
1. Meiosis II: the formation of spermatids from secondary spermatocytes.
2. Differentiation of spermatids to spermatozoa.
427
during fertilisation what happens immediately before th penetration of the gg membrane by a sperm
1. A sperm cell penetrates the follicle cells and binds to the receptors of the zona pellucida.
2. The acrosomal reaction occurs when hydrolytic enzymes make a hole in the zona pellucida to reach the egg membrane.
428
sliding filament theory
An action potential arrives at the end of a motor neuron.
This causes the release of Ca2+ from the sarcoplasmic reticulum.
Ca2+ binds to troponin on actin fibres.
This causes troponin and tropomyosin to move, exposing the binding sites on actin for myosin heads.
429
what do ligaments attach together
bones
430
what do tendons attach together
muscle to bone
431
active immunity
Immunity due to the production of antibodies by the organism itself after the body’s defense mechanisms have been stimulated by antigens.
