coordination and control - nervous system - eye - brain- hormones (human+plant) Flashcards
1
Q
nervous system function
A
allows communication
2
Q
CNS - central nervous system
A
- brain + spinal chord
- revives /processes info - gives out instructions
3
Q
PNS - peripheral nervous system
A
- neurones, receptor cells, effectors
- collects info then sends to CNS - acts on instructions from CNS
4
Q
neurones
A
- special nervous cells
- motor - sensory - relay
- carry electrical impulses round the body
5
Q
adaptions of neurones
A
- long
- myelin sheath - insulates impulses
- numerous dendrites - connections to many neurones
6
Q
sequence of events
A
- stimulus - receptor - coordinator - effector - response
7
Q
sequence of neurones
A
receptor - sensory - relay - motor - effector
8
Q
sensory neurones
A
receptor - sensory - relay (CNS)
dendrites - cell body in middle - receptors
9
Q
relay neurone
A
sensory - relay - motor
round with dendrites
10
Q
motor neurone
A
relay (CNS) - motor - muscles / glands
cell body - long bit - dendrites
11
Q
flow of impulse
A
to dendrites
12
Q
synapse
A
GAP BETWEEN NEURONES
- end of cell (electrical- chemical message)
- chemical transmitter molecules carry across synapse
- binds to receptor - open channels
- initiates new nerve impulse
(transmitter taken back to presynaptic neurone)
13
Q
reflex arc
A
subconscious response to dangerous stimuli extremely quick (not involve brain)
survival instinct
14
Q
sight
A
eye
light
15
Q
hearing
A
ear
sound
16
Q
smell
A
nose
chemicals in the air
17
Q
taste
A
tongues
chemical la in air reacting with tastebuds
18
Q
touch
A
skin
pressure pain temperature
19
Q
reflex arc sequence of events
A
stimuli- receptor - sensory - relay (spinal cord) - motor - effector - response
20
Q
voluntary actions
A
- decide to carry out
- have to think
- slower and purposeful
21
Q
iris
A
coloured ring of muscle
- alters pupil size by contracting and reacting
22
Q
cornea
A
transparent coating in front of eye
- protects eye refracts light into eye
23
Q
lens
A
transparent biconvex lens
- focuses light clearly into the retina
24
Q
ciliary body
A
ring of muscle tissues
- alters shape of lens
25
suspending ligaments
```
ligament tissues (by ciliary body)
- connects ciliary muscle to lens
```
26
optic nerve
nervous tissue
| - carries nerve impulses to brain
27
retina
made of light sensitive cells - back of the eye
| - cells produce nervous impulse that travels down the optic nerve
28
pupil
hole in iris
| - allows light to enter eye
29
what makes up the retin
photoreceptor cells
- rods
- cones
30
rods
respond to light
| - allows us to see in low light levels
31
cones
respond to colours
| - different cone cells respond to red, blue and green light
32
how do we see in dim light
outer RADIAL muscles contract (muscles pull)
| - pupil larger
33
how to see in bright light
inner CIRCULAR muscles contract (muscles bigger)
| - pupil smaller
34
focusing image on the retina
- cornea reflects light
- lens produces further refraction
- an image is in focus on retina
- optic nerve carries nerve impulses to brain
35
seeing distant objects
- ciliary muscles relax
- suspensory ligaments pull taut
- lens pulled thin
- light doesn’t bend as much
36
seeing near objects
- ciliary muscles contract
- suspensory ligament slack
- allowing lens to become fat
- bend lights more
37
accommodation
ability of lens to change shape and allow the eye to focus on objects at diff distances
38
short sighted - myopia cause
eyeball is too long or cornea is too sharply curved
- light rays meet in front of retina
- image is blurred
39
long sightedness - hyperopia cause
eyeball too short or cornea not curved enough or lens is too weak (not thick)
- light rays meet past retina
- image is blurred
40
myopia correction
diverging lens
| - light refracted outwards before it hits the lens (diverged) making light rays meet on retina
41
hyperopia correction
converging lens
| - refracts light more (converged) to make the light rays meet on retina
42
myopia
short sighted
| can only see near objects clear
43
hyperopia
long sighted
| can only see far objects
44
pituitary gland
- stores + releases hormones that regulate bodily functions
| little ball
45
medulla
- controls automatic actions
(heart/breathing rate)
(bottom stem)
46
cerebellum
- controls involuntary movement posture/balance
| big ball at back
47
cerebrum
- controls complex behaviour (learning memory personality)
| big folded bit
48
how do we know about brain
examine functional changes in people with brain damage
(phineas cage, mike the chicken)
imaging techniques
49
difficulties of investigating brain function
difficult to obtain + interpret case studies
| - ethical issues of investigating brains
50
hard to treat brain damage
- limited ability to repair nervous tissue
- irreversible damage
- difficult to access parts
51
endocrine system
- co ordinates organs (work together)
- produces chemical messengers
- produced in small quantities+ transported in blood
- slower
- acts for longer + targets larger area
52
thyroid gland (hormones)
```
THYROXINE
- regulates metabolic rate
(speed to transfer energy from chemical)
- controlled by hypothalamus + pituitary gland (negative feedback)
+ excess - hyperactivity
- deficiency - overweight + sluggish
```
53
ovaries (hormones)
```
OESTROGEN
- development of female sec characteristics
- regulates menstrual cycle
PROGESTERONE
- maintains uterine wall
```
54
testes (hormones)
TESTOSTERONE
| - promotes development of male sex characteristics
55
pancreas (hormones)
```
INSULIN
- converts blood glucose > glycogen
- increases metabolic rate (stimulates glucose uptake)
GLUCAGON
-converts glycogen > glucose
```
56
pituitary gland (hormones)
```
STH
- bone + muscle growth
ADH
- reabsorption of water into blood by kidneys
TSH
- controls function of thyroid
FSH
- follicle to develop
LH
- causes ovulation
```
57
negative feedback loop
```
change from optimum
receptor detects change
processing centre receives/processes info
effector brings about change
back to optimum
```
58
adrenal gland’s (hormones)
```
ADRENALINE
fight/flight
- increase heart/ breathing rate
- blood diverted to muscles
- increases respiration
```
59
thyroxine too high
| negative feedback
- detected by hypothalamus - inhibits release of TRH
- pituitary stops releasing TSH
- thyroid STOPS producing thyroxine
- return to ideal
60
thyroxine too low
| negative feedback
- detected by hypothalamus - releases TRH
- pituitary releases TSH
- thyroid produces thyroxine
- return to ideal
61
adrenaline
- causes fight/flight
- increases heart/breathing rate
- blood diverted to muscles
- increases respiration
- breakdown glycogen to glucose
62
release of adrenaline
- visual stimuli causes fright
- nervous impulses sent to brain + adrenal gland
- release adrenaline
63
menstrual cycle
28 days
day 1-5 (period) - breakdown uterus lining
day 14 ovulation
age 50-55 - menopause (no menstrual cycle)
64
menstrual cycle hormones
- pituitary gland > FSH
- FSH - maturation of eggs/ follicle
> OESTROGEN- repairs uterus wall
- inhibits FSH + stimulates LH - triggers ovulation
- follicle develops into corpus luteum
> PROGESTERONE - maintains thickness of uterus lining
- inhibits FSH + LH
- if egg isn’t fertilised- corpus luteum degenerates - progesteron levels fall
- triggers menstruation
- stops inhibition if FSH (cycle repeats)
65
FSH
produced - pituitary gland
stimulates follicle + egg maturation
causes oestrogen secretion
66
oestrogen
produced ovary tissue
builds up/ repairs uterus lining
stops FSH
stimulates LH
67
LH
produced pituitary gland
causes ovulation
follicle develops into corpus luteum - secretes progesterone
68
progesterone
```
produces - corpus luteum
maintains uterus lining thickness
inhibits FSH+ LH
if egg isn’t fertilised corpus luteum degenerates (progesterone levels fall)
triggers menstruation
FSH inhibition stops
```
69
pill
inhibits FSH + LH - inhibits follicle maturation + ovulation
| vagina thick with mucus - prevents sperm reaching egg
70
implant
releases progesterone
| inhibits FSH +LH
71
IUD
releases copper - kills sperm
72
condom / diaphragm
barrier - blocks sperm
| spermicide - kills sperm
73
causes of infertility
- eggs not mature
- eggs not releasing
- blocks oviducts
- low speed count
- poor quality sperm
74
infertility treatment
fertility drugs - FSH + LH
surgery (unblock oviducts)
IVF
egg/sperm donation
75
IVF
egg fertilised in lab with parents egg/speen
- woman given FSH+ LH (stimulate egg maturation)
- egg collected
- eggs mixed with sperm
- monitored and allowed to develop
- one or two selected and placed in uterus
counselling important - must prepare for failure
76
IVF disadvantages
multiple births may happen
success rate low
strong reaction to hormones
77
IVF is more successful if woman
```
is younger
has previously been pregnant
has BMI in range 19-30
has low alcohol / caffeine intake
doesn’t smoke
```
78
tropism
growth response of a plant toward or away from stimulus
79
auxin
found in tips of roots/shoot
no tip = no growth
covered tip grows straight
80
auxin - shoots
accumulates on shaded side
cell elongation - cell growth
shoot bends towards lightt
81
auxin - roots
accumulates on lower side
inhibits growth - grow slower
root bends downwards (to gravity)
82
meristems
found in shoot tip
areas of undifferentiated cells
- divide to form new cells
- can take to grow genetically identical plants (clones)
83
ethene gas
stimulates conversion of starch > sugar
| only gaseous plant hormone
84
gibberelins
promotes growth - cell elongation
ends dormancy period of seeds/buds
(shoots/flowers open)
85
auxin uses
- selective weed killer - grow so fast they die (broad leaf)
- rooting powder - promotes new root growth
- prevents ripe fruit dropping- high dose drops all at once
- seedless fruit - applied to unpollinated flowers
86
gibberelins uses
speed up germination (farmers)
87
ethene uses
makes fruit ripen fast in time for sale
88
hypothalamus
- regulates internal conditions (temp, water balance)
- produces major hormones
(above pituitary gland)
89
negative feedback
respond to change in conditions by initiating responses that will counteract change
maintains steady state
