bio chapter 10 and 11 Flashcards
By the end of this topic, students should be able to: (l) Describe the structure of the eye as seen in front view and in horizontal section (m) State the principal functions of component parts of the eye in producing a focused image of near and distant objects on the retina (n) Describe the pupil reflex in response to bright and dim light
1
Q
10
what is a stimulus
A
A change in the environment
that causes a reaction
2
Q
10
what is sensitivity
A
Sensitivity is the ability to respond to a stimulus
3
Q
10
what is response
A
An organism’s reaction
to a stimulus
4
Q
10
role of nervous system
A
regulates bodily functions and activities and how we response to stimuli
5
Q
10
what are the 2 types of actions controlled by the nervous system
A
- voluntary actions: controlled consiously
- involuntary actions: not controlled consiously
6
Q
10
what is the nervous system made up of
A
- central nervous system (cns): brain and spinal cord
- peripheral nervous system (pns): nerves spinal nerves
7
Q
10
brain and spine consists of what nerves?
A
cranial (b)
spinal (s)
8
Q
10
what is nerves
A
A nerve is a bundle of nerve cells called neurones enclosed in a sheath of
connective tissue
9
Q
10
what are the 3 types of neurones
A
Sensory neurones
Relay neurones
* Motor neurones
10
Q
10
function of sensory neurone
A
Transmit nerve impulses from the receptors to the relay
neurones in the CNS (brain or spinal cord)
10
Q
10
function of relay neurone
A
Transmit nerve impulses from sensory neurones to motor
neurones / sensory neurones to the brain / the brain to motor neurones
11
Q
10
function of motor neurone
A
Transmit nerve impulses from the CNS to the effectors
(muscle fibres or glands)
12
Q
10
how does the neurones work together
A
Sensory → Relay (CNS) → Motor
13
Q
10
what are the components of the human nervous system
A
- stimulus
- receptor
- cns
- effector
- response
14
Q
10
sturucture of motor neurone
A
- cell body
- axons
- axon terminal
- dendrons
- dentrites of dendron
15
Q
10
structure of sensory neurone
A
- cell body
- short axon
- long dendron
- receptor
16
Q
10
what is a synapse
A
The junction between two neurons, or a neurone and an effector (eg. muscle
or gland).
17
Q
10
how are nerve impulses transmitted across synaose
A
via chemicals (neurotransmitters) released by axon
18
Q
10
types of nervous system pathways
A
sensation
voluntary
reflex
19
Q
10
what is reflex action
A
A reflex action is a type of involuntary action
* It is an immediate response to a specific stimulus without conscious control
20
Q
10
reflex vs voluntary response
A
refer bio slides 1 page 53-54
21
Q
10
2 types of reflex actions
A
cranial
spinal
22
Q
10
explain the reflex of touching a hot object
A
- Heat stimulates thermo receptors in skin, which then produces nerve impulses
- Nerve impulses travel along sensory neurone to spinal cord
- In the spinal cord, nerve impulses are transmitted from the sensory neurone to the relay neurone across a synapse then from the relay neurone to the motor neurone across another synapse
- At the same time, the same relay neurone also transmits impulses to the brain
- The motor neurone transmits impulses from spinal cord to the effector
- The effector (bicep muscle) contracts and hand is withdrawn suddenly.
23
Q
10
function of eyelids
A
Protect the cornea from mechanical damage
* Squinting prevents excessive entry of light which can damage
retina
* Blinking spreads tears over the eyes so that dust can be wiped off
24
# 10
funciton of eyelashes
Shield the eye from dust particles
25
# 10
function of pupil
allows
light to enter the eye
26
# 10
function of iris
Controls the amount of light entering the eye
27
# 10
types of muscles in iris
circular and radial
28
# 10
function of Sclera
Protects eye from mechanical damage
29
# 10
Cornea function
Most refraction of light in the eye occurs here
30
# 10
conjuctivia funciton
secretes mucus to keep the front of the eyeball moist
31
# 10
what is pink eye
* Inflammation of the conjunctiva
* Can be caused by irritation, allergies
(eg. pollen), viral, or bacterial infections
* Viral and bacterial conjunctivitis is
highly contagious
* Through direct or indirect contact with
infectious eye, tears, etc.
32
# 10
function of tear gland
Secretes tears which:
* Wash away dust particles
* Keep the cornea moist for atmospheric oxygen to dissolve
* Lubricates the conjunctiva, reducing friction when eyelids move
33
# 10
how many layers does the wall of the eyeball have
* Sclera / sclerotic coat – outermost
layer
* Choroid – middle layer
* Retina – innermost later
34
# 10
function of choroid
* Pigmented black to prevent internal
reflection of light
* Contains blood vessels that carry
oxygen and nutrients to and remove
metabolic waste products from the
eyeball
35
# 10
retina function
* Contains light-sensitive cells called
photoreceptors, which comprise
rods and cones
* Photoreceptors are connected to
nerve endings from the optic nerve
36
# 10
function of cones
* Cones enable us to see colours in bright
light
* Three types of cones: red, green, blue
* Contain different pigments to absorb
lights at different wavelengths
* Do not work well in dim light
37
# 10
rods function
* Rods enable us to see black and white
vision in dim light
* Contain pigment called visual purple
which enables high sensitivity to light
* Visual purple is bleached when eye is
exposed to bright light so impulses will
not be sent to the brain
38
39
# 10
types of colourblindness
* Red-green colourblindness
* Blue-yellow colourblindness
* Complete colourblindness
40
# 10
fovea function
* Contains greatest concentration of
cones, but no rods
* Enables detailed colour vision in
bright light
41
# 10
function of optic nerve
* Transmits impulses from stimulated
photoreceptors in the retina to the
brain
42
# 10
function and structure of lens
* Transparent, circular, and biconvex
structure
* Shape or thickness (curvature) can
be changed in order to refract light
onto the retina
43
# 10
function of ciliary body
Contains ciliary muscles that
control curvature of lens
44
# 10
function of suspensory ligament
Attaches the edge of the lens to the ciliary body
45
# 10
function of aqueous chamber
* Filled with aqueous humour, a
transparent, watery fluid
* Aqueous humour keeps the front
of the eyeball firm and refracts
light into the pupil
46
# 10
function of vitreous chamber
* Filled with vitreous humour, a
transparent jelly-like substance
* Vitreous humour keeps eyeball
firm and refracts light onto the
retina
47
# 10
what is pupil reflex and what is it for
* Pupil size changes in response to light intensity
* To prevent excessive light from entering the eye
and damaging the retina
48
# 10
circular and radial muscles are
antagonistic
one contracts the other relaxes
49
# 10
in bright light
1. The circular muscles of the
iris contract.
2. The radial muscles of the iris
relax.
3. The pupil constricts, reducing
the amount of light that enters
the eye.
50
# 10
in dim light
1. circular muscles of the iris relax
2. radial muscles of the iris contract
3. pupil dialates, increasing amt of light entering the eye
51
# 10
what is a reflex
immediate response to a specific stimulus without conscious control
52
# 10
explain pupil reflex in terms of light intensity
1. change in light intensity (stimulus)
2. will stimulate the photoreceptors in retina (receptor)
3. transmits nerve impulses by sensory nerurone in optic nerve
4. to the brain (cns)
5. which then sends nerve impulses by relay neurone across a synape then by motor neurone across a synapse
6. causing radial muscles in iris... circlular muscles in iris... contract/relax-> change in size of pupil(effector) +(response)
53
# 10
how are images formed on the retina
1. light rays are refracted when it passes through the cornea and awueous humour
2. light rays are further refracted when they pass through the lens
3. light rays on retina either stimulates the rods or cones, depending on light intesity of
54
# 10
nature of images formed
* Vertically inverted
* Laterally inverted
* Smaller than the object
55
# 10
what is focusing
adjustment of lens of eye to form clear images of objects at different dist on retina
56
# 10
focusing on distant object
1. Suspensory ligaments become taut, pulling on edge of lens
2. Ciliary muscles relax, pulling
on suspensory ligaments
3. lens become thinner and less convex, increasing focal length
57
# 10
focusing on near object
1. Suspensory ligaments become slacken, relaxing its pull on edge of lens
2. Ciliary muscles contract, relaxing pull
on suspensory ligaments
3. lens become thicker and more convex, decreasing focal length
58
# 11
differeneces between signs symptoms disease
signs-obsevable
symptom-felt by paitient
diesease-confition produces signs/symptoms
59
# 11
explain infetious disease
* Spread from person to person
* Caused by pathogens
60
# 11
exaplin non-infectious disease
* Cannot spread from person to
person
* Not caused by pathogens
* Inherited, caused by
malnutrition, environmental
factors, lifestyle changes
61
# 11
explain how infectious diseases are caused by pathogens such as bacteria and viruses and can be spread from person to person through body fluids, food and water
* Droplets in the air (~1m)
Coughing/sneezing
* Direct contact of bodily fluids
Blood from infected person comes into contact with mucous
membranes / blood stream of uninfected person
* Contaminated food and water e.g. cholera
62
# 11
structure of bacterial cell
cell wall
cell membrane
ribosome
circular DNA
cytoplasm
plasmid
flagellium
63
# 11
feature of bacterial cell
* Bacteria are single-celled
organisms
* They can be pathogenic or
non-pathogenic
64
# 11
structure of virus
protein coat
DNA or RNA
65
# 11
feature of virus
* Viruses have both living and non-
living characteristics
* Does not contain cellular organelles
* Does not grow, move, feed, respire,
excrete
* Reproduces only in living host cells
66
# 11
difference bewteen bacterial cell and virus
refer to slide page 19
67
# 11
structure of influenza
spike protein
protein coat
lipid envelope
genetic material
68
# 11
how is influenza transmitted
Droplets, direct contact with
virus (e.g. touching
contaminated surface)
69
# 11
signs and symptoms of influenza
High fever, headache, stuffy
nose, cough, sore throat,
muscle aches
70
# 11
where does influenza attacks and caused by what
attacks respiratory system caused by influenza virus
71
# 11
how to reduce influenza transmission
* Annual vaccination
* Distance from infected persons
* Cover nose and mouth with tissue when coughing or sneezing
/ wear a surgical mask
* Wash hands with soap and water/disinfectant
* Avoid touching eyes, nose, and mouth
* Take prescribed antiviral drugs
72
# 11
pneumococcal disease signs and symptoms
Fever, headache, vomiting, cough, chest
pain, rapid breathing
73
# 11
pneumococcal disease transmitted by what
Droplets, direct contact with virus (e.g.
touching contaminated surface)
74
# 11
pneomococcak disease cause by what
pneumococcus bacteria
75
# 11
pneumococcal disease reduce transmissoni
* Vaccination
* Daily preventive actions (ie. like for influenza)
* Take prescribed antibiotics
76
# 11
difference signs and symptoms influenza and PD
refer slide page 29
77
# 11
what are vaccines
Contains an agent that resembles a pathogen
Prevents infectious diseases by stimulating white blood cells to quickly produce antibodies when the pathogen invades
78
# 11
how do vaccines work
1.vaccines contain an agent that resembles the pathogen that causes the disease which will cause white blood cel to bind to agent.
2.whitle blood cell is stimulated by antigents on its surface to divide and produce antibodies which destories the agent in vaccine.
3. some of these white blood cells known as memory cells remain in bloodstream
4. in the future, if the live pathogens enter the bloodstrean, the white blood cells will recognise them and quickly produce antibodies to destory the pathogens before the can infect our cells
79
# 11
what is antibiotics
* Produced by microorganisms, treat bacterial infections
* Kill/inhibit growth of fungi and bacteria
80
# 11
is antibiotics effective against viruses
no
81
# 11
how antibiotics target bacteria
- Inhibit synthesis of bacterial cell wall
* Inhibit function of cell membrane
* Iinhibit enzyme action in cytoplasm
* Iinhibit protein synthesis in ribosome + growth
->preventing synthesis of cellular structures
82
# 11
why are antibiotics ineffective agaist viruses
Antibiotics are ineffective
against viruses
* Viruses do not have cell walls so anti biotica cannot Inhibit synthesis of bacterial cell wall
* Viruses do not have cell membranes so antibiotics cannot inhibit function of cell membrane
* Viruses do not have ribosomes, and do not grow so antibiotic cannot Iinhibit protein synthesis in ribosome + growth
83
# 11
antibiotic misuse and overuse will cause
antibiotic resistance
84
# 11
explain how antibiotic resistance occur
1. Some bacteria with mutations that confer resistance to antibiotics
2. Most bacteria killed by antibiotics
3. Antibiotic-resistant bacteria
more likely to survive and reproduce
4. Antibiotic-resistant bacteria population increases in body
85
# 11
how to reduce antibiotic resistance
- not misusing/ overusing antibiotics
- completing the full course of antibiotics so all bacteria are killed
- using antibiotics only when necessary
