Responding To The Environment Flashcards
(105 cards)
1
Q
Stimulus
A
Is an incoming message from the external
2
Q
Central nervous system
A
A network of nerve tissues that are responsible for sending and receiving impulses in order to coordinative activities
3
Q
Meninges
A
Membranes that surround and protect the CNS
4
Q
Cranium
A
A part of the skull that encloses the brain in order to provide protection
5
Q
Cerebrospinal fluid
A
Acts as a shock absorber and prevents dehydration
6
Q
Cerebrum
A
Controls all voluntary movements
Interprets all sensations
Higher thought process(memories)
7
Q
Cerebellum
A
• Coordinates voluntary movements
• Controls balance, equilibrium and muscle tone
8
Q
Corpus callosum
A
Connects the left and the right hemisphere to allow communication between them
9
Q
Medulla oblongata
A
Controls involuntary actions (such as heartbeat and breathing)
10
Q
Pituitary gland
A
Master gland that secretes a variety of hormones
11
Q
Hypothalamus
A
Controls thirst, emotion, sleep, body temperature and hormone secretion
12
Q
Peripheral nervous system
A
Part of the nervous system which consists of cranial and spinal nerves
13
Q
Somatic nervous system
A
Receives information from sensory organs and the brain in order to enable the body to react to change in the external environment
14
Q
Autonomic nervous system
A
Controls involuntary actions
15
Q
Sympathetic nervous system
A
A branch of the autonomic nervous system that increases the heartbeat and breathing rate
16
Q
Parasympathetic nervous system
A
A branch of the autonomic nervous system that decreases the heartbeat and breathing rate back to normal
17
Q
Neuron
A
Structural unit of the nervous system that receives and transmits impulses between the brain and the rest of the body
18
Q
Relax action
A
Is a rapid, involuntary response to a stimulus received by an organ or other receptor
19
Q
Reflex arc
A
The path taken by an impulse in bringing about a response to a stimulus during a reflex action
20
Q
Receptor
A
Specialised cells that detect a variety of different stimuli and convert them into nerve impulse
eg eye, nose, ear, tongue and hand
21
Q
Dorsal root
A
Contains incoming sensory neuron
22
Q
Sensory neuron
A
Transmits impulses from receptors to CNS
23
Q
Dorsal root ganglion
A
Contains the cell body of the sensory neuron
24
Q
Interneuron
A
Transmits impulses from sensory neuron to motor neuron
25
Central canal
Contains cerebrospinal fluid
26
Grey matter
Consists of cell bodies and dendrites of numerous axons
27
White matter
Consists of myelinated axons of numerous neuron
28
Spinal cord
Transmits impulses between the brain and the rest of the body
29
Synaptic gap
Controls one-directional transmission of impulses
30
Motor neuron
Transmits impulses from the CNS to effector
31
Ventral root
Contains outgoing motor neurons
32
Effector
An organ or cell that acts in response to a stimulus
eg muscle, muscle cells and glands
33
What are the disorders in the CNS
Multiple sclerosis
Alzheimer's disease
34
What does the CNS consist of ??
Brain
Spinal cord
35
What protects the brain
Cranium
Meninges
Cerebrospinal fluid
36
What protects the spinal cord
Meninges
Cerebrospinal fluid
37
What causes multiple sclerosis
When the body's own immune system destroys the myelin sheath
38
Effects of multiple sclerosis
Muscle weakness
Speech difficulties
Visual problems
39
What causes Alzheimer's disease
A irreversible neuro-degenerative disease that damages the brain
40
Effects of Alzheimer's disease
Memory loss
Diminished intellectual capacity
Loss of judgement
40
Consequence when Cerebrum is damaged
Failure to interpret sensation and inability to perform voluntary actions and higher thought processes
41
Consequences when Cerebellum is damaged
Failure to maintain balance and lack of coordination of voluntary actions
42
Consequences when Medulla oblongata is damaged
Difficulties in breathing may lead to death
43
Consequences when Sensory neuron is damaged
Loss of sensation
Impulses will not be travel to the CNS
43
Consequences when Spinal cord is damaged
Paralysis as no impulses will be transmitted between the brain and the body
44
Consequences when Interneuron is damaged
Loss of both sensation and ability to respond
45
Consequences when Motor neuron is damaged
Impulse will not be transmitted to the effector and there will be no response
46
Accommodation
The series of changes that take place in the shape of the lens and the eyeball in response to the distance of an object from the eye
47
Cornea
Assist in the refraction of light rays
50
Aqueous humour
Liquid that helps to keep the shape of the cornea
51
Pupil
An opening in the iris which allows light to enter the eye
52
Iris
• Regulates the diameter of the pupil
• Controls the amount of light entering the eye
• Responsible for the colour of the eye
53
Ciliary muscle
• Contracts or relaxes when the distance of ana object from the eye changes
• Changes the shape of the lens
54
Suspensory ligament
• keeps the lens in place
• Attaches to the ciliary body in order to change the shape of the lens
55
Lens
Focuses light onto the retina to form an image
56
Vitreous humour
Provides support and prevents the eye from collapsing
57
Blind spot
Area on the retina with no photoreceptors and no image formed
58
Optic nerve
Transmits impulses to the cerebrum
59
Yellow spot/Fovea
Contains cones and is the area of the clearest vision
60
Retina
Contains photoreceptors that convert light into an impulse
61
Choroid
• Prevents internal refraction of light in the eye
• Contains a dark pigment that absorbs excess light in the eye
• Consists of blood vessels that supply nutrients and oxygen to the eye
62
Sclera
Protects the internal structure of the eye
63
Radial muscle
Like radius
64
Circular muscle
Circles
65
Bright light
• Radial muscle relax
• Circular muscle of the iris contract
• Pupil constricts
• Less light enters the eye
66
Dim light
• Radial muscle contract
• Circular muscle of the iris relax
• Pupil dilate
• More light enters the eye
67
Distance vision
(6m or more)
• Circular muscle relaxes
• Suspensory ligaments became taut
• Tension on the lens increases
• Lens become less convex
• Less refraction
• An image of the object falls on the retina
68
Near vision
(Less than 6m)
• Ciliary muscle contract
• Suspensory ligaments slacken
• Tension on the lens is reduced
• Lens become more convex
• more refraction
• An image of the object falls on the retina
69
Cause of short sightedness
• Inability of the lens to become more flat
• Eyeball is longer than normal
• Lens bends light too much
• Light falls in front of the retina
70
Treatment of short sightedness
Glasses with concave lens
71
Short sightedness
• Can see near objects clearly
• Image forms before retina
72
Long sightedness
• Can see objects that are far away
• Image falls behind the retina
73
Causes of long sightedness
• Inability of the lens to become more convex
• Eyeball is shorter than normal
• Lens does not bend light rays enough
• Light falls behind the retina
74
Treatment for long sightedness
Glasses with a convex lens
75
Astigmatism
A disorder of the eye caused by the curvature of the lens or cornea being uneven resuin distorted images
76
Treat of astigmatism
• Glasses with lens shaped to correct distortion
• Surgery
77
Cataracts
Defect of the eye due to a clouding of the eye's normal,clear,transparent lens affecting acuity of vision
78
Treatment of cataracts
• Cataracts removed surgically
• Lens replacement
79
Pinna
Directs sound waves to the auditory canal
80
Auditory canal
Directs sound waves to the tympanum
81
Tympanic membrane
Converts sound waves into vibrations and transmits them to the middle ear
82
Ossicles
Amplify vibrations to the oval window
83
Oval window
Converts vibration into pressure waves and transmits them to the inner ear
84
Round window
Relieves pressure from the inner ear to prevent an echo in the inner ear
85
Eustachian tube
Equalises pressure on either side of the tympanic membrane
86
Cochlea
Contains organ of corti
87
Auditory nerve
Transmits impulses to the cerebrum
88
Semi-circular canals
Contains cristae and maculae which are responsible for restoring balance and equilibrium
89
Organ of corti
Converts sound stimulus into an impulse
90
Amplification of sound
• The sound vibrations are transmitted from the large tympanic membrane
• to the smaller oval window
• through the ossicles
• which are arranged from largest to smallest
• thus concentrates the vibrations and amplifying them
91
Hearing
• Pinna traps and directs the sound waves
• into the ear canal
• this causes the tympanic membrane to vibrate
• the vibration is transmitted to the auditory ossicles
• the ossicles amplify the vibration
• and transmit it to the oval window
• the oval window vibrates creating waves
• in the endolymph of the cochlea
• which stimulates the organ of corti
• to convert the wave into an impulse
• the impulse travels along the auditory nerve
• to the cerebrum where it is interpreted as the roar of the lion
92
Change in posture/ position of the head
• A change in position of the head in space
• stimulates the maculae
• in the utriculus and succulus
• the stimulus is converted to an impulse
• the impulse is transmitted to the cerebellum
• via the auditory nerve
• the cerebellum sends impulses to the muscles to restore posture
93
Change in speed and direction
• A change in speed/ direction of movement
• stimulates the cristae
• in the semi-circular canals
• the stimulus is converted to an impulse
• the impulse is transmitted to the cerebellum
• via the auditory nerve
• the cerebellum sends impulses to.the muscles to restore balance
94
Ossicles are divided into three small bones
• Hammer
• Anvil
• Stirrup
95
How is pressure equalized in the ear
• Excess pressure in the inner ear is eased through the round window
• and exits through the eustachian tube
96
Middle ear infection
Bacterial infection that disturbs the functioning of the eustachian tube blocked by fluid
97
Treatment of middle ear infection
• Inserting a grommet
• Antibiotics
98
Causes of deafness
• Injury to parts of the ear
• Injury to parts of the brain responsible for hearing
• Hardened wax
• Fused ossicles
99
Treatment for deafness
• Hearing aids
• Cochlear implants
100
Functions of a grommet
• Allows air to enter the middle ear, thereby taking over the function of the eustachian tube
• Allows excess fluid to drain from the middle ear
101
Peripheral nervous system is divided into?
• Autonomic nervous system
• Somatic nervous system
102
103
What are photoreceptors
Cones and rods
104
What is the function of rods
Are active in dim light
105
Cones
Active in bright light
