the 5 sensory organs Flashcards
(111 cards)
1
Q
What do sensory receptors allow an individual’s body to do?
A
Inform about the state of its environment
2
Q
What do sensory receptors react to?
A
Stimulus
3
Q
Where are sensory receptors mainly found?
A
Sense organs
4
Q
What types of stimuli can sensory receptors intercept?
A
- Mechanical
- Chemical
- Luminous
- Thermal
5
Q
What is the organ responsible for vision?
A
The eye
6
Q
How many different colors can the eye recognize?
A
About 2000
7
Q
What is the main function of the sclera?
A
Protects and gives the eye its shape
8
Q
What is the choroid?
A
Middle layer of the eye with blood vessels that provide nourishment
9
Q
What is the retina and where is it located?
A
Thin, beige layer at the back of the eye with light-sensitive nerve cells
10
Q
What is the blind spot in the eye?
A
Where the retina meets the optic nerve, not sensitive to light
11
Q
Describe the cornea.
A
Dome shaped, clear, and rigid; an extension of the sclera
12
Q
What is the function of the iris?
A
Regulates the amount of light let in through the pupil
13
Q
What does the lens do?
A
Focuses light rays on the retina
14
Q
What is the aqueous humour?
A
Transparent liquid that fills the space between the cornea and the lens
15
Q
What is the vitreous humour?
A
Transparent jelly-like substance that fills the space between lens and retina
16
Q
Fill in the blank: The eye can adapt to various _______.
A
Light intensities
17
Q
True or False: The retina is sensitive to light.
A
True
18
Q
What is the outermost layer of the eye called?
A
The sclera
The sclera protects the eye and gives it its shape.
19
Q
What does the sclera form in the eye?
A
The white of the eye
The sclera is an opaque layer.
20
Q
What does the sclera become at the front of the eye?
A
The cornea
The cornea is transparent and curved.
21
Q
What is the second layer of the eye called?
A
The choroid
The choroid is rich in blood vessels.
22
Q
What color is the choroid?
A
Dark brown
This layer supplies nutrients and dioxygen to the eye.
23
Q
What part of the eye does the choroid form at the front?
A
The iris
The iris is the colored part of the eye.
24
Q
What does the iris control?
A
The opening and closing of the pupil
This regulates the amount of light entering the retina.
25
What happens to the pupil in strong light?
The pupil shrinks
## Footnote
This is called pupil constriction.
26
What happens to the iris and pupil in low light?
The iris contracts and the pupil gets bigger
## Footnote
This allows more light to enter the eye, known as pupil dilation.
27
What type of lens is the crystalline lens?
Biconvex lens
## Footnote
Curved on both sides.
28
Where is the crystalline lens located?
Just behind the iris
## Footnote
It plays a crucial role in focusing light.
29
What is the phenomenon called when the lens changes shape to focus on objects at different distances?
Accommodation
## Footnote
Similar to how a camera lens adjusts for focus.
30
What happens to the lens when looking at a distant object?
The lens does not change its shape
## Footnote
Light rays are essentially parallel.
31
What type of light rays reach the eye when looking at a close object?
Divergent rays
## Footnote
Rays move away from each other.
32
What shape does the lens take when focusing on a close object?
More bulging shape
## Footnote
Gives the impression of being thicker.
33
What happens to the light rays when the lens bulges for close viewing?
The light rays are deviated and converge on the retina
## Footnote
Essential for clear vision of close objects.
34
What occurs when the ciliary muscles contract?
They loosen the ciliary fibers
## Footnote
This allows the lens to relax into a more curved shape.
35
What is the effect of the lens relaxing into a more curved shape?
Increases its refractive power
## Footnote
Necessary for accommodating closer viewing.
36
What is the retina?
The inner layer of the eye that contains photoreceptors
## Footnote
The retina is pinkish-beige in color.
37
What are the two types of photoreceptors found in the retina?
Cones and rods
38
What is the function of cones in the retina?
Responsible for day vision and color perception
39
What is the function of rods in the retina?
Responsible for night vision
40
What is the blind spot in the retina?
A special place where there are no cones or rods
41
What begins at the blind spot of the retina?
The optic nerve
42
How do cones and rods function in relation to sensory nerves?
They turn light (stimulus) into nerve impulses
43
What are the three sections of the ear?
Outer ear, middle ear, inner ear
44
What is the function of the outer ear?
Funnels sound into the ear
45
What is the pinna?
The only visible part of the ear, funnel-shaped
46
What is the role of the eardrum (tympanic membrane)?
Moves to vibrations
47
What are the ossicles?
Three small bones: hammer, stirrup, and anvil that move
48
What is the function of the Eustachian tube?
Equalizes pressure when swallowing
49
What structures are found in the inner ear?
Semi-circular canals, vestibule, cochlea
50
What is the function of semi-circular canals?
Help with balance when the body is in motion
51
What does the vestibule connect?
Connects semi-circular canals with cochlea
52
What is the role of the cochlea?
Contains auditory nerve cells linked to the auditory nerve
53
What is the ear's role in balance?
The center for balance in the body
54
Which cells in the vestibule detect the position of the head?
Cells responsible for balance in a stationary position
55
What do other cells in the inner ear detect?
Changes in speed and direction for balance while moving
56
Fill in the blank: The eardrum is also known as the _______.
Tympanic membrane
57
True or False: The cochlea is filled with air.
False
58
What is the largest organ of the human body?
The skin
## Footnote
The skin is associated with touch and plays various roles in protection and sensation.
59
Name the three layers of the skin.
* Epidermis
* Dermis
* Hypodermis
## Footnote
Each layer has distinct structures and functions.
60
What are the two structures within the epidermis?
* Dead Layer
* Living Layer
## Footnote
The Dead Layer consists of dead cells, while the Living Layer contains actively dividing cells.
61
What do keratinocytes produce?
Keratin
## Footnote
Keratin provides strength and protection against wear and germs.
62
What is the function of melanocytes?
Synthesize melanin
## Footnote
Melanin is a pigment that protects against sunlight and is responsible for skin tanning.
63
How often is the epidermis renewed on average?
Every 60 days
## Footnote
This renewal process involves the shedding of dead cells and the growth of new ones.
64
What structures compose the dermis?
* Sensory Receptors
* Blood Vessels
* Sebaceous Glands
* Sweat Glands
* Hair
## Footnote
Each structure plays a vital role in skin function and sensation.
65
What do sebaceous glands produce?
Sebum
## Footnote
Sebum is an oil that waterproofs the skin.
66
What is the role of sweat glands?
Produce sweat
## Footnote
Sweat is sent to the surface of the skin to help regulate body temperature.
67
What are the main components of the hypodermis?
Fat Cells
## Footnote
Fat cells insulate the body and serve as an energy source.
68
What types of sensations do the sensory receptors in the skin perceive?
* Tactile sensations (pressure and touch)
* Thermal sensations (heat, cold)
* Painful sensations (pain)
## Footnote
These receptors are essential for the sense of touch and temperature.
69
True or False: Sensory receptors are evenly distributed throughout the body.
False
## Footnote
Some body areas have more receptors of one type than others, leading to varying sensitivity.
70
Fill in the blank: The _______ layer of the skin is composed of dead cells.
Dead Layer
## Footnote
This layer is part of the epidermis.
71
Fill in the blank: The _______ glands produce an oil that waterproofs the skin.
Sebaceous
## Footnote
Sebaceous glands are located in the dermis.
72
Which layer of the skin contains hair follicles?
Dermis
## Footnote
Hair is rooted in the dermis and can be affected by nearby muscles.
73
What effect do arrector pili muscles have on hair?
Cause goose bumps
## Footnote
These muscles contract and pull hair upright.
74
What is one of the important functions of the skin?
Protection
## Footnote
The superficial layer of the skin protects against bacteria.
75
What substance produced by sebaceous glands makes the skin impermeable?
Sebum
## Footnote
Sebum is secreted by sebaceous glands and helps protect the skin.
76
What does melanin protect the skin from?
UV rays of the Sun
## Footnote
Melanin is a pigment that helps shield the skin from ultraviolet radiation.
77
What is the second role of the skin?
Regulation of body temperature
## Footnote
The skin helps maintain a stable body temperature through various mechanisms.
78
What happens to dermal blood vessels when it is hot?
They dilate
## Footnote
Dilation of blood vessels allows for increased blood flow to the skin.
79
How much sweat is produced per day at room temperature?
Approximately 200mL
## Footnote
This is the typical amount of sweat produced in moderate conditions.
80
In extreme heat, how much sweat can be lost in one hour?
Up to 1L
## Footnote
High temperatures can significantly increase sweat production.
81
What happens to capillaries in the dermis when it is very cold?
They constrict
## Footnote
Constriction reduces blood flow to the skin to conserve heat.
82
What is the purpose of blood flow constriction in cold conditions?
To prioritize blood supply to internal organs
## Footnote
This helps maintain the body's core temperature.
83
What is the hypodermis primarily composed of?
Adipose tissue (fat)
## Footnote
The hypodermis acts as a thermal insulator.
84
What additional function does the skin have besides protection?
It is an excretory organ
## Footnote
The skin helps eliminate waste products from the body.
85
What vitamin does the skin help produce?
Vitamin D
## Footnote
Sunlight exposure is essential for vitamin D synthesis.
86
What type of radiation stimulates the production of vitamin D3?
Solar ultraviolet-B radiation (UVB)
## Footnote
UVB radiation is crucial for the conversion of 7-DHC to vitamin D3.
87
What compound is converted to vitamin D3 in the skin?
7-dehydrocholesterol (7-DHC)
## Footnote
This compound is found in the epidermis and is vital for vitamin D production.
88
What are the primary functions of the nose?
Inhaling and exhaling air, responsible for smell
## Footnote
The nose allows for the detection of odors through specialized receptors.
89
Where are the smell sensory receptors located?
At the top of the nasal cavity
## Footnote
This area is part of the olfactory epithelium.
90
How large is the area of the olfactory epithelium?
About 5 cm²
## Footnote
This area contains millions of olfactory cells.
91
Approximately how many olfactory sensory receptors are there?
About 15 million
## Footnote
These receptors transmit information to the cerebrum.
92
What is the role of the olfactory nerve?
Transmits information from the olfactory receptors to the cerebrum
## Footnote
It connects the olfactory bulb with the brain.
93
What is the olfactory epithelium?
A region in the upper part of the nose containing olfactory cells
## Footnote
It plays a crucial role in the sense of smell.
94
What are olfactory cilia?
Specialized sensory neurons in the olfactory epithelium
## Footnote
They are responsible for detecting odors.
95
What structure does the axon of olfactory neurons cross?
Ethmoid bone
## Footnote
This is the bone that forms the ceiling of the nasal fossae.
96
What is the function of the olfactory bulb?
It is the end of the olfactory nerve that processes smell information
## Footnote
It is where nerve impulses from the olfactory epithelium are sent.
97
How many different odors can human olfaction detect?
About 10,000 different odors
## Footnote
This makes it challenging to classify odors into groups.
98
What are the four conditions for a substance to be perceived by smell?
1. Must be odorous
2. Must be volatile
3. Must have high concentration
4. Must contact the cilia
## Footnote
These conditions ensure that the olfactory cilia can react to the substance.
99
Fill in the blank: During inhalation, odorous molecules enter the nasal cavity and stimulate the _______.
olfactory cilia
## Footnote
These cilia are responsible for transforming the odor into a nerve impulse.
100
What happens to the nerve impulse after it is transformed by the olfactory epithelium?
It is conveyed to the olfactory bulb
## Footnote
The impulse then travels along the olfactory nerve to the brain for analysis.
101
True or False: The brain analyzes the influx of nerve impulses to perceive smell.
True
## Footnote
This analysis allows for the identification of different odors.
102
What is the primary function of the tongue?
The tongue lets us enjoy the sense of taste.
## Footnote
The tongue is a muscle involved in taste perception.
103
What are the bumps on the tongue called?
Papillae
## Footnote
Papillae are the structures that contain taste buds.
104
What are sensory receptors in the papillae called?
Taste buds
## Footnote
Taste buds are responsible for detecting different tastes.
105
How many cranial nerves transmit impulses related to taste?
Three
## Footnote
These cranial nerves send signals to the cerebrum.
106
What types of tastes can the human tongue detect?
Bitter, sour, sweet, salty, umami
## Footnote
Umami is a Japanese term meaning 'yummy'.
107
What percentage do smell and taste contribute to flavor perception?
Smell 90%, taste 10%
## Footnote
The sense of smell significantly influences taste.
108
How does the smell of food affect taste?
It goes up the throat to the olfactory receptors
## Footnote
This connection enhances flavor perception.
109
What additional sensations can the receptors on the tongue sense?
Temperature, pain, discomfort, tactile properties of food
## Footnote
These sensations contribute to the overall eating experience.
110
What are the four conditions for a flavor to be perceived by the tongue?
* To be palatable
* Being soluble in saliva
* Have sufficient concentration
* Touch the taste buds
## Footnote
All these conditions are necessary for flavor perception.
111
What happens to sapid molecules when they contact the tongue?
They stimulate the taste buds and transform into nerve impulses
## Footnote
This process leads to flavor analysis in the brain.
