Chapter 14 : Integration of Nervous sys functions Flashcards Preview

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Flashcards in Chapter 14 : Integration of Nervous sys functions Deck (21)
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1
Q

stimulus

A

environmental event that excites sensory receptors

2
Q

sensation

A

what is perceived in the brain when sensory receptors are stimulated
• may be conscious or unconscious
• differ in modality (the energy form associated with the stimulus), quality and quantity

3
Q

senses

A

the means by which the brain receives information about the environment and the body.

4
Q

Senses are divided into 2 groups

A

1) general senses : have receptors distributed over a large part of the body.
also divided into 2 groups: the somatic sense and the visceral senses.

2) o Special Senses
– modified neurons localized in sensory organs of head
• vision, hearing, taste, smell, rotational and linear acceleration of head

5
Q

Somatic sense

A

Provides sensory information about the body and the environment . This includes touch, pressure , itch, vibration, temp, and pain.

6
Q

Visceral sense

A

provide information about internal organs
• pain, stretch, chemoreceptors, baroreceptors, osmoreceptors

  • consist primarily of pain and pressure.
7
Q

mechanoreceptors

A

respond to mechanical stimuli such as o compression, bending, stretching of cells.
The sense of touch , tickle , itch , vibration , pressure, hearing and balance all depend on a variety of mechanical receptors.

8
Q

chemoreceptors

A

respond to chemicals

o ex : taste, smell, plasma pH and concentrations of carbon dioxide and oxygen

9
Q

Thermoreceptors

A

detect changes in temperature

o cold receptor – increase rate of action potentials as skin is cooled (35o→12oC)
• 10-15 times more numerous than warm receptors
• also activated by menthol
o warm receptor – increase rate of action potential as skin is warmed (25o→47oC)
o comfortable temperature between 25o-35oC → both cold and warm receptors stimulated

10
Q

photoreceptors

A

detect light

are necessary for vision

11
Q

nociceptors

A

pain receptors – free naked nerve endings that respond to physical or chemical damage of tissues

12
Q

cutaneous receptors

A

are associated with the skin

13
Q

free nerve endings

A

unspecialized neuronal branches similar to dendrites.
• most common and distributed throughout most parts of the body
- These receptors are responsible for a number of sensations, including pain , temp, itch and movement.

14
Q

proprioceptors

A

information regarding body’s position and movement of parts in space, weight differences, and the extent of stretch or the force of muscular contractions.

15
Q

merkel discs

A

detect light touch and superficial pressure

16
Q

Hair follicle receptors

A

detect light touch due to very slight bending of the hair (breeze, bug)

17
Q

Pacinian corpuscles

A

– deep cutaneous pressure, vibration, proprioception (in joint capsule) = relay information about joint location.

18
Q

Meissner corpuscles

A

they are distributed throughout the dermal papillae (check it out)
and are involved in 2 points discrimination.

= (fine touch) is the ability to detect simultaneous stimulation of Meissner corpuscles in 2 distinct receptor fields by touching at 2 points on the skin.

• indicates distance between receptive field of two sensory neurons and varies in different areas of the body

ex: They are numerous and close together in the tongue and fingertips but are less numerous and more widely separated in the back.

19
Q

o Ruffini end organs

A

– detect continuous touch or pressure and responds to depression or stretch of skin
- important in responding to continuous touch or pressure.

20
Q

Muscle spindle

A

o muscle spindle (Fig 14.4) = 3-10 specialized muscle cells in skeletal muscle innervated with nerve endings
- provide information about length of the muscle.
• detect muscle stretch and rate of stretch
• important in control and tone of skeletal muscle

21
Q

o Golgi tendon organ

A

afferent associated with the fibres of the tendon near the junction between skeletal muscle and tendon
• respond to increased tendon tension caused either by contraction of the muscle or by passive stretch of the tendon.