9 General Senses (Somatic and Visceral Senses) Flashcards
are the awareness of a stimulus
Sensations
involves the interpretation of the sensation and occurs in the CNS.
perception
All senses involve three steps:
- A physical stimulus
- Transformation of stimulus into nerve impulse
- Response to the sensation in the form of a perception or conscious experience of sensation.
signals that originate from the cutaneous areas, muscles, or joints
Somatosensory signals
signals that originate from the internal structures of the body.
viscerosensory signals
Sensory receptors are present in every tissue except in the ____
nervous system
Sensory receptors are classified
into two categories
free nerve endings
encapsulated nerve endings
-receptors with no special
modifications
-Examples are the thermoreceptors and nociceptors.
free nerve endings
-sensory terminals that are ensheathed by a connective tissue capsule.
-example are the mechanoreceptors
encapsulated nerve endings.
Classes of sensory receptors
- Mechanoreceptors
- Chemoreceptors
- Nociceptors
- Thermoreceptors
- Photoreceptors
-detect touch proprioceptive sensation (muscle stretch or contraction), joint position, hearing, and sense of balance.
-These receptors detect distortions in their cell membrane (bending and stretching).
Mechanoreceptors
-function in the sensing of itches, taste, and smell.
-responsible for detecting changes in concentrations of specific chemicals or compounds. These receptors are also responsible for the special senses of taste (gustation) and smell (olfaction). They are responsible for sensing irritating substances on the skin, or nutrients within the GI tract or brain, and carbon dioxide or oxygen levels in our blood.
Chemoreceptors
-detect pain.
-Pain is mediated by this receptor
-These receptors respond to stimuli that can damage tissue.
-Some respond directly to stimuli, and others respond indirectly since they respond to chemicals released by damaged tissue.
Nociceptors
-can sense either warm or cold.
-alter their firing rate as a result of changes in temperature.
Thermoreceptors
sense electromagnetic energy.
Photoreceptors