HEENT Structure and Functional Organization Flashcards
What is a conscious or subconscious awareness of changes in the external or internal environment?
Sensation
What are the special senses?
- Smell
- Taste
- Vision
- Hearing
- Equilibrium
What conditions must be satisfied for a sensation to occur?
- A stimulus
- A sensory receptor converting the stimulus to an electrical signal.
- A nerve pathway conducts the information to the brain.
- A region of the brain translates/integrates the nerve impulse into a sensation.
What is the conscious awareness and interpretation of sensations?
Perception
What senses include tactile, thermal, pain, and proprioceptive sensations?
Somatic
What senses provide sensations from internal organs?
Visceral
Perceptions are a function of what?
Cerebral Cortex
What is the decrease in the strength of a sensation during prolonged exposure to a stimulus?
Adaptation
What type of receptors detect mechanical deformation of adjacent cells?
Mechanoreceptors
What type of receptors detect changes in temperature?
Thermoreceptors
What type of receptors detect pain?
Nociceptors
Are nociceptors adaptable?
No
What receptors are virtually located in all tissues of the body except for the brain?
Nociceptors
What type of pain is known as acute, sharp, or pricking?
Fast pain
What type of pain is precisely located?
Fast pain
What type of pain tends to be chronic, aching, burning, or throbbing?
Slow pain
What type of pain is more diffuse?
Slow pain
Thermal receptors are located in the epidermis and dermis. Which is cold and which is hot?
Epidermis - Cold
Dermis - Warm
Thermal receptors for cold are located in what?
Epidermis
Thermal receptors for warm are located where?
Dermis
What type of receptors are deep dermal and located everywhere?
Mechanoreceptors
Which receptor for somatic senses include touch, pressure, vibration, itch, and tickle?
Tactile
Between what temperatures activates cold receptors located in the epidermis?
10-40 C (50-105 F)
Between what temperatures activates warm receptors located in the dermis?
32-48 C (90-118 F)
What happens when temperatures fall below 10 C (50 F) and rise above 48 C (118 F)?
Stimulates nociceptors, instead of thermoreceptors, thus eliciting painful simulations.
What informs which muscles are contracting?
Muscle spindles
What informs the amount of tension in our tendons?
Tendons organs
What informs the position of our joints while doing work?
Joint kinesthetic
What monitors the orientation of the head relative to the ground and positioning during movements?
Hair cells in the middle ear
What allows us to estimate the weight of objects and determines the muscular effort needed to perform a task?
Proprioceptive sensations
Where are olfactory receptors located?
Nasal epithelium
What is gustation?
Sense of taste
What are the 5 primary tastes?
- Salt
- Sweet
- Bitter
- Sour
- Umami
What converts the stimulus to an electrical signal?
Sensory receptor
Most tactile sensations are detected by what type of receptors?
Mechanoreceptors
Where are mechanoreceptors located?
Superficial and deep dermal layers
Where are proprioceptors located?
- Skeletal muscles (muscle spindles) - Contraction
- Tendons (tendon organs) - too much weight
The olfactory pathway has axons that form olfactory nerves (CN-I) and they extend through cribriform plate to ________ _________ via holes in the cribriform plate?
Olfactory bulb
What houses the emotional response to odors?
Limbic system
The olfactory tract will project to what for awareness of smell and to limbic system for emotional responses to odor?
Cerebral cortex
Taste buds convey impulses to what cranial nerves?
- CN VII Facial
- CN IX Glossopharyngeal
- CN X Vagus
What cranial nerve carries taste information from the anterior 2/3 of the tongue?
CN VIII Facial
What cranial nerve carries taste information from the posterior 1/3 of the tongue?
CN IX Glossopharyngeal
What cranial nerve carriest tase informtion from taste buds on the epiglottis and in the throat?
CN X Vagus
From the midbrain, the axons go to the final destination of primary gustatory area (parietal lobe of the cerebral cortex) for what?
Conscious perception of taste
Where is the finaldestination for the conscious perception of taste?
Primary gustatory area (parietal lobe of cerebral cortex)
How do tears drain from the surface of the eye?
Through lacrimal canaliculi and then to the nasolacrimal duct.
What six muscles move the eyeball from left to right and up and down?
- Superior rectus
- Inferior rectus
- Lateral rectus
- Medial rectus
- Superior oblique
- Inferior oblique
Which cranial nerve assists with mastication?
CN V Trigeminal
The fibrous tunic is divided into what two regions?
- Posterior sclera
- Anterior cornea
What is layer of the eyeball is divided into the posterior sclera and anterior cornea?
Fibrous tunic
What is the middle layer of the eyeball?
Vascular tunic
What layer of the eyeball is composed of three portions: choroid, ciliary body, and iris?
Vascular tunic
The vascular tunic is composed of what three portions?
- Choroid
- Ciliary body
- Iris
What is the inner layer of the eyeball?
Retina
What layer of the eyeball lies in the poster three-quarters of the eye and functions in image formation?
Retina - internal layer
Where is the retina and what is its function?
Posterior three-quarters of the eye and functions in image formation.
Photoreceptors are called what?
Rods and Cones
The eye’s interior is divided into what by the lens?
Anterior cavity and the vitreous chamber
What is filled with a watery fluid called the aqueous humor that is continuously produced by the ciliary process?
Anterior cavity
What helps maintain shape of the eye and nourishes the lens in the cornea?
Anterior cavity
What is the larger of the cavities?
Vitreous chamber
What lies anterior to the lens and is filled with aqueous humor?
Anterior cavity
What lies between the retina and the lens which contains a clear, jellylike substance?
Vitreous chamber
What helps maintain the eye’s shape and holes the retina in place?
Vitreous chamber
How is inta ocular pressure produced?
By the aqueous humor (mainly) and the vitreous body.
What is normal IOP?
16 mm Hg
What does IOP do?
- Maintains the shape of the eyeball
- Keeps the retina in position and nourished
What begins with the absorption of light rays by the rods and cones of the retina?
Visual stimulation
Visual stimulation begins with what?
The absorption of light rays by the rods and cones of the retina.
A deficiency in what vitamin leads to night blindness?
Vitamin A
What is missing in colorblindness?
Red and green cones
Rods versus Cones. Which is dark, shades of gray? Which is bright, color?
Cones - bright, color
Rods - dark, shades of gray
What part of the ear is a small air-filled cavity?
Middle ear
What type of cavity lies between the eardrum and the internal ear?
Air-filled
What are the three bones of the middle ear?
- Malleus
- Incus
- Stapes
What is the largest of the auditory ossicles?
Malleus
What bone attaches to the tympanic membrane?
Malleus
Which auditory osscile attaches to the oval window?
Stapes
What repeatedly strikes the oval window?
Stapes
Sound waves enter the ear through the external auditory canal, strike the tympanic membrane, and are conducted through what?
The ossicles: Malleus, Incus, Stapes
What refers to the maintenance of the position of the body relative to the force of gravity?
Static equilibrium
What is static equilibrium?
Maintenance of the position of the body relative to the force of gravity.
What is the maintenance of the body position in response to sudden movements?
Dynamic equilibrium
What is dynamic equilibrium?
Maintenance of the body position in response to sudden movements.
Where are the receptor organs for equilibrium located?
Internal eara
What are the receptor organs for equilibrium?
- Saccule
- Utricle
- Semicircular ducts
What is CN VIII?
Vestibulocochlear
What cranial nerve can be associated with the medulla and cerebellum?
CN VIII Vestibulocochlear
