HEENT A&P Flashcards
What is the conscious and subconscious awareness of changes in the external and internal environment?
Sensation
This sensation provides sensation from the internal organs
Visceral sensation
What sensation includes tactile, thermal, pain and proprioceptive sensations?
Somatic sensation
What are 4 things need to be present for a sensation to occur?
- Stimulus
- sensory receptor converts the stimulus to an electrical signal
- nerve pathway sends it to the brain
- A region translates and integrates the nerve impulse into a sensation
What is the decrease in strength of a sensation during prolonged exposure to a stimulus?
Adaptation
What receptors detect mechanical deformation of adjacent cells?
Mechanoreceptors
What receptors detect changes in temperature?
Thermoreceptors
What receptors detect pain?
Nociceptors
What receptors detect light?
Photoreceptors
What receptors detect the presence of chemicals in solution?
Chemoreceptors
What receptors detect osmotic pressure of fluids?
osmoreceptors
What receptors can be found in the somatic sensory tissues?
- Tactile
- Thermal
- Pain
Where are pain receptors not found in the body?
In the brain
True or false, mechanoreceptors (tactile) receptors are found in the superficial and deep dermal layers?
True
What temperature activates cold receptors?
50-105 in epidermis
What temperature activates the warm receptors?
90-118 in the dermis
At what temperature range does the body stimulate nociceptors rather than thermoreceptors?
less than 50
greater than 118
What is considered slow pain?
chronic, aching burning and throbbing’s
What is considered acute pain?
stabbing, sharp, acute
Where are the proprioceptors found?
skeletal muscle
tendons
synovial joints
inner ear
How many receptors are found in the nose for sense of smell?
10-100 million
What are the three types of cells in the olfactory epithelium?
olfactory cells
supporting cells
basal cells
What is secreted by the olfactory glands that allows us to inhale odorants?
Mucus
What is the olfactory pathway?
- detection by olfactory cilia and epithelium
- olfactory nerves extend through the cribriform plate via the olfactory bulb
- nerves synapse at olfactory bulb forming the olfactory tract
- travels to the cerebral cortex (frontal and temporal) associated with the limbic system
What is gustation?
it is the sense of taste
What are the five primary tastes?
salty sweet sour bitter umami
What are the three types of epithelial cells found in the tongue?
- Supporting cells
- Gustatory cells
- Basal cells
Describe the gustatory pathway
- taste buds convey impulses from CN VII,IX,X
- From tastes buds impulses travel to midbrain
Both of these act to protect the eye from foreign objects. perspiration and direct sun
Eyebrows and eyelashes
What shades the eyes during sleep, protect it from excessive light and spread lubrication over the eyeballs by blinking
Eyelids
A group of glands, duct canals the that produce and drain tears in both eyes
Lacrimal apparatus
What are the six extrinsic muscles of the eye
Superior/inferior rectus, lateral/medial rectus, superior/inferior oblique
What is the fibrous tunic of the eye composed of?
The sclera and cornea
What are the three layers of the vascular tunic?
The choroid, ciliary body, and iris
This is a thin membrane that lines most the the interior of the sclera.
The choroid
This consists of folds on the internal surface of the ciliary body whose capillaries secrete aqueous humor
Ciliary Process
This is smooth muscle that alters the shape of the lens for near and far vision.
The ciliary muscle
This is a circular colored portion seen through the cornea
The iris
What is the iris’s function?
it regulates the amount of light that is let into the eye
This focuses light rays onto the retina
The lens
What three types of neurons can be found in the retnia?
Photoreceptors
Bipolar cell layer
Ganglion cell layer
Cones and rods are densely concentrated in what area of the eye?
The fovea centralis
what watery fluid is found in the anterior portion of the eye?
Aqueous humor
filtered through the ciliary process
What is the posterior fluid found in the eye?
Vitreous Humor
What is a normal Intra Ocular Pressure
16 mmHG
What % of the cornea carries out refraction?
75%
Are images focused on the retina upside-down?
Yes
deficiency of what vitamin can lead to night blindness?
Vitamin A
