Chap 1 A&P Flashcards
Conscious or subconscious awareness of changes in the external or internal enviroment
Sensation
Smell, taste, vision, hearing, equilibrium
Special senses
Two categories of general senses
Somatic
Visceral
Senses that include tactile, thermal, pain, and proprioceptive sensations
Somatic senses
Senses that provide sensations from internal organs
Visceral senses
Four conditions that must be satisfied for a sensation to occur
- Stimulus
- Sensory receptor converts stimulus to an electrical signal
- Nerve pathway conducts it to the brain
- Brain translates the nerve impulse into a sensation
Conscious awareness and interpretation of sensations
Perception
Perceptions are primarily a function of which part of the brain?
Cerebral cortex
Decrease in the strength of a sensation during prolonged exposure to a stimulus
Adaption
Detect mechanical deformation of adjacent cells
Mechanoreceptors
Detect changes in temperature
Thermoreceptors
Detect Pain
Nociceptors
Detect light
Photoreceptors
Detect the presence of chemicals in solution
Chemoreceptors
Detect the osmotic pressure of fluids
Osmoreceptors
Sensations arise from stimulation of sensory receptors in the skin, mucous membranes, muscles, tendons, and joints
Somatic sensations
How are sensory receptors for somatic sensations distributed over the body?
Widely and unevenly
Touch, pressure, vibration, itch and tickle
Tactile
Most tactile sensation receptors are located in the:
Skin and subcutaneous tissue
Warm, cold
Thermal
Thermal receptors are located in the:
Epidermis and dermis
Pain receptors are located in virtually all tissues of the body, except for?
The brain
What detects most tactile sensations?
Mechanoreceptors (superficial and deep dermal layers)
What temperatures activates cold receptors located in the epidermis?
10-40C (50-105F)
What temperatures activate warm receptors in the dermis?
32-48C (90-118F)
Temperatures below 10C (50F) and above 48C (118F) stimulates what receptors?
Nociceptors (Pain)
Nociceptors respond to:
Extreme temperatures
Inadequate blood flow to an organ
Excessive stretching of an organ
What type of pain is acute, sharp, pricking pain?
Fast (localized pain)
What type of pain is chronic, aching, burning, or throbbing?
Slow pain
Proprioceptors in the skeletal muscles
Muscle spindles
Proprioceptors in the tendons
Tendon organs
Proprioceptors around the synovial joints
Joint kinesthetic receptors
Proprioceptors of the inner ears
Hair cells
Kinesthetic sense or the perception of body movements
Proprioception
What allows us to estimate the weight of objects and determine the muscular effort needed to perform a task?
Proprioceptive sensations
Sense of smell
Olfaction
What type of sense is smell?
Chemical (based on changing of the environment)
How many receptors are located in the olfactory epithelium?
10-100 million
Where is the nasal epithelium in conjunction with the cribriform plate?
Inferior surface
Three types of cells in the olfactory epithelium
Receptor cells
Supporting cells
Basal cells
In order to be smelled, substances must be:
Dissolved
What serves has a solvent for the inhaled odorants?
Mucus secreted by the olfactory glands
Adaption to odors occurs quickly, and the threshold of smell is:
Low
Olfactory tract will project to which locations of the brain?
- Cerebral cortex (frontal & temporal lobe)
2. Limbic system (emotional response to odors)
Sense of taste
Gustation
Five primary tastes
Salty, sweet, bitter, sour, and umami
Gustatory receptor cells are located mainly in:
Taste buds on the surface of the tongue
Taste buds are found in raised bumps on the tongue called:
Fungiform papillae
Each taste bud is an oval body, consisting of three kinds of epithelial cells
Supporting cells
Gustatory receptor cells
Basal cells
To be tasted, substances must be:
Dissolved
Once dissolved tastants enter taste pores and make contact with:
Gustatory hairs
Adaption to taste occurs quickly and the threshold for taste:
Varies for each of the primary tastes
Carries taste information from the anterior 2/3 of the tongue
CN VII (Facial)
Carries taste information from the posterior 1/3 of the tongue
CN IX (Glossopharyngeal)
Carries taste information from taste buds on the epiglottis and in the throat
CN X (Vagus)
Primary gustatory area of the brain
Parietal lobe of the cerebral cortex
Emotions related to food are sent to which parts of the brain
Limbic system
Hypothalamus
Tears flow from lacrimal gland through:
Lacrimal Ducts
Tears drain from the surface of the eye through canaliculi and then to:
Nasolacrimal Duct
Six extrinsic muscles work together to move the eyeball:
- Superiour rectus
- Inferior rectus
- Lateral rectus
- Medial rectus
- Superior oblique
- Inferior oblique
Two regions of the fibrous tunic
Posterior sclera
Anterior cornea
Nonvascular, transparent, fibrous coat that covers the eyes.
Bends light rays to help focus them on the retina.
Cornea
White of the eye, comprised of dense connective tissue
Sclera
Provides shape and affords protection to the inner parts of the eye
Posterior aspect is pierced by the optic nerve (CN II)
Sclera
Vascular tunic (middle layer) is composed of what three portions?
Choroid
Ciliary body
Iris
This membrane that lines most of the internal surface of the sclera. It contains blood vessels that nourishes the retina, and contains pigment melanin that absorbs stray light rays
Choroid
Consists of folds on the internal surface of the ciliary body whose capillaries secrete aqueous humor
Ciliary processes
Smooth muscle that alters the shape of the lens for near and far vision (accommodation)
Ciliary muscle
Circular colored portion seen through the cornea
Iris
Part of the eye that functions to regulate the amount of light that passes through the lens into the posterior cavity of the eye. The lens focuses light rays onto the retina.
Iris
Inner layer of the eye, lies in the posterior three-quarters and functions in image formation
Retina
Three zones of the neural layer of the retina
Photoreceptor layer
Bipolar cell layer
Ganglion cell layer
Allow us to see shades of gray in dim light
Rods
Instrumental in color vision and visual acuity (color vision in bright light)
Cones
Area of the sharpest vision because of the high concentration of cones
Fovea centralis
What helps absorb stray light rays?
Melanin in the pigmented layer of the retina
Choroid
How do nerve impulses travel from photoceptors?
Outer synaptic layer to Bipolar cells through The inner synaptic layer to Ganglion cells and Exit the optic nerve
The eye’s interior is divided into the anterior cavity and the vitreous chamber by the:
Lens
Transparent structure that focuses light rays on to the retina constructed of many layers of elastic protein fibers
Lens
What fibers attach the lens to the ciliary muscle to keep the lens in place?
Zonular
Anterior cavity (anterior of the lens) of the eye is filled with what watery substance?
Aqueous humor
Aqueous humor is continuously produced by:
Ciliary process
Nourishes the lens and the cornea, helps maintain the shape of the eye
Aqueous humor
Larger of the eye cavities and lies between the retina and the lens
Vitreous chamber
Intra Ocular Pressure (IOP) is produced by:
Aqueous humor (mainly)
Vitreous body
Maintains the shape of the eyeball
IOP
Normal IOP
16 mmHg
Formation of an image on the retina, stimulation of photoreceptors, and visual pathway to the brain
Processes in the physiology of vision
Bending of light rays where two different substances meet
Refraction
Refraction media are the:
Cornea, aqueous humor, lens, and vitreous body
What carries out 75% of refraction?
Cornea
Refraction abnormalities can result in:
Myopia
Hyperopia
Astigmatism
Ability of the lens to instantly change its curvature for near or far vision
Accommodation
What does the ciliary muscle do in order to view objects that are near?
Contracts
What does the ciliary muscle do to view objects that are far?
Relaxes
Medial movement of both eyeballs so that they are directed on the object being viewed.
Convergence
What allows for binocular vision?
Convergence
Where does visual stimulation begin?
Absorption of light rays by the rods and cones of the retina
Rods contain what photopigment?
Rhodopsin
What vitamin deficiency decreases rhodopsin production and leads to night blindness?
Vitamin A
Cones contain how many different opsins?
Three
Colorblindness is from what color cones missing?
Red or green
Impulses from ganglion cells are conveyed along axons through the retina to the optic nerve, then to:
Optic chiasm, optic tract, and the cerebral cortex
What percentage of neurons cross the optic chiasm and reach the opposite of the brain?
50%
Sight is perceived in what location of the brain?
Occipital lobe
Which side of the brain receives images from the left side of objects seen by each eye?
Right
Three anatomical subdivisions of the ear
External, Middle, Internal
Part of the ear designed to direct sound waves
External ear
External ear is comprised of:
Auricle
External auditory canal
Tympanic membrane
Small, air-filled cavity between the eardrum and the internal ear
Middle ear
Three tiny bones called the auditory ossicles
Malleus
Incus
Stapes
Part of the ear where all the receptors for hearing and equilibrium are housed.
Internal ear
Two regions of the internal ear
Outer bony labyrinth
Inner membranous labyrinth
Part of the temporal bone and is divided into the cochlea, vestibule, and semicircular canals and contains a fluid called perilymph, which surrounds the membranous labyrinth
Bony Labyrinth
Series of sacs and tubes in the same general shape as the bony labyrinth and contains a fluid called endolymph
Membranous labyrinth
Two sacs of the membranous labyrinth
Utricle and saccule
Posterior to the vestibule are three bony semicircular canals arranged at right angles to one another, at what projection?
Two vertical
One horizontal
Organ of hearing
Cochlea
What repeatedly strikes the oval window, which sets up waves in the perilymph of the cochlea?
Stapes
Primary auditory area of the brain
Temporal lobe
Which sides of the brain hear from the left and right ears?
Both sides receive impulses from both ears
Two kinds of equilibrium
Static and dynamic
Maintenance of the position of the body relative to the force of gravity
Static equilibrium
Maintenance of the body position in response to sudden movements such as rotational acceleration or deceleration
Dynamic equilibrium
Receptor organs for equilibrium
Saccule
Utricle
Semicircular ducts
Receptors for static equilibrium
Maculae in the walls of the utricle and saccule
Thick gelatinous material floating over the hair cells on the macula
Otolithic membrane
Calcium carbonate crystals that imbeds the otolithic membrane for equilibrium
Otoliths
What maintains dynamic equilibrium?
Three semicircular ducts within the semicircular canals
Dilated portion of each semicircular duct
Ampulla
Small elevation of the ampulla
Cristae
Jellylike material that covers the cristae
Cupula
Which branch is stimulated to CN VIII for equilibrium?
Vestibular branch
Equilibrium information continuously is being monitored by the cerebellum, which also works with what part of the brain to make continuous adjustments to coordinate movement?
Cerebrum