after loss of a hand, the person may still feel that the hand is really there. The receptor in the hands are no longer present, but the severed nerve endings continue to generate impulses.
some sensation are felt more distinctly and to greater degree than are others. when more receptors are stimulated, more impulses will arrive in the sensory part of the brain.
The effect of a current sensation may be exaggerated.
A stimulus is still present, but we become unaware of it.
the stimulus stops, but we remain aware of the sensation.
Ex: the ringing in the ear you hear after hearing a loud sound.
Found in dermis of skin. Gives us information about changes in external environment.
Location of Cutaneous Senses
For the senses of pain, heat, cold, and itch, the receptors are?
Free Nerve Endings
For the senses of touch and pressure, the receptors are?
Encapsulated nerve endings
The pain that originates in an internal organ may be felt as?
Are in the taste buds on the tongue.
Impulses are interpreted in a sensory area that overlaps the temporal-parietal lobes.
Cranial nerve that is sensory is the facial nerve.
Cranial nerve that is sensory is the glossopharyngeal nerve.
Receptors detect chemicals in solution in saliva.
Taste Buds (Chemoreceptors)
Chemoreceptors are in the upper nasal cavities
impulses are interpreted in a sensory area in the temporal lobes only.
a cranial nerve that is sensory is the olfactory nerve.
the receptor detects vaporized chemicals.
triggered by internal changes
hunger and thirst
detects changes in blood nutrient levels, the blood levels of hormones from the stomach and small intestines and hormone leptin released by adipose tissue.
Stimulus for hunger
no adaptation. if body water is lost, then the amount keeps decreasing and doesn't stabilize.
stimulus for thirst
a thin membrane that lines the eyelids and covers the whites of eyes. merge with the corneal epithelium.
within the orbits; secrete tears. mostly H2O with 1% Na.
An enzyme in tears that inhibits the growth of bacteria on the front of the eyeballs.
Medial corner of the eyelids are 2 small openings into the superior and inferior lacrimal canals located in the lacrimal bone.
Takes tears to the nasal cavity. This is why crying often makes the nose run.
the transparent part of the sclera that refracts light.
contains a dark blue pigment to absorb light and prevent glare within the eyeball
The only adjustable part of the light-refracting system.
Regulates the size of the pupil
the layer of the eyeball that contains the visual receptors.
Contains rhodopsin and detect the presence of light
The receptors that detect color.
there are 2 cavities within the eye. The larger cavity formed between the lens and retina. Contains the vitreous humor/vitreous body.
semisolid substance keeps the retina in place.
vitreous humor/vitreous body
found between the back of cornea and the front of the lens, contains aqueous humor
Tissue fluid of the eyeball. Formed by capillaries in the ciliary body, flows anteriorly through the pupil and is reasorbed by canal of schlemm at junction of the iris and cornea.
light ray is the deflection/bend of light ray as it passes through one object and into another object of greater/lesser density.
formed by ganglion neurons, transmits impulses from the retina to the brain.
light travels through cornea, aqueous humor, lens, and vitreous humor.
pathway of refraction
where optic nerves from both eye come together at. Just in front of pituitary gland.
the lobes of the cerebral cortex that contain the sensory areas for vision.
The ear contains receptors for senses of _____ and _____.
Hearing & Equilibrium
Name 3 major parts of the ear?
Outer ear, middle ear, inner ear.
is made of skin supported by cartilage. Outer ear.
Does auricle have a significant function to humans?
No, because it's not movable.
Pinna is alternate name for?
The _____ is a tunnel into the temporal bone. Curving slightly forward and down.
Also known as External auditory meatus.
Part of the middle ear. Ear drum. At end of ear canal. vibrates when sound waves strike it.
transmit vibrations from the eardrum to the incus bone.
transmit vibrations from the malleous to the stapes
transmits vibrations from the incus to the oval window of the inner ear
Permits air to enter/leave the middle ear cavity to equalize pressure on both side of the ear drum.
in the cochlea, the hair cells are part of this?
Organ of corti
receptors of "organ of corti". specialized microvilli.
Hair cells (stereocilia)
The utricle and saccule are 2 membranous sacs located in an area called this?
The hair cells bend in response to the pull of gravity as the position of the head changes.
Vestibule areas that sense equilibrium.
In each inner ear, there are 3 _______. Their hair cells bend in response to movement.
detect changes in blood pressure and are located in the carotid sinus and aortic sinus.
Detect changes in pH, O2, CO2 levels in blood and are located in the carotid body and aortic body.
The part of the brain that regulates vital functions.
Secretes hormones which enters capillaries directly and circulation in the blood throughout the body.
The cells on which a hormone exerts its specific effects?
These cells respond to particular hormones because of the presence of _____ for these hormones often on the cell membrane.
Ductless. No ducts to take their secretions to specific sites.
Stimulates contraction of the uterus at the end of pregnancy and stimulates release of milk from the mammary glands when the baby is nursing.
Secretes its hormones in response to releasing hormones from hypothalamus.
Anterior Pituitary Hormones
increase the transport of amino acids into cells and the synthesis of proteins.
increase the rate of mitosis
increase the use of fats for energy
Growth hormone Functions
Stimulates the adrenal cortex to secrete cortisol
Adrenocorticotropic Hormone (ACTH)
Stimulate the thyroid gland to secrete thyroxine and T3
Thyroid stimulating hormone (TSH)
In women, development of egg cells & secretion of estrogen.
Follicle stimulating hormone (FSH)
in women causes ovulation and causes ruptured follicle to become corpus luteum and secrete hormone progesterone as well as estrogen.
Luteinizing hormone (LH)
causes production of milk of mammary glands.
The stimulus for secretion of GH from hypothalamus
Growth hormone-releasing hormone (GHRH)
secretion of GH is inhibited by _____ from hypothalamus.
Growth hormone-inhibiting hormone (GHIH or Somatostatin)
the endocrine glands of the pancreas. Contains Alpha and Beta Cells.
Islets of Langerhans
produce hormone glucagon
produce the hormone insulin.
Primary target organ is liver. causes liver to convert stored glycogen to glucose to be used for energy production. increase use of fats & amino acids for energy production.
cause liver to change glucose to glycogen to be stored. glycogen also stored in skeletal muscle. increase intake on amino acids and fatty acids by cells to be used for the synthesis of proteins and fat.
decrease of blood glucose level with this vital hormone.
secretion of insulin is stimulated by this?
secreted in any type of physiological stress situations: diseases, physical injury, hemorrhage, fear/anger, exercise and hunger.
Cortisol Hormone type
essential first step if tissue repair is to take place.
comes from damaged tissue. "mast cells" make capillaries more permeable and lysosomes of damaged cells release their enzymes, which help break down damaged tissue for easier cleanup by macrophages.
Direct stimulus for cortisol secretion from anterior pituitary gland in situations of physiological stress.
Adrenocorticotropic Hormone (ACTH)
secretion of estrogen by the follicle cells of the ovary is stimulated by this.
a mature ovarian follicle releases an ovum, the follicles becomes this, and begins secreting progesterone in addition to estrogen.
progesterone corpus luteum
Corpus luteum is stimulated by _____ from the anterior pituitary gland?
secreted by corpus luteium. helps decrease the secretion of FSH by anterior pituitary gland, and GNRH by hypothalamus.
secreted by sustentacular cells of the testes; the stimulus for secretion is increased testosterone.
produced by pineal gland. In people this hormone brings about the onset of sleep.
hormone-like substance made by cells from the phospholipids of their cell membranes.