Unit A - Nervous & Endocrine System Flashcards
Which gland in the endocrine system is a neuroendocrine gland?
Posterior pituitary gland
What are the two peripheral nervous system parts?
Somatic and autonomic
The sympathetic and parasympathetic nervous system are part of which system?
Autonomic (peripheral) nervous system
What is sensory adaptation?
The ability of the brain to filter out redundant, insignificant or repetitive information.
What are the four types of sensory receptors?
Photoreceptors, chemoreceptors, mechanoreceptors and thermoreceptors.
Define homeostasis.
The tendency of the body to maintain a relatively constant environment; critical for survival.
What part of the brain receives impulses from chemoreceptors in the tastebuds?
The parietal lobe.
What part of the brain receives impulses from chemoreceptors in the olfactory cells?
The temporal lobe.
What structure receives info from olfactory sensory receptors and transmits it to the brain?
Olfactory bulb
What is the sensory pathway for the nose/smell?
Sensory receptors > sensory neurons > olfactory bulb > temporal lobe (cerebrum)
What type of sensory receptors relay tactile acuity?
Mechanoreceptors
What is tactile acuity?
The minimum separation needed for the brain to perceive more than one point separately.
What type of sensory receptors are present in the retina?
Photoreceptors
What are the two types of photoreceptors in the retina?
Rods and cones.
List three differences between the two photoreceptors in the eye?
Cones exist primarily in the fovea centralis, rods are in the peripheral only.
Cones need adequate light to function and perceive colour by detecting different light wavelengths. Rods function in low light and do not register colour, only contrast/shape.
Cones have dedicated receptors. Multiple rods are connected to a single receptor.
Name the two humours of the eye and their functions.
Aqueous humour: maintains shape of cornea and provides oxygen to surrounding cells.
Vitreous humour: maintains shape of eyeball.
What causes the condition glaucoma?
Fluid in the aqueous chamber doesn’t drain properly, it builds up and causes tunnel vision as cells in the peripheral (retina) deteriorate.
What are the two structures of the external eye layer?
Sclera and cornea.
What are the four intermediate structures of the eye?
Choroid, iris, pupil and ciliary muscles.
What is the function of the cornea?
Bends light rays into the eye.
What is the function of the choroid?
Absorbs scattered light rays, and contains blood vessels to nourish cells.
What structure of the eye regulates the amount of light that enters it?
Iris.
What is the function of the pupil?
Opening for light to enter the eye.
What controls the shape of the lens?
Ciliary muscles.
What is the fovea centralis?
A small depression in the back of the eye that contains a high concentration of cones (for acute vision).
What structure focuses light on the fovea centralis?
Lens.
What structure transmits information from the photoreceptors in the eye to the brain?
Optic nerve.
The ability of the lens to focus light on the retina is called?
Accommodation.
Steroid hormones, which include the male and female sex hormones and cortisol, are made from?
Cholesterol
Transmission in a neuron is one way because of the:
a) flow of charges across the membrane
b) flow of sodium
c) location of the synaptic vesicles
d) myelination of the axon
c) location of the synaptic vesicles
Myxedema is the result of:
a) hyposecretion of insulin
b) hyper secretion of insulin
c) hyposecretion of thyroxine
d) hypersecretion of thyroxine
c) hyposecretion of thyroxine (hypothyroidism)
________ hormones are made from amino acids and include insulin, epinephrine and growth hormones.
Protein
Inadequate production of dopamine could degenerate into which disease?
Parkinson’s disease
Human growth hormone (hGH) is produced where?
The anterior pituitary gland.
The gaps between myelin sheath cells along an axon terminal are identified as?
Nodes of Ranvier
Alzheimer’s disease js associated with what neurological conditions, and related to a decrease in the production of?
Lack of memory and mental capacity. Decrease in the production of acetylcholine in the frontal lobe.
Uneven curvature of the cornea that causes light not to reach the focal point results in which condition? How is the vision affected?
Astigmatism. Blurred vision.
What is the physical condition that causes myopia? What kind of lens correction resolves it?
Cornea is too curved and/or eyeball is elongated. Concave lenses.
Hyperopia is caused by what physical condition? Which shape of lens corrects it?
Cornea is too flat and/or eyeball is shortened. Convex lens.
Fill in the blanks: light > _____ > _____ humour > pupil and lens > _____ humour > _____ > optic nerve > _____ lobe (brain)
Cornea, aqueous, vitreous, retina, occipital.
When visual information enters the brain, some of it crosses over to ensure each side of the brain receives some part of the visual field from each eye. Where does this occur?
The optic chiasm.
For the eyes to focus on a distant object the ciliary muscles _____ and the suspensory ligaments _____ to _____ the lens.
Relax, constrict, stretch.
When the eyes focus on nearby objects the _____ muscles contract (stretch) and the _____ ligaments relax to allow the lens to _____.
Ciliary, suspensory, bulge/thicken/compress.
Presbyopia is the inability of the _____ to adjust and focus light on the retina.
Lens.
The retina converts _____ energy into _____ impulses that transfer visual information into the brain.
Light, electrochemical.
By physical structure in the retina, how do rods and cones differ?
Cones have dedicated bipolar cells (receptors) while multiple rods are connected to a single bipolar cell.
What kind of cells attach to the retina and become part of the optic nerve? Hint: they’re transparent.
Ganglion cells.
Which cone colour is stimulated by long wavelengths (L-cones)?
Red
Which cone colour is stimulated by medium wavelengths (M-cones)?
Green
Which cone colour is stimulated by short wavelengths (S-cones)?
Blue
What type of receptors do rods and cones contain?
Photoreceptors
Rods and cones contain a vitamin A derivative called _____. When they absorb light, the molecules change shape to initiate nerve impulses. Until they return to their original shape, they can’t respond again. This is called _____.
Retinol, bleaching.
Rhodopsin in the _____ of the retina is extremely sensitive to light changes and _____. In high intensity light it is broken down as fast as it is used, causing the _____ to become non-functional and the _____ take over completely.
Rods, shapes/movement, rods, cones.
What eye condition is caused by protein degeneration, leading to the lens becoming opaque and resulting in cloudy vision?
Cataracts
Similar to hyperopia, presbyopia is the loss of near-focusing ability. It is caused by the hardening of the _____.
Lens
What structure of the eye is affected by glaucoma, what cells are caused to die, and how does the vision change?
Anterior chamber/aqueous humour. Retinal cells slowly die. Vision begins to deteriorate around the perimeter, causing tunnel vision.
When the cones of the retina are destroyed due to the thickening of the choroid vessels, what condition is caused and how does it affect vision?
Macular degeneration. Central vision becomes blurry.
If someone has night blindness, which photoreceptors are affected?
Rods
The outermost and most obvious part of the ear is called the?
Pinna
Sound waves entering the ear are first collected in the?
Auditory canal.
What is another name for the eardrum?
Tympanic membrane or tympanum.
The tympanum converts _____ energy/waves into _____ energy.
Sound, mechanical.
What two parts of the ear are considered the outer ear?
Pinna and auditory canal.
What are the four parts of the middle ear?
Tympanum (eardrum), ossicles, oval window and Eustachian tube.
What is the primary function of the ossicles?
To amplify vibrations as they reach the oval window.
What kind of receptors in the ear convert sound waves into electrochemical impulses?
Mechanoreceptors.
Which part of the ear is fluid-filled?
The inner ear.
Which structure of the ear contains the organ of Corti, and converts mechanical energy into nerve impulses?
Cochlea
What is the function of the round window in the ear?
Dissipating sound waves in the inner ear.
What structure composed of sensory fibres becomes the auditory nerve and transmits information to the brain?
Organ of Corti
The basilar membrane is made of sensory mechanoreceptors called?
Hair cells.
Which part of the cochlea moves up and down causing steriocilia to bend against the tectorial membrane?
Basilar membrane.
Fill in the blanks of the sound pathway: pinna > auditory canal > _____ > _____ > _____ window > _____ > auditory nerve > _____ lobe (brain)
Tympanum, ossicles, oval, cochlea, temporal.
In the base of the cochlea the basilar membrane is very _____ and only moves in response to _____ wavelengths or _____ frequency sounds.
Stiff, short, high.
Deeper inside the ear, in the apex cochlea, steriocilia are more _____ and respond to _____ wavelengths or _____ frequency sounds.
Flexible, long, low.
Which three structures of the eat function to amplify sound?
Auditory canal, tympanum and ossicles.
What can cause conduction deafness/hearing loss?
Damage to the tympanum, ossicles or the connection between the ossicles and the oval window; impacted earwax, colds or infections, physical trauma.
What part of the ear does perception deafness affect?
Inner ear.
Which three structures of the ear are responsible for maintaining balance?
The semicircular canals, saccule and utricle.
The semicircular canals of the ears are responsible for maintaining _____ equilibrium.
Rotational
_____ equilibrium is determined by nerve impulses in the utricle and saccule.
Gravitational
What is the function of Eustachian tubes in the ears?
Regulating air pressure in the middle ear.
What is the primary organ of hearing?
Organ of Corti
Steriocilia are embedded in what structure of the ear, to stimulate hair cells of the basilar membrane?
Tectorial membrane.
What are the two major components (sub-systems) of the peripheral nervous system’s motor pathways?
Somatic and autonomic nervous system.
The sympathetic and parasympathetic nervous systems are part of which other two nervous systems?
Autonomic and peripheral.
What parts of the peripheral nervous system communicate directly with the central nervous system?
Sensory and motor pathways.
Which nervous system responds to external stimuli?
Somatic nervous system.
Which part of the nervous system regulates internal body functions?
Autonomic nervous system.
Which nervous system regulates our fight-or-flight instincts?
Sympathetic nervous system.
What structure protects the brain from toxins and bacteria, but allows oxygen and glucose to transfer?
The blood-brain barrier.