Lab: Nervous System Flashcards
Cranial Nerve I
Name: Olfactory Nerve (Bulb)
Function: Smell
SMB: Sensory
Cranial Nerve II
Name: Optic nerve (chiasm)
Function: Vision
SMB: Sensory
Cranial Nerve III
Name: Occulomotor Nerve
Function: Move eyeball, lift eyelid, change pupil diameter
SMB: Motor
Cranial Nerve IV
Name: Trochlear nerve
Function: controls superior oblique eye muscle
SMB: Motor
Cranial Nerve V
Name: Trigeminal nerve
Function: facial sensation, mastication
SMB: Both
Cranial Nerve VI
Name: Abducens
Function: abducts eye (lateral rectus)
SMB: Motor
Cranial nerve VII
Name: Facial nerve
Function: taste, facial expressions, innervates lacrimal and salivary glands
SMB: Both
Cranial neve VIII
Name: Vestibulocochlear nerve
Function: Equilibrium, hearing
SMB: Sensory
Cranial nerve IX
Name: Glossopharyngeal nerve
Function: taste/touch from tongue, swallowing
SMB: Both
Cranial nerve X
Name: Vagus nerve
Function: pharynx/larynx movement, taste, visceral sensation
SMB: Both
Cranial nerve XI
Name: Accessory nerve
Function: innervates sternocleidomastoid and trapezius
SMB: Motor
Cranial nerve XII
Name: Hypoglossal nerve
Function: moves tongue
SMB: Motor
Types of tactile receptors
free nerve endings, root hair plexus, tactile (Merkel) disc, end bulb, lamellated corpuscle, bulbous corpuscle, tactile corpuscle
Free nerve ending
Structure: dendrites of sensory neurons
Location: Closest to skin surface, mucus membranes
Function: Temp, pain, light touch, pressure detection
Rate of adaptation: Phasic or tonic
Root hair plexus
Structure: dendrites of sensory neurons around hair follicles
Location: Reticular layer of dermis
Function: detects hair movement
Rate of adaptation: phasic
Tactile (Merkel) Disc
Structure: Flattened dendrites of sensory neurons ending next to merkel (tactile) cell
Location: stratum basale of epidermis
Function: detect light touch
Rate of adaptation: tonic
End bulb
Structure: dendrites of sensory neurons ensheathed in connective tissue
Location: dermis, mucus membranes
Function: Detect light pressure and low frequency vibration
Rate of adaptation: Tonic
Lamellated corpuscles
Structure: Dendrites of sensory neurons ensheathed with inner core of neurolemmocytes and outer concentric layers of connective tissue
Location: Reticular layer of dermis, hypodermis of palms/soles, breasts, external genitalia, walls of some organs
Function: Coarse touch: continuous, deep pressure and high frequency vibration
rate of adaptation: phasic
bulbous corpuscle
Structure: dendrites of sensory neurons within connective tissue
Location: Dermis and subQ layer
Function: detect continuous deep pressure and skin distortion
Rate of adaptation: Tonic
Tactile corpuscle
Structure: intertwined dendrites of sensory neurons enclosed by modified neurolemmocytes and dense irregular connective tissue
Location: dermal papillae, especially in lips, palms, eyelids, nipples, and genitals
Function: discriminative touch for distinguishing texture, shape; light touch
Rate of adaptation: Phasic
photoreceptors
used to detect light, color and movements
diameter of eye
about 2.5 cm
how much of the eyes surface is visible?
anterior 1/6
fibrous tunic
sclera
cornea
sclera
“white” of eye
provides shape
protects internal parts
attaches extrinsic eye muscles
cornea
convex, transparent structure forming anterior 1/6 of tunic
convex shape refracts light rays coming into eye
vascular tunic
choroid
ciliary body
iris
pupil
Choroid
highly vascular, dark pigmented membrane
prevents scattering of light rays in eye as pigmented layer absorbs them
ciliary body
composed of ciliary muscles and ciliary processes
iris
visible colored part of eye attached to ciliary body
2 layers of pigment-forming cells
vascular and nervous structures
pupil
round, central opening allowing light to enter
controls amount of light entering eye
retina
deepest tunic composed of 2 layers
pigmented layer
neural layer
pigmented layer
outer single layer of melanocytes
functions like choroid to absorb light and prevent it from scattering in eye
neural layer
innter sheet of nervous tissue containing 3 main types of neurons
houses photoreceptors and associated neurons
responsible for absorbing light rays
converts into nerve signals transmitted into brain
ora serrata
edge of retina
the lens
thick, transparent, biconvex disc changing shape to allow precise focusing of light on the retina
composed of precisely arranged layers of cells with no organelles filled completely with crystallin protein
focuses incoming light onto retina
suspensory ligaments and ciliary muscles help change shape to view objects near and far-accommodationn
posterior cavity
posterior to elns and anterior to retina
occupied by vitreous humor
helps maintain eye shape, support retina
transmits light from lens to retina
vitreous humor
transparent, gelatinous fluid present between lens and retina
anterior cavity
anterior to lens and posterior to cornea
divided into anterior chamber and posterior chamber
anterior chamber
between iris and cornea
posterior chamber
between lens and iris
outer ear function
hearing
middle ear function
hearing
inner ear function
hearing and equilibrium
the auricle (pinna)
surrounds opening of external acoustic meatus, consists of elastic cartilage covered with skin
gathers and funnels to sound waves to amplify them into the external acoustic meatus
external acoustic meatus
short tube running medially from auricle to eardrum
lined with skin containing hairs, sebaceous glands, and ceruminous glands
tympanic membrane
forms boundary btwn external and middle ear
lined by thin mucus membrane
tympanic cavity
AKA middle ear
small air-filled space inside petrous portion of temporal bone
medial wall
separates the middle ear from the outer ear
oval window
superior small hole penetrating medial wall
round window
inferior small hole penetrating medial wall
pharyngotympanic tube (auditory/eustachian tube)
links middle ear and pharynx
auditory ossicles
smallest bones in body that transmit vibrations of eardrum across cavity to fluid in inner ear
malleus (hammer)
most lateral ossicle
attaches to the eardrum
incus (anvil)
middle ossicle
btwn malleus and stapes
stapes (stirrup)
most medial ossicle
vibrates against oval window
inner ear (labyrinth)
lies in petrous portion of temporal bone
2 main divisions (bony labyrinth and membranous labyrinth)
bony labyrinth
cavity consisting of system of twisting channels 3 three parts
semicircular canals, vestibule and cochlea
membranous labyrinth
series of membrane-walled sacs and ducts that fit loosely in bony labyrinth
consists of three main parts
semicircular ducts, utricle + saccule, and cochlear duct
endolymph
clear fluid that fills membranous labyrinth that is confined to the membranous labyrinth
perilymph
continuous with cerebrospinal fluid that fills the subarachnoid space and fills the bony labyrinth
vestibule
central cavity of bony labyrinth
lies medial to middle ear and oval window in lateral wall
utricle and saccule
egg shaped parts of membranous labyrinth
utricle is continuous with the semicircular ducts
saccule is continuous with cochlear duct
houses macula
macula
a spot of sensory epithelium
semicircular canals
lie posterior and lateral to vestibule
anterior and posterior semicircular canals
lie in vertical plane at right angles
lateral semicircular canal
lies in the horizontal plane
semicircular duct
snakes through each semicircular canals
cochlea
spiraling chamber in the bony labyrinth
coils around modiolus from attachment to vestibule at the base
modiolus
pillar of bone cochlea coils around
cochlear duct
coils part of membranous labyrinth in cochlear
location of sensory receptors for hearing
2 categories of endocrine organs
pure endocrine organs
organs containing endocrine cells
pure endocrine organs
pituitary, pineal, thyroid, parathyroid, and adrenal glands
organs containing endocrine cells
pancreas, thymus, gonads, and the hypothalamus
functions of endocrine system
maintain homeostasis
control development of reproductive organs
regulating development, growth and metabolism
controlling digestive processes
function of hypothalamus
receives input from limbic system, cerebral cortex, and thalamus
infundibulum
connects hypothalamus and pituitary
breakdown of synthesizing hormones of hypothalamus
5 releasing hormones
2 inhibiting hormones that target anterior pituitary
2 hormones made by hypothalamus and stored in and released through posterior pituitary
pituitary gland secretes
7 hormones
2 basic divisions of pituitary gland
adenohypophysis
neurohypophysis
each has 3 sub divisions
adenohypophysis
anterior glandular hypophysis made up of glandular tissue
neurohypophysis
posterior neural hypophysis composed of neural tissue
3 divisions of adenohypophysis
pars distalis (anterior lobe)
pars intermedia
pars tuberalis
3 divisions of neurohypophysis
pars nervosa (posterior lobe)
infundibular stalk
median eminence
the adenohypophysis contains
5 different types of endocrine cells that make and release 7 different hormones
somatotropic cells make and release
growth hormone (GH)
mammotropic cells make and release
prolactin (PRL)
thyrotropic cells make and release
thyroid-stimulating hormone (TSH)
corticotropic cells make and release
adrenocortico-tropic hormone (ACTH) and melanocyte-stimulation hormone (MSH)
Gonadotropic cells make and release
follicle-stimulating hormone (FSH) and luteinizing hormone (LH)
the neurohypophysis consists of nervous tissue with
unmyelinated axons and neuroglia
the neurohypophysis does not make
hormones
the neurohypophysis only
stores and releases hormones produced in the hypothalamus
the neurohypophysis releases 2 peptide hormones
Antidiuretic hormone (ADH)/Vasopressin
Oxytocin
thyroid gland
largest pure endocrine gland
butterfly shaped located in anterior neck on trachea inferior to larynx
2 lateral lobes, connected by isthmus
isthmus
median bridge connecting lobes of thyroid
the thyroid gland produces
thyroid hormones (T3 and T4)-follicular cells
calcitonin-parafollicular cells
functions of thyroid hormone
increase basal metabolic rate (BMR)
Stimulate production of additional Na+/K+ ATPase pumps
Stimulate protein synthesis
increases use of glucose and fatty acids for ATP production
Increase lipolysis
Increase cholesterol excretion
Enhance actions of catecholamines (Norepinephrine and Epinephrine)
Accelerate body growth
The parathyroid contains 2 types of endocrine cells
chief cells
oxyphil cells
chief cells function
produce small protein hormone called parathyroid hormone (PTH)
Oxyphil cells function
unknown
parathyroid hormone (PTH) and calcitonin maintain
calcium homeostasis in the blood
PTH and calcitonin have effects
antagonistic
Adrenal (suprarenal) glands
paired adrenal glands are crescent/pyramid shaped organs on superior kidneys
Nerve supply is almost exclusively sympathetic fibers to adrenal medulla
each adrenal gland has 2 endocrine glands in 1
adrenal medulla
adrenal cortex
adrenal medulla
cluster or neurons located centrally in adrenal gland
part of autonomic nervous system
spherical chromaffin cells secrete epinephrine and norepinephrine
adrenal cortex
bulk of the adrenal gland
secretes variety of lipid based steroid hormones
cortex is composed of 3 zones
chromaffin cells
spherical, modified postganglionic sympathetic neurons that secrete epinephrine and norepinephrine
in adrenal medulla, arranged in spherical clusters with some branching cords
3 zones of adrenal cortex external to internal
Zona glomerulosa
Zona fasciculata
Zona reticularis
pineal gland
small, pine cone shaped glans at end of short stalk on the roof of the diencephalon
pinealocytes
star shaped cells with long, branching processes
secrete melatonin
pineal sand
in adults, dense particles of calcium in btwn the cell clusters
radiopaque
Pancreas
posterior wall of abdominal cavity
contains both endocrine and exocrine cells
acinar cells
exocrine cells in the pancreas that form most of the gland
secrete digestive enzymes into small intestine during food digestion
pancreatic islets (islets of Langerhans)
spherical bodies of endocrine cells
1M islets scattered throughout pancreas
alpha cells (a cells)
secrete glucagon
glucagon
produced by-ALPHA CELLS IN PANCREAS
target organs-LIVER
biological action-MAKE GLUCOSE FROM GLYCOGEN
beta cells (B cells)
secrete insulin
insulin
produced by-BETA CELLS IN PANCREAS
target organs-LIVER, ADPIOSE TISSUE
biological action-TAKE GLUCOSE OUT OF BLOOD AND STORE IT AS GLYCOGEN
pancreatic islets (islets of langerhans) contain 2 rare cell types
Delta (D) cells
F (PP) Cells
Delta (D) Cells
secrete somatostatin
somatostatin
produced by-DELTA CELLS IN PANCREAS
target organs-LIVER
biological action- INHIBITS SECRETION OF GLUCAGON/INSULIN
F (PP) Cells
secrete pancreatic polypeptide
Pancreatic Polypeptide (PP)
produced by-F (PP) CELLS OF PANCREAS
target organs-PANCREAS
biological action-MAY INHIBIT EXOCRINE ACTIVITY OF PANCREAS
Thymus
located in lower neck and anterior thorax
important immune organ (T-lymphocytes arise from precursor cells)
Precursor cells transformation to T-lymphocytes
stimulated by thymic hormones
thymic hormones
secreted by epithelial reticular cells
family of peptide molecules
Thymopoietin and Thymosin
epithelial reticular cells
secrete thymic hormones
structural cells of thymus
gonads
testes and ovaries
main sources of steroid sex hormones
testes
male gonads
interstitial cells btwn sperm forming tubules secrete androgens (mostly testosterone)
Testosterone
produced by-GONADS
target organs-SEX ORGANS
biological action-MAINTAIN REPRODUCTIVE ORGANS, PROMOTE FORMATION OF SPERM, MAINTAIN SECONDARY SEX CHARACTERISTICS
ovaries
female gonads
theca folliculi secrete androgens converted to estrogen by follicular granulosa cells
also produce progesterone
estrogen
produced by-FOLLICULAR GRANULOSA CELLS (OVARIES)
target organs-UTERUS, BREASTS
biological action-MAINTAIN REPRODUCTIVE ORGANS, SECONDARY SEX CHARACTERISTICS
progesterone
produced by- FOLLICULAR GRANULOSA CELLS (OVARY)
target organs-UTERUS
biological action-SIGNAL UTERUS TO PREP FOR PREGNANCY
the heart produced the hormone
atrial natriuretic peptide (ANP)
atrial natriuretic peptide (ANP)
produced by-ATRIA OF HEART
target organs-KIDNEY
biological action-DECREASE EXCESS BLOOD VOLUME, HIGH BLOOD PRESSURE, AND HIGH BLOOD SODIUM (KIDNEY INCREASE SECRETION OF SALT-PRODUCTION OF SALTY URINE)
the pancreas SECRETES
insulin
glucagon
the thyroid SECRETES
calcitonin
T3/T4
the ovaries PRODUCE
estrogen
progesterone
the testes PRODUCE
testosterone
the adrenal cortex SECRETES
aldosterone
glucocorticoids (cortisol)
androgenic steroids (DHEA)
the hypothalamus RELEASES
TRH-stimulate release of TSH
PRH-stimulate production of breast milk
GnRH-stimulate release of LH and FSH
CRH-stimulate release of ACTH
GHRH-stimulate release of growth hormone
the hypothalamus INHIBITS
PIH-inhibits prolactin, milk production
GHIH-inhibits growth hormone
Growth hormone (GH)
Produced by- ANTERIOR PITUITARY
Target organs- ALL BODY TISSUES
Biological action-STIMULATE GROWTH
Adrenocorticotropic hormone (ACTH)
Produced by- ANTERIOR PITUITARY
Target organs- ADRENAL CORTEX
Biological action- RELEASE OF CORTICOSTEROIDS
Follicle-stimulating hormone (FSH)
Produced by- ANTERIOR PITUITARY
Target organs-OVARIES/TESTES
Biological action-STIMULATE DEVELOPMENT OF GAMETES (sperm/egg)
Luteinizing hormone (LH)
Produced by- ANTERIOR PITUITARY
Target Organs-OVARIES/TESTES
Biological action-STIMULATE DEVELPOMENT OF GAMETES (sperm/egg)
Prolactin (PRL)
Produced by-ANTERIOR PITUITARY
Target organs-MAMMARY GLANDS
Biological action-MILK PRODUCTION
Thyroid-stimulating hormone (TSH)
Produced by-ANTERIOR PITUITARY
Target organs-THYROID GLAND
Biological action-RELEASE THYROID HORMONE
Antidiuretic hormone (ADH)/Vasopressin
Produced by-HYPOTHALAMUS (released in POSTERIOR PITUITARY)
Target organs-KIDNEYS
Biological action-FLUID RETENTION
Oxytocin
Produced by-HYPOTHALAMUS (released in POSTERIOR PITUITARY)
Target organs-UTERUS AND BREASTS
Biological action-UTERUS CONTRACTION IN CHILDBIRTH and MILK RELSEASE
Thyroid hormones (T3 & T4)
Produced by-THYROID GLAND (stored in FOLLICULAR CELLS)
Target organs-MOST CELLS
Biological action-INCREASE BMR, INCREASE LIPOLYSIS, ACCELERATE BODY GROWTH, STIMULATE PROTEIN SYNTHESIS, ETC.
Calcitonin
Produced by-THYROID GLAND (stored in PARAFOLLICULAR CELLS)
Target organs-BONE
Biological action-LOWERS BLOOD CALCIUM
Parathyroid hormone (PTH)
Produced by-PARATHYROID GLAND
Target organs-BONES AND KIDNEYS
Biological action-RAISES BLOOD CALCIUM
Norepinephrine (NE) and Epinephrine (EPI)
Produced by-ADRENAL MEDULLA (CHROMAFFIN CELLS)
Target organs-ALL ORGANS
Biological action-FIGHT OR FLIGHT
Aldosterone
Produced by-ADRENAL CORTEX (ZONA GLOMERULOSA)
Target organs-KIDNEYS
Biological action-INCREASE NA AND H2O RETENTION
Cortisol
Produced by-ADRENAL CORTEX (ZONA FASCICULATA)
Target organ-LIVER/PANCREAS
Biological action-INCREASE BLOOD GLUCOSE
Dehydroepiandrosterone (DHEA)
Produced by-ADRENAL CORTEX (ZONA RETICULARIS)
Target organ-GONADS, BRAIN, LIVER, KIDNEYS
Biological action-PRODUCE OTHER HORMONES (ESTROGEN/TESTOSTERONE)
Melatonin
Produced by-PINEAL GLAND
Target organs-VARIOUS TISSUES
Biological action-REGULATE CIRCADIAN RHYTHM
Thymopoietin (TMPO)
produced by-THYMUS (EPITHELIAL RETICULAR CELLS)
target organs-T-LYMPHOCYTES
biological action-MATURATION AND SELECTION OF T-LYMPHOCYTES
Thymosin
produced by-THYMUS (EPITHELIAL RETICULAR CELLS)
target organ-WHITE BLOOD CELLS
biological action-PRODUCTION OF T-CELLS