LAB EXAM I Flashcards
What does the longitudinal fissure separate?
cerebrum into L & R hemispheres
What does the transverse fissure separate?
cerebellum from cerebrum
What is the insula?
5th part of cerebrum (aside from 4 lobes); within lateral cerebral sulcus
What is the arbor vitae?
tracts of white matter in the cerebellum
What is the infundibulum?
connects the pituitary gland to the hypothalamus
What is the interthalamic adhesion?
joins L & R halves of thalamus
What are the 4 major regions of the hypothalamus?
mammillary, tuberal, supraoptic, preoptic
What does the septum pellucidum separate?
the two lateral ventricles in the cerebral hemispheres
Where is the 3rd ventricle located?
between L & R halves of the thalamus, sup. to hypothalamus
Where is the 4th ventricle located?
between brainstem & cerebellum
How does venous blood circulate and leave the brain?
through venous sinuses b/t 2 layers of dura mater; leave the brain through internal jugular veins
Which muscles are innervated from the oculomotor nerve?
supe/med/inf rectus
inf oblique
ciliary muscle
Which muscles are innervated by the trochlear nerve?
sup oblique
Which muscles are innervated by the abducens nerve?
lateral rectus
What do corpuscles of touch detect?
touch, low frequency vibration
What do hair root plexus detect?
movements that disturb hair
Which tactile receptors are free nerve endings?
hair root plexus, type I cutaneous mechanoreceptors
What do type I cutaneous mechanoreceptors detect?
pressure, continuous touch
What do type II cutaneous mechanoreceptors detect?
stretching, steady pressure
What do lamellated corpuscles detect?
high frequency vibrations
Where do the axons of the olfactory nerve pass through?
cribriform plate of ethmoid bone
What are Bowman’s glands?
(olfactory gland) produce mucus that is carried to surface of epithelium by duct
What is the function of mucus produced by Bowman’s gland?
dissolves odorants so transduction can occur
Where is the site of olfactory transduction?
olfactory hair/cilia
What is adaptation?
receptor’s decreasing sensitivity to a constant stimulus over time
Where are sensory receptors for gustation located?
taste buds on tongue, soft palate, pharynx, epiglottis
Which three CN transmit sensory info from taste buds to the brain?
facial (VII), glossopharyngeal (IX), vagus (X)
Which three CN control eye movement?
oculomotor (III), trochlear (IV), abducens (VI)
What is the iris suspended between?
cornea & lens
What part of the eye do external eye muscles attach to?
sclera
What is the function of the ciliary muscle?
alters shape of lens to adapt for near/far vision
What is the function of the ciliary process?
contain blood capillaries that secrete aqueous humor
Where does the anterior chamber lie?
b/t cornear & iris
Where does the posterior chamber lie?
behind iris & in front of lens
What are the components of the anterior cavity?
aqueous humor
anterior chamber
posterior chamber
What is the function of the cornea?
focus light on retina; admits/refracts light
What is the function of the lens?
refracts light
What are zonular fibres?
extensions of ciliary processes
What is the function of the retina?
receives and converts light into receptorpotentials & nerve impulses
What is the choroid and what is its function?
highly vascularized lining of internal surface of sclera; absorbs scattered light
What does the fovea centralis contain?
only cones
What is the optic disc/blind spot?
where optic nerve exits the eyeball; contains no rods/cones
Where does the vitreous chamber lie?
between the lens and retina; posterior of eyeball
What are the intrinsic muscles of the eye?
ciliary muscle, muscle of iris
What is the function of the ciliary muscles?
alter curvature of lens
What is the function of muscles of the iris?
control pupil size (i.e. amount of light entering eye)
Describe the muscle position of the eye when focusing on a close object
ciliary muscles are contracted; lens is curved
Describe the muscle position of the eye when focusing on a distant object
ciliary muscles are relaxed; lens is flat
What is convergence?
medial rotation of the eyeballs as an object moves closer to us to allow light rays to strike same points on both retinas
Where is the tympanic membrane (eardrum) located?
between external auditory meatus and the middle ear
Where does the base of the stapes fit into?
oval window
What does the eustachian (auditory) tube connect?
middle ear with the nasopharynx
What does the vestibular branch of CN VIII contain?
ampullary, utricular, saccular nerves that synapse with receptors for equilibrium
What is the function of the cochlea?
transmits vibrations to spiral organ where hair cells produce receptor potentials
What does the spiral organ contain?
hair cells that act as hearing receptors
What does the vestibule contain?
utricle and saccule
What does the utricle detect?
linear acceleration/deceleration in a horizontal direction
What does the saccule detect?
linear acceleration/deceleration in a vertical direction
What is the macula and where is it located?
in utricle and saccule; contains receptors
What are otoliths?
layer of CaCO3 crystals that extend over entire surface of otolithic membrane
What are 3 somatic sensations detected by encapsulated nerve endings?
tactile (pressure/vibration)
type II cutaneous mechanoreceptors
proprioceptors
Which receptors detect static equilibrium?
hair cells of maculae in saccule & utricle (in vestibule)
Which receptors detect dynamic equilibrium?
hair cells in crista (in ampulla of semicircular ducts)
What are 2 hormones produced by the hypothalamus and where are they stored?
OT & ADH; posterior pituitary
What hormones are released by the anterior pituitary?
growth hormone, thyroid-stimulating hormone, follicle-stimulating hormone, luteinizing hormone, prolactin, adrenocorticotropic hormone, melanocyte-stimulating hormone
What hormones are released by the posterior pituitary?
OT, ADH
How does FSH function in biological females?
initiate oocyte develeopment; induces ovarion secretion of estrogen
How does FSH function in biological males?
stimulate testes to produce sperm
How does LH function in biological females?
stimulate secretion of estrogen and progesterone; ovulation; formation of corpus luteum
How does LH function in biological males?
stimulate testes to produce testosterone
How does adrenocorticotropic hormone (ACTH) function in the adrenal gland?
stimulate secretion of glucocorticoids, primarily cortisol, by adrenal cortex
What is the function of OT?
- stimulate contraction of smooth muscle cells of uterus during childbirth
- stimulate contraction of myoepithelial cells in mammary glands to cause milk ejection
What is the function of ADH?
- conserves H2O in body by decreasing urine volume
- decrease H2O loss via perspiration
- increase BP by constricting arteries
Where are hormones stored in the thyroid gland? What do they secrete?
follicles (large oval sacs); thyroglubilin (TGB)
What are parafollicular cells (C cells) and where are they found?
hormone-producing cuboidal cells; in between follicles
What do C cells produce?
calcitonin
How does the structure of the thyroid gland compare to the parathyroid gland?
thyroid - large follicles
parathyroid - dense mass of cuboidal cells with many capillaries and have Chief cells and oxyphil cells
What do Chief cells produce?
parathyroid hormone (PTH)
What hormones are released by the thyroid gland?
follicle cells: triiodothyronine (T3) and thyroxine (T4)
parafollicular cells: calcitonin
What is the function of T3 and T4 hormones?
stimulate prot synthesis, increase use of glucose and FA for ATP prod
What is the function of calcitonin?
decrease Ca2+ and HPO4 levels in blood by inhibiting bone resorption (increasing ion uptake)
What hormones does the parathyroid gland release?
parathyroid hormone
What is the function of the parathyroid hormone?
increase Ca2+ and Mg2+ levels in blood
increase bone resorption by osteoclasts
promotes formation of calcitriol
What are the 3 zones of cells in the adrenal cortex and what do they secrete?
- outermost - mineralocorticoids (aldosterone)
- intermediate - glucocorticoids (cortisol)
- inner - androgens (DHEA)
What is the function of aldosterone?
increase blood levels of Na+, H2O
decrease blood levels of K+
What is the function of cortisol?
depress immune responses
provide resistance to stress
What is the function of DHEA?
assist in early growth of axillary/pubic hair in M/F
contribute to libido
source of estrogen after menopause
What are the functions of E/NE from the adrenal medulla?
enhance effects of sympathetic division of ANS during stress
What do the pancreatic islets of the pancreas produce?
insulin and glucagon
What is the function of glucagon (from alpha cells) ?
increase blood glucose levels by accelerating breakdown of glycogen into glucose in the liver (glycogenolysis)
What is the function of insulin (from beta cells) ?
decrease blood glucose levels by accelerating transport of glucose into cells via glycogenesis (glucose –> glycogen)
What structures are in the ovary and what hormones do they produce?
corpus luteum & granulosa cells; progesterone, estrogens, inhibin, relaxin
What structures are in the testes and what hormones do they produce?
sertoli cells (inhibin) and interstitial cells (testosterone)
What is the function of estrogen?
regulate repro cycle, maintain pregnancy, promote development and maintenance of secondary sex characteristics
What is the function of progesterone?
prepare uterus for implantation of a fertilized ovum
help prepare mammary glands for milk secretion
What is the function of relaxin?
increase flexibility of pubic symphysis during pregnancy
help dilate uterine cervix during labor and delivery
What is the function of inhibin in males and females?
inhibit secretion of FSH from anterior pituitary
What is the function of testosterone?
regulate sperm production
promote secondary sex characteristics
What are the 4 thymic hormones?
thymosin, thymic humoral factor (THF), thymic factor (TF) thymopoietin
What are the function of the hormones produced by the thymus?
promote maturation of T cells (WBC that destroy microbes and foreign substances)
What can hyposecretion of GH lead to?
pituitary dwarfism
What can hypersecretion of hGH lead to?
giantism (childhood)
acromegaly (adulthood)
What can hyposecretion of ADH lead to?
neurogenic diabetes insipidus
What can hyposecretion of thyroid hormone lead to?
congenital hypothyroidism (childhood)
myxedema (adulthood)
What can hyperthyroidism lead to?
Graves disease (immune system attacks thyroid)
What can lack of iodine lead to?
goiter (enlarged thyroid gland)
What is type I diabetes?
inability to produce insulin b/c immune system destroys beta cells
What is type II diabetes?
target cells in pancreas have fewer insulin receptors
What is hyperinsulism?
too much insulin injected by diabetic?
Which 2 hormones are also NT?
norepinephrine, nitric oxide
What happens when blood glucose level goes up?
hyperglycemia inhibits release of glucagon
insulin helps lower blood glucose
What happens when blood glucose level goes down?
stimulate release of glucagon
inhibits release of insulin
What is the difference between paracrine and autocrine?
P - local hormones that act on neighbouring cells
A - local hormones that act on the same cell that secreted them
What is the difference between holocrine and apocrine?
H - accumulated secretory product ruptures
A - secretory product accumulates at apical surface, pinches off via exocytosis to release
