somatic nervous system
voluntary/conscious control
somatic sensory
signals from skin, special senses to CNS
somatic motor
signals from CNS to skeletal muscle
autonomic nervous system
involuntary/autonomic control
autonomic sensory
signals from organs, blood vessels to CNS
autonomic motor
signals to glands, smooth and cardiac muscle from CNS
2 divisions of the autonomic nervous system
sympathetic and parasympathetic
sympathetic nervous system
fight or flight" maintain homeostasis during times of stress and exercise
parasympathetic nervous system
rest and digest" maintain homeostasis and conserve energy
low motor neuron differences: somatic
single motor neuron fro CNS to muscle
myelinated axons
release acetylcholine at NMJ
low motor neuron differences: autonomic
chain of two motor neurons from CNS to cardiac muscle, smooth muscle and glands
preganglionic neuron
cell body in CNS
preganglionic axon
extends from preganglionic cell body and exits CNS in cranial or spinal nerves
ganglionic neuron
cell body in ganglion
postganglionic neuron
extends from the ganglionic cell body to effector
neuronal convergence
axons from many preganglionic neurons influence a single ganglionic neuron
neuronal divergence
axons from one preganglionic cell influence numerous ganglionic neurons
control of the autonomic nervous system
hypothalamus, brain stem, spinal cord
Hypothamlamus
integration and command center from autonomic functions; involved in emotions
brain stem
contains major ANS reflex centers
spinal cord
contains ANS reflex centers for defecation and urination
parasympathetic origin
brain
sympathetic origin
spinal cord
local response
only stimulates few structures at a time
mass activation
activates many structures at once
terminal ganglia
ganglia are close to the effector organ
intramural ganglia
ganglia are within effector organ
sympathetic trunk ganglia
connects to spinal nerves and houses neuron cell bodies in the "ganglia" connected by bundled axons (pearls on a pearl necklace)
bundles of axons
string of the pearl necklace
Acetylocholine
always excitatory
cholinergic neurons
synthesize and release ACh
cholinergic receptors
receptors that bind ACh
2 types: Nicotinic and Muscarinic
response time for parasympathetic
longer pathways=slower system
norepinephrine
excitatory or inhibitory
adrenergic neurons
synthesize and release NE
adrenergic receptors
receptors that bind to NE
response speed for sympathetic
shorter pathways=faster system
dual intervention
most organs are innervated by both the sympathetic and parasympathetic innervation
autonomic tone
continual release of neurotransmitters by both sympathetic and parasympathetic divisions onto effector organ
antagonistic effects
parasympathetic and sympathetic innervations oppose each other
-heart rate
-pupil size
-helps maintain homeostatsis
cooperative effects
parasympathetic and sympathetic innervations work together to achieve a common goal
-digestion
-reproduction
reflex arcs
a neural pathway that controls reflex actions
vision
use photoreceptors within the eyes to detect light color and movement
accessory eye structures
eyebrows, eyelids, glands, eyelashes
conjunctiva
continuous covering between eye and eyelid: contains blood vessels and nerve endings
ocular conjunctiva
eye
palpebral conjunctiva
eyelid
conjunctival fornix
junction of ocular and palpebral conjunctiva
conjunctivitis
inflammation of the conjunctiva
"pink eye
lacrimal apparatus
produces, collects and drains lacrimal fluid
lacrimal fluid
reduces friction
prevents bacterial infection
provides oxygen and nutrients
orbital fat
cushions eyeball
anterior cavity
in front of lens, filled with aqueous humor
posterior cavity
backside of lens, filled with vitreous humor
wall of eye is formed by 3 layers
fibrous tunic
vascular tunic
retina
fibrous tunic
sclera and cornea
vascular tunic
choroid, ciliary body, iris
sclera
white of the eye
cornea
bends light waves so the image can be focused on the retina
iris
Colored part of the eye
ciliary body
dilating/contracting pupil
choroid
blood supply
pigmented layer of retina
absorbs light and prevents it from scattering in the eye
neural layer
contains neurons for sight
rods
function in dim light
cones
function in high light and are responsible for color vision
bipolar cells
middle cell layer
rods and cones form synapses on the dendrites of
ganglion cells
innermost layer of cells; produce action potentials
axons of ganglionic cells form the optic nerve
pupillary reflex parasympathetic
pupil constriction
pupillary reflex sympathetic
pupil dilation
optic disc
blind spot
fovea centralis
tiny pit or depression in the retina that is the region of clearest vision
3 regions of the ear
external ear, middle ear, inner ear
auricle
captures sound waves and funnels to auditory canal
external auditory canal
transmits waves to eardrum
tympanic membrane
amplifies vibrations received by ear and transmits sound energy to ossicles of middle ear
auditory ossicles
malleus, incus, stapes
oval window
transmits vibrations of middle ear to fluid in inner ear
auditory (eustachian) tube
helps equalize pressure between external and middle ear (ear pop)
otitis media
inflammation of the middle ear
cochlea
a coiled, bony, fluid-filled tube in the inner ear through which sound waves trigger nerve impulses "snail
cochlear duct
a fluid filled cavity within the cochlea that vibrates when sound waves strike it
vestibule
central part of the bony labyrinth in the inner ear
semicircular canals
three canals within the inner ear that contain specialized receptor cells that generate nerve impulses with body movement
semicircular ducts
three small membranous tubes of the vestibular labyrinth within the bony semicircular canals
spiral organ
Organ of hearing, rests on the basilar membrane inside of the cochlear duct
hair cells
receptor cells for hearing found in the cochlea
stereocilia
small hairlike projections on the tops of inner and outer hair cells
cochlear implants
a device for converting sounds into electrical signals and stimulating the auditory nerve through electrodes threaded into the cochlea
conductive hearing loss
blocked sound conduction to fluid of internal ear
neural/sensory hearing loss
inner ear hearing loss
endocrine glands
secrete hormones directly into the bloodstream
endocrine organs
thyroid gland, pituitary gland, sex glands, adrenal glands, pancreas, parathyroid glands
endocrine cells
alpha and beta cells
target cells
cells that have receptors for a particular hormone
functions of the endocrine system
1. regulating growth, development and metabolism
2. maintaining homeostasis of blood composition and volume
3. controlling digestive processes
4. controlling reproductive activities
hormonal stimulation
release of a hormone in response to another hormone
humoral stimulation
release of a hormone in response to changes in level of nutrient or ion in the blood
nervous system stimulation
release of a hormone in response to stimulation by the nervous system
Sterioids
lipid-soluble
biogenic amines
water soluble
proteins
water soluble
Eicosandoids
type of local hormone that stimulates pain receptors, reduce fever, etc
Autocrine stimulation
act on the same cell
paracrine stimulation
act on the neighboring cell
lipid soluble hormones
does not dissolve in blood; require carrier molecules
water soluble hormones
do dissolve in blood; carrier molecules are sometime used
bound hormone
readily available source of hormone in the blood
unbound hormone
able to exit the blood and bind target organs
carrier molecule
Protein that binds to substances and moves them across the plasma membrane.
upregulation
increase in receptor number in response to low concentration of hormone
Downregulation
Decrease in receptor number in response to high concentration of hormone
Synergestic Interaction
hormone works together to produce greater effect
permissive interaction
first hormone allows action of second hormone
Antagonistic interaction
one hormone causes opposite effect of another hormone
direct control
pituitary glands
indirect control
thyroid gland, adrenal gland, liver, testes, ovaries
Hormones released by posterior pituitary
oxytocin and antidiuretic hormone (ADH)
Oxytocin
stimulates uterus contraction during delivery and breast milk ejection
Antiduretic hormone (ADH)
stimulates kidneys to decrease urine output and increase fluid intake
-released dehydrated to decrease urine output
hypothalamus to posterior pituitary
nerve signals
hormones released by anterior pituitary
thyroid stimulating hormone
prolactin
follicle-stimulating hormone and luteinizing hormone
adrenocorticotropic hormone
growth hormone
Hormones released by hypothalamus
Thyrotropin-releasing hormone
Prolactin-releasing hormone
Gonadotropin-releasing hormone
Corticotropin-releasing hormone
Growth hormone-releasing hormone
Prolactin-inhibiting hormone
Growth hormone-inhibitory hormone
stimulates anterior pituitary to release thyroid stimulating hormone
thyrotropin-releasing hormone
stimulates anterior pituitary to release prolactin
prolactin-releasing hormone
stimulates anterior pituitary to release follicle-stimulating hormone and luteinizing hormone
gonadotropin-releasing hormone
stimulates anterior pituitary to release adrenocorticotropic horomone
corticotropin-releasing hormone
simulates anterior pituitary to release growth hormone
growth hormone releasing horomone
inhibits prolactin release from anterior pituitary
prolactin inhibiting hormone
inhibits growth hormone release from anterior pituitary
growth hormone inhibitory hormone
stimulates thyroid gland to release thyroid hormone. Results in increase metabolic rate in neurons liver, adipose, lungs and heart
thyroid stimulating hormone
disorders of thyroid stimulating hormone
hyperthyroidism: increase release increase metabolism
hypothyroidism: decrease release decrease metabolism
goiter: iodine deficiency
acts on mammary glands to stimulate milk production
prolactin
act on gonads to stimulate development of gametes (ovaries and testis)
follicle-stimulating hormone and luteinizing hormone
Acts on the adrenal cortex to cause release of corticosteroids like cortisol which increases nutrients
adrenocorticotropic hormone
adrenocorticotropic hormone disorder
stress
stimulates release of IGF's from the liver, which act on all body tissues to stimulate growth (bone, muscle, adipose tissue, etc.) results in increase in cell division release of stored nutrients
growth hormone
growth hormone disorders
growth hormone deficiency, pituitary gigantism, acromegaly
posterior pituitary
does not create own hormones. hypothalamus creates the hormones and ______ stores and releases them
anterior pituitary
creates and releases own hormones
alarm reaction
sympathetic nervous system is activated (seconds/minutes)
stage of resistance
hours
glycogen depletes
stage of exhaustion
weeks to months
1. insulin: stimulus
increase in blood glucose levels
2. insulin: receptor
beta cells within pancreas detect an increase in blood glucose levels
3. insulin: control center
beta cells within pancreas release insulin
4. insulin
stimulates target cells
5. insulin: net effect
decrease blood glucose levels occur (fatty acids and amino acids are also decreased in the blood)
negative feedback insulin
insulin is released inhibited as blood glucose levels decrease to normal.
liver tissue insulin
increased glycogenesis
decreased glycogenolysis and glucoenognesis
adipose connective tissue insulin
increase lipogenesis
decreased lipolysis
1. glucagon: stimulus
decrease in blood glucose levels
2. glucagon: receptor
alpha cells within pancreas detect a decrease in blood glucose levels
3. glucagon: control center
alpha cells within the pancreas release glucagon
liver glucagon
increased glycogenolysis and gluconeogenesis
decrease glycogenesis
adipose connective tissue glucagon
increase lipolysis
decreased lipogenesis
5. glucagon: net effect
increased blood glucose and fatty acid levels occur (no change in amino acids or proteins
type 1 diabetes
juvenile diabetes
type 2 diabetes
produce enough insulin but cells dont respond insulin
gestastional diabetes
occurs in pregnant women resolves after pregnancy however more prone to get type 2 later in life