A&p 1 - Ch 14-16

Front 1

Anterior (ventral) horns

Back 1

w/in gray matter

cell bodies of somatic motor neurons

Front 2

Posterior (dorsal) horns

Back 2

w/in gray matter

axons of sensory neurons &

cell bodies of interneurons

Front 3

Lateral horns

Back 3

w/in gray matter

found in T1-L2 of spinal cord

cell bodies of autonomic motor neurons

Front 4

Gray Commissure

Back 4

w/in gray matter

unmyelinated axons of interneurons

horizontal band of gray matter surrounding central canal

Front 5

Central Canal

Back 5

filled with CSF

Front 6

Anterior column (funiculus)

Back 6

w/in white matter

b/w ant. gray horns & ant. median fissure

motor & sensory axons

Front 7

Posterior column (funiculus)

Back 7

w/in white matter

b/w post. gray horns & post. median sulcus

sensory axons only

Front 8

Lateral column (funiculus)

Back 8

w/in white matter

on each lateral side of spinal cord

motor & sensory axons

Front 9

Anterior median fissure

Back 9

w/in white matter

wider groove on the anterior external surface

Front 10

Posterior median sulcus

Back 10

w/in white matter

narrow groove on the posterior external surface

Front 11

Posterior root ganglion

Back 11

somas of somatic and visceral sensory neurons

Front 12

Posterior root

Back 12

axons of somatic and visceral sensory neurons

Front 13

Anterior root

Back 13

axons of somatic motor neurons & autonomic neurons

Front 14

Spinal nerve

Back 14

axons of somatic & visceral sensory neurons and

axons of somatic autonomic neurons

Front 15

sensory pathways

Back 15

ascending pathways

nerve signals from sensory receptors ascending to brain

Front 16

motor pathways

Back 16

descending pathways

nerve signals from brain to muscles or glands

Front 17

contralateral

Back 17

relationship to opposite side

Front 18

ipsilateral

Back 18

relationship to same side

Front 19

decussate

Back 19

cross over from one side of the body to another

Front 20

Anterolateral pathway

Back 20

in anterior & lateral white funuculi

-primary neurons synapse on 2ndary neuron w/in posterior horns

related to crude touch, pressure, pain

(require responsive act, like an itch)

-2ndary neurons decussate though anterior white commisure (opposite side of brain)

synapse on tertiary neurons in thalamus

tertiaty neur conduct signals to primary somatosensory cortex

Front 21

Posterior funiculus-medial lemniscal pathway

Back 21

Projects through spinal cord, brainstem & thalamus

terminates w/in cerebral cortex

2 tracts: PF(spinal cord) & ML(brainstem)

sensory stimuli of proprioception - discriminative touch, precise pressure, vibration

primary neurons in spinal nerves, reach CNS, ascend with specific posterior funiculi, synapse on 2ndary neurons in medulla oblongata

tertiary neurons in thalamus-primary somatosensory cortex

Front 22

Spinocerebellar pathway

Back 22

conducts proprioceptive info to cerebellum

to coordinate body movements subconsciously

only primary and secondary neurons

anterior tract- signals from inferior trunk & lower lime

posterior tract-signals from lower limbs, part of trunk & upper limbs

Front 23

Tectospinal tracts

Back 23

part of medial pathway

conduct motor commands from inferior & superior colliculi

regulates positional changes in response to visual & auditory stimuli

Front 24

Nerve plexus

Back 24

network of interweaving anterior rami of spinal nerves

Front 25

Cervical nerve plexus

Back 25

C1-C4

innervate head, neck and shoulders

Phrenic Nerve: innervates diaphragm

Front 26

Brachial Plexus

Back 26

C5 - T1

Axillary Nerve: deltoid, teres minor

Median Nerve: muscles that flex wrist & fingers

Musculocutaneous Nerve: muscles that flex forearm, brachialis, biceps brachii

Radial Nerve: extensor muscles of forearm & wrist

Ulnar Nerve: muscles that flex wrist & digits, "funny bone"

Front 27

Lumbar Plexus

Back 27

L1-L4

Femoral Nerve: iliacus, quadriceps femoris, sartorius

Obturator Nerve: gracilis, adductor longus, adductor magnus

Front 28

Sacral Plexus

Back 28

L4-S4

gluteal region, pelvis, perineum, posterior thigh, almost all of leg & foot

Sciatic Nerve - splits into two

Tibial Nerve: hamstrings, gastrocnemius, soleus

Common Fibular Nerve: biceps femoris

Front 29

5 steps of the Reflec Arc

Back 29

1. stimulus activates a sensorial receptor

2. nerve signal travels through sensory neurons to CNS

3. info from nerve signal processed by interneurons

4. motor neuron transmits nerve signal to effector

5. effector responds to nerve signal from motor neuron

Front 30

Patellar Knee Reflex

Back 30

example of Stretch Reflex(monosynaptic-no interneurons)

1. tap on patellar ligament(stimulus)

2. muscle spindle in quads stretches (receptor)

3. femoral nerve (sensory nerve)

4. spinal cord L2-L4 (integration center)

5. femoral nerve (motor nerve)

6. quadriceps muscle contracts (effector 1)

7. extension of knee joint (response)

8. hamstrings stay relaxed, extension of leg (effector 2, reciprocal inhibition)

Front 31

Sympathetic Nerve Division

Back 31

Fight-or-flight

prepares body to cope with emergencies, release energy

increase alertness & metabolic activity in response to stressful situations

Front 32

Parasympathetic Nerve Division

Back 32

Resting and digesting system

maintain homeostasis when at rest, conserves energy, replenishes energy stores

Front 33

Effectors & Effects of Sympathetic Division

Back 33

1. Heart: increases heart rate & contraction

2. Blood vessels: vasodilation in skeletal muscles, vasoconstriction in other body parts

3. Digestive: viscous saliva, inhibits GI tract glands and motility, glycogenesis stimulated in liver

4. Respiratory: bronchodilation in lungs

5. Urinary: bladder relaxes, sphincter contracts,

6. Reproductive: stimulates penile ejaculation, vaginal contraction

7. Skin: arrector pili contracts, secretes sweat glands

8. Eye: pupils dilate, no effect to lacrimal/ciliary

9. Adipose Tissue: lipolysis(break down of fat)

10. Adrenal Medulla Gland: secretes catecholamines- epinephrine & noepinephrine

Front 34

Effectors & Effects of Parasympathetic Division

Back 34

1. Heart: decreases heart rate & contraction

2. Blood vessels: no effect in body

3. Digestive: watery saliva, stimulates GI tract glands & motility, glycogenesis stimulated in liver

4. Respiratory: bronchoconstriction

5. Urinary: contraction of bladder, sphincter relaxes

6. Reproductive: stimulates erection & gland secretion

7. Skin: no effect

8. Eye: constricts pupil, lacrimal secretion, ciliary muscle contract for near vision

9./10. - adipose/adrenal muscle gland: no effect

Front 35

Chemoreceptor

Back 35

detect chemicals involved in fluid

(from food, body fluids, inhaled air)

ex. taste buds on tongue, in blood vessels - monitor oxygen & carbon dioxide in blood)

Front 36

Nocioceptor

Back 36

respond to painful stimuli

-somatic: chemical, heat, mechanical damage to surface or skeletal muscles

-visceral: detect internal body damage; ex. oxygen deprivation, tissue trauma, overstretched smooth muscle

Front 37

Mechanoreceptors

Back 37

respond to touch, pressure, vibration and stretch

most cutaneous receptors

also located in the ear

Front 38

Photoreceptor

Back 38

located in the eye

detect changes in light intensity, color, movement

Front 39

Thermoreceptors

Back 39

respond to changes in temperature

present in both skin and hypothalamus

components of reflexes regulating body temp

Front 40

Baroreceptors

Back 40

detect changes in stretch or distension

branch repeatedly in vessel or organ walls

stimulated by changes in wall deformation

involved in regulation of blood pressure

Front 41

Olfactory receptor cells

Back 41

within olfactory epithelium

detecting odors

primary neuron in smell sensory pathway

contains olfactory hairs & olfactory nerves (CN I)

Front 42

Olfactory supporting cells

Back 42

within olfactory epithelium

sustaining receptors

Front 43

Olfactory basal cells

Back 43

within olfactory epithelium

replacing olfactory receptor cells every 40-60 days

Front 44

Olfactory Pathway

Back 44

action potential propagated through axon of olfactory receptor cells - causes release of neurotransmitter from terminal ends of axon (in old bulbs) - propagates signals through olfactory pathways/tracts - sensory information reaches: cerebral cortex (smell), hypothalamus (visceral reactions) and amygdala (odor recognition & emotional association)

Front 45

Vallate Papillae

Back 45

most taste buds housed here

arranged in inverted V on posterior dorsal tongue

least numerous, largest papillae

Front 46

Filiform Papillae

Back 46

short and spiked, on anterior 2/3s of tongue

do not house taste buds

Front 47

Cranial nerves involved in Taste

Back 47

CN VII - Facial (anterior 2/3s)

CN IX - Glossopharyngeal (posterior 1/3)

Front 48

Gustatory Pathway

Back 48

g proteins activated by sweet, bitter & umami stimuli - works thru 2nd messenger - cell depolarization - direct depolarization by salt & sour stimuli - action pot. & neurotransmitter release - stimulates sensory neuron to convey info to the brain (CN 8 & 9) - reaches nucleus solarium w/in medulla - triggers salivation & stomach secretions (or gag/vomiting w/ noxious stimuli) - relayed to thalamus - then relayed to gustatory cortex for conscious taste

Front 49

Tympanic Membrane

Back 49

B/w external and middle ears

Vibrates in response to sound

transfers sound energy to ossicles of middle ear

Front 50

Pharyngotympanic/Auditory Tube

Back 50

connects middle ear to nasopharynx

Equalizes pressure in middle ear cavity with external air pressure

Front 51

Vestibule

Back 51

central egg-shaped cavity of bony labyrinth

(internal ear)

containing 2 membrane sacs

Front 52

Saccule

Back 52

w/in the vestibule of internal ear

continuous with the cochlear duct

house equilibrium receptor regions

respond to gravity & changes in position of head

(Vertical Acceleration)

Front 53

Utricle

Back 53

w/in the vestibule of internal ear

continuous with semicircular canals

house equilibrium receptor regionsrespond to gravity & changes in position of head

(Horizontal Movement)

Front 54

Cranial nerve that is part of the auditory pathway

Back 54

CN VIII - Vestibulocochlear

Front 55

Names of the Ossicles of the Ear

Back 55

Malleus, Incus, Stapes

Front 56

Function of 2 muscles connecting to the Ossicles

Back 56

Tensor Tympani & Stapedius Muscles

contract reflexively in response to loud sounds to prevent damage to hearing receptors

Front 57

Spiral Organ

Back 57

sensory organ for hearing

contains hair cells that transmit sound vibrations to nerve fibers

Front 58

Cochlea

Back 58

spiral shape with 3 chambers

translates sound into nerve signals

Front 59

Nucleus in Thalamus that auditory pathway goes through

Back 59

Medial Geniculate Nucleus

Front 60

Nucleus in Thalamus that visual pathway goes through

Back 60

Lateral Geniculate Nucleus

Front 61

Rods

Back 61

Photoreceptor in the Retina

dim light/black & white

peripheral vision, no sharp images

Front 62

Cones

Back 62

Photoreceptor in the Retina

bright light

high-resolution color images/sharp

Front 63

Fovea Centralis

Back 63

tiny pit in center of macula with all cones

best vision

Front 64

Lens

Back 64

focuses incoming light onto the retina

transparent structure

Front 65

Cornea

Back 65

clear window through which light enters the eye

bends light as it enters the eye

Front 66

Iris

Back 66

contracts/dilates the pupil

Front 67

Retina

Back 67

internal layer of the eye wall containing 2 layers - pigmented and neural

neural layer contains photoreceptors

receives light that the lens has focused and converts that into neural signals

Front 68

Superior Rectus

Back 68

Elevates eye and turns it medially

Front 69

Inferior Rectus

Back 69

Depresses eye and turns it medially

Front 70

Cateracts

Back 70

clouding of the lens from aging, smoking, diabetes, sunlight exposure

crystallin proteins clump

vitamin c increases cataract formation

can be replaced surgically w/ artificial lens

Front 71

Upper Motor Neurons

Back 71

housed w/in cerebral cortex

synapse directly on lower m. n. or interneurons

excites or inhibits activity of lower m. n.

Front 72

Lower Motor Neurons

Back 72

housed w/in anterior horn of spinal cord or brainstem

exit CNS and project to skeletal muscle

always excitatory

Front 73

this happens in the optic chiasm in the visual pathway

Back 73

the optic nerves cross sides and become optic tracts

allows visual cortex to receive the same visual field from both eyes

Front 74

pathway of light in the eye

Back 74

light through the eye to the cornea -aqueous humor - through pupil -lens - vitreous humor - retina -optic nerve - brain - the occipital lobe

Front 75

auditory pathway

Back 75

pinna - auditory canal -tympani membrane - malleus,incus, and staples -oval window - cochlea (organ of corti) -vestibulocochlear nerve - brain - the temporal lobe