Anatomy Final ((Special Senses And Nerve Part 4)

Front 1

Central nervous system 2 subdivsions

Back 1

1. Somatic (effector + lower motor neurons)

2. Autonomic (parasympathetic and sympathetic)

Front 2

Lower motor neuron(somatic)

Back 2

Single multipolar neuron

-cell body in ventral horn of spinal cord

- axon to effector

Or

- cell body in brain steam

- axon to effector

Front 3

Autonomic neurons

Back 3

1) preganglionic neuron

- myelinated

-cell body in brain stem or lateral horn

2) postganglionic neuron

- unmyelinated

- cell body in autonomic ganglion (PNS)

Front 4

Difference in preganlionic neurons in parasympatic NS and sympaticNS

Back 4

PSNS = Lateral horn (T1-L2) automatic

SNS = Brain stem (S3-S4) conscious

Front 5

Difference in parasympathetic and sympathetic ganglia

Back 5

PSNS = terminal at effector

SNS = trunk (either side of vert. Column) OR collateral (front of vert. Column)

Front 6

Differnce in postganglionic neurons (PSNS and SNS)

Back 6

PSNS = long axons

SNS = short axons

Front 7

Where do nerves exist the CNS in PSNS and SNS

Back 7

PSNS = mainly via Vagus (cranial nerve 10)

SNS = mainly thoracic nerves

Front 8

Ascending spinal pathways (sensory)

Back 8

1. First order neurons

- unipolar

- signal from receptor to dorsal horn/medulla)

2. Second order neurons

- interneruons and multipolar

- cell body in dorsal horn/medulla

3. Third order neurons

- interneruons and mutlipolar

- cell body in thalamus

- impulses to postcentral gyrus

Front 9

Ascending spinal tract

Back 9

Formed by first or second order neurons

All pathways named by their location of the tracts

Front 10

Dorsal column tract

Back 10

Sensation can be precisely located (touch)

Receptors = free nerve endings, meissner's, ect.

Front 11

Spinothalamic tract

Back 11

Non specific, difficult to localize

Receptors = temperature, pain

Front 12

Spinalcerebellar tracts

Back 12

Spinal cord - cerebellum

Receptors = proprioceptors

2nd order neurons directly to cerebellum (no conscious perception)

Front 13

Somatic descending pathways

Back 13

Conduct impulses from brain to effector

1. Upper motor neurons (interneurons)

- cell body in correct or brainstem nuceli

2. Lower motor neurons (motor neurons)

- cell body in ventral horn, axons at effector

Front 14

Descending spinal tracts

Back 14

Corticospinal tract (brain - spine)

- cell bodies in cerebral cortext

- tracts decussate medulla

(Finer motor novement)

Indirect tracts

- cell bodies in brainstem nucli

- receives impulse from motor cortex (deals with things like your balance shifting as you grab a pencil)

Front 15

3 layers if eye

Back 15

1. Fibrous tunic (superfical)

2. Vascular tunic

3. Nervous tunic (retina/deep)

Front 16

Parts of fibrous tunic of eye

Back 16

1. Sclera (white) avascular

2. Cornea (transparent) avascular

3. Conjunctiva (covers front of sclera) vascular mucous membrane

Front 17

Vascular tunic parts

Back 17

1. Choroid (posterior)

- vascular, contain melanin

2. Ciliary body (anterior)

- focus lens

3. Pupil

- hole in iris

Front 18

Nervous tunic (4)

Back 18

1.Outer pigmented layer

2. Inner neural layer (3 layers of

neurons)

3. Fovea centralis

4. Optic disc

Front 19

Inner neural layer

Back 19

Layer of Nervous tunic

1. Photoreceptors

-rods and cones

2. Bioplolar cells

3. Ganglion cells (form cranial nerve 2)

Front 20

Forvea centralis

Back 20

Where light is focused

Area of greatest visual activity

Only cones

Front 21

Optic disc

Back 21

Bind spot where blood vessels and optic nerve exit eye

Front 22

Lens of eye

Back 22

Avascular, transparent

Cataracts = clouding of lens

Front 23

Lens of eye

Back 23

Avascular, transparent

Cataracts = clouding of lens

Front 24

Anterior segment of eye

Back 24

Anterior to legs

Contains aqueous humour (fluid similar to plasma)

Front 25

Posterior segment

Back 25

Posterior to lens

Contains vitreous humor (gel like)

Front 26

External ear parts

Back 26

1. Auricle (pinna)

-elastic cartilage covered with skin

2. External auditory canal/meatus

3. Tympanic membrane (eardrum)

Front 27

Middle ear parta

Back 27

1. Eustachian tube/ pharyngotympabic tube

2. Ear ossicles

- Malleus (secured to tympanic membrane)

- incus

- stapes (transmits sound to inner ear via oval window)

Front 28

Inner ear (labyrinth)

Back 28

Detect sounds

Involved with equilibrium

Two parts

1. Bony labyrinth (tunnels in temporal bone

2. Membranous labyrinth - working part (protected by bony labyrinth

Front 29

Bony labyrinth parts

Back 29

1. Semicircular canals (equilibrium)

2. Vestibule (equilibrum)

3. Cochlea (hearing)

* contains perilymth

Front 30

Membranous labyrinth

Back 30

1. Semicircular ducts (inside canals)

2. Utricle and saccule (inside vestibule)

3. Cochlear duct (inside cochlea)

*contain endolymph

Front 31

Cochlea

Back 31

Coiled

3 coiled channels and 3 membranes

Front 32

Cochlea 3 channels

Back 32

1. Scala vestibule (upper, perilympth)

2. Scala tympani (lower, perilympth)

3. Cochlear duct (middle, endolymph)

Front 33

Cochlea 3 membranes

Back 33

1. Vestibular membrane (between cochlear duct and scala vestibule)

2. Basilar membrane (between cochlear duct and scala tympani)

3. Tectorial membrane (covers hair cells)

Front 34

Receptors in inner ear

Back 34

Hair cells that synapses with associated neurons

1. Send impulse to brain via vestisibule cranial nerve (nerve 8)

2. Are cilia that extend into endolymph

3. Embedded in tectorial membrane for stability

Front 35

Trigeminal nerve

Back 35

Chewing and general senses

Nerve 5

Front 36

Vestibulocochlear

Back 36

Sound and balance

Nerve 8

Front 37

Vagus

Back 37

Parasympathetic

Nerve 10

Front 38

What nervous system is the adrenal medulla

Back 38

Modified postganglionic neurons of SNS (sympathetic)