Quiz 9 anatomy, (spinal cord, reflexes, cranial nerves)

Dura mater (tough)—protection

Deep skull (what we peeled off sheep brain)

Arachnoid mater—protection

deep to dura mater, cerebrospinal fluid (CSF)

Pia mater:

deep to arachnoid mater, covers brain surface

Dural sinuses

Drains blood from brain, main artery: jugular vein

Meningitis

• Bacterial = antibiotics/vaccine

• Viral is more deadly (more pressure on the brain)

Microglia:

White blood cells = remove pathogens, dead cells

Cerebrospinal fluid

Buoyancy, surrounds brain, spinal tap = diagnose infections (diagnose meningitis, only in lower vertebra)

Blood brain barrier (BBB)

• BBB = Astrocytes (cells that make it up)

• Astrocytes wrap around blood vessels in brain to prevent pathogens from getting to neurons 

Neuroglia 

• Can divide (mitosis)

• Brain cancer caused by neuroglia, called gliomas

Brain bleeding

 puts pressure on neurons, kills neurons

PNS

nervous system

CNS

brain + spinal cord

Somatic sensory division

• Afferent to CNS (info is going to CNS)

• Skin, muscles, joint

• Ex: itch

Visceral--deep to muscles--sensory division 

 Afferent to CNS (visceral organs)

Somatic motor division

• Efferent to PNS (info goes opposite direction)

• skeletal muscle

Mixed nerves

• Carries sensory + motor info (afferent and efferent)

Cranial nerves (12)

• PNS nerves attach to brainstem

Spinal nerves (31)

PNS nerves attached to spinal cord

L1

where the spinal cord ends

Breathing=connects medulla oblongata to the diaphragm

• Hiccups: when we eat too fast, diaphragm spasms, we hiccup

Cranial nerves types

sensory, motor, mixed

Olfactory I, connects nose to…

• Temporal lobe

• Limbic systems

• Smell: strongest sense in memory

• Abnormal = anosmia
  SENSORY

Optic II, connects eyes to…

• Superior colliculi

• Occipital lobe

• Vision 

• Abnormal = blindness

• SENSORY

Vestibulocochlear

• Inferior colliculi

• Temporal lobe

• Balance and hearing

• Abnormalities = Ataxia, Deafness

SENSORY

Oculomotor

• Midbrain

• Pupil constriction

• Abnormal = pupil dilation

MOTOR

Trochlear

• Midbrain

• Symmetrical eye movement

• Abnormal = Nystagmus (eyes skip back and forth)

MOTOR

Abducens

• Pons

• Symmetrical eye movement

• Abnormal = eye deviates to middle side (toward nose)

MOTOR

Accessory

• Medulla oblongata

• Affects trapezius and sternocleidomastoid

• Contraction of these muscles

• Abnormal = weak or no contractions

MOTOR

Hypoglossal

• Medulla oblongata

• Tongue movements

• Food speech, manipulation, swallowing

MOTOR

Trigeminal

• midbrain/pons

• Sensory-face

• Motor-masticulation (chewing)

MIXED

Facial

• Medulla oblongata

• Taste = anterior ⅖ of tongue

• Facial expression muscles

MIXED

glossopharyngeal

• Medulla oblongata

• Taste = posterior ⅓ of tongue

• Swallowing + gag reflux

• Swallowing = pharynx (funnel in back of throat)

MIXED

vagus

• Medulla oblongata

• Visceral motor = larynx, heart, digestive tract

MIXED

Lateral gray horn (visceral motor)

Dorsal gray horn (sensory), afferent

Ventral gray horn (somatic motor)

polio

Dorsal root ganglion

stores viruses (herpes), efferent (motor)

Effector

goes to internal organs, leads to target organs (where symptoms appear)

Muscle spindle

Stretch receptors in skeletal muscles (excitatory- once stimuli will have reaction)

Golgi tendon organ

Stretch receptor in tendons (inhibitory- tells muscles to relax)

Monosynaptic reflex

1 synapse = very fast

Fast = stretch reflexes (involves 2 neurons)

Polysynaptic reflex

Involves 3+ neurons, a little slower

Flexion (withdrawal) reflex (pulls away from pain)

• Pain (polysynaptic)

• Neuron travels to the brain so you remember pain

Crossed extension reflex

• Involves both sides of the body (polysynaptic)

• Ex: pulling away leg + keeping balance w the other

Peripheral neuropathy

• Neuralgia, nerve pain

• Palsies: (nerves get pinched, affects functions)