wgu s5: nervous system/brain

purpose games

  • cranial nerves

  • brain anatomy

  • eye anatomy'

  • ear

the somatic nervous system controls all voluntary movements in skeletal muscles

the enteric nervous system controls digestive tract

Medulla oblongata controls vital involuntary functions in the body

PONS bridges the nervous system together

White matter - axons

grey matter - synapses

Somatostatin - a neurotransmitter/hormone inhibits other hormones or neurotransmitters

  • Glial cells

    • Astrocytes are the most abundant glial cells, found in the central nervous system

    • Microglial cells are kind of thorny and also found in the CNS are your main defense against any invaders

    • Ependymal cells line the barriers of the brain and spinal cord and are what make and manage cerebrospinal fluid(CSF)

    • Oligodendrocytes… insulation/make myelin

Cranial nerves (sensory or motor or both)

  • 1. Olfactory nerve                                                                        S

  • 2. Optic nerve                                                                               S

  • 3. Oculomotor nerve - controls 4 of 6 eye muscles                       M

  • 4. Trochlear nerve - controls a single eye muscle(looking down)    M

  • 5. Trigeminal nerve - Largest, control face and jaw muscles            B

  • 6. Abducens - controls eye muscle looking side to side                    M

  • 7. Facial nerve - makes facial expressions possible                        B

  • 8. Auditory nerve                                                                              S

  • 9. Glossopharyngeal nerve - tongue                                                B

  • 10. Vagus nerve - heart and digestive tract                                        B

  • 11. Spinal accessory nerve - head and shoulder movement            M

  • 12. Hypoglossal - swallow and talk                                                    M

back-to-front

  • brainstem 

  • cerebellum 

  • diencephalon 

  • cerebrum

Thalamus:
Acts as a relay station. It sends most sensory information (touch, pain, temperature, etc.) to the correct parts of the cerebrum.

Hypothalamus:
Maintains homeostasis. It controls things like body temperature, hunger, thirst, and hormone release.

Epithalamus:
Part of the diencephalon that helps regulate sleep cycles and connects parts of the limbic system.

Pineal gland:
Produces the hormone melatonin, which helps control the sleep–wake cycle.

Pituitary gland:
Known as the “master gland.” It releases hormones that control other endocrine glands in the body.

carotid arteries and vertebral arteries. are the ones that supply the brain

Limbic system - emotional system

a nerve is just a bundle of axons

glucose is the only source of brain energy

Choroid plexus produces cerebrospinal fluid

gap junctions are never in skeletal muscle

The meninges are three protective layers of tissue that cover and protect the brain and     spinal cord. The three layers are the dura mater, arachnoid mater, and pia mater(DAP)

Eye ANATOMY is made of three layers

  • Fibrous

    • Sclera(back) - provides attachment for eye muscles

    • Cornea(avascular)

  • Vascular

    • Choroid(back)

    • Ciliary body - ring of muscle tissue that surrounds the lens

    • Iris - the colored part of your eye(made of smooth muscle) that contracts and expands to dilate or protect the pupil

      • Pupil

        • Lens - projects light onto the retina

  • Inner

    • Retina = nervous tissue responsible for photoreception

      • Photoreceptors

        • rods - color vision

        • cones - night vision and motion detection

TASTE

• Filiform papillae – most common; help with texture and movement of food (no taste buds)
• Fungiform papillae – mushroom-shaped
• Circumvallate papillae – large papillae at the back of the tongue
• Foliate papillae – folds on the sides of the tongue

EAR

External ear

  • Oracle/Pinna is the outermost and visible part of the ear that’s job is to catch sounds

  • Auditory canal

  • Eardrum (aka tympanic membrane)- catches those sound waves and vibrates

Middle ear

  • tympanic cavity - amplifies those waves - swings back and forth based on frequency and volume

    • Malleus(HAMMER)

    • incus(ANVIL)

    • stapes(STIRRUP)

oval window - separates mid and inner ear

Inner ear(labyrinth)

  • Cochlea

    • basilar membrane

    • hair cells - contain the mechanically gated potassium channels

    • organ of corti - contains the sensory cells that transduce sound vibration into electrical signals

  • Semicircular canals - balance and equilibrium

    • Vestibular apparatus - series of sacs and canals responsible for sensing movement and position of head

Myelin in the CNS - oligodendrocytes

Myelin in the PNS - Schwann cells

Microglia - CNS immune cells

Ependymal cells - make cerebrospinalfluid

Astrocytes are just glial cells

OLFACTORY (in temporal lobe)

  • Nerve fibers > nerves > bulb > tract