Bio 223 exam 4

4 regions of the brain

cerebrum, diencephalon, brainstem, cerebellum

Cerebrum functions

- performs higher mental functions

- interprets sensory stimuli

- plans & initiates movement

Hypoglossal nerve XII

- motor

- medulla oblongata

- tongue

- swallowing and food manipulation

Accessory Nerve XI

swallowing, head, neck, and shoulder movements (motor)

- medulla oblongata

Vagus Nerve X

sensory: origin: tongue neck & pharynx

destination: medulla oblongata

taste from posterior tongue & hunger sensation

Motor: origin: medulla oblongata

destination most/all vital organs

controls glands and smooth muscle

Glossopharynheal nerve IX

Sensory:

Origin: tongue & pharynx

Destination: cerebrum

Function: taste sensation from remaining 2/3 of the tongue

Motor:

origin: medulla oblongata

Destination: tongue & pharynx

Function: swallowing, salivation and gagging

Vestibulocochlear nerve VIII

Sensory

Origin: choclea within the ear

vestibule of ear

Destination: Cochlear nuclei & vestibular nuclei within medulla oblongata

Function: Hearing, balance and equilibrium

Facial nerve VII

Sensory

Origin: tongue eye palate and nasal cavity

Destination: Primary somatosensory cortex

Function: taste sensation from anterior 2/3 of tongue

Motor:

Origin: Pon

Destination: Facial muscles

Function: facial expression & tear/ salvia secretion

Abducens Nerve VI

Motor

Origin: Pons

Destination: Lateral rectus muscle

Function: lateral eye movements

Trigeminal nerve

sensory

Origin: within receptors of the face

Destination: Primary somatosensory context

Function: tactile sensations from face & head- sneeze reflex

Motor

Origin: pons

Destination: facial muscles

Function: to control chewing

Trochlear nerve IV

Motor

Origin: mesencephalon

Destination: Superior oblique muscle

Function: inferolateral eye movements

Oculomotor nerve III

Motor

Origin: mesencephalon of the brain

Destination: Intrisnic and extrinsic eye muscles

Function: moves eye up/down/medially

- visual accommadation

- opens eye life & pupil constriction

damage : dipolopia

Optic Nerve II

Sensory

Origin:retina of the eye

Destination:diencephalon

Function: Sense of vision

Olfactory nerve

sensory

Origin:originates on the olfactory epithelium

Destination:olfactory bulbs

Function: sense of smell

Damage: causes anosmia (lack of smell)

Shingles

viral disease that affects the peripheral nerves and causes blisters on the skin that follow the course of the affected nerves

Polio

A highly contagious infectious disease of the spinal cord caused by a filterable virus.

Multiple sclerosis

MS- autoimmune disorder inflammation of brain and spinal cord

Paraplegia

paralysis of the lower limbs

Quadriplegia

paralysis of all four limbs

Withdrawl Reflex

avoidance of painful stimuli

ex: touching a hot pan

Stretch reflex

muscle contracts in response to stretch

simplest reflex

Development reflex

Innate: @ birth

Acquired: Develop/change after birth

Response reflex

Somatic : contraction/relaxation of skeletal muscles

Autonomic: involves cardia muscle, smooth muscle or glands

Processing site reflex

Cranial : processed in the brain

Spinal: processed in spinal cord

Ipsilateral / contralateral reflex

Ips: receptor & effector on the same side of the body

Contr: receptor & effector on opposite sides of the body

Number of synapses

Monosynaptic: direct communication of sensory& motor neurons

Polysynaptic: interneurons present

Sacral plexus nerve

L4-S4

Sciatic nerve

Lumbar plexus

L1-L4

innervates anterloateral body wall, genitalia, parts of lower limb

Brachial plexus

C5-T1

ulnar nerve & median nerve

Cervical plexus

C1-C5

*phrenic nerve: innervates the diaphragm - breathing_

Peripheral neuropathies

regional losses of sensory and motor function most often resulting from nerve trauma or compression

Dermatome

Area of skin supplied by a single spinal nerve

Dorsal ramus

sensory & motor information to and from the back

Ventral ramus

sensory & motor information to and from the limbs

Ventral rami: merge to form the nerve plexuses

Gray ramus

carries unmyelinated postganglionic neurons

white ramus

carries myelinated preganglion neurons

Epineurium

surrounds the entire nerve

Perineurium

surrounds each fascicle

Endoneurium

surrounds the axons

Ventral root

motor

Dorsal root

sensory

Dorsal root ganglion

forms spinal nerve

unipolar neurons

Nerve tracts

Fasciculus

Ascending nerve tracts

Contains sensory information

Descending nerve tracts

Contains motor information

Anterior white commissure

site of crossing over axons

Anterior median fissure

wider groove on the anterior surface

Posterior median sulcus

Narrow groove on posterior surface

Posterior gray commissure

Sites of neuron/ axons crossing over

Central canal

contains the cerebral spinal fluid

Conus medullaris

tapered end of the spinal cord (L1-L2)

Cauda equina

collection of spinal nerves below the end of the spinal cord

Filum terminale

anchors spinal cord to coccyx

Cervical enlargement

where nerves supply upper limbs and enter+exit the spinal cord

Lumbar enlargement

nerves of pelvis and lower limbs

Epidural

injecting anesthesis into epidural space

Lumbar puncture

Inserting a needle into subrachnoid space

- below spinal cord so no risk of hitting the cord

- pulls out spinal fluid

- Checks for meningitis

Epidural space

space between the dura mater and the wall of the vertebral canal

Subdural space

space between dura mater and arachnoid mater

Subarachnoid space

arachnoid & pia mater contains CSF

Dura mater

Single layer

Arachnoid Mater

middle layer of the meninges

Pia mater

Bound to spinal cord surface

helps anchor spinal cord in place

Functions of CSF

buoyancy, protection, chemical stability

Choroid plexus

A highly vascular portion of the lining of the ventricles that secretes cerebrospinal fluid.

80% made in the lateral ventricles

3rd ventricle

diencephalon

Cerebral aqueduct

connects 3rd and 4th ventricles

4th ventricle

begins in the mesencephalon extends into medulla oblongata and becomes the central canal of spinal cord

Lateral ventricles

A set of paired ventricles lying within the cerebral hemispheres.

Interventricular foramen

connects lateral ventricles to third ventricle

Arachnoid mater

Thin & delicate layer

Arachnoid granulations

collections of arachnoid villi

returns CSF back into the blood

Pia mater

thin, delicate inner membrane of the meninges

bound by astrocytes

Subdural space

between the dura and arachnoid mater

subdural hematoma occurs here

what do the dural folds do?

stabilize and support the brain

Falax cerebri

separates cerebral hemispheres

Falx Cerebelli

separates the two hemispheres of the cerebellum

Tentorium cerebelli

separates cerebellum from cerebrum

Dura mater

TOugh leather layer and has 2 portions

Periosteal layer

fuse to the periosteum of skull

highly vascular

Meningeal layer

Inner layer

continuous with the dura mater of spinal cord

Avascular

Blood brain barrier

A mechanism that prevents certain molecule from entering the brain but allows others to cross

ASTROCYTES wrap around capillaries of the brain

water soluble yes can pass

Alpha waves

Healthy awake adults

Change to another wave when you fall asleep or start to concentrat

Beta waves

Seen when concentrating or during stress

normal wakening brain wave

Theta waves

common in kids

seen in adults when frusterated

Delta waves

common when sleeping at all ages

Cerebellar functions

1. Vestibulocerebellum

2. spinocerebellum

3. Cerebrocerebellum

Vestibulocerebellum

maintains muscle tone and postural muscles

Spinocerebellum

Enhances muscle tone and coordinates skilled, voluntary movements

Cerebrocerebellum

motor planning

Cerebellum

communicates with other regions of the CNS via cerebellar peduncles

Superior cerebellar peduncles

Connects mesencephalon, diencephalon and cerebrum

Middle cerebellar peduncles

Connects to pons

Inferior cerebellar peduncles

connect medulla oblongata and spinal cord

Arbor vitae

white mater in cerebellum

folia

folds in the cerebellum

Vermis

Seperates 2 hemispheres of cerebellum

Purkinje cells

Largest cells in cns

within the coretex of cerebellum

mainly acts as inhibiotry neuron

Anterior nucleus (hypo)

contains thirst centers

Arcuate nucleus

regulate appetite by controlling hunger sensations

produces hormones of the anterior pituitary gland