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Flashcards in Exam 2 Deck (45)
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1
Q

Arteries if the forebrian

A

Anterior cerebral artery—
Middle cerebral artery—- branches of the internal carotid artery
Posterior cerebral artery– (Gets blood from vertebral artery too)

2
Q

Anterior Cerebral Artery

A

Supplies most of the medial brain

Arches over the corpus callosum

3
Q

Middle Cerebral Artery

A

Biggest of the 3
Receives 80% of the internal carotid blood flow
Located along the lateral fissure
2 branches: upper (frontal & parietal) and lower ( temporal & occipital)
Supplies blood to 2/3 of the lateral surface
Lateral striated arteries –> lesion pyramidal tract fibers @ internal capsule.

4
Q

Posterior Cerebral Artery

A
25% of the blood flow comes from the internal carotid artery.
Other 75% comes from vertebral artery
Supplies occipital (medial part) and temporal (inferior part) lobes.
5
Q

Blood supply to the brain

Vertebral Artery

A

Posterior inferior cerebellar artery- lateral side of the medulla
Anterior spinal artery- ventral and medial aspects of the medulla
Posterior spinal artery- dorsal and medial aspects of the medulla

6
Q

Blood supply to the brain

Anterior Inferior Cerebellar Artery

A

Supplies the lateral sides of the pons and the inner ear ( artery it the inner ear, labyrinthine artery)

7
Q

Blood supply to the brain

Pontine

A

Small and striated

Supplies midpons

8
Q

Blood supply to the brain

Posterior Cerebral

A

Supplies the midbrain

9
Q

Venous Drainage

Superficial

A

Superior brain-superior sagittal sinus
Middle brain-cavernous sinus
Inferior brain-transverse sinus

10
Q

Venus Drainage

Deep

A

Great cerebral vein of Galen

11
Q

Regulation of blood flow

A

Auto-regulation:

  • H+ concentration
  • intraluminar pressure
12
Q

Meninges

A

Dura mater
Arachnoid membrane
Pia mater

Difference in brain and vertebral canal

13
Q

Cranial dura

A
Two layers:
Periosteal layer-rich blood supply
Meningeal layer-no vascular supply 
Potential space - located inbetween the two layers
Innervated by Trigeminal nerve c1-c3
14
Q

Folds of the Meningeal layer

A
Falx Cerebri (longitudinal fissure)
Tentorium Cerebelli
Falx Cerebelli (separating the cerebellum)
15
Q

Cranial arachnoid

A
Space between dura and arachnoid = subdural space
Arachnoid trabeculae suspends the brain in the CSF
Arachnoid cisterns (found near sinuses, pouches)
16
Q

Arachnoid granulation

A

CSF passes through the sinuses (helps get ride of old CSF)

17
Q

Cranial pia

A

Follows contours of the brain (right up against the brain! big space between arachnoid and pia)

18
Q

Spinal dura

A

One layer
Epidural fat and a plexus of veins separates intro the vertebral periosteum.
Ends at S2
Coccygeal ligament ( filum terminale externa) anchors it to periosteum of cx1 and cx2

19
Q

Spinal arachnoid

A

Potential subdural space
Trabeculae suspends the spinal cord
Lumbar cistern L2-S2 ( pouch, elongated roots, cauda equina found within

20
Q

Spinal pia

A

Filum terminale
21 (pairs) denticulate ligaments attach to dura from foramen magnum to below tv12
Pia is tightly attached to spinal cord as it is in the brain
Extention-filum terminale interna, has pia and dura inside the dural sac, thicker.

21
Q

Dural sinuses

A
Lined with endothelium
No valves 
Collects blood from brain and emissary veins
Collects CSF from subarachnoid space 
Drains into the internal jugular vein
Carry deoxygenated blood
22
Q

Anterior inferior sinuses

A

Cavernous - sellar tursica,surround pituitary gland
Sphenoparietal - less wing of sphenoid bone
Superior petrosal
Inferior petrosal
Basilar plexus - lies along basic skull, clivous

23
Q

Posterior superior sinuses

A

Superior sagittal
Inferior sagittal Both longitudinal fissure
Straight - runs bw tentorium falx Cerebelli
Transverse - runs in sigmoid sinus
Sigmoid
Confluence - all sinuses come together here, creating a whirlpool. Sucks the blood up by creating a vacuum.

24
Q

Cerebral spinal fluid

A

Formed by the choroid plexus
- 14-35ml per hour
- 800 ml per day
- 150 ml at any given moment
High sodium, potassium, and chloride
Low in protein, lymphocytes, and epitheliod cells
Cushions the brain and removes waste products

25
Q

Ventricles

A
Lateral ventricles (connected through 3rd ven. Through interventricular foramen. 4th bw pons and cerebellum connected to 3rd ven. Through cerebral aqueduct.
- anterior horn-frontal lobe
- posterior horn-occipital lobe
- body-parietal lobe
- inferior horn-temporal lobe
Interventricular foramen
3rd ventricle
Cerebral aqueduct
4th ventricle
Central canal
26
Q

Sensory unit

A

Stem fiber (axon) and all of its endings (receptors)
Receptive field
- territory from which a sensory unit can be excited
- not the same as a dermatome!!

27
Q

Dermatome

A

Strip of skin Innervated by a single spinal nerve

Large amount of overlap by adjacent, small amount of overlap by non-adjacent, more neurons

28
Q

Sensory transduction

A

The transformation of a stimulus into an electrical signal

29
Q

Rapid adapting receptors phasic

A

(Bursting) respond quickly and maximally

Will stop responding even when stimulus continues.

30
Q

Slowly adapting receptors tonic

A

(Continuous) continue to respond to stimulus

Don’t react as strongly as fast but stimulus is still there

31
Q

Classification by source

A

Exteroceptor-stimuli from outside environment
Interoceptor-stimuli from internal environment
Proprioceptors- position sense (body position, tense on joints and muscles

32
Q

Classification by function (modality)

A

Nociceptor - pain (noctious)
Thermoceptor - temperature
Mechanoceptor - “physical deformation”

33
Q

Receptor types

No capsules

A
Free endings
- pain 
- temperature
- SA (slow adapting)
Follicular ( wraps around follicule, responds to movement of hair)
- touch (hair)
- RA ( rapid adapting)
Merkel cell (hold on to something or pressure)
- edge detector
- SA 
Specialized endothelial cells
34
Q

Receptor types

Capsules

A
Encapsulated
- meissner's 
 RA
Ruffini's (deeper, responds to outside forces against you)
- shearing (drag)
- SA
Pacinian (largest receptor visible w/out magnification, deep, several layers of CT)
- vibration
- RA
35
Q

Sensory inflammation of joints, muscles, and skin are…

A

Integrated in the parietal lobe ( major association of awareness)

36
Q

The brain…

A

Comprises 2% of the entire body weight
Utilizes 20% of the body’s O2
17% of the cardiac output goes there.

37
Q

Reticular formation

A

Net of fibers
Phylogenetically old
- poorly organized
- survival

38
Q

Cellular regions

A
Raphe (seam)
- midline (median) --> cells secret serotonin (5-HT)
Mangocellular/Gigntocellular (big/really big)
- paramedian - surrounding the Raphe 
- central - center of 1/2 brainstem
- medial - center of 1/2 brainstem
Parvocellular (small)
- lateral
39
Q

Neurotransmitter

Acetylcholine

A

motor system, excitatory

  • influences movement
  • peduncleopontine -> found here
40
Q

Neurotransmitters

Noadrenergic/Norepinephrine

A

Awareness
- locus coeruleus -> found here
Nucleus of the solitary tract -> found in medulla, sensory area, viseral control
Ven trilateral medulla

41
Q

Neurotransmitter

Dopamine

A

Motivation
Decision making
Ventral tegmental area -> found here
* precurserto norepinephrine

42
Q

Neurotransmitter

Serotonin

A

Awareness/arousal
Mood
Decrease pain
Raphe nucleus -> found here

43
Q

Goes everywhere, does everything

A

Afferent, efferent, autonomic, endocrine, awareness, biorhythms, motor, sensory, limbic, association

44
Q

Functions

A
Levels of awareness
- ARAS (ascending reticular activation system)
  > acoustic startle responses
  > protects from injury by a predator
Modulate muscle tone
Respiration and cardiac rhythm
Pain suppression -> Raphe nucleus helps this
Emotion of pain (limbic)
45
Q

Reticulospinal tract

A

Medullary -> lateral! movements of limbs
- reticulospinal tract
Pontine reticulospinal tract -> medial affect trunk
Affect motor neurons
* sensory comes in dorsal horn -> blocked by Raphe nucleus