what nervous system are the cranial nerves part of?
Peripheral nervous system
Where are the cranial nerves attached to?
Where do most cranial nerves begin or end? What are the exceptions?
Brainstem CNI and CNII
What are the functions of most cranial nerves? What is the exception?
mostly localized to structures in the head and neck exception: CN X (vagus nerve)
CN I : brain attachment: cranial opening: Notes on pathway:
CN I : olfactory nerve brain attachment: olfactory bulbs of frontal lobe cranial opening: cribrifrom plate of ethmoid Notes on pathway: receptors located in nasal epithelium, neurons travel through cribriform plate of the ethmoid bone, located in roof of nasal cavity, to reach olfactory bulbs under frontal lobes of cerebrum. Not attached to brainstem!!
CN X : brain attachment: cranial opening: Notes on pathway:
CN X : vagus brain attachment: brainstem cranial opening: jugular foramen Notes on pathway: nerves originate in brainstem and exit via jugular foramen. nerve has wide distribution in head, descends along the carotid artery and internal jugular vein
CNI GSA: smell GSE: NA GVE: NA GVA: NA Test: can you smell? Damage: loss of smell
CN II : brain attachment: cranial opening: Notes on pathway:
optic nerve brain attachment: thalamus of diencephalon cranial opening: optic canal (sphenoid) Notes on pathway:receptors located in retina of eyes; neurons travel via optic nerves through optic canal in sephnoid bone
CN III: Oculomotor Nerve GSA: NA GSE: Eye movements to 4 of 6 extrinsic mm GVE: parasympathetic to intrinsic eye musles that do pupil constriction and change lens shape GVA: NA Test: follow finger in H shape with eyes Damage: problems with light reflex (always dilated) double vision
CN IV : brain attachment: cranial opening: Notes on pathway:
CN IV : trochlear nerve brain attachment: brainstem cranial opening: superior orbital fissure Notes on pathway: originate in midbrain and travel to the eye orbit exiting the cranial vault via the superior orbital fissure in the sphenoid bone
CN IV: Trochlear Nerve GSA: NA GSE: eye movement 1 of 6 extrinsic mm GVE: NA GVA: NA Test: follow finger in H shape with eyes Damage: eye movement, could have lazy eye
CN V V1 : brain attachment: cranial opening: Notes on pathway:
CN V : Trigeminal nerve brain attachment: brainstem cranial opening: superior orbital fissure, and divides within the eye orbit Notes on pathway: sensory axons enter cranium via superior orbital fissure and travel to trigerminal ganglion
CN V V1: Ophthalmic Division of Trigeminal Nerve GSA: somatic sensory nerve from areas around orbit, the forehead, anterior scalp, upper nasal cavity GSE: NA GVE: NA GVA: NA Test: Touch area and feel it Damage: loss of sensation to area
CN V V2 : brain attachment: cranial opening: Notes on pathway:
CN V V2 : maxillary division of trigeminal nerve brain attachment: brainstem cranial opening: foramen rotundum Notes on pathway: sensory axons enter cranium via foramen rotundum and travel to trigeminal ganglion before entering pons
CN__: Maxillary Division of Trigeminal Nerve GSA: somatic sensory nerve from area of mid-face (lower eyelid, nasal cavity, nose, cheecks, upper teeth and gums, upper lip and palate) GSE: NA GVE: NA GVA: NA Test: touching area and feeling it Damage: loss of sensation in area
CN V V3 : brain attachment: cranial opening: Notes on pathway:
CN V V3 : Mandibular division of trigeminal nerve brain attachment: brainstem cranial opening: foramen ovale, branches into infratemporal fossa Notes on pathway: motor axons leave brainstem and exit cranium via foramen ovale to supply muslces. Sensory fibers travel through foramen ovale to trigeminal ganglion before entering brainstem
CN__: Mandibular Division of Trigeminal Nerve GSA: somatic sensory from area of face including lower lip, teeth, gums and anterior 2/3 tongue GSE: somatic motor innervation to muscle of mastication GVE: NA GVA: NA Test: touching area and feeling it Damage: intense pain (skin on fire), could cause lock jaw
CN VI : brain attachment: cranial opening: Notes on pathway:
CN VI : abducens nerve brain attachment: brainstem cranial opening: superior orbital fissure Notes on pathway: nerves originate at brainstem and travel toward eye orbit exiting cranial vault via superior orbital fissue
CN VII Facial Nerve GSA: taste from anterior 2/3 tongue GSE: somatic motor to facial expression mm; parasympathetic motor to lacrimal and salivary glands GVE: NA GVA: NA Test: can you taste? Damage: paralysis of face, dry mouth
If you had Bell Palsy what CN would be damaged?
Facial Nerve Nerve VII
CN VIII : brain attachment: cranial opening: Notes on pathway:
CN VIII : vestibulocochlear brain attachment: brainstem cranial opening: internal auditory meatus, never exits skull Notes on pathway: nerve terminate in brainstem, travel from inner ear and do not leave skill.
CN IX: Glossopharyngeal Nerve GSA: sensory and pharynx and posterior 1/3, taste from posterior 1/3 tongue GSE: somatic motor to pharynx muscle GVE: parasympathetic visceral motor to parotid (salivary) gland GVA: visceral sensory from chemo and baroreceptors of carotid artery Test: sensory part of gag reflex Damage: dry mouth, loss of taste posterior 1/3 tongue
CN X: Vagus Nerve GSA: sensory from palate and larynx GSE: somatic motor to muscles of the palate, pharynx, and larynx GVE: parasympathetic visceral motor to pharynx, heart, lungs, and most of GI tract GVA: viscera sensory from thoracic and abdominoplevic organs Test: Say AHH, look at uvula, will go to normal side, Damage: voice impairment, difficulty swallowing
What is the motor part of gag reflex?
Vagus CN X
CN XI : brain attachment: cranial opening: Notes on pathway:
CN XI : spinal accessory nerve brain attachment: brainstem cranial opening: jugular foramen Notes on pathway: originate in brainstem and exit the cranium via jugular foramen. passes through SCM muscles and trapzius muscles
CN XI: Spinal Accessory Nerve GSA: NA GSE: somatic motor to sternocleidomastoid (SCM) and trapezius mm. GVE: NA GVA: NA Test: rotate head with force, shrug shoulders, use actions of muscles Damage: loss of motor movement to SCM and trap
CN XII : brain attachment: cranial opening: Notes on pathway:
CN XII : hypoglossal nerve brain attachment: brainstem cranial opening: hypoglossal canal Notes on pathway: originate in brainstem and exit via hypoglossal canal in occipital bone.
CN XII: Hypoglossal Nerve GSA: NA GSE: somatic motor to most extrinsic and intrinsic tongue muscles GVE: NA GVA: NA Test: have patient stick tongue out, center is no damage, it goes to the side OF the damage Damage: slurred speech, impaired speech
Where does the spinal cord begin? Is it continuous with what?
begins at foramen magnum It's continuous with medulla oblongata
What is the spinal cord continuous with
Where does the spinal cord end in the spine? Why?
Ends at level of L1 or L2 vertebra. Growth ends of spinal cord before growth of vertebral column stops
What is the tapered terminal portion of the spinal cord called?
What does the cauda equina look like? what is it comprised of?
resembles horse's tail extends inferiorly from the conus medullaris and comprised of the anterior and posterior roots from inferior spinal cord segments.
Where is spinal tap performed? why?
between L3 and L4 because spinal cord is not present so will not puncture it.
In a spinal tap where does the needle pierce and where does it get CSF from?
pierces dura and arachnoid layers. pushes aside fibers of the cauda equina and withdraws CSF from subarachnoid space
What is CSF analyzed for?
analyzed to detect viruses, bacteria, toxins, drugs, blood cells, glucose and protein levels, and CSF pressure
What is normal CSF like?
clear and odorless
Epidural block is injected in between what vertebrates?
injected through a catheter into the epidural space between L4 and L5
What does an epidural block do?
provides mainly sensory anesthesia
injected into epidural space in lumbar region before child birth
-between L2 and L3
-numbing of sensory nerves
-injected through a catheter into the EPIDURAL SPACE in lumbar region before childbirth, between spinous processes of L4 and L5.
-does NOT pass through the dura mater
Injected through a catheter into the epidural space in lumbar region before childbirth, typically between spinous processes L4 and L5
- Does not pass through the dura matter
Where is a spinal block injected to?
into subarachnoid space between L3 and L4.
What does a spinal block do?
provides motor and sensory anesthesia. works very quickly!
What is a spinal block used for?
surgical procedures below the level of umbilicus
needle injected into subarachnoid space, between L3 and L4
-pierces dura and arachnoid layers, pushes aside fibers of cauda equine as it enters the SUBARACHNOID SPACE
-used for surgical procedures below the umbilicus
Injected from a needle into the subarachnoid space, typically between spinous processes of L3 and L4
What does gray matter contain? Is there myelination
NO myelination contains cell bodies
What 3 components of spinal cord are made up of gray matter?
located between the distal radius and the scaphoid, lunate, and triquentrum
Where is the wrist joint located
between the distal radius and the scaphoid, lunate, and triquetrum
The proximal and distal radioulnar joints are what type of joints?
Where is the proximal radioulnar joint located between?
located between the head of the radius and the radial notch of the radius
near the elbow joint
Where is the distal radioulnar joint located between?
located between the ulna and the ulnar notch of the ulna.
near the wrist
What are the allowed voluntary motions of the proximal and distal radioulnar joints?
supination pronation proximal RU joint (head of radius spins) distal RU joint (radius rolls over the ulna)
muscles that move the scapula act on what joint?
muscles that move the scapula allow the scapula to do what motions? (6)
elevation- raise scapula (shrug shoulders) Depression- draws scapula inferiorly Upward rotation: turns the glenoid fossa so it faces upward downward rotation- turns glenoid fossa so it faces downward protraction- scapula slides forward retraction- brings medial borders of the scapulae closer together
What muscles move the scapula?
trapezius rhomboids levator scapulae pectoralis minor serratus anterior
the thickest layer of the heart wall. composed of cardiac muscle. thickest in the ventricles and thinnest in the atria
middle layer, cardiac muscle, thickest in the ventricles and thinnest in atria.
What is the endocardium?
inner layer of the heart wall. type of epithelial tissue known as endothelium. Lines the chambers of the heart and is continuous with the lining of the blood vessels
inner layer, type of epithelial tissue (endothelium). lines chambers of the heart and is continuous with lining of blood vessels that enter/exit the heart
What is the order of thickness of wall of the heart?
What is a sulcus?
Where is the atrioventricular groove?
between the atria and ventricles
What major structures are in the atrioventricular groove?
right and left coronary arteries and the coronary sinus
Where is the anterior interventricular groove?
between the right and left ventricles and on the anterior/sternocostal surface of the heart
What does the anterior interventricular groove contain?
anterior interventricular artery and the great cardiac vein
Where is the posterior interventricular groove located?
between the right and left ventricles on the posterior/inferior surface of the heart
What does the posterior interventricular groove contain?
posterior interventricular artery and the middle cardiac vein
What are the auricles?
expandable pouches of the right and left atria.
*only see anteriorly
expandable pouches of the left and right atria
What is pericarditis? What does it cause? What does it result in?
*inflammation of the pericardium * inflammataion causes the capillaries to become leaky resulting in fluid accumulation in pericardial fluid *if too much filling result is cardiac temponade= heart is unable to pump blood, leading to medical emergency resulting in heart failure and death
What is the general flow of blood in the heart?
deoxygenated blood enters the right atria--> tricuspid valve--> right ventricle--> semilunar valve--> lungs (becomes oxygenated)--> left atria --> bicuspid (mitral) valve--> left ventricle--> semilunar valve--> body --> now deoxygenated and cycle repeats!!
In relation to pressure, how to blood flow?
area of high pressure toward area of low pressure.
what causes pressure gradients in heart?
contraction of heart muscles
What is the function of heart valves?
prevent backflow of blood, this is called regurgiation
What are the two different types of valves in the heart?
antriventricular valves (atrium and ventricle)semilunar valves (RV and pulmonary trunk OR LV and aorta)
What makes up the antrioventricular valve in thee heart?
papillary muscle, chordae tendineae and cusp
What is the tricuspid valve between?
right antrioventricular valve. between R. atrium and R. ventricle
What is the mitral (bicuspid) valve between?
L. atrium and L. ventricle
The pulmonary valve is a ___ valve. It is between...
semilunar r. ventricle and pulmonary trunk
The aortic valve is a ___ valve. It is between...se
semilunar between left ventricle and aorta
What are the semilunar valves composed of?
ONLY CUSPS!NO MUSLCES!!!
How do heart valves work? (mechanism)
*pressure as blood moves 1. AV valves open before atria contract 2. AV valves are forced closed when ventricles are full of blood 3. papillary muscles contract prevent valve flaps from being pushed into atria 4. semilunar valves forced open wehn ventricles contract 5. semilunar valves are forced closed when ventricles relax and blood, the aorta nd the pulmonary trunk fills
In ventricle systole which valves are open? closed?
open: semilunar closed: AV
In ventricle diastole what valves are open? closed?
open: AVclosed: semilunar
What are the anatomical features of the right atrium?
*openings for SVC (superior vena cava), IVC (inferior vena cava), and coronary sinus *pectinate muscle *interatial septum - fossa ovalis
Clinical correlate: atrioseptal defect (ASD)what is it?
foramen ovaule doesn't fuse in infant. (can occur in adults, always have hole but get blood clot)the oxygenated and deoxygentated blood mix, this dilutes the oxygentaed blood. BLOOD GOES FROM L ATRIA TO R ATRRIA BECAUSE PRESSURE
What are the anatomical features of the right ventricle?
*trabeculae carneae * cusps of tricuspid *papillary muscles and chordae tendinea *pulmonary semilunar valves *interventricular septum
What are the anatomical features of the left atrium?
*openings for 4 pulmonary veins *pectinate muscles (auricle) *interarteral septum
What are the anatomical features of the left ventricle?
*trabeculae carneae*papillary muscles and chordae tendineae *interventricular septum *cusps of bicuspid valve
What wall is thicker the RV or LV? Why?
left ventricle, because has to generate higher pressure to push blood through the systemic circuit
Clinical correlate: ventriculoseptal defect (VSD) what is the problem? What is a sign?
allows blood to flow L to R, overworking R side of heart.*hole in interventricular septum *sign: large L-ventricle could be a sign
Is there more defects with mitral valve or tricuspid?
clinical correlate: mitral valve prolapse what is it? (associated with?) May cause...? Treatment?
*cusps bulge back into L. atrium *associated with heart murmur. *may cause: shortness of breath, dizziness, palpitations *if prolapse results in enlargement of LV or leakage of blood can be treated with prescriptions or surgery
Clinical correlate: mitral valve stenosis What is it?
What are causes in adults? kids?
*valve does not open fully and restricts blood flow into LV from LAadults: rheumatic fever (strep throat, scarlet fever); may not develope until 5-10 years after illness children: congential birth defect
Clinical correlate: ausculatationwhat is it?
listening to body sounds, usully with a stethoscope
Heart sounds:what is lub? what is dub?
lub: closing of the AV valves dub: closing of the semilunar valves
When listening to the heart, what is the surface location to hear the aortic valve?
Right 2nd intercostal space, near the sternum
When listening to the heart, what is the surface location to hear the pulmonary valve?
Left 2nd intercostal space near sternum
When listening to the heart, what is the surface location to hear the tricuspid valve?
left 4th intercostal space near sternum
When listening to the heart, what is the surface location to hear the mitral valve?
left 5th intercostal space in mid-clavicular plane
What is the nemonic to remember heart sound listening points?
All- aortic- 2nd right intercostal space
Physicians- pulmonary- 2nd left intercostal space
Teach- tricuspid- 4th left intercostal space
Medicine- mitral- 5th intercostal space in mid-clavicular plane
In the cardiac cycle, the heart muscles__ during systole.
in the cardiac cycle, the muscles ___ during diastole?
during the cardiac cycle, what contracts first? second?
first- both atria
second- both ventricles
what is myogentic conduction?
specialized cardiac muscle cells conduct and control the timing of spontaneously generated electrical currents.
Is there neural conduction in the heart?
What does the SA node determine?
Where is the SA node located in the heart?
upper wall of the right atrium near the entrance of the superior vena cava.
On its own, how many impulses does the SA node generate per minute?
Where is the AV node located in the heart?
lower part of interartrial septum near the opening of the right AV valve (tricuspid)
What does the AV node do?
delays the signal so the ventricles and atria do not contract at the same time
lower part of the interatrial septum near the opening of the right AV valve. delays signal
Where is the AV bundle (bundle of his) located?
in the upper part of the septum (intraventricular septum)
What route does the AV bundle provide?
route for an electrical impulse to travel from the atria to the ventricles
When the AV bundle splits, it forms what?
R and L bundle branches
Where are the R and L bundle branches located?
lower part of the interventricular septum
What do the r and l bundle branches carry?
electrical signals to the right and left ventricles
What do the R and L bunch branches from when they ramify (split)?
termial branches of the conducting system
How do electrical impulses travel through the heart? (mechanism)
SA node--> atria contract--> AV node-->AV bundle--> R and L bundle branches in interventricular septum--> purkinje fibers
Where is the cardiac plexus located?
on the pulmonary trunk and aortic arch
What does the cardiac plexus contain?
POSTganglionic sympathetic axons and PRE and POST-ganglionic parasympathetic axons, and GVA
Preganglionic sympathetic GVEs orginiate where?
The postganglionicsympathetic GVEs pass through what?
superior mediastinmun in rough to the heart and lungs
What is the effect of increased sympathetic GVE stimulation?
increased heart rate and force contraction and blood flow to heart muscle via coronary aa
What is it called if you have an increase heart rate?
parasympathetic innervation in the heart originates from what cranial nerve?
what happens to the heart if there is parasympathetic innervation?
decreased heart rate BUT NO EFFECT ON FORCE OF CONTRACTION
parasympathetic heart innervation
vagus nerve-PREgang fibers synapse in cardiac ganglia. parasymp stimulation decreases heart rate but has no effect on force of contraction. Bradycardia
What is it called if heart rate is slow?
What type of afferent innervation does the heart have?
What is the affect on the heart because there is no GSAs?
heart is insensitive to touch, cutting, hot/cold
In the heart, where are GVA receptors located? What are they they sensitive to?
located in the myocardium
ischemia (reduction of blood flow)
How do GVAs travel?
anti-parallel to sympathetic GVE pathways back to the upper thoracic spinal cord
What type of pain are GVAs involved in?
cardiac referred pain
GVAs carry visceral pain from ____ and back to__.
from myocaridal infarction (heart attack)
back to T1-T4/5
When having a heart attack, where might the brain interpret the pain being from?
What is the hollow central canal of blood vessels called?
lumen (blood is found in lumen)
What are the three concentric layers (tunics) of blood vessels?