Test 1 YSK

Question 1

What is the afferent system?**

Answer 1

Afferent system (nerve cells that convey information from the periphery of the body to the CNS) first neurons to receive information) **

Question 2

What is the efferent system?*****

Answer 2

Efferent system (nerve cells form the CNS to muscles and glands, cause muscle to contract or muscles to secrete)

Question 3

What is the control center of the entire system?

Answer 3

Central nervous system is the control center for the entire system (he repeated this)

Question 4

What does the CNS consist of?

Answer 4

CNS consists of the brain and spinal cord, is enclosed in bone and wrapped in protective coverings (meninges) and fluid filled spaces

Question 5

PNS is formed by the what nerves?

Answer 5

PNS is formed by the cranial nerves and spinal nerves and may be divided into Afferent and Efferent system

Question 6

What does the somatic nervous system consist of?*****

Answer 6

Somatic nervous system (SNS): consists of efferent neurons that conduct impulses from the CNS to skeletal muscle tissue.* The SNS is under conscious control and therefore voluntary* (Under conscience control and is voluntary system)

Question 7

What is the autonomic nervous system?

Answer 7

Autonomic nervous system (ANS): consists of efferent neurons that conduct impulses from the CNS to smooth muscle tissue, cardiac muscle tissue, and glands. Produces responses in involuntary muscles and glands (typically involuntary control)

Question 8

Efferent system is subdivided into what two systems?

Answer 8

Somatic nervous system and autonomic nervous system

Question 9

What are the three components of the brainstem?

Answer 9

Midbrain, pons, and medulla oblingota

Question 10

The parasympathetic nervous system division, nerve fibers do what to end organ activity?**

Answer 10

Parasympathetic (craniosacral) nervous system division*****(carries nerve fibers that inhibit or decrease end organ activity)

Question 11

When does development of the nervous system begin?**

Answer 11

Development of the nervous system begins in the third week of gestation*****

Question 12

What are the two division of the ANS?

Answer 12

Sympathetic (thoracolumbar) nervous system division

Parasympathetic (craniosacral) nervous system division

Question 13

Pre embyotic stages
Embrotic stage
Fetal period

When are these stages or periods?

Answer 13

Pre embyotic stages ( 1 to 2 and half weeks)
Embrotic stage ( 2 and half weeks to 8 weeks)
Fetal period (eight weeks to birth)

Question 14

What myelin sheaths do??? ***

Answer 14

What myelin sheaths do **
Acts as insulator **
Speeds action velocity **

Question 15

What is an axon and what is myelin?**

Answer 15

Axon: single axon arises from most neurons. Conducts electrical signals from the initial segment to synaptic terminals. Many axons covered by myelin (myelin does two things, acts as an insulator and speeds up action velocity)*****

Question 16

What is a dendrite?

Answer 16

Dendrite: receive incoming synaptic information from the environment (sensory neurons) or other neurons (typically most neurons contain more than one dendrite)

Question 17

In the pre-embryonic period, blastocyst are differentiated into what three things?**

Answer 17

Trophectoderm (ultimately forms part of the membrane, comprising the fetal portion of the placenta)***
Inner cell mass (develops into the embyro)
Blastocoel (internal fluid filled cavity)

Question 18

Following implantation inner cell mass (develops into the embryo)*** of the blastocyst begins to differentiate into three primary germ layers from which all tissues and organs of the body will develop:

Answer 18

Following implantation inner cell mass (develops into the embryo)*** of the blastocyst begins to differentiate into three primary germ layers from which all tissues and organs of the body will develop:

Endoderm (becomes epithelial lining of the GI tract, Resp Tract, and a number of other organs)
Mesoderm (forms peritoneum, as well as muscle, bone, and connective tissue)
Ectoderm (develops into the nerves system and well as the skin)*******

Question 19

Development of the nervous system begins with a thickening of what?**

(Embryonic period)

Answer 19

Development of the nervous system** begins with a thickening of the ectoderm (neural plate) (the thickening of the plate begins in the third week of pregnancy)**

Plate folds inward (or invaginates on itself) and forms a longitudinal groove (known as a neural groove)

Question 20

Three kinds of layers for the neural tube are?*****

Answer 20

Three kinds of layers for the neural tube****

Marginal layer - eventually develop white and gray matter of the nervous system

Mantle layer – eventually develop white and gray matter of the nervous system

Ependimal layer – eventually will line the cerebral vesicles and central canal of the spinal cord**

Question 21

What are the Prosencephalon,
Mesencephalon, and
Rhombencephalon?**

Answer 21

Prosencephalon - forebrain
Mesencephalon – midbrain vesicle)*
Rhombencephalon – hine brain Vesicle

Question 22

What does the diencephalon develop into?

Answer 22

Diencephalon develops into the thalamus, hypothalamus, and pineal gland (part of thalamus but not part of the brain, small endocrine gland, produces melatonin)[he repeats this] (melatonin is for the modulation of sleep patterns)

Question 23

In the spinal cord, the Area of the neural tube posterior to the myelencephalon (he repeats this) thickens and gives rise to what?

Answer 23

Area of the neural tube posterior to the myelencephalon (he repeats this) thickens and gives rise to the spinal cord

Question 24

In the spinal cord, Cells of the wall that encloses the neural tube eventually differentiates into:****

Answer 24

Cells of the wall that encloses the neural tube eventually differentiates into:
Marginal layer (outer) develops into the white matter of the nerves system****** 
Mantle layer develops into the gray matter of the nervous system 
Ependymal layer (inner) eventually will line the cerebral vesicles and central canal of the spinal cord****
Conus medullaris is anchored by an extension of pia to coccyx****** this is the cranial mengial layers

Question 25

Cranial bones, what bones form the inferior sides of the cranium and part of the cranial floor?****

Answer 25

Temporal bones form inferior sides of cranium and part of the cranial floor****** contains carotid foramen, posterior to this is the jugular foramen (9 10 11 nerve pass through this)****

Question 26

Anterior fontanel is between what bones?****

Answer 26

Anterior (frontal) fontanel between perital bones****closes 18-24 months after birth Should be closed by 24 months following birth (he just repeated this a lot)

Question 27

The posterior fontanel is between what bones?****

Answer 27

Posterior (occipital) fontanel between ociipital and perital bones, closes 2 months after birth*** Should be closed by 24 months following birth (he just repeated this a lot)

Question 28

Three membranes envelope the brain: What are they?*****

Answer 28

``` Three membranes envelope the brain: Dura (outermost layer) Subdural space**** Arachnoid Subarachnoid space Pia (innermost layer) ```

Question 29

What are the two potential spaces between the membranes of the spinal cord?****

Answer 29

Spaces dura and arachnoid are seperated by the subdural space**** this contains only a few drops of CSF Arachnnoid and pia are seperated by subaracnoid space – contains CSF and arteries (he repeated these statements later on in the lecture as well

Question 30

What is the dura?

Answer 30

Dura | Tough fibrous structure containing an inner (meningeal) layer and outer (periosteal) layer (he just repeated this)

Question 31

Arachnoid granulations project into BLANK****

Answer 31

Arachnoid granulations project into the superior sagittal sinus****

Question 32

How much total blood volume circulates in the brain?***** How much total body oxygen does the brain consume????

Answer 32

CEREBRAL VASCULARIZATION ~ 18% of total blood volume circulates in the brain Brain is responsible for 20% of total body oxygen consumption*******most of this is to generate ATP to support neuronal electrical activity

Question 33

Constant flow of oxygen must be maintained: Loss of consciousness occurs when? Irreparable damage occurs when?

Answer 33

Constant flow of oxygen must be maintained: Loss of consciousness occurs in less than 15 seconds after the blood flow to the brain has stopped Irreparable damage occurs within 5 minutes

Question 34

What does the brain stem do?****

Answer 34

Relays motor and sensory impulses between other parts of the brain and spinal cord (some tracts decussate)****

Question 35

Vasomotor center regulates what?*****

Answer 35

Vasomotor center – regulate the diameter of blood vessels*******

Question 36

What does the Pons do?****

Answer 36

Relays impulses within the brain and between parts of the brain and the spinal cord******

Question 37

How many hemispheres does the cerebellum have?****

Answer 37

Second-largest portion of the brain, occupies inferior and posterior aspects of the cranial cavity Cerebellum has two hemispheres****you should know Falx cerebeli separates two cerebral hemispheres

Question 38

What are the three effects of the efferent nerves?

Answer 38

Efferent (have three effects) Motor ,contraction of muscles secretory, glands to secret inhibitory cause some organ systems to become less active

Question 39

Describe the afferent and efferent fibers?****

Answer 39

Nerves contain nerve fibers that conduct information to (afferent) or from (efferent) the CNS****** In general, efferent fibers convey information from the CNS to muscles and glands. These nerve cells are called efferent (motor) neurons Afferent fibers usually convey sensory stimuli from receptors in the periphery of the body to the CNS.****** These nerve cells are called afferent (sensory) neurons first cells to receive incoming information

Question 40

How many pairs of spinal nerves arise from the spinal cord?

Answer 40

There are 31 pairs of spinal nerves that arise from the spinal cord

Question 41

Where does the spinal cord end in the adult and peds?*****

Answer 41

Spinal cord ends at L1-L2 in adult***** also known as the conus medullarus Peds L3-L4*****

Question 42

What are the gray and white matter of the spina cord?

Answer 42

Gray matter; cross section of the spinal cord shows an H-shaped internal mass of gray matter surrounded by white matter White matter; composed of myelinated and unmyelinated nerve fibers. Fast-conducting myelinated fibers form bundles that ascend or descend varying distances

Question 43

What part of the spinal cord is considered motor, what is considered sensory?

Answer 43

Ventral (anterior) roots constitute motor outflow tracts from the spinal cord**** Dorsal (posterior) roots are largely sensory*****

Question 44

Where do nerve roots exit in the vertebral column?

Answer 44

Nerve roots exit from the vertebral column through intervertebral foramina small openings in the vertebral body

Question 45

How do cervical roots exit the spinal cord?

Answer 45

In the cervical spine, numbered roots exit vertebral column above corresponding vertebral body. The C8 root exits between vertebral bodies C7 and T1 In the lower portions of the spine, the numbered roots exit below the corresponding numbered vertebral body

Question 46

What are two important dermatomes?****

Answer 46

Dermatomes: (sensory) Sensory component of each spinal nerve distributed to dermatome (for the most part, well defined) Nipple T4 ****** Umbilicus T10 *******

Question 47

If a patient has a sensation at T4, the motor and sympathetic components are where?

Answer 47

Motor is two lower Sympathetic is two levels higher T1-T4 is the cardiac accelerators

Question 48

Where is the sacral plexus formed?*****

Answer 48

SACRAL PLEXUS Formed by spinal nerves L4-L5 and S1-S4 Supplies the buttocks, perineum, and lower extremities***** Foot drop is when we see damage here

Question 49

What is the saying for the 12 cranial nerves, to determine if it is sensory motor or both?*****

Answer 49

Sesory*** Motor** Both** Some say marry money but my brother says big boobs marry money*****

Question 50

Which nerves are both motor and sensory?*****

Answer 50

5 7 9 10 are mixed*******

Question 51

Which nerves have sensory input for smell vision and hearing?

Answer 51

1 2 8 sensory input smell vision and hearing

Question 52

Which nerves care parasympathetic fibers?

Answer 52

3 7 9 10 carry parasymthatic fibers

Question 53

Which nerves control eye movement and pupillary constriction???****

Answer 53

3 4 6 – control eye movement and pupillary constriction*********

Question 54

Which nerves are purely motor?

Answer 54

11 and 12 are purely motor (muscle of the tounge, trapezis, stenorcloemasotid)

Question 55

What supplies the occipital lobes and brain stem???***

Answer 55

Two vertebral arteries (arising from the subclavian arteries) join to form the basilar artery (circle of willis) which gives rise to the posterior cerebral artery; supplying occipital lobes and brain stem*****

Question 56

What is the circle of willis?*****

Answer 56

Circle of Willis is a confluence of vessels that gives rise to all major cerebral arteries** (major advantage of the circle of willis is collateral flow, this gives rises to all the major arteries) It is fed by the paired internal carotid arteries and the basilar artery*** When the circle is complete, it contains a posterior communicating artery on each side and an anterior communicating artery*** Each major artery supplies a certain territory*** Sudden occlusion affects its territory immediately, sometimes irreversibly***

Question 57

Total cerebral blood is how much of cardiac output?***

Answer 57

Total cerebral blood flow is 15-20% of cardiac output**** 750ml/min

Question 58

What is normal CPP???****

Answer 58

CPP = MAP – ICP | CPP is normally 80 – 100 mmHg***** primary dependent on MAP, ICP is normally lower than 10

Question 59

When can you get slowing in the EEG, flat EEG, or irreversible damage? These are associated with what readings of CPP.

Answer 59

CPP less than 50 will have a slowing in the EEG (he repeats this) CPP between 25-40 will correspond to a flat EEG (he repeats this) Sustained CPP less than 25 mmHg results in irreversible damage

Question 60

What is cerebral blood flow? normal between MAP of?

Answer 60

Cerebral blood flow remains nearly constant between MAP of 60 – 160 mmHg

Question 61

CBF directly proportionate to what??***

Answer 61

CBF directly proportionate to PaCO2**** If we increase PaCO2, we will increase cerebral blood flow, if we decrease this we will decrease cerebral blood flow

Question 62

What can enter the brain freely and what substances penetrate the brain poorly?****

Answer 62

Carbon dioxide, oxygen, and lipid-soluble substances freely enter the brain, whereas most ions, proteins, and large substances penetrate poorly******

Question 63

What does acute hypertonicity of plasma result in? in regards to the BBB.****

Answer 63

Acute hypertonicity of plasma results in net movement of water out of the brain, while acute hypotonicity of plasma results in a net movement of water into the brain*****(when we give mannitol we increase the tonicity, this will draw the fluid out of the brain) (any underdeveloped BBB this will prob last longer, such as in neonates and for elderly due to degernative states)

Question 64

High or low temp can stabilize the BBB?****

Answer 64

Hypothermia stabilizes the blood-brain barrier*** due to a decrease in arterial co2….decrease cerebral blood blow, which will over decrease blood flow)

Question 65

Where is the CSF found?****

Answer 65

CSF found in cerebral ventricles and cisterns and in subarachnoid space surrounding brain and spinal cord***

Question 66

Do brains have lymphatics? | Can the brain accommodate for increase volume?*****

Answer 66

Brain does not have lymphatics Due to its rigid structure the skull can not accommodate an increase volume without increase pressure especially after the age of 2*******************

Question 67

what is total CSF volume? How much is produced daily? What is normal production hr?******

Answer 67

CSF VOLUME In adults, total volume of CSF in all spaces combined is normally about 150 mL**** Between 400–500 mL of CSF is produced and reabsorbed daily**** Normal production is about 21 ml per out**** 0.35 ml/ min

Question 68

Where is CSF formed?****

Answer 68

CSF formed primarily by the choroid plexuses of the cerebral ventricles*****

Question 69

What are factors that decrease CSF production???*****

Answer 69

``` Factors that decrease CSF production:** Carbonic anhydrase inhibitors** Corticosteroids** Spironolactone** Furosemide** Isoflurane** Vasoconstrictors** ```

Question 70

What is the CSF flow??****

Answer 70

CSF flows from lateral ventricles through interventricular foramina (of Monro), into third ventricle, through cerebral aqueduct (of Sylvius), into fourth ventricle, through median aperture (foramen of Magendie) and lateral apertures (foramina of Luschka) into cisterna magna. CSF enters subarachnoid space, circulating around brain and spinal cord before being absorbed in arachnoid granulations over cerebral hemispheres

Question 71

CSF absorption is directly proportionate to BLANK and Inversely proportionate to BLACK*******

Answer 71

Absorption directly proportionate to ICP and inversely proportionate to cerebral venous pressure***** Most of the CSF with be absorbed in the superior sagittal sinus Entire CSF volume will be replaced every 3-4hrs

Question 72

Which type of hydrocephalus occurs more frequently?****

Answer 72

Noncommunicating (obstructive) hydrocephalus occurs more frequently****

Question 73

What is communicating hydrocephalus??***

Answer 73

Communicating hydrocephalus; obstruction is in subarchnoid space due to thickening of the arachnoid with resultant block of return-flow channels*****