Unit 2

Question 1

Brainstem

Answer 1

Extension of the spinal cord into the cortex
Connection between the spinal cord and the cortex – connects PNS with CNS
Contains most of the cranial nerves
3 parts (top down)
-midbrain
-pons
-medulla oblongata

Question 2

Corpora quadrigemina

Answer 2

the superior and inferior colliculi together they form the tectum or roof of the midbrain
Superior – a visual center
Inferior – Auditory Center - It acts as the channel for almost all auditory signals in the human body. Plays roles in signal integration, frequency recognition, and pitch discrimination.
-startle reflex

Question 3

Reticular Formation

Answer 3

contains nuclei throughout the brainstem and thalamus
integrates sensorimotor stimuli with thoughts and emotions
Responsible for regulating visceral, neuroendocrine (SLEEP WAKE CYCLE)–pineal gland, blood pressure and movement
Regulates respiration, swallowing, alertness
Damage = coma, ventilator dependency, death
-helps you to be ready
down the back side of the brainstem

Question 4

main functions of brainstem

Answer 4

Alertness
Arousal
Breathing
Blood pressure
Digestion
Heart rate
Controls reflexes:
-coughing, gagging, swallowing, vomiting, startle
Balance

Question 5

Midbrain Structures

Answer 5

Tectum
Tegmentum
Basis pedunculli-
The red nucleus and substantia nigra produce
dopamine for the basal ganglia if damaged
Parkinson’s disease may develop
looks like mickey mouse on scan

Question 6

tectum

Answer 6

makes a 3D map of the body in space

Question 7

Tegmentum

Answer 7

a nuclei center RED NUCLEOUS- big circles

Question 8

basis pendunculli

Answer 8

pyramidal tracts and substantia nigra–>(stripes on ears)

same as the crus cerebra (the ears)

Question 9

Pons

Answer 9

ALL Descending motor fibers
ALL Ascending sensory fibers
Cranial nerve nuclei
Transverse fibers that form the middle cerebellar peduncle
skull looking thing

Question 10

raphe nucleus

Answer 10

makes serratonin

in the pons

Question 11

lateral lemniscus

Answer 11

auditory information tract

Question 12

medial lemniscus

Answer 12

is a tract ofaxonsin thebrainstemthat carries information about sound from thecochlear nucleus to various brainstem nuclei and ultimately the contralateralinferior colliculusof themidbrain.
carrying deep touch, vibrational, and visceral pain information
Gracile Fasiculus – below t6- all sensations belly button down “feeling the grass between your toes”
Cuneate fasiculus – above t6 above belly button

Question 13

Medulla oblongata

Answer 13

decussation happens here, right before the brainstem becomes the spinal chord
Looks like a butterfly

Question 14

Neurons

Answer 14

generate impulses that are excitatory or inhibitory

Question 15

Neuroglia

Answer 15

‘glia’ support and protect nerve cells and help repair tissue
there are way more than neurons

Question 16

cell body

Answer 16

Nucleus– controlling center of the cell
Cytoplasm – Protein molecules + auqueous substance enclosed in cell membrane
There are many Organelles – subcellular units that synthesize and metabolize proteins

Question 17

know the organelles!

Answer 17

on worksheet

Question 18

metabolism

Answer 18

The chemical processes occurring within a living cell that are necessary for the maintenance of life. Substances are broken down to yield energy or are synthesized
Nerve cells have high metabolic activity– dependent upon glucose
Nerves manufacture own proteins which are packaged by golgi bodies and exported through microtubules OR incorporated into cell membrane

Question 19

Cytoskeleton

Answer 19

3 components that act together to give neurons their shape and create a roadway to proteins to be transported
Microtubules
Neurofilaments
Microfilaments
**Abnormalities in the cytoskeleton (plaques and tangles) do not allow proteins to travel and cause Alzheimer’s

Question 20

anterograde movement

Answer 20

from cell body to axon and dendrites

Question 21

retrograde

Answer 21

from axon or dendrite to the cell body

Question 22

abnormalities in the cytoskeleton creates

Answer 22

(plaques and tangles) that do not allow proteins to travel and cause Alzheimer’s

Question 23

plaques

Answer 23

too much amyloid protein

Question 24

tangles

Answer 24

too much Tau protein

Question 25

Dendrite

Answer 25

A cytoplasmic extension Afferent in that they receive information via synapses Are short and have many branches to increase surface available for synapses – may be 100,000s synapses Spines cover the surface of dendrites to create synapse, transmit electrical signals and may even help synthesize proteins several shapes of spines

Question 26

filopodium

Answer 26

long tall and skinny

Question 27

thin

Answer 27

short but thin

Question 28

stubby

Answer 28

short and stout

Question 29

mushroom

Answer 29

looks like a mushroom cap

Question 30

cup

Answer 30

like a tuning fork

Question 31

axon

Answer 31

Cytoplasmic extension Are efferent that transmit impulses away from the soma Do not produce protein – unlike dendrites Generally one per neuron Typically form a long branch from a cone-shaped axon hillock then create collaterals to communicate with many dendrites on its way to its final destination Terminate in synaptic terminals or terminal boutons

Question 32

myelin

Answer 32

The entire process of brain growth is a process of myelination  Neurons can conduct an impulse prior to myelination but the ability to conduct repetitive impulses at a rapid rate requires myelin Rapid repetitive firing of impulses is necessary for many functions i.e.) walking, talking, thinking, feeling, etc. A multi-layered lipid (fat) material that insulates and protects the axon prevents the escape of electrical energy The speed of nerve conduction is determined by the diameter of the nerve and its myelin sheath The sheath is divided by Nodes of Ranvier which allows for saltatory conduction

Question 33

In general, myelination follows a phylogenic pattern

Answer 33

structures that are more primitive are likely to myelinate early Phylogenic – 1. The evolutionary development and history of a species or higher taxonomic grouping of organisms. Also called phylogenesis. 2. The evolutionary development of an organ or other part of an organism

Question 34

CNS myelin makers

Answer 34

Oligodendroglia cells | produce myelin for multiple axons/cells

Question 35

PNS myelin makers

Answer 35

Schwann cell | one cell myelinates one axon

Question 36

Endoneurium (endoneurial tube)

Answer 36

made by the Schwann cell is a layer of delicate connective tissue around the myelin sheath of several nerve fibers which creates a group of axons called nerve fascicles  

Question 37

The Synapse

Answer 37

``` Connection point between neurons 3 parts Presynaptic terminal/bouton Synaptic cleft Postsynaptic cell ```

Question 38

nerve cells classified by

Answer 38

``` # of receptive processes from soma Length of the axon Both dendritic and axonal processes add to cells’ ability to respond 3 basic classifications Multipolar Bipolar Unipolar ```

Question 39

multipolar

Answer 39

``` Many dendrites– one axon Differ in size and shape Make numerous synapses with other cells Most multipolar cells– in CNS Examples- Spinal interneurons, cerebellar Purkinje cells ```

Question 40

bipolar

Answer 40

2 processes- one extending from each pole of body Includes peripheral process (dendrite) and central process (axon) Found in the Retina and INNER EAR

Question 41

unipolar

Answer 41

``` One process only extending from body Divides into central and peripheral portions Central portion – axonal process Peripheral portion- dendritic process Found in spinal dorsal roots ```

Question 42

Glia

Answer 42

Neuroglia cells Found in grey and white matter 40 -50 times as many glial cells as nerve cells Support and protect nerve cells

Question 43

Astrocytes

Answer 43

act as connective tissue in white matter create the blood brain barrier in grey matter Regulate the extracellular concentration of ions

Question 44

Microglia

Answer 44

phagocytose – they engulf and digest cellular debris especially after injury Move to site of injury and begin to destroy the damaged tissue – one reason for edema

Question 45

Ependymal

Answer 45

line the surface of ventricles | choroid plexus

Question 46

Satellite

Answer 46

the astrocytes of the PNS – have a role in how we feel pain

Question 47

transmission

Answer 47

Neurons send messages through electrochemical processes Chemicals in the body are electrically charged – ions Important ions in the nervous system are sodium (Na) potassium (K +2), calcium (ca), and chloride (cl-)

Question 48

where is transmission

Answer 48

Nerve cells are made with a semi-permeable membrane that allows some ions to pass through while it blocks other ions This occurs at the internodes and the synapse

Question 49

transmission at the button

Answer 49

Neurotransmitters are released for impulse transmission Nerve impulses do not cross the synaptic cleft rather they signal the release of neurotransmitters The neurotransmitter then activates the post synaptic cell to depolarize or hyperpolarize the postsynaptic cell

Question 50

action potential

Answer 50

``` Chemical exchanges generate the electrical impulses that stimulate the nerve cell body -series of rapid changes resulting in the formation of nerve impulses Results from ions moving through cell membranes at ion channels It is an explosion of electrical activity that is created by a depolarizing current An event (stimulus) causes the neuron to move from resting potential to action potential ```

Question 51

resting membrane potential

Answer 51

When a neuron is not sending a signal it is at rest At rest = the inside of the neuron is negative relative to the outside (- 55- to -70) Stable resting environment secondary to selective permeability All of this is made possible by sodium and potassium pumps– which move Na+ and K+ out/ in the cell.

Question 52

sodium potassium pumps (Ligand)

Answer 52

move Na+ and K+ out/ in the cell all the time

Question 53

Mechanical

Answer 53

open when stretched

Question 54

voltage

Answer 54

open according to the charge of the cell

Question 55

Hormone

Answer 55

Chemical messenger from one cell to another – secreted into the blood Signal a change – play a part in activation or inhibition of the immune system, regulating metabolism, regulating phases of life (puberty, caring for offspring, menopause) Regulate organs and tissue growth

Question 56

Neurotransmitters

Answer 56

Chemical released at the synapse that allow movement of impulses Critical in regulation of all functions/behaviors A deficiency or abundance = dysfunction Produced in the cell body – soma Some facilitate transmission while others inhibit transmission In some way they either relay, amplify or modulate the electrical signal between neurons 2types small and large

Question 57

small molecules

Answer 57

``` derived from amino acids and have short lasting effects Acetylcholine Dopamine Norepinephrine Serotonin Glutamate GABA ```

Question 58

large molecules

Answer 58

peptides- have long lasting effects Substance p Endorphines

Question 59

myasthenia Gravis

Answer 59

50% of patients have enlarged thymus glands | speech is hard