NPB 101 Midterm 3

AV nodal delay

- Pacemaker activity is conducted relatively slowly through the AV node resulting in a delay of approximately 100 ms. -This delay ensures that the ventricles contract after atrial contraction.

amygdala

- a collection of nuclei located at the anterior end of the hippocampus -receives input from and provides output to many subcortical and cortical structures -involved in the regulation of emotional responses such as fear

sensory systems (how many + how organized)

-6 major sensory systems in the mammalian brain -each is organized according to a common anatomical plan

cardiac cells

-99% of cells are force producing cells - called myocytes or contractile cells -contain stated muscle -muscle contraction follows a myosin/actin interaction -1% of cells are the conduction system -called pacemaker cells -do not have contractile components

SA node parasympethic input

-Ach increases permeability of SA nodal cells to K+ by delaying inactivation of K+ channels that occurs after an AP -this effect leads to greater hyper polarization of the SA nodal cells and a slowing of the K+ component of the pacemaker potential

second heart sound

-High-pitched, sharp and relatively short sound associated with the closing of the semilunar valves. -Often referred to as "dup"

first heart sound

-Low-pitched, soft and relatively long sound associated with the closure of the AV valves -Often referred to as "lub"

acuity/resolution + example

-acuity is influenced by receptive field size and lateral inhibition -simulates presentation of stimuli example: 2 point discrimination threshold

venous return

-amount of blood in the ventricles -most important factor causing stretch in the amount of blood in the ventricles

brain stem

-area where most cranial nerves arise (head stuff/control) -contains centers that control cardiovascular, respiratory, and digestive function -regulates equilibrium and postural reflexes -controls overall degree of cortical alertness (br when sleeping) -centers that govern sleep are housed within the brain stem and hypothalamus

multiple sclerosis

-autoimmune disease that causes demyelination of neurons in the cerebellum -difficulty making precise movements -action tremors

choroid

-behind retina -provides nourishment to cells in the retina

sinoatrial (SA) node

-bundle of specialized cardiac pacemaker cells located in the wall of the right atrium near the opening of the superior vena cava -tis node exhibits an autorhythmicity of 70 action potentials per minute and leads the activity of the other pacemaker structures in the heart

atrioventricular (AV) node

-bundle of specialized, cardiac pacemaker cells located at the base of the right atrium -this node exhibits an autorhythmicity of 50 action potentials per minute -under normal conditions, this node follows the faster SA node at 70 A.P./min

modality specificity + examples

-category of stimuli to which a receptor is sensitive examples: photoreceptor, pacinian corpuscle

stimulus

-change detectable by the body -exist in various E forms or modalities

limbic system + what's part of it

-collection of nuclei, interconnected to the thalamus and cerebral cortex, that play a key role in learning, memory and emotions -hippocampus + amygdala

spinal cord

-column of neural tissue from the medulla to the lower end of the spinal column -contains the input and output pathways of the CNS

elastic arteries

-conduit vessels near the hart that carry blood for circulation -aorta is major example -pressure reservoirs that expand and contract (recoil) as blood is ejected by the heart; allows blood flow to be continuous

retina

-contains neurons that do transduction -lines back of eye

pitch discrimination

-depends on the region of the basilar membrane that vibrates -ability to distinguish among various frequencies of incoming sound waves

Parkinsons disease

-disease that destroys dopaminergic neurons in the basal ganglia -difficulty initiating movements -resting tremors

hippocampus

-elongated cortical structure located within the temporal lobe -anatomically connected with other parts of the limbic system and cerebral cortex -is involved in memory formation, spatial guidance of behavior and epileptic activity

ganglion cells

-have axons that leave eye, need to have action potential -axons have to go long distance (why need AP)

afferent neurons

-have sensory receptors at their peripheral endings -respond to stimuli in both the external world and the internal environment

thin filaments

-helical actin molecules -each with a myosin binding site to allow for cross bridge formation -specialized assemblies composed of 3 proteins, actin, tropomyosin and troponin, arranged to form an elongated double helical strand

phototransduction in dark

-high levels of intracellular cGMP keep the cGMP-gated Na+ channel opens -cell depolarized -cell constitutively releases neurotransmitter

lateral inhibition

-inhibition of adjacent neurons in a map -facilitates localization of stimuli

cerebellum

-large neural lobe located in the lower posterior region of the brain -involved in numerous functions, and particularly important in balance and the control of motor coordination -heavily interconnect with cerebrum, particularly cerebral cortex -amkes corrections so intention and actually happening same

thalamus

-large nucleus, composed of many smaller subnuclei, -lying in the center of the brain just posterior to the Basal Ganglia -functions cooperatively with, and is highly connected to, the cerebral cortex -sensory relay station and is important in motor control -"relay station" for preliminary processing of sensory input

phototransduction in light

-light stimulation of rhodopsin leads to activation of a G protein, transducin -activated G protein activates cGMP phosphodiesterase -PDE hydrolyzes cGMP, reducing its concentration -cGMP - gated Na+ channels close, cell hyper polarizes, and the cells stops releasing neurotransmitter

extrastriate cortex

-located anterior to and receives input from the primary visual cortex -damage leads to cognitive blindness

prefrontal association areas

-located anterior to the premotor regions in the frontal lobe -receives input and provides output to many areas of the cerebral cortex -damage results in deficits of planning, personality, and social behavior

parietal - temporal - occipital association areas

-located at the junction of the parietal, temporal, and occipital lobes -receives input from all the sensory modalities and provides output to many other cortical and subcortical structures -damage results in deficits of attention and multi modal sensory integration

brocas area

-located in the ventral and posterior region of the left frontal lobe and sends output to the Motor areas of the cortex -damage results in a deficit in speech production

wernickes area

-located ventral and posterior to auditory cortex and receives input from the auditory, visual and somatosensory cortices -damage results in a deficit in language comprehension

receptive field + examples

-location (zone) on the sensory surface within the stimulus (of the appropriate modality) can influence the activity of a sensory neuron - zone where stimulus will evoke response from cell examples: somatosensory, auditory

fovea

-make eye movements so that we can direct fovea on what we want to examine, has highest density of photoreceptors

myocardium

-middle layer of the heart wall, composed of cardiac muscle

myasthenia gravis symptoms

-muscle weakness, particularly during sustained activity -commonly affects muscles controlling the eyelids, facial expression, swallowing -in the lab, decreases size of end plate potentials in muscle afflicted with myasthenia gravis

thick filaments

-myosin molecules: 2 golf club shaped subunits -tails aligned toward middle -globular heads protrude out at regular intervals

Sensory homunculus

-orderly mapping of body parts -overrepresentation of regions with great acuity (hand and head)

maps + examples

-organized array of surface of receptor cells on the sensory surface examples: retinotopic or visuotopic map, somatotropin map, tonotopic map

sclera

-outermost tissue -white of eye -job is protection (tough)

somatic division + 2 parts

-portion of the PNS containing all of the somatic sensory and motor nerves and ganglia 1) sensory-somatic sensory nerves and ganglia 2)motor- somatic motor nerves and ganglia

autonomic division + 3 parts

-portion of the PNS responsible for regulating the involuntary actions of the internal organs 1) sympathetic - division of the autonomic nervous system that prepares the body fro strenuous physical activity 2) parasympathetic - division of the autonomic nervous system that maintains resting functions of the internal organs 3) enteric - division of the autonomic nervous system that regulates the functions of the gut

color vision depends on

-ratios of stimulation of the 3 cone types -each cone type is most effectively activated by a particular wavelength of light in the range of color indicated by its name

hypothalamus

-regulates many homeostatic functions -collection of specific nuclei and associated fibers that lie beneath the thalamus -integrating center for many important homeostatic functions

why is the macula dark?

-retina thinner at fovea bc cells pushed to side -can see pigment (why dark)

purkinje fibers

-small terminal fibers of specialized, cardiac pacemaker cells that extend from the Bundle of His and spread throughout the ventricular myocardium... very fast conduction velocity -these fibers exhibits an autorhythmicity of 30 action potentials per minute -under normal conditions, they follow the faster SA node (and AV node) at 70 A.P/min

sarcomere defintion

-smallest unit of a muscle cell containing all the elements necessary for contraction -composed of interdigitating and partially overlapping thick and thin filaments

receptor potential + examples

-stimulus alters receptors permeability (leads to a graded receptor potential) -receptor potentials may initiate action potentials in the afferent neuron - large receptor potential triggers opening of voltage gated na+ channels examples: photoreceptor, pacinian corpuscle; photoreceptor:

parasympathetic input

-supplied by vagus nerve -mediated by the neurotransmitter (Ach) through muscarinic receptors -causes heart rate to decrease

sympethic input

-supply the atria (the SA and AV nodes) and richly innervate the ventricles 0mediated by the neurotransmitter NE through beta adreneigc receptors -causes heart rate to increase

6 major sensory systems

-visual -auditory -somatosensory -olfactory -gustatory -vestibular

optic disc

-where all axons bundle together and leave, has no photoreceptors (blind spots) -where optic nerve is projecting away from eye

weight training + muscle fiber adaptation

1-5 reps: increased neuromuscular efficiency --> no increase in size as fibre contraction force increases 6-8 reps: myofibrillar hypertrophy --> increase size as fibre gains myofibrils and contraction force increases 9-15 reps: sarcoplasmic hypertrophy --> increase size as fibre gains sarcoplasm with NO contraction force increases

conduction speed of myelinated axons

120 m/s

motor neuron axon terminals releases _____ to _____

ACh to simulate muscle contraction

treatment of myasthenia gravis

ACh-esterase inhibitors (neostigmine): by reducing the rate of ACh degradation, ACh persists in the NMJ longer and has the increased potential to find healthy ACh receptors allows nt to be present for longer of time

secondary cerebral cortex

Anatomically defined areas of the cerebral cortex that process signals from primary sensory cortex and transmit signals to association cortex, motor cortex and subcortical structures

lub

Av valves closing

axons of motor neurons originate in the ______ and end on ____ _____

CNS and end on skeletal muscle

relay nuclei

Groups of neurons located in the central nervous system that process signals from receptor neurons and transmit signals to the thalamus

SA node sympathetic input

NE decreases the permeability of SA nodal cells to K+ by accelerating the inactivation of K+ channels that occurs after an action potential effect leads to less hyperpolariztion of the SA noal cells and an acceleration of the K+ component of pacemaker potential

correct sequence of current flow through the heart wall

SA node, AV node, AV bundle of His, right and left bundle branches, Purkinje fibers

receptor

a cell whose axon or dendrite is capable of transduction in a particular sensory modality

interatrial pathway

a pathway of specialized cardiac cells that conducts pacemaker activity from the right atrium to the left atrium

stenotic valve

a stiff, narrow valve that does not open completely turbulent flow is induced bc blood must be forced through the valve at high velocity produces an abnormal whistling sound

limbic system

a system of cortical and subcortical structures that form a loosely defined ring around the thalamus, involved in emotion, motivation, learning and memory

Bundle of His

a tract of specialized, cardiac pacemaker cells that originates at the AV node and divides and projects into the left and right ventricles

tetanus contracted via _____

a wound which becomes contaminated w the bacteria clostridium tetani

murmurs

abnormal heart sounds often associated with cardiac disease that are due to the turbulent flow of blood through malfunctioning valves

the auditory cortex is mapped ...

according to tone tonotopically organized

cardiac cycle

all the events involved with blood flow through the heart during one heart beat

primary cerebral cortex

anatomically defined areas of the cerebral cortex that process signals from the thalamus and transmit signals to secondary cerebral cortex

language areas

areas of cerebral cortex located in the left hemisphere in approx 97% of the population

higher order sensory and motor cortex

areas of cortex that provide input to motor areas or receive and integrate output from sensory areas

underlying cause of myasthenia gravis

autoimmune disease where the body generates antibodies that attack nicotenic ACh receptors

neuromuscular junction

axons of these neurons protect out the ventral root of the spinal cord and make synaptic contact with skeletal muscles at the neuromuscular junction

systemic loop

carries blood from the heart to the rest of the body

pulmonary loop

carries oxygen poor blood to the lungs and back to the heart

lens

changes shape based on distance (flat when viewing fat)

motor neurons are the final

common pathway

in the fovea, there are only _____ (cones or rods)

cones

cones vs rods acuity

cones: high acuity rods: low acuity

motor unit

consists of a motor neuron and all of the muscle fibers it innervates

loudness discrimination

depends on the amplitude of vibration

spinal cord

each segment contains motor neurons that protect to specific skeletal muscles via the ventral root

during during systole

ejection phase volume increases

myofibrils defintion

elongated, cylindrically shaped contractile elements composed of a population of sarcomeres connected end to end

3 layers of heart wall

endocardium myocardium epicardium

terminal button

enlarged knoblike structure at the end of axon terminal branches

Acetylcholinesterase (AchE)

enzyme localized in the synaptic cleft that degrades ACh

somatic motor system

final common pathway for neural control of the skeletal musculature

mechanism for tetanus and botulism

for both diseases, the toxins from the 2 bacteria block release of neurotransmitter

tension

force exerted on an object by contracting muscle is known as muscle tension

load

force exerted on the muscle by an object is the load

cornea

front end, allows photons to pass through, living tissue

the gap junctions enable the cardiac muscle to form a _____ _____

functional syncytium

rods provide indistinct ________ vision at night; cones provide sharp ______ vision during the day

gray; color

thalamus

groups of neurons, organized into nuclei within the thalamus, that process signals from relay nuclei and transmit signals to the cerebral cortex

auditory receptors

hair cells located in the cochlea

auditory system

hearing

pupil

hole; opening that light travels to black pc pigment behind tissue

flow pressure relationship increase resistance increase flow

if you increase resistance by vasoconstriction and keep pressure the same, then flow to a tissue decreases increase flow to a tissue, then you either increase the pressure or vasodilate to decrease resistance

botulism contracted via ______

ingesting spores from bacteria (clostridium botulinum) allowed to grow in an anaerobic env

tetanus toxin blocks the release of ----- while botulinum toxin blocks release of ......

inibitory nt excitatory nt

swish

insufficient valve (back flow of blood)

cardiac muscle cells are connected end to end by _____________ where to types of contacts are formed: _______ and ______

intercalated disks desmosomes and gap junctions

the lens _______ and__________ the visual stimulus onto the surface of the retina

inverts and focuses

during early diastole

isovolumetric ventricular contraction volume remains constant

during early systole

isovolumetric ventricular contraction volume remains constant but pressure changing?

4 chambers of dual pump system

left and right atria left and right ventricles

heart valve: left AV valve/bicuspid/mitral

left atria from left ventricle

heart valve: aortic/semilunar valve

left ventricle from aorta

eccentric contraction

lengthening

primary motor cortex

located on the precentral gyrus, and contains a somatotropin map of the skeletal musculature subset of the neurons project directly to the spinal cord forming the corticospinal tract

macula

location of fovea

z line

made up of the protein alpha actinic that anchors the thin actin filaments and acts as a boundary between sarcomere units

desmosomes

mechanically hold the cells together, and the gap junctions provide paths of low resistance to the flow of electrical current between muscle cells

twitch

mechanism response of a muscle fiber to a single action potential

longest axon

meter long

what does the brain stem consist of

midbrain, pons, medulla

hyperplasia

more muscle cells does not typically occur

supplementary motor and premotor cortices

motor cortical areas that project to and are located anterior to the primary motor cortex. Involved in complex motor sequences and movement preparation

isotonic contraction

muscle changes length while the load remains constant

isometric contraction

muscle develops tension but does not shorten or lengthen

botulism symptoms

muscle weakness

motor homunculus

muscles that we have control over

motor neurons and skeletal muscle fibers are chemically linked at

neuromuscular junctions

Acetylcholine (ACh)

neurotransmitter used by motoneurons; ACh increases the membrane permeability to Na+ leading to an EPSP called the end plate potential (EPP)

deep nuclei

nuclear structures, analogous to the basal ganglia in the cerebrum, that lie below the cortex in the depth of the cerebellum

each muscle cell only has _____ neuromuscular junction

one

parts of inner ear

oval window, cochlea, vestibular apparatus, round window

chambers on the right pump ...

oxygen-poor blood through the pulmonary circulation to the lungs

chambers on the left pump ...

oxygen-rich blood through the systemic circulation to the body tissues

neurotransmitters of parasympathetic + sympathetic nervous system

parasymp: acetyl choline (ACh) sympathetic: ACh, ... norepinephrine (NE)/ epinephrine

internodal pathway

pathway of specialized, cardiac cells that conducts pacemaker activity from the SA node to the AV node

cones serve _______ vision

photooptic

visual receptors

photoreceptors (rods/cones) located in retina rods: dim cones: light

parts of external ear

pinna, external auditory meatus, tympanic membrane

vestibular system

posture and balance sensors close to auditory

pulse pressure

pressure Dif between systolic pressure and diastolic

mean arterial pressure

pressure that is monitored and regulated by blood pressure reflexes

bipolar cells

processes extend in both directions

messier corpuscles + pacinian corpuscles

rapidly adapting

stimuli bring about the receptor potentials in the ______

receptor - sensory transduction

5 things involved in transduction

receptor relay nuclei thalamus primary cerebral cortex secondary cerebral cortex

3 classes of cones

red, green, blue

withdrawal reflex

reflex circuit that mediates withdrawal from a painful stimulus

heart rate

regulated by parasymp and symp ns

stroke volume

regulated intrisincially by volume of venous blood returning to the ventricles, and extrinsically by the sympathetic nervous system

heart regulation

regulated primarily by autonomic influences that control the excitability of the SA node

association cortex

remaining areas of cerebral cortex are referred to as association areas, responsible for integration of multiple sensory, motor and cognitive processes

heart valve: pulmonary/semilunar valve

right ventricle from pulmonary artery

rods vs cones sensitivity

rods have high sensitivity cones have lower sensitivity

in the spinal cord, each segments contains motor neurons that project to specific skeletal muscles on the ____ side of the body

same (ipsilateral)

rods serve ______ vision

scotopic

dub

semilunar valves closing

heart valve: right AV valve/tricuspid

sep right atria from right ventricle

basal ganglia

set of large nuclei lying in the center of the brain, highly interconnected with the cerebral cortex and the thalamus involved in motor planning and initiation of motor sequences

motor end plate

shallow depression where Xon terminal end

concentric contraction

shortening

spinal reflexes

simple neuromuscular circuits that mediate reflex responses to sensory stimuli

stretch reflex

simple reflex circuit that mediates muscular contraction following stretch of the homonymous muscle

muscle fiber

single, long and cylindrical muscle cell

motor neurons supply ______ +

skeletal muscle bring about movement

3 types muscle

skeletal, cardiac, smooth

rufini ndings + merkel discs

slowly adapting

olfactory system *

smell

2 divisions of peripheral nervous system

somatic division autonomic division

Summary of sound transduction

sound waves --> vibration of tympanic membrane --> vibration of middle ear bones --> vibration of oval window --> fluid movement within the cochlea --> vibration of basilar membrane --> bending of hair cells --> graded receptor potential --> action potentials generated in auditory nerve --> propagation to auditory cortex

nodes

specialized cardiac muscle cells capable of pacemaker activity are grouped together to form nodes

somatosensory receptors touch pain temp proprioception

specific receptors for different modalities/sensations touch: mechanoreceptors pain:nociceptors temperature: thermoreceptors proprioception: mechanoreceptors

brain stem is a vital link between ...

spinal cord and higher brain regions

whistle

stenotic valve (forcing blood at high velocity)

tetanus symptoms

stiffness (lockjaw), rigidity

stimuli are _______ by _________ grouped together to form a ____ ____

stimuli are transduced by receptors grouped together to form a sensory surface

myofibrils are the structures that give skeletal and cardiac muscle their

straited appearance

cardiac muscle

straited, involuntary

skeletal muscle

straited, voluntary

2 spinal reflexes

stretch and withdrawal reflex

insufficient valve

structurally damaged valve that does not close properly, turbulence occurs when the blood flows backward through the valve and collides with blood moving in the opposite direction, produces an abnormal swishing sound

central motor system

system of neural structures that carry out specific controls of the skeletal musculature

2 "loops" in cardiovascular system

systemic and pulmonary

2 phases of cardiac cycle

systole and diastole

gustatory system

taste

transduction

the conversion of stimulus energy to a neuronal signal

Starlings law

the critical factor controlling stroke volume is preload

preload

the degree to which cardiac muscle cells are stretched just before they contract optimal length/tension relationship is needed for maximal force generation

cerebellar cortex

the outer, highly folded surface of the cerebellum

peripheral nervous system (PNS)

the portion of the nervous system not located within the skull or spinal column

afterload

the pressure that ventricles must overcome to force open the aortic and pulmonary valves anything that increases systemic or pulmonary arterial pressure can increase after load

striations result from the orderly arrangements of

thick and thin filament s

sarcomere - thick filaments -thin

thick filaments: myosin thin: actin, tropomyosin, troponin

epicardium

thin external membrane covering the heart and is filmed with a small volume of pericardial fluid

endocardium

thin layer of endothelial tissue lining the interior of each chamber continuous with the lining of the blood vessels entering and leaving the heart

P wave

this component of the ECG represents depolarization of the atria

QRS complex

this component of the ECG represents depolarization of the ventricles

T wave

this component of the ECG represents depolarization of the ventricles

somatosensory

touch, pain, temperature, proprioception

parts of middle ear

tympanic cavity, auditory ossicles, oval window

lub dup swish type of valve defect timing of murmur valve disorder

type of valve defect: insufficient timing of murmur: diastolic valve disorder: insufficient semilunar valve

smooth muscle

unstraited, involuntary

lub swish dup type of valve defect timing of murmur valve disorder

valve defect: insufficient timing of murmur: systolic valve disorder: insufficient AV Valve

lub dub whistle type of valve defect timing of murmur valve disorder

valve defect: stenotic timing of murmur: diastolic valve disorder: insufficient AV Valve

lub whistle dup type of valve defect timing of murmur valve disorder

valve defect: stenotic timing of murmur: systolic valve disorder: stenotic semilunar valve

systole

ventricular contraction phase

diastole

ventricular relaxation phase

during late diastole

ventricular relaxation/filling volume increases

The axon terminals of a motor neuron contain _______ like the vesicles found at synaptic junctions between 2 neurons the vesicles contain the neurotransmitter _____ the region of the muscle fiber plasma membrane that lies directly under the terminal portion of the axon is known as the _______ the junction of an axon terminal with the motor end plate is known as ______

vesicles acetylcholine (ACh0 motor end plate neuromuscular junction

visual system

vision, sleep waking cycle

ventral stream

what pathway eg: area IT involved in face recognition (object identification)

heart valves ensure a one way flow of blood valve opened vs valved closed

when pressure is greater behind the valve, it opens when pressure is greater in front of the valve, it closes *valve closed; does not open in opposite direction

dorsal stream

where pathway eg: area MT involved in motion detection

muscle organization (diff. levels)

whole muscle fascicle (bundle of fibers) muscle fiber (single cell) myofibril A bands and I bands (make up sarcomere) Sarcomere Z lines, M lines, H zone thick (myosin) filaments thin (actin) filaments

greater venous return .....

will increase contraction strength, and hence stroke volume, via this instrinsic mechanism

intrinsic control

Direct correlation between end-diastolic volume (EDV) and stroke volume (SV) Depends on the length-tension relationship of cardiac muscle

each muscle fiber is innervated by just one axon, but each axon

branches to innervate all fibers in its unit

vitreous humor

back of eye

aqueous humor

between cornea and lens

hypertrophy

bigger muscle cells triggered by micro tears induced by proper weight training

primary visual cortex (V1, area 17)

binocularity, orientation selectivity

sensory inputs

body --> brain

motor inputs

brain --> body