human anatomy lecture quiz #9

what are the three overlapping functions of the nervous system?

sensory receptors monitor changes (afferent path)

integration-makes decisions (processing)

motor output- sends response ( efferent path)

what are the two basic divisions of the nervous system?

central nervous system, peripheral nervous system

central nervous system(CNS) includes?

brain, spinal cord, integrative and control center

peripheral nervous system(PNS)

cranial nerves and spinal nerves, communication lines between the CNS and the rest of the body

how can PNS be divided relative to direction of flow of information? name for these?

because of the sensory division and the motor division

sensory (afferent) division-

somatic and visceral sensory nerve fibers, conducts impulses from receptors to the CNS

motor(efferent) division-

motor nerve fibers, conducts impulses from the CNS to effectors(muscle and glands)

from where is the sensory info coming from?

somatic sensory fiber( found in skin), and visceral sensory fiber(found in stomach)

what are the four subdivisions of PNS?

somatic sensory, visceral sensory, somatic motor, and visceral motor

somatic sensory- general? special?

general- touch, pain, pressure, vibration, temperature and proprioception in skin, body wall, and limbs

special- hearing, equilibrium, vision, and smells

visceral sensory- general? special?

general- Strech, pain, temperature chemical changes, and irritation in viscera, nausea and hunger

special- taste

somatic motor-

motor innervation of all skeletal muscles(expect pharyngeal arch muscles)

visceral motor-

motor innervation of smooth muscle, cardiac muscle, and glands equivalent to automatic nervous sytem

where is the motor output going?

heart, bladder, skeletal muscle

somatic body region vs visceral body region? what is another name for these?

inner tube and outer tube

cell theory-

all organisms are made up of one or more cells, all cells arise from preexisting cells, cell is the structural and functional unit of life

Matthias Schleiden-

all plants were made of cells(1838)

theodor schwann-

all animals were made of cells(1839)

Rudolph virchow-

new cells were created only from division of preexisting cells

what are the two main cell types

neurons, support cells(neuroglial cells)

nervous tissue-

cells are densely packed and intertwined

a different cellularity-

As a simple consequence of this cellular geometry, the cell body of a neuron may comprise less than one percent of the entire cell volume. From this, you may deduce that the bulk of nervous tissue consists of nerve cell processes rather than nerve cell bodies, longevity, do not divide high metabolic rate(why?) different cellularity

who solved the problem? How?

Camillo golgi and ramon y cajal

Ramon y cajal won the Nobel prize in…?

cellularity, synaptic communication, connection specificity, principle of dynamic polarization

the cell body(perikaryon)-

size varies from 5-140um, most neuronal cell bodies, most located within the CNS( what are exceptions called?) ganglia, nissl bodies, protected by bones of the skull and vertebral column, ganglia vs. nuclei

neuron processes- dendrites

mms in length(volume of a pea), not myelinated, graded potentials, function as receptive sites

neuron processes-axons

neuron has only one, cms in length(can be a meter), impulse generator(axon hillock) and conductor no protein synthesis in axon, neurofilaments and mircrotubles(strength and transport, axon terminals for synapses

classification of neurons- structural classififcation

multipolar, bipolar unipolar(pseudounipolar)

sensory(afferent) neurons-

transmit impulses toward the CNS, unipolar neurons, cell bodies in ganglia outside the CNS

cell bodies in ganglia outside the CNS( who takes care of them)?

satile cells

motor(efferent) neurons

multipolar, cell bodies are within the CNS, junctions with effector cells

interneurons(association neurons)-

most are multipolar, confined to the CNS

nerve impulse

generated at the initial segment of the axon(axon hillock), conducted along the axon, releases neurotransmitters at axon terminals

signals carried by neurons

plasma membranes of neurons conduct electrical signals, resting neuron, depolarization

action potentials on axons

1). strong stimulus

2). neuron depolarizes

3). propagation

4). repolarization

synapses-

signals pass across synapse in one direction. presynaptic neuron, postsynaptic neuron, chemical junctions, synaptic vesicles on presynaptic side, synaptic cleft

types of synapses?

axosomatic , axoaxonic, axodendritic

what are dendritic spines? Where are they located?

bumps, pillars, each dendrite is none

how many contracts per neuron? how many per brain?

each neuron has on average about 7000, synapse count in the neighborhood of 600 trillion

why was it so hard to find cells in brain tissue?

because of the neuropil

neuropil-

a dense network of interwoven nerve fibers and their branches and synapses, together with gilal filaments

neurotransmitters and the neurons that secrete them can be divided into what two groups?

excitatory vs. inhibitory

are there other cells in nervous tissue besides neurons?

no

neuroglia-

usually only refers to supporting cells in the CNS, glial cells have branched processes and a central cell body, outnumber neurons 10 to 1, make up half the mass of the brain, can divide throughout life (what don’t they do relative to neurons?)

types of neuroglial cells- ASTROCYTES

– most abundant glial cell type Take up and release ions to control the environment around neurons Recapture and recycle neurotransmitters Help create BBB Structural integrity of nervous tissue Produce molecules needed for neural growth

types of neuroglial cells?

astrocytes, microglia, oligodendrocytes, ependymal cells

microglia-

smallest and least abundant, phagocytes the macrophages of the CNS, (How did they get in CNS?) macrophages

oligodendrocytes-

have branches(processes), wrap their cell processes around axons in CNS, produce myelin sheaths

ependymal cells-

line the central cavity of the spinal cord and brain, bear cilia-help circulate the cerebrospinal fluid

what about neurons outside the CNS? who supports them?

satellite and Schwann cells

satellite cells-

surround neuron cell bodies within ganglia

schwann cells(neurolemmocytes)-

surround axons in the PNS, form myelin sheath around axons of the PNS

myelin sheaths-

Schwann cells(PNS); oligodendrocytes(CNS), wrap in concentric layers around the axon, cover the axon in a tightly packed coil of membrane, nodes of ranvier

nerves- cordlike organs in the PNS

consists of numerous axons wrapped in connective tissue, endoneurium; nerve fascicles

reflex Arc- model for neuronal organization

1. receptor
2. sensory neuron
3. integration center
4. motor neuron
5. effector-muscle of gland cell, contracting or secreting

types of reflexes

monosynaptic, polysynaptic

name the neuronal circuits

diverging, converging, and reverberating circuit

diverging circuit-

one presynaptic neuron synapses with several other neurons(divergence)

converging circuit-

many neurons synapse on a single postsynaptic neuron(convergence)

reverberating circuit-

circuit that receives feedback via a collateral axon from a neuron in the circuit

serial procesing-

neurons pass a signal to a specific destination along a single pathway from one to another

parallel processing-

input is delivered along many pathways; a single sensory stimulus results in multiple perceptions

withdrawal reflex-

a painful stimulus triggers nerve impulses in a sensory neuron, which initiate the polysynaptic withdrawal reflex

voluntary motor response-

a nonreflexive motor response in initiated in the gray matter and transmitted down a descending fiber in the white matter to stimulate somatic motor neurons

CNS divided into regions, what regions?

gray matter and white matter

gray matter in the spinal cord(central and H-shaped)

dorsal half-cell bodies of interneurons

ventral half-cell bodies of motor neurons, cell bodies are clustered in the gray matter

white matter in the spinal cord(external location)

contains no neuronal cell bodies, but millions of axons, myelin sheath-white color, tracts-bundles of axons traveling to similar destinations

what happens if you injure a nerve?

some end bad

neuronal refeneration-

Neural injuries may cause permanent dysfunction  If axons alone are destroyed, cells bodies often survive and the axons may regenerate  PNS—macrophages invade and destroy axon distal to the injury  Schwann cells form regeneration tube.  Axon filaments grow peripherally from injured site  Partial recovery is sometimes possible

neuroglia never form :bread crumb trails”…

to guide re-growing axons and may hinder axon growth with growth inhibiting chemicals. no effective regeneration after injury to the spinal cord and brain

disorders of the nervous system

Multiple sclerosis – common cause of neural disability  Varies widely in intensity among those affected  Cause is incompletely understood  autoimmune disease

the brain=-

Performs the most complex neural functions, Intelligence, Consciousness , Memory, Sensory-motor integration, involved in innervation of the head, Brain also controls: Heart rate, respiratory rate, blood pressure, Autonomic nervous system, Endocrine system

brain divided into four regions?

cerebral hemispheres, diencephalon, brain stem; midbrain,pons, and medulla, cerebellum

protection of the brain

meninges

functions of meninges?

protect the central nervous sytem

meninges-

cover and protect the CNS, enclose and protect the vessels that supply the CNS, contain the cerebrospinal fluid(where?)

the dura mater

strongest of the meninges, composed of two layers, periosteal layer and meningeal layer, two layers are fused except to enclose the Dural sinuses(functions?), extends inward to subduvude the cranial cavity (name and locations) flax cerebri

what do sinuses do? the sinuses includes?

produce mucus, transverse, internal jugular, superior sagittal

arachnoid mater-

located beneath the dura mater, arachnoid villi, protect through the dura mater, functions? allow CSF to pass into the dural blood sinuses

the pia mater-

delicate connective tissue, clings tightly to the surface of the brain, follows all convolutions of the cortex

what do all these muscle in the arm have in common?

tendon, common flexor tendon,

common flexor tendon(attachment

is a tendon that attaches to the medial epicondyle of the humerus. it serves as the upper attachment point for the superficial muscles of the front of the forearm

what is medial epicondylitis? AKA?

tendonitis, golfers elbow, lifters elbow

> 90% of cases are not sports related

bowlers, baseball players, CrossFit athletes, weightlifters, tennis, construction, plumbing, carpentry

what muscle action do all these activities share on common? whoch muscles provide this?

flexor carpi radialsi

flexor carpi radialis-

orgin- medial epicondyle of humerus, insertion- base of 2nd metacarpal, action- flexes and radial deviates the hand(at wrist), innervation-median nerve(c6 and c7)

palmaris longus-

origin- medial epicondyle of humerus, insertion- distal half of flexor retinaculum and palmar aponeurosis, action- flexes hand at the wrist, innervation-median nerve (c7and c8)

flexor digitorum superficialis-

origin- medial epicondyle of humerus and coronoid process of ulna, insertion- middle phalanges of fingers, action- flexes fingers and wrist

flexor carpi ulnaris-

origin- medial epicondyle of humerus, insertion-pisiform bone, hook of hamate bone, and 5th metacarpal bone, action-flexes and ulnar deviates hand as wrist, innervation- ulnar nerve

pronator teres-

origin- medial epicondyle of humerus; coronoid process of ulna, insertion-lateral surface of midshaft of radius, actions- pronation, weak flexion

pronator quadratus-

origin- distal, anterior end of ulna, actions pronation, removing a screw with the right hand

thenar-

relating to the rounded fleshy part of the hand at the base of the thumb(the ball of the thumb)

pollicis meaning

of the thumb

what is the larynx? AKA?

voice box, structure to the respiratory tract, funnel to the trayes, produces sound, regulates opening to trachea, respiratory system

larynx clinical-

obstruction of larynx can produce suffocation

how does the larynx produce sound?

voice cord can be adduction, abduction

what do intrinsic muscles do?

change tension of shape of the voice box

what is the clinical relevance of larynx? why should you know its anatomy?

entrance for respiratory system, mainly air, stops food from entering into the lungs w

where do you perform tracheotomy?

cricothyroid membrane

purpose and location of tracheotomy?

heimlich, cut between thyroid cartilage and cricoid cartilage