Histology Nervous Tissue I

Front 1

General Functions of the Nervous System

Back 1

respond to changes in the internal and external environment

Front 2

Anatomical Divisions of Nervous System

Back 2

CNS: spinal cord & brain
PNS: nerves that transmit information to and from the CNS

Front 3

Afferent Nerves

Back 3

travel towards the CNS (afferents arrive)

Front 4

Efferent Nerves

Back 4

travel away from the CNS (efferents exit)

Front 5

Functional Divisions of the Nervous System

Back 5

Somatic nervous system
Autonomic Nervous System

Front 6

Somatic Nervous System

Back 6

provides sensory and motor innervation to all parts of the body except viscera, smooth muscle, glands

Front 7

Autonomic Nervous System

Back 7

efferent involuntary motor innervation to smooth muscle, the conducting system of the heart and glands
Afferent sensory innervation from viscera (pain & reflexes)

Front 8

Divisions of Autonomic Nervous System

Back 8

Sympathetic
Parasympathetic
Enteric

Front 9

Sympathetic Autonomic Nervous System

Back 9

"Fight or Flight"
increases heart rate, respiration, blood pressure, and blood flow to skeletal muscles, dilate pupils
Decreases visceral function

Front 10

Parasympathetic Autonomic Nervous System

Back 10

"rest and digest"
Stimulates secretion, decreases heart rate, respiration, blood pressure, constricts pupils
Increases visceral function

Front 11

Enteric ANS

Back 11

innervates the gut
alimentary canal
can function independently of the CNS

Front 12

Development of the Nervous System

Back 12

Ectoderm germ layer > neural crest & neural plate
Neural plate grows in response to signals from notochord > invaginates > neural groove > closes to form neural tube > CNS structures
Neural crest separates from neural tube and ectoderm > PNS neurons, glial cells, arachnoid, and pia mater

Front 13

Neurons

Back 13

1. structural & functional unit of the nervous system
2. function: receives & transmits info as electrical impulses
3. Sympases: site of interaction/contact between neurons and/or target cells

Front 14

Neurons
Where are they derived from?

Back 14

CNS; neural tube
PNS: neural crest cells

Front 15

What are the 3 Functional units of a neuron?

Back 15

Dendrite
Cell body
Axon

Front 16

Neuron Cell Body
Light Microscope Appearance

Back 16

large, euchromatic nucleus with prominent nucleolus (****), mitochondria, golgi, lysosomes, microtubules, neurofilaments, vesicles

Front 17

Neuron Cell Body Organelles

Back 17

Nissel bodies, free ribosomes, golgi, extend into dendrites but NOT into axon

Front 18

Neuron Cell Body Axon Hilock

Back 18

region of cell body free of LARGE cytoplasmic organelles
LACK OF STAINING

Front 19

Lysosomes in Neurons Cell Body

Back 19

Lipofuscin: aging pigment
granules, found more in certain neurons (motor neurons of sympathetic ganglia)
elevated number with age

Front 20

AXON

Back 20

one/neuron
largest process extending from cell: originates from axon hilock, may give rise to recurrent branch near cell body

Front 21

AXON FUNCTIONS

Back 21

transmits impulses AWAY from cell body to target cell

Front 22

AXON ORGANELLES

Back 22

microtubules, neurofilaments, mitochondria, vesicles

Front 23

AXON INITIAL SEGMENT

Back 23

region of axon between apex of axon hilock and beginning of myelin sheath
*SITE OF GENERATION FOR ACTION POTENTIAL

Front 24

AXON PERIAXOPLASMIC PLAQUE

Back 24

site of protein synthesis in large nerve terminals

Front 25

DENDRITE

Back 25

usually many per neuron
shorter process with greater diameter than axons

Front 26

DENDRITE FUNCTIONS

Back 26

Receives and transmits information TOWARD the cell body
UNMYELINATED & can form extensive aborborization called dendritic trees
Does not contain Golgi apparatus

Front 27

Morphological classification of neurons

Back 27

1. Multipolar
2. Bipolar
3. Pseudounipolar (unipolar)

Front 28

Multipolar Neurons

Back 28

1 axon and 2 or more dendrites
MOST ABUNDANT neuron in nervous system
includes: motor, interneurons, pyramidal cells of cerebral cortex, Purkinje cells or crebellar cortex

Front 29

BIPOLAR NEURONS

Back 29

1 axon and 1 dendrite
SENSORY NEURONS
located in olfactory bulb, vestibular and auditory
WILL NOT SEE IN LAB

Front 30

PSEUDOUNIPOLAR

Back 30

1 process, axon divides into 2 long processes
majority located in dorsal root ganglia and cranial nerve ganglia
SENSORY GANGLIA