PRACTICAL ROADMAP
SPECIAL NERVE ENDINGS
PT/OT
NOTE:
Encapsulated nerve endings have a ct sheath, and include Meissners
corpuscles, Pacinian corpuscles, Ruffini’s corpuscles, Krause’s end
bulb, Muscle spindles and Golgi tendon organs.
Free nerve endings consist of a bare axon.
Bold – can be identified with H&E
Epidermis
ENCAPSULATED NERVE
ENDINGS IN SKIN
Pacinian corpuscles
Slides 35/42
Dermis
The sensory nerves of the skin are the axons of the large
cell bodies of the dorsal root ganglion, only the axons are
present in the skin. Pacinian corpuscles are pressure and
vibration receptors and are found usually in the deep
dermis or hypodermis.Free nerve endings are also found.
Motor nerve endings (N) are associated with the glands
and hair follicles
Hypodermis
PC
N
NERVE ENDINGS ENCAPSULATED IN SKIN
• Slides 35/42
Pacinian corpuscles
Cut onion appearance, thin
concentric layers of thin cell
processes, lamellae,
produced by flat fibroblast
like cells, continuous with
the perineurium of the nerve
fibre. The central axon(A)
travelds longitudinally
through the centre of the
corpuscle. The spaces are
fluid filled.
A
ENCAPSULATEDNERVE ENDINGS IN SKIN
Slides 35/42
Meissners corpuscles
are tactile,
found in the
dermal papillae
of the skin.
Many in the
finger tips and
toes. Note the
axon (1or2)
spiral or zig-zag
from one side
of the corpuscle
to the other,
the axon ends
directly below
the epithelium.
Schwann cell
processes
surround the
axon (arrow) .
Fibrous capsule
Epidermis
M
M
M
M
M
M
M
NEUROMUSCULAR JUNCTION
Slide 4 (SNAKE SKELETAL MUSCLE )
This is a whole mount of snake
muscle. The nerve enters the field
top left, running at right angles to
the muscle branching and ending in
the motor end plate, the physiologic
contact between nerve and muscle,
and is the synapse between the two
tissues. The structure is mylinated
until the final branching.
NEUROMUSCULAR JUNCTION
Slide 4 (SNAKE SKELETAL MUSCLE )
This HP micrograph and EMG shows
motor end plates. Note the areas
where the synaptic clefts are .
MUSCLE SPINDLE
Slide 50
Muscle spindles provide information regarding
muscle stretch and position. Two types of of
modified muscle fibres, spindle cells and neuronal
terminals. Surrounded by an internal capsule. A
fluid filled space lies between the internal and
external capsule. Cross section through a muscle
spindle. A single bundle of spindle cells (S) is seen
inside the internal capsule (arrow). The external
capsule (big arrow). The capsule is fluid filled. Small
blood vessels are present in the capsule (BV)
S
BV