P2P nervous

what structure does the pudendal nerve provide

• somatic motor innervation

• somatic sensory innervation

• the anal sphincter

• the perineal skin

where does the pudendal nerve convey parasympathetic fibres from

sacral spinal cord to rectal smooth muscle

what is another thing that the pudendal parasympathetic division controls

urinary bladder contraction

what nerve is responsible for hamstring, distal limb muscle and cutaneous innervation below the stifle

the sciatic nerve

what is the largest foramen and what major structures pass through

foramen magnum

• the spinal cord into the cranial cavity where it becomes continuous with the lower end of the medulla oblongata

• vertebral arteries

• anterior and posterior spinal arteries

• spinal roots of the accessory nerve

3 foramina and nerves that exit through

• foramen ovale: mandibular nerve

• jugular foramen: glossopharyngeal nerve, vagus nerve, accessory nerve

• foramen rotundum: maxillary nerve

a) Name two important structures that pass through the intervertebral spaces and foramina?

The articulation of the skull and the Atlas (the atlanto-occipital joint) creates a large space on the dorsal aspect. Identify this space. b) What might be the clinical significance of this space?

• craniocervical junction

• protets the structures transitioning from the skull to the spinal column

  • foramen magnum is a critical passage point

• conduit for major blood vessels supplying the brain eg the vertebral arteires

white and grey matter of the brain

• grey matter consists of neuronal cell bodies and dendrites and synpases and glial cells

• white matter is myelinated axons

Identify and name the tough membrane that covers the outer surface of the brain.

dura mater

Name the other two layers of membranes that cover the brain.

• arachnoid mater

• pia mater

Briefly explain why the two membranes you have named in (b) above are not discernible over the brain surface.

what are the elevations and depressions on the brain called

gyri and sulci

How far caudally does the spinal cord extend in the vertebral column? Use the vertebrae number (e.g. C1, T1 etc.) as a marker.

L2

here are two areas of the spinal cord where it briefly thickens, known as the intumescences. They correspond to the regions of the forelimb and hindlimb, respectively. b) What is the likely reason for these swellings?

Describe how the spinal cord terminates at its most caudal end.

• it travels inferiorly within the vertebral canal surrounded by spinal meninges containing csf

• at the l2 vertebrae level the spinal cord tapers off forming the conus medullaris

• the spinal nerves that arise from the end of the spinal cord are bundled together forming the cauda equina

What does the DRG consist of?

a collection of neuronal cell bodies of sensory neurons

How does the location of the dura mater in the vertebral column compare to that of the cranium?

• cranial dura mater

  • consist of an outer periosteal layer and an inner meningeal dura

  • periosteal is closely attached to the internal surface of skull bones

  • meningeal is continuous with th dura of the spinal cord

  • periosteal and meningeal are tightlly fused together except for where they separate to for the dural ventral sinuses

• spinal

  • only one layer

  • not closely integrated with the overlying bones

  • there is an epidural space

Some cranial nerves travel away from the cranium to innervate structures far away from the head. In pot 361, observe the nerve passing down the neck all the way to the thorax. The same nerve can be viewed in the additional pots and laminates, running very close to the base of the heart. i) Identify this cranial nerve

What is the effect of stimulation of this nerve on the heart?

What is the effect of stimulation of this nerve on the intestines?

Which part of the brain connects directly to the neurons projecting the nasal cavity?

what are the 4 main nerves supplying the canine forelimb?

• radial nerve

• musculocutaneous nerve

• median nerve

• ulnar nerve

which nrve passes down the neck to the thorax and runs close to the base of the heart?

vagus nerve

• mainly parasympathetic autonomic

• both afferent and efferent

• slow heart rate

• increases intestinal activity

what are the major cell types found in the retina

• rods and cones

• retinal ganglion cells: transmit info from the rods and cones to the brain, a bundle forms the optic nerve