Anatomy 5. 30a at UWO (Functional Neuroanatomy)Last updated: 1. November 2. 00. 7Click here to go directly to list of topics. ANNOUNCEMENTS APPEAR HERE. This web site contains introductory remarks and notes relating to. Human Neuroanatomy lectures by J.

A. Kiernan. Owing to current limitations. Occupational. Therapy (OT) and Physical Therapy (PT) programmes.

Every year a few graduate students took Anatomy & Cell Biology 5. They remain on the Web  in the. This document contains some advice to students that may no longer be. Anatomy 3. 50a and 5. OT and PT students at UWO. Kiernan  MB, Ch. B, Ph. D, DSc Professor, Department of Anatomy & Cell Biology.

Figure 3.2 Drawing of the 8, 12, 5, 5 and 1 cervical, thoracic, lumbar, sacral and coccygeal spinal nerves and their exit from the vertebrate, respectively. This article is about the descending tracts of the central nervous system. The descending tracts are the pathways by which motor signals are sent from the brain to.

Room 4. 53, Medical Sciences Building, U. W. O.(ACB web page)  GENERAL STUFF ABOUT THE COURSEPlease read this.

You do not need to make an appointment. Call 6. 61- 2. 11. I'm there or ask a question on the phone. If you attend in person you will get better service.

Talking on the phone is. Our museum contains many. Unfortunately there is a charge of $5 to cover the cost. CD- ROM. Montemurro, formerly of the Department. Anatomy at UWO, has produced numerous VHS videotapes that explain. Some. will be shown in 3. All are available in the Taylor Library.

There is also a. sample of the video lab exam. The file Basic. Neuro. If you don't have this program, click on the link to download it from adobe. If you understand everything in. Basic. Neuro. pdf.

CD- ROM, you will certainly obtain at least a B grade for the course. Two lectures on the peripheral nervous. There are one- hour lectures. Wednesday lab classes. Run the file (needs Windows 9. For these. the teachers assume that the students remember most of the.

Not all. the functional systems of the brain are included in this course. The. last lecture brings together the pathways and the topographical. Much of the material in. Questions in both. Rushlow, who provides paper handouts. These. links are not active in this version of the web notes for Anatomy 3. Major parts of the central and peripheral nervous systems.

Now for the neuroanatomy! The thickness of the wall of the tube. The complicated shape of the brain is due partly. The CNS is made of fragile, gelatinous tissue. It is. contained entirely within the axial skeleton (cranium and vertebral column).

The autonomic nervous system (ANS), formerly the vegetative nervous system, is a division of the peripheral nervous system that supplies smooth muscle and glands, and.

A nerve is ensheathed in collagenous connective. Nerves go out. from the axial skeleton by way of foramina . This general plan applies to all.

Use the index or the glossary of your textbook to look up. Do not attempt to learn the definition unless the word either. An example is the. For example. the lateral sulcus is near to areas of the cerebral cortex concerned with hearing, understanding what's heard, formulation of. Bollywood Songs Mp3 Free Download Sad Girl. The PNS. A ganglion is a collection of. CNS. Typically a ganglion is a lump on a nerve, but many of the ganglia.

These vary greatly in. Picture of some types of neuron), but most types have long cytoplasmic. The primary sensory neuron (dorsal root ganglion cell) differs from.

It is pink because it contains many capillary. It goes grey when the tissue is preserved in formaldehyde. Grey matter also contains dendrites.

Synapses are functional connections between neurons, typically from end branches of axons to. Synapses occur in grey matter (and also in autonomic ganglia). Conduction of signals occurs much more rapidly in a.

Tissue consisting largely of myelinated axons in the CNS. In the PNS myelin sheaths are formed by. Schwann cells. In the PNS satellite cells accompany neuronal cell bodies in. Schwann cells ensheath axons and form their myelin sheaths. In the CNS oligodendrocytes form.

Microglia are small. The neural tube, formed. CNS (except for the sacral and lower lumbar segments of the spinal cord). In addition, many neural crest cells give rise to.

Some of the neurons in some cranial nerve. The olfactory. epithelium and the sensory receptors of the inner ear also arise from placodes. Consequently the adult cord. L2. Below that level the vertebral canal contains the. The filum terminale is the stretched- out remnant of the embryonic. The ventral horn contains motor neurons.

Consequently neurons derived from. The rostral and caudal neuropores. Days 2. 3 and 2. 7 respectively, and by Day 2. The fetal period is characterized.

Longitudinal section of 2. The enlargements of the rostral end (initially the rostral half) of the neural tube are the. Flexures in the developing brain serve to (a) accommodate.

Enlargement of the cerebral and cerebral cortex proceeds during. Growth of the brain continues into childhood, with most of.

Those that migrate along the courses of growing axons become the. Schwann cells of nerve roots and nerves and the cells associated with specialized peripheral nerve- endings. Some become the endocrine cells of the adrenal medulla. Many cranial neural crest cells differentiate into bones and. Microsoft Dynamics Nav Download Crack Internet.

Most types of spina bifida are due to failure of development of vertebral laminae. The overlying skin and muscles may be present (spina bifida occulta) or they may be missing (meningocoele. Some drawings of developmental abnormalities follow.

Internal hydrocephalus: Cerebrospinal fluid (CSF) fails to escape from the ventricles, which expand. A common type is due. There are malformations that include both hydrocephalus and spina bifida. The. Chiari malformations are the most common. Neuronal cell- bodies. The spinal nerves are. Each has a dorsal and a ventral root, separately connected with the spinal cord.

The dorsal roots are exclusively sensory in mammals, whereas the ventral roots contain. The olfactory nerves, concerned with. The optic nerves, like the. They are therefore not real nerves but outgrowths. The remaining cranial nerves emerge from the brain stem, which consists of the midbrain.

This diagram also shows structural elements that will be referred to later in this Section. The highest spinal nerve penetrates the atlanto- occipital membrane, above. C1. The. second cervical nerve passes between the atlas.

C1) and the axis (C2). There are 7 cervical vertebrae. The. lowest cervical nerve is therefore C8. Cervical nerves 1 to 7 go. The roots of nerve C8 pass below. C7 and above that of T1.

All the thoracic (T1 - . T1. 2), lumbar (L1 - L5) and sacral (S1 - S5) nerves go through foramina below the equivalently numbered vertebrae. To complete the story, a single.

S5 in supplying the perianal skin. Consequently, it. Transection. of a single spinal nerve, or destruction of its ganglion, diminishes.

The cutaneous. lesions of herpes zoster, a common virus that infects certain. The nerve supply to the skin of the limbs is. The areas supplied by cutaneous. They are sharply. Dermatomes). A cutaneous nerve lesion, such as an. The areas are sharply demarcated, and. Cranial nerves VII, IX and X.

Most. of the muscles of the limbs are supplied nerves formed in the limb. Table 6 (Segmental landmarks) shows. A stretch reflex (tendon jerk) requires the integrity of both the motor and the proprioceptive sensory innervation of the muscle. The lower. spinal nerves must therefore. The. consequences depend on the level of the.

In the cervical and upper thoracic spine. There is little free space in this part of the neural canal. The body of. vertebra T1. T1. 1. Below this level. All the spinal cord. T1. 1 are in the range of just three vertebrae, T1. L1. and L2. Consequently, a herniated disk below C7 cannot.

Physiological afferents from internal. Elevation of upper eyelid. Constriction of pupil (ciliary ganglion)  IV    Trochlear.

Certain downward eye movements   V     Trigeminal. Muscles that open and close the mouth; tensor tympani muscle of middle ear. Skin of face; mouth, teeth, nose, sinuses, dura mater of anterior and middle fossa  VI    Abducens. Abduction of eye   VII   Facial. Muscles of face; stapedius muscle of middle ear. Lacrimal and nasal glands (pterygopalatine ganglion); sublingual & submandibular salivary glands (submandibular ganglion)Part of external ear and tympanic membrane. Taste: palate & anterior two thirds of tongue.

VIII  Vestibulocochlear: Vestibular. Cochlear   Equilibration. Hearing. IX    Glossopharyngeal.

The Descending Tracts - Pyramidal. This article is about the descending tracts of the central nervous system. The descending tracts are the pathways by which motor signals are sent from the brain to lower motor neurones. The lower motor neurones then directly innervate muscles to produce movement. The motor tracts can be functionally divided into two major groups: Pyramidal tracts – These tracts originate in the cerebral cortex, carrying motor fibres to the spinal cord and brain stem. They are responsible for the voluntary control of the musculature of the body and face.

Extrapyramidal tracts – These tracts originate in the brain stem, carrying motor fibres to the spinal cord. They are responsible for the involuntary and automatic control of all musculature, such as muscle tone, balance, posture and locomotion. There are no synapses within the descending pathways.

At the termination of the descending tracts, the neurones synapse with a lower motor neurone. Thus, all the neurones within the descending motor system are classed as upper motor neurones. Their cell bodies are found in the cerebral cortex or the brain stem, with their axons remaining within the CNS.

Fig 1 – Schematic of the motor nervous system. The descending tracts are represented by upper motor neurones. Pyramidal Tracts. The pyramidal tracts derive their name from the medullary pyramids of the medulla oblongata, which they pass through. These pathways are responsible for the voluntary control of the musculature of the body and face. Functionally, these tracts can be subdivided into two: Corticospinal tracts – supplies the musculature of the body.

Corticobulbar tracts – supplies the musculature of the head and neck. We shall now discuss both pathways in further detail. Corticospinal Tracts. The corticospinal tracts begin in the cerebral cortex, from which they receive a range of inputs: Primary motor cortex.

Premotor cortex. Supplementary motor area. They also receive nerve fibres from the somatosensory area, which play a role in regulating the activity of the ascending tracts. After originating from the cortex, the neurones converge, and descend through the internal capsule (a white matter pathway, located between the thalamus and the basal ganglia). This is clinically important, as the internal capsule is particularly susceptible to compression from haemorrhagic bleeds, known as a . They then descend into the spinal cord, terminating in the ventral horn (at all segmental levels). From the ventral horn, the lower motor neurones go on to supply the muscles of the body.

The anterior corticospinal tract remains ipsilateral, descending into the spinal cord. They then decussate and terminate in the ventral horn of the cervical and upper thoracic segmental levels. Fig 3 – The corticospinal tracts. Note the area of decussation of the lateral corticospinal tract in the medulla. Corticobulbar Tracts Fig 4 – Overview of the right corticobulbar tract. Note that this is a simplified diagram, ignoring the bilateral nature of these pathways.

The corticobulbar tracts arise from the lateral aspect of the primary motor cortex. They receive the same inputs as the corticospinal tracts. The fibres converge and pass through the internal capsule to the brainstem.

The neurones terminate on the motor nuclei of the cranial nerves. Here, they synapse with lower motor neurones, which carry the motor signals to the muscles of the face and neck. Clinically, it is important to understand the organisation of the corticobulbar fibres. Many of these fibres innervate the motor neurones bilaterally. For example, fibres from the left primary motor cortex act as upper motor neurones for the right and left trochlear nerves. There are a few exceptions to this rule: Upper motor neurones for the facial nerve (CN VII) have a contralateral innervation. This only affects the muscles in the lower quadrant of the face – below the eyes.

They are responsible for the involuntary and automatic control of all musculature, such as muscle tone, balance, posture and locomotion. There are four tracts in total. The vestibulospinal and reticulospinal tracts do not decussate, providing ipsilateral innervation.

The rubrospinal and tectospinal tracts do decussate, and therefore provide contralateral innervation. Vestibulospinal Tracts. There are two vestibulospinal pathways; medial and lateral.

They arise from the vestibular nuclei, which receive input from the organs of balance. The tracts convey this balance information to the spinal cord, where it remains ipsilateral.

Fibres in this pathway control balance and posture by innervating the . It facilitates voluntary movements, and increases muscle tone.

The lateral reticulospinal tract arises from the medulla. It inhibits voluntary movements, and reduces muscle tone. Rubrospinal Tracts.

The rubrospinal tract originates from the red nucleus, a midbrain structure. As the fibres emerge, they decussate (cross over to the other side of the CNS), and descend into the spinal cord. Thus, they have a contralateral innervation.

Its exact function is unclear, but it is thought to play a role in the fine control of hand movements. Tectospinal Tracts. This pathway begins at the superior colliculus of the midbrain. The superior colliculus is a structure that receives input from the optic nerves.

They terminate at the cervical levels of the spinal cord. The tectospinal tract coordinates movements of the head in relation to vision stimuli. Clinical Relevance: Upper Motor Neurone Lesion.

Upper motor neurone lesions are also known as supranuclear lesions. Damage to the Corticospinal Tracts. The pyramidal tracts are susceptible to damage, because they extend almost the whole length of the central nervous system.

As mentioned previously, they particularly vulnerable as they pass through the internal capsule – a common site of cerebrovascular accidents (CVA). If there is only a unilateral lesion of the left or right corticospinal tract, symptoms will appear on the contralateral side of the body.

The cardinal signs of an upper motor neurone lesion are: Hypertonia – an increased muscle tone. Hyperreflexia – increased muscle reflexes. Clonus – involuntary, rhythmic muscle contractions. Babinski sign – extension of the hallux in response to blunt stimulation of the sole of the foot. Muscle weakness Damage to the Corticobulbar Tracts. Due to the bilateral nature of the majority of the corticobulbar tracts, a unilateral lesion usually results in mild muscle weakness.

However, not all the cranial nerves receive bilateral input, and so there are a few exceptions: Hypoglossal nerve – a lesion to the upper motor neurones for CN XII will result in spastic paralysis of the contralateral side of the genioglossus. This will result in the deviation of the tongue to the contralateral side. Facial nerve – a lesion to the upper motor neurones for CN VII will result in spastic paralysis of the muscles in the contralateral lower quadrant of the face.

Extrapyramidal tract lesions are commonly seen in degenerative diseases, encephalitis and tumours. They result in various types of dyskinesias or disorders of involuntary movement.