PHYSIOLOGY II SHEETS FOR PHARMACY STUDENTS
Central nervous system
Lecture 2 SECOND SEMESTER 2019l2020 Dr.Faisal mohamad
qat Checked by : Dina Alzyoud
In the last lecture we have talked about the central nervous system and how it
works with endocrine system to keep homeostasis through spinal cord and brain.
The work starts in the sensory system with receptor (pain,pressure,touch)
that attach or very close to neuron and this neuron is called a sensory neuron that
transmits impulses up the spinal cord into the cerebral cortex ( ascending) .We will
study the receptor and the mechanism of working for it and how this receptor
convert any type of energy into electrical energy which goes to cerebral cortex,
the cerebral cortex can differentiate between different types of sensations by the
specificity of the receptors. Now the information from cerebral cortex or brain
stem goes down the spinal through motor tract ( descending ) and then synapse
with motor neuron that supply skeletal muscle or gland.
Note: myelinated axons are faster than unmyelinated axon and the speed of
transmission depends on the diameter of neurons.
Now we know that human being starts as a tube which is divided into segments,
and for each segment, there are three layers: endoderm, mesoderm, ectoderm.
31 segments , and everyone has a bone and spinal cord segment that has a right
and left nerves through intervertebral foramina .But the bones grow faster than
ends ( spinal cord ) at L1,L2.
Spinal cord is shorter than vertebral column.
Importance : to know the position of spinal tap .
Cerebrospinal Fluid circulation :
CSF(plasma minus protein) is formed in the ventricles choroid plexus (all
ventricles can form CSF) and absorbed into the blood by arachnoid villi of dural
venous sinuses. CSF is continuously absorbed and reformed (almost fixed
quantities) constant pressure.
If the CSF pressure increased , this increment is due to either increased formation
of CSF or decreased absorption by the venous system. Note: babies below 2 years
1
, latrat ventricle echo rid plexus) interventricular fora min
3.ventricle cerebral Aqua duet# 4¥ lat rat & median
-
have incompletely closed sutures, so when the intracranial pressure increases
they will have hydrocephalus, but in adults there are no space so it will cause
headache .
Lateral ventricles Third ventricle Fourth ventricle central canal
Or subarachnoid space
Explanation: CSF which is formed in the lateral ventricles goes
through interventricular foramina into third ventricle and then though cerebral
aqueduct into fourth ventricle and through lateral and median apertures to
subarachnoid apace and then goes to venous blood .
2-
Note: CSF has no cells , so in CSF lumber puncture if we have found WBCs
(lymphocyte) this is a hint for viral infection, WBCS (neutrophils) this is hint
for bacterial infection , and if we found RBCs this is sign of bleeding (
Hemorrhage) .
Apparatus suisArachnoid Absorbed into venou
blood by Arachnoid Vili of dural venous sinus .
Spinal cord structure and function
Spinal cord consists of 31 segments , and each one has a collection of axons which
is called white matter and in the middle there are a collection 0f cell bodies and
dendrites which is called gray matter. Gray matter forms horns posterior and
anterior horns , sometimes there are a lateral horn especially in the thoracic
vertebra (autonomic NS originates from it), gray matter divides the spinal cord
mm
into columns : posterior (dorsal ) , anterior ( posterior ) , lateral columns.
We call the collection of cell bodies and dendrites Ganglia in the PNS, on the
other hand we call it nucleus in the CNS. In addition we call the collection of axons
2
Central nervous system
Lecture 2 SECOND SEMESTER 2019l2020 Dr.Faisal mohamad
qat Checked by : Dina Alzyoud
In the last lecture we have talked about the central nervous system and how it
works with endocrine system to keep homeostasis through spinal cord and brain.
The work starts in the sensory system with receptor (pain,pressure,touch)
that attach or very close to neuron and this neuron is called a sensory neuron that
transmits impulses up the spinal cord into the cerebral cortex ( ascending) .We will
study the receptor and the mechanism of working for it and how this receptor
convert any type of energy into electrical energy which goes to cerebral cortex,
the cerebral cortex can differentiate between different types of sensations by the
specificity of the receptors. Now the information from cerebral cortex or brain
stem goes down the spinal through motor tract ( descending ) and then synapse
with motor neuron that supply skeletal muscle or gland.
Note: myelinated axons are faster than unmyelinated axon and the speed of
transmission depends on the diameter of neurons.
Now we know that human being starts as a tube which is divided into segments,
and for each segment, there are three layers: endoderm, mesoderm, ectoderm.
31 segments , and everyone has a bone and spinal cord segment that has a right
and left nerves through intervertebral foramina .But the bones grow faster than
ends ( spinal cord ) at L1,L2.
Spinal cord is shorter than vertebral column.
Importance : to know the position of spinal tap .
Cerebrospinal Fluid circulation :
CSF(plasma minus protein) is formed in the ventricles choroid plexus (all
ventricles can form CSF) and absorbed into the blood by arachnoid villi of dural
venous sinuses. CSF is continuously absorbed and reformed (almost fixed
quantities) constant pressure.
If the CSF pressure increased , this increment is due to either increased formation
of CSF or decreased absorption by the venous system. Note: babies below 2 years
1
, latrat ventricle echo rid plexus) interventricular fora min
3.ventricle cerebral Aqua duet# 4¥ lat rat & median
-
have incompletely closed sutures, so when the intracranial pressure increases
they will have hydrocephalus, but in adults there are no space so it will cause
headache .
Lateral ventricles Third ventricle Fourth ventricle central canal
Or subarachnoid space
Explanation: CSF which is formed in the lateral ventricles goes
through interventricular foramina into third ventricle and then though cerebral
aqueduct into fourth ventricle and through lateral and median apertures to
subarachnoid apace and then goes to venous blood .
2-
Note: CSF has no cells , so in CSF lumber puncture if we have found WBCs
(lymphocyte) this is a hint for viral infection, WBCS (neutrophils) this is hint
for bacterial infection , and if we found RBCs this is sign of bleeding (
Hemorrhage) .
Apparatus suisArachnoid Absorbed into venou
blood by Arachnoid Vili of dural venous sinus .
Spinal cord structure and function
Spinal cord consists of 31 segments , and each one has a collection of axons which
is called white matter and in the middle there are a collection 0f cell bodies and
dendrites which is called gray matter. Gray matter forms horns posterior and
anterior horns , sometimes there are a lateral horn especially in the thoracic
vertebra (autonomic NS originates from it), gray matter divides the spinal cord
mm
into columns : posterior (dorsal ) , anterior ( posterior ) , lateral columns.
We call the collection of cell bodies and dendrites Ganglia in the PNS, on the
other hand we call it nucleus in the CNS. In addition we call the collection of axons
2
