Nervous System

1
Nervous System
2
Central Nervous system
Brain and spinal cord
Peripheral nervous system
Nerves
3
(No Transcript)
4
Neurons are the basic structural unit of the
nervous system
Dendrites Nerve fibers that carry impulses toward
the cell body
Axon A single nerve fiber that carries impulses
away from the cell body
5
(No Transcript)
6
The Myelin Sheath - lipid and protein protection
Insulates and Speeds Up transmission of an
impulse.
In the Peripheral Nervous System, Myelin is
produced by SCHWANN CELLS, which surround the
Axon
GAPS (NODES) in the Myelin Sheath along the
length of the Axon are known as the NODES OF
RANVIER.
7
(No Transcript)
8
Sensory neurons stimuli receptors throughout
body send stimulus to brain ( afferent nerves)
Interneurons found exclusively within the spinal
cord and brain stimulated by signals reaching
them from sensory neurons other
interneurons or both.
Motor neurons transmit impulses away from the
brain to the muscles and glands (efferent
nerves) that carry out the response.
9
Synapse is a space between the axon of a neuron
and dendrite of another neuron
10
(No Transcript)
11
The Meningies cover and protect the brain and
spinal cord.
There are 3 layers dura mater thick
tough outer layer arachnoid membrane Middle
layer delicate and weblike pia
mater innermost layer, closely attached to
brain and spinal cord and contains blood
vessels that nourish the nerve tissue
12
4 ventricles filled with Cerebrospinal Fluid or
CSF. CSFshock absorber protects the brain an
spinal cord carries nutrients to some parts of
the brain. Removes metabolic products and wastes
13

• Peripheral Nervous System
• Somatic
• 12 pairs of cranial nerves and 31 pairs of spinal
  nerves

14
Peripheral Nervous System cont.
Autonomic-------Divided into sympathetic and
parasympathetic
15
Homeostasis-balanced state in the body
Paraplegia- paralysis of the lower extremities
Encephalitits- inflammation of the brain usually
caused by a virus, bacteria or chemical agent
Hydrocephalus- excessive accumulation of
cerebrospinal fluid
Neuralgia - nerve pain
Cerebrovascular accident- stroke, damange to the
brain resulting from a blood clot or hemorrhage
16
Epilepsy- condition involving abnormal electrical
impulses in the brain resulting from seizures
Cerebral Palsy- disturbance in voluntary muscle
action caused by brain damage
Parkinsons disease- Chronic progressive
condition involving degeneration of brain cells
17
(No Transcript)
18
Medulla oblongata The medulla looks like a
swollen tip to the spinal cord. Nerve impulses
arising here rhythmically stimulate the
intercostal muscles and v diaphragm making
breathing possible regulate heartbeat
regulate the diameter of arterioles thus
adjusting blood flow.
19
Pons
serve as a relay station carrying signals from
various parts of the cerebral cortex to the
cerebellum.
The pons also participates in the reflexes that
regulate breathing.
20
Cerebellum The cerebellum consists of two
deeply-convoluted hemispheres. Its most
clearly-understood function is to coordinate body
movements. People with damage to their
cerebellum are able to perceive the world as
before and to contract their muscles, but their
motions are jerky and uncoordinated. center for
learning motor skills.
21
27 week fetus
40 week fetus
22
Hypothalamus. The seat of the autonomic
nervous system. Damage to the hypothalamus is
quickly fatal as the normal homeostasis of body
temperature, blood chemistry, etc. goes out of
control. The source of 8 hormones, two of
which pass into the posterior lobe of the
pituitary gland. example thyroid stimulating
hormone, growth hormone, ADH, Oxytocin and more
23
Brain stem Functions Breathing Heart Rate
Blood Pressure
24
Abcess
Abcess of patient with SLE
25
Carcinoma of brain
26
Acute Hypertensive Cerebral Hemorrhage
27
Cat Scan
Traumatic brain injury subdural and
epidural hematoma