8)General anatomy and histology of nervous system Flashcards
What are the 2 main parts of nervous system?
Central Nervous System (CNS)
Peripheral Nervous System (PNS)
What does CNS contain?
Brain and spinal cord
Function of Central Nervous System (CNS)
Receiving, Processing, and responding to sensory information
Both CNS and PNS are surrounded and protected by which three layers of fibrous tissue?
Dura mater (Toughest layer) outside
Arachnoid mater (Intermediate)
Pia Mater (Inner)
(MCQ) The space between the arachnoid & pia mater is
1)____ and it contains 2)_____________
Subarachnoid space
cerebro-spinal fluid (CSF)
-float the brain, bc brain are heavy
What is Neuroglia?
Specialized tissue which supports the neurons, and the interior of the CNS is organized into gray & white matter
Gray matter is composed (组成) of
bodies of neurons
White matter is composed (组成) of
Nerve fibers
Peripheral Nervous System (PNS) is composed of?
1) Cranial nerve
2) Spinal nerve
3) Associated ganglions
4) Bundle of nerve fibers
Ganglion definition (MCQ)
A collection of nerve cells outside the CNS (dorsal root ganglion)
***Discuss the cranial nerve and spinal nerves in Peripheral Nervous System (PNS)
12 pairs (24) of cranial nerves and their ganglia
- exit via foramens in skull
-cranial nerves innervate muscle, joints and skin of the head
31 pairs (62) of spinal nerves and their ganglia
-exit the vertebral column through intervertebral foramina
- Innervate muscle, joints and skin of the trunk and limbs
***Discuss about the primary focus of somatic component in term of innervation(supply) and how does it differ from the role of the autonomic component?
Somatic component is involved in the nerve supply of voluntary structure like striated muscle, tendons, joints and skin
Autonomic component is responsible for nerve supply of involuntary structure, including heart smooth muscle and glands
What are the 31 pairs of spinal nerves
8 pairs of Cervical nerves
12 pairs of Thoracic nerves
5 pairs of Lumbar nerves
5 pairs of Sacral nerves
1 pairs of coccygeal nerves
Must memorize in order 1-12
I. Olfactory: concerned with sense of smell (olfaction).
II. Optic: concerned with sense of sight (vision).
III. Oculomotor: supplies most of the extraocular muscles.
IV. Trochlear: supplies one extraocular muscle.
V. Trigeminal: provides sensory innervation to head and face. (Dentistry)
VI. Abducent: supplies an extraocular muscle.
VII. Facial: supplies muscle of facial expression, and salivary glands. (Dentistry)
VIII.Vestibulocochlear: concerned with the sense of hearing and balance.
IX. Glossopharyngeal: tongue and pharynx, and motor supply to a pharyngeal muscle.
X. Vagus: provides motor supply to gut, heart and respiratory tract, and abdominal
viscera.
XI. Accessory: provides motor innervation to muscles of palate, pharynx, larynx and neck.
XII. Hypoglossal: provides motor supply to muscles of tongue.
What is autonomic nervous system (ANS)
A division of the peripheral nervous system
What autonomic nervous system regulates?
Heart rate
Digestion
respiratory rate
pupillary response
urination
sexual arousal
_______ regulate autonomic nervous system in brain
Hypothalamus
What hypothalamus regulate?
control of respiration
cardiac regulation
vasomotor (constriction& dilatation of blood)
reflex actions
coughing
sneezing
swallowing
vomiting
What are the 2 part of autonomic nervous system (ANS)
1) Sympathetic system
2) Parasympathetic system
Function of sympathetic system
stimulates activities that are performed during emergency and stress situations (fight, fright, flight)
Function of parasympathetic system
stimulates activities that conserve and restore body resources
(MCQ) Parasympathetic under which outflow
Cranio- sacral outflow
Differences between sympathetic & parasympathetic systems (10marks***)
Sympathetic
1. Thoraco-lumbar outflow. (T1 to L2)
- Preganglionic neurone → lateral horn
- Preganglionic fiber →short
- Ganglion → near vertebral column
- Postganglionic fiber → long
- Neurotransmitter at pre-ganglionic ending →Acetylcholine (Ach)
- Neurotransmitter at post-ganglionic ending → norepinephrine
- Action → Prepares body for emergency
- Widespread due to many postganglionic fibers
Parasympathetic
1. Cranio-sacral outflow (CN: 3,7,9 &10 and S 2,3,4)
- Preganglionic neurone → brainstem & sacral segment of S/cord
- Preganglionic fiber → long
- Ganglion → near target organ
- Postganglionic fiber → short
- Acetylcholine
- Acetylcholine at all endings
- Conserves & restores energy
- Discrete action with few postganglionic fibers
MCQ: Only postganglionic fiber of sympatactic is ______
Acetylcholine
