Abdomen, Pelvis and Perineum Revision Flashcards
Name the green part.
Central Nervous System
Brain + Spinal Cord
Define the green part.
Neurons start and end in brain/ spinal cord
Central Nervous System
Name the pink part.
Peripheral Nervous System
Cranial nerves + Spinal nerves
Define the green part.
Cell bodies in CNS but axons leave CNS OR Cell bodies outside CNS
Peripheral Nervous System
What is the function of the PNS?
Conveying information to and from the CNS
How many pairs of cranial nerves are there?
12 pairs
What is the function of the cranial nerves?
Innervation of the head and neck (mostly)
What is the composition of the cranial nerves?
Motor, sensory or mixed (including parasympathetics)
How many pairs of spinal nerves are there?
31 pairs
What is the function of the spinal nerves?
Take somatic and visceral information to / from spinal cord
What is the composition of the spinal nerves?
Always mixed nerves (motor and sensory info)
What are plexuses?
Mixing of fibers to create terminal branches containing fibers from different cranial and spinal nerves
What is the function of plexuses?
Compensation and protection
What are the 2 functional divisions of the nervous system?
- Somatic nervous system
- Visceral nervous system
What is the efferent function of the somatic nervous function?
- Innervates structures derived from the somites namely skeletal muscle and skin
What is the afferent function of the somatic nervous system?
- Responds to information from the external environment
What is the efferent function of the visceral nervous system?
- Innervates the viscera namely smooth muscle, cardiac muscle and glands
What is the afferent function of the visceral nervous system?
- Responds to information from the internal environment
What is the difference between the visceral and autonomic nervous system?
- Autonomic nervous system is a division underneath the visceral nervous system.
- Autonomic nervous system is purely motor in function (efferent)
- Visceranl nervous system involves both efferent and afferent neurones (umbrella)
What is the autonomic system divided into?
- Sympathetic
- Parasympathetic
Where does the sympathetic nervous system (fight or flight) originate?
Also known as thoracolumbar outflow
T1 - L2
Forms sympathetic chain to reach cervical and sacral areas of the body
Where does the parasympathetic nervous system originate?
- CNIII
- CNVII
- CNIX
- CNX
- S2 - S4
How does the structure of the spinal cord differ at the points where the visceral nervous system originates?
- Little lateral horn present, beside the ventral and dorsal horn
What path do the sympatehtic neurones follow in the spinal cord?
- Preganglionic cell bodies are in lateral horn of spinal cord between T1-L2
- Leave spinal cord via anterior horn and anterior root to enter T1-L2 spinal nerve
- Enter the sympathetic chain from here via white and grey rami communicantes
Give 5 functions of the sympathetic nervous system (fight or flight) (8).
- Increases heart rate
- Bronchodilation
- Vasodilation of skeletal muscle
- Vasodilation of skin
- Piloerection of hairs on skin
- Sweating
- Dilation of pupils (mydriasis)
- Ejaculation (shoot)
Give 5 functions of the parasympathetic nervous system (rest & digest) (7).
- Decreases heart rate
- Bronchoconstriction
- Increase blood flow to viscera
- Increase peristalsis of GIT
- Secretion from accessory glands of GIT
- Constriction of pupils (miosis)
- Erection (point)
What are the sympathetic splanchnic nerves?
Bundles of sympathetic nerve fibers innervating the viscera
Name the sympathetic splanchnic nerves.
- Greater splanchnic nerves
- Lesser splanchnic nerves
- Least splanchnic nerves
- Lumbar splanchnic nerves
At what level does the greater splanchic nerve originate?
T5 - T9
At what level does the lesser splanchic nerve originate?
T10 - T11
At what level does the least splanchic nerve originate?
T12
At what level does the lumbar splanchic nerve originate?
L1 - L2
What is the function of the splanchnic nerves?
Travel towards the aorta and mix with parasympathetic neres to form visceral plexuses to supply abdominal and pelvic organs
What is the pelvic splanchnic nerve?
The parasympathetic nervous system originating in S2-S4
Name the prevertbral plexuses (4).
- Celiac plexus
- Aortic plexus
- Superior hypogastric plexus
- Inferior hypogastric plexus
What makes up the prevertabral plexuses?
- Greater splanchinc nerve
- Vagus nerve
- Pelvic splachnic nerve
Name structure 1.
Celiac ganglion
Nerves innervating the foregut originate here.
Name structure 2.
Aorticorenal ganglion
Nerves innervating the aorta and the kidneys originate here.
Name structure 3.
Superior mesenteric ganglion
Nerves innervating the foregut originate here.
Name structure 4.
Inferior mesenteric ganglion
Nerves innervating the hindgut originate here.
What is the hypogastric nerve?
The continuation of the prevertebral plexus in the pelvic region.
What are the limits of the foregut?
- From the abdominal oesophagus to the major duodenal papilla
What major structures are found in the foregut (5)?
- Stomach
- Liver
- Spleen
- Pancreas
- Gallbladder
What is main sympathetic innervation of the foregut?
- Greater splanchnic nerve (T5-T9) via the coeliac ganglion
What is main parasympathetic innervation of the foregut?
- Vagus nerve via the coeliac ganglion
Where does foregut pain refer to?
Lower thorax and epigastric region
T5 - T9
What are the limits of the midgut?
From the major duodenal papilla to the final 2/3s of the transverse colon
What major structures are found in the midgut (4)?
- Jejunum
- Ileum
- Caecum
- Appendix