Neuro; A&P and Drugs Flashcards
(39 cards)
2 Parts of the NS and what do they Split into?
- CNS (brain and spinal cord)
- Peripheral NS (everything else) these divide into spinal and cranial nerve
What does the Peripheral Nervous System Split into?
Somatic - Controls skeletal muscle (conscious control)
Autonomic - Controls visceral (smooth) muscle, cardiac muscle, glands (unconscious control)
What does the Autonomic System Split into and what does it correspond to?
Sympathetic NS - fight/flight/freeze (speed up) Parasympathetic NS - rest/digest/feed/breed (slow down)
Difference Between the Sensory and Nervous Systems
- Nerves are either afferent or efferent
- Afferent - sensory neurones, travels towards the brain, informing it eg vision, smell
- Efferent - motor neurones, travel away from the brain to carry out actions eg moving hand
Path of Neurone Transmission
- Impulses are electrical signals that travel across neurones (cells) in a single direction across the nervous system
- They start by travelling into the dendrites, then the cell body, then conduct down a (usually) myelinated axon to the terminals of the neurones
- At the terminal, structures called synapses synthesise neurotransmitters which are released and travel across the synaptic cleft to another neurones dendrites
- Receptors for the NTs live on the other side and continue the action potential of the message
Structure and Function of Neurones
Cell bodies - make up the grey matter of the NS. Contains all the organelles needed for survival
Axon - part of the white matter. The path the signal travels down. Can be insulated with myelin, a type of fat that speeds up the conduction of the impulse
Function of Neurones
Neurones make up nerves that make up the pathway for chemical signal to be made, to control organ function, movement of muscle and brain activity
How is the Spinal Cord Connected to the Brain? And how is it being Protected?
- The spinal cord is a continuation of the medulla oblongata and brain stem
- It’s surrounded by meninges and bathed in CSF
What are the Different Spinal Vertebrae and how many are there?
- Cervical x7
- Thoracic x12
- Lumbar x5
- Sacral x5 (fused)
How many Spinal Nerves are there? And What/Where is the Cauda Equina?
- here are 31 pairs of spinal nerves extending from the spinal cords as ‘nerve root’s between each vertebrae
- The Cauda Equina hangs from the conus medullaris at the 2nd lumbar vertebrae (L2) - responsible for sensory function to the legs and the bladder
Intervertebral Discs; What do they do?
Intervertebral discs or laminae made of cartilage act as shock absorbers, but the discs can slip and put pressure on the cranial nerve
Functions of the Spinal Chord
- Transmitting nerve signals from the brain to the body and from the sensory neurons to the brain
- Coordinating many reflexes and containing reflex arcs that can independently control them
- Providing structural support and building a body posture
What is Grey Matter? And What is it responsible for?
- Contains most of the brains neural cell bodies connected to unmyelinated axons
- Includes regions of brain involved in muscle control, sensory perception (seeing, hearing, memory, emotion, speech, decision making and self-control)
What is Cerebral White Matter? And what is it responsible for?
- Tissue in which messages pass between different areas of grey matter in the CNS
- Contains myelinated axons connecting cells bodies in deep structures of the brain
- Responsible for communication between cerebral cortex/lower CNS and cerebrum areas
What does the Cerebellum do?
- Balance
- Skill
- Fine motor movement
What does the Hypothalamus do?
- Regulates the heart
- Regulates breathing
- Maintaines body temp
- Regulates sleep cycle
What is the Cerebral Cortex do?
Enables sense, communication, memory, understanding, voluntary movements
How is the Brain Protected?
By bone, meninges and cerebrospinal fluid (CSF). Harmful substances are shielded from the brain by the blood brain barrier.
What does the Cerebrospinal Fluid do?
- Forms cushion layer supporting CNS organs
- Prevents brain crushing under its own weight
- Absorbs pressure impact to CNS from blows and other trauma
- Nourishes brain/carries chemical signals throughout it
How does the Blood Brain Barrier Protect the Brain?
- It has a selective barrier to allow nutrients to pass freely, stopping pathogens crossing. Allows hydrophobic (O2, CO2)
- Separates bloodborne substances from neurones
The Meninges Structure; What each Layer does
- X3 Layers; Dura Mater, Arachnoid Mater and Pia Mater
- Dura Mater - Outer layer, very hard to tear/extremely tough. Closely adhered to the skull
- Arachnoid Mater - Between dura and Subarachnoid space. Bleeding in this area = subdural haematoma
- Subarachnoid Space - Has CSF and large blood vessels. Vessel rupture called subarachnoid haematoma
- Pia Mater - delicate connective tissue that clings to the brain
What is the Munroe-Kelly Hypothesis?
The sum of volumes of the brain, CSF and intracranial blood stays constant so when one increases/decreases the other two decrease/increase
Presentation of PR Diazepam
Suppository tube containing either 5/10mg in 2.5ml
Indications of PR Diazepam
- Convulsion of over 5 minutes, who are currently seizing where IV access can’t be established
- Repeat convulsions of 3 or more in 1 hour who are currently seizing - not secondary to uncorrected hypoglycaemia or hypoxia - where IV access can’t be established
- Eclamptic convulsion - if the seizure laster over 2 minutes and persists or is recurrent - where IV access cannot be established
