Overview of the Nervous System Flashcards
What are the two main subdivisons of the nervous system?
Central Nervous System
Peripheral Nervous System
What is CNS composed of?
Brain and spinal chord
What is PNS composed of?
peripheral nerves and they contain a mixture of sensory fibres which carry info from periphery (touch or pain) to CNS
OR
contain motor fibres which carry instructions from brain to limb telling them to move
What can peripheral nervous system be further divided into?
autonomic (involuntary)
and
somatic (voluntary nervous system)
Give examples of autonomic nervous system?
blood pressure, heartrate, respiratory rate
Give examples of somatic nervous system?
skeletal (movements you are aware of)
What further 3 subdivisions can we divide autonomic nervous system into?
sympathetic - adrenaline , fight or flight response
parasympathetic - responsible for rest and digest
enteric - controls gastrointestinal tract
Where is cerebrum and what is its function?
Large bit of brain on top
Where is cerebellum and what is its function?
bit of brain below and responsible for controlling balance and coordination
Describe the physical appearance of the cerebrum?
not perfectly smooth
bumps on surface- gyri
groves between - sulci
What are the purpose of sulci?
increase surface area of cerebrum and pack in a lot more neurons
What are the important sulci?
Lateral sulcus (divides temporal brain from rest of the cerebrum)
Central sulcus (separates frontal lobe from parietal lobe)
Sulcus at the back ( separates parietal lobe from occipital lobe)
Why does surface of brain looks shiny?
brain not anchored to skull by any ligaments, instead protected by three layers of connective tissue known as meninges and brain floats in cerebrospinal fluid to cushion it
What is the pia matter?
deepest layer of meninges and the thinnest
really tight layer of cling film that clings to surface of brain
What is the arachnoid matter?
above the pia matter
What is the dura matter ?
most superficial layer of meninges
What is diencephalon made up of ?
thalamus
hypothalamus (body temp, thirst and hunger)
What is brain stem composed of?
midbrain
pons
medulla oblongata
What is spinal cord composed of?
-31 pairs of spinal nerves
8 in cervical region (necks, shoulders and arms)
12 in thoracic (chest and abdomen)
5 in lumbar (hips and legs)
5 in sacral (genitalia and gastrointestinal tract)
1 in coccygeal
What is role of dorsal root and dorsal root ganglia?
dorsal root- carries sensory fibres that carry info from periphery to central nervous system
dorsa root ganglia- where cell bodies of sensory fibres are contained
What is ventral root
contains the motor fibres, carry signals away from CNS to the periphery
Describe physical characteristics of spinal cord?
on outside of spinal cord have white matter and this is because it mostly contains axons
grey matter on inside and this is because mostly contains cell bodies
in grey matter- dorsal horn and ventral horn
and this goes with dorsal root ganglion and ventral root
What happens to afferent/ sensory fibres?
carry signals through dorsal root towards spinal cord
cell bodies are in dorsal root ganglia
synapse in dorsal root horn
What happens to efferent/ motor fibres?
cell bodies in ventral root horn
travel along ventral root and off to periphery
How do afferents and efferents communicate?
through inter neurons
