Nervous System Lecture 1 Flashcards
what are the 3 type of cell communication concepts
Autocrine - communication with the same cell
Paracrine - communication with neighbouring cells
Endocrine- communication with distant cells
4 elements of a negative feedback loop
1) sensor to detect parameter
2) there is an internal standard - too high etc
3)Output signal in response
4) Output activates effector and removes stimulus
What is neuron and examples
transmit information to other nerve cells, muscle, or gland cells - basic working unit of the brain
Types
-Pseudounipolar which is a Sensory neuron in PNS
Bipolar
Receptor-axon-cell body-axon-CNS
e.g. peripheral sensory neurons for olfaction (smell), vision, hearing & balance
Multipolar
Found throughout CNS
Multiple dendrites-single axon
e.g. motor neurons
Function of Glia and examples in the PNS + CNS
Provide structural support and myelin
PNS , an example is the Oligodendrocytes produce myelin
CNS, and example is that Schwann cells produce myelin
Meninges
it is a connective tissue membrane and three layer surrounding the brain and spinal cord
What are the 3 layers of the meninges
Dura mater, arachnoid, pia
Sub-arachnoid space between arachnoid & pia
Filled with cerebrospinal fluid Arteries
What does the spinal cord forma and its function
From foramen magnum at base of skull to LI vertebra
Continuous with medulla oblongata
Surrounded by meninges, cerebrospinal fluid and bone
Functions:
Reflex center for each spinal cord segment (e.g. spinal reflexes)
Conduction pathway for impulses going to and from the brain
Spinal nerves
8 cervical (neck)
C1-8 for neck and upper limb
12 thoracic
T1-12 for upper limb and thorax
5 lumbar
L1-5 for abdomen and lower limb
5 sacral
S1-5 for lower limb and perineum
The urinary and anal sphincters, and the external genitalia, are supplied by S2-4 (sphincters and sex)
1 coccygeal
are sensory and motor efferent and afferent
sensory - afferent Towards the CNS
motor - efferent - Away from the CNS
Ganglion
cluster of neural cell bodies outside the CNS
what are the two types of reflex arcs
Monosynaptic - Knee
Polysnaptic
What is the difference between somatic and visceral sensory
Somatic sensation: we are acutely aware of these; well localised (e.g. sharp pain, touch). Generally originate in body wall structures rather than internal organs.
Visceral sensation: either imperceptible, only vaguely localisable, or only become perceptible in disease. From blood vessels and internal organs (viscera
Two types of Automatic/Visceral motor
Sympathetic - Flight and Fight - eg increase HR, pupil dilation
Parasympathetic - Rest and digest - eg Decrease HR, pupil contraction
