Chedy - theme 3 Flashcards
Animals and neurons:
All animals have neurons except for snails. Number varies as a function of size and behavioural complexity.
Steps of processing info in single neurons:
Incoming signals are converted to a change in membrane potential, which initiates action potentials, which are conducted to axon terminals, which releases Ntransmitters.
Glial cells or neuroglia:
The non-nervous cells of the nervous system. Structural and functional support of neurons.
Glia : neurons
In the human brain, one glia for one neuron. In cerebral gray matter, three glia for two neurons.
Different kinds of glial cells:
Astrocytes, oligodendrocytes, Schwann cells; microglia, ependymal cells, satellite cells
Schwann cells:
Principal glia of PNS. Make myelin sheath on motor/sensory neurons.
Development of CNS:
4 weeks - three parts. 5 weeks - -encephalon names.
Bits of the adult brain:
Cerebrum, thalamus, hypothalamus, midbrain, cerebellum, pons, medulla oblongata
Cerebellum:
Integrates signals from eyes, ears, and muscle with motor signals from cerebrum.
Pons:
Traffic centre for info between cerebellum and cerebrum.
Medulla oblongata:
Controls vital involuntary tasks.
Brain stem parts:
Midbrain, pons, medulla
Midbrain:
Coordinates reflex responses. Relays involuntary reactions to the cerebrum.
Cerebrum:
Largest part of the human brain. Controls higher functions.
Thalamus:
Centre for sensory input. Relays input to cerebellum.
Hypothalamus:
Centre for homeostatic control.
Neocortex:
Newly gained in evolution. Covers the two cerebral hemispheres. Involved in higher functions. Consists of grey matter (unmyelinated) and white matter (myelinated) in the deeper part of the brain.
Neocortex and animals:
Smooth in small mammals. Has deep grooves (sulci) and ridges (gyri) in primates and larger mammals to increase surface area.
PNS breakdown:
Afferent - sensory information coming in. Efferent - effectors going out. Efferent is broken into somatic and autonomic.
Somatic NS:
Conscious/voluntary movements. Also reflexes like shivering, posture, balance. Carries messages from CNS to skeletal muscles.
Autonomic NS:
Automatic. All that stuff, you know. Controls smooth muscle contraction. Two kinds of neurons: one with dendrites and cell body in the CNS with ganglia in PNS. The other extends from the ganglion to the effector.
Reflexes: you know what they are. what kinds are there?
Patellar, babinski (fanning toes when touched), grasping, suckling, rooting
