Lec 1 Flashcards
Intercellular communication
All activities of animals require cellular communication
autocrine
Relating to, promoted by, or being a substance secreted by a cell and acting on surface of receptors of the same cell
Paracrine
Created by a cell and acting on an adjacent cell
Endocrine
Producing secretions that are distributed in the bloodstream
Nervous system signaling
-Control functions of other cells
-Relatively fast
-Highly spatially selective
-Control discrete short term events
-Neurons can innervate the endocrine system
Endocrine system signaling
-Control functions of other cells
-Relatively slow
-Less spatially specific
-Control long term events
-Can act upon neurons
What are tissues under the influence of
Nervous and endocrine signaling
Cephalization
Growing from the head and outwards
Brain (or centralized ganglia)
Controls and coordinates other organs
Allows the organism to sense its environment and make decisions
Controls and coordinates muscle and movement
Ganglia
Collections of neurons
-In the PNS of vertebrates
Nuclei
Collection of neurons in the CNS
Nerves
A bundle of axons in the PNS
Tract
A bundle of axons in the CNS
Interneurons are in the
CNS
Sensory and motor neurons are in
The PNS
Sympathetic
Calming
Parasympathetic
Arousing
CNS of vertebrates is encased in
Cartilage or bone
3 main divisions of brain
Forebrain, midbrain, hindbrain
PNS is divided into
Autonomic
Somatic
Somatic neurons
Do not have peripheral neuron-neuron synapse (no middle man, synapse goes directly to skeletal muscle)
Autonomic neurons
Neurons synapse travel to ganglia then to heart (middle man)
Somatic nervous system contains
Cranial nerves plus spinal nerves
Third division of the autonomic nervous system
Enteric system- Innervates organs of alimentary canal
Sympathetic
Active during stress
Mobilizing energy
Fight or flight
Parasympathetic
Resting and digesting
Storing energy
Sympathetic and Parasympathetic innervate
Smooth muscle of body
Exocrine glands (pancreas)
Endocrine glands (adrenal glands)
Heart pacemaker
Processes affected by sympathetic and parasympathetic system
Digestion
Heartbeat
Blood movement through vessels
Blood pressure
Lung passages
Secretion of epinephrine and norepinephrine
Enteric division
Supplied by input from the vagus nerve and spinal nerves
Receives input from sympathetic and parasympathetic
Where is the enteric division
Esophagus
Stomach
Small and large intestines
Pancreas
Galbladder
Why is the enteric division considered separate from the autonomic and sympathetic
It is considered a second brain with 200-600 million neurons, including interneurons and glial cells
Ganglia of enteric system
Receive input from both sympathetic and parasympathetic system
Parasympathetic from preganglia
Sympathetic receive input from postganglia
Reticular theory (Golgi)
The brain is a single continuous network
Cajal found
The neuron doctrine
Neurons are distinct separate cells separated by synapses
Afferent
Convey info to neuron
Efferent
Convey info from a neuron
Interneurons
Connections between regions
4 functional zones of neurons
Dendrites
Axon hillock
Axon
Signal transmission area
Dendrites vs axons
Dendrites are rough because they have dendritic spines which allow synapses
Axon does not receive info from other cells and is covered in myelin
Molecular motors that move materials across axons (microtubules)
Kinesin
Dynein
Kinesin
Anterograde transport(away from cell body)
Dynein
Retrograde transport (toward the cell body)
Cell body
Known as soma
Location of nucleus
Site of mitochondrial biogenesis
Glial cells
10x more glial cells than neurons
Provide structural support for the brain
Surround neurons and hold them in place
Insulate one neuron from another
Supply nutrients and oxygens to neurons
Destroy pathogens
Speed up axonal conduction
5 types of glial cells
Schwann cells
Astrocytes
Oligodendrocytes
Microglial cells
Ependymal cells
Schwann cells
Form myelin sheaths in the PNS
Oligendodrocytes
Provide myelin sheath in the CNS
Astrocytes
Transport nutrients
Remove debris
Regular space around the synapse
Microglia
Equivalent to macrophages- provide active immune defense
Most active following trauma/injury
Role in neurodegeneration
Ependymal cells
Line fluid-filled cavities (ventricles) of the brain
Circulate cerebral spinal fluid- ciliated
Radial glia cells
Very important during development
Give rise to neurons, oligodendrocytes, and astrocytes
Scaffolds for neuronal migration in the cerebral and cerebellar cortices
Electrical signals
Virtually identical in all nerve cells
Similar across species
Signals can be classified into 2 classes
