Anatomy - Nervous System Flashcards
Central Nervous System
Brain, spinal cord
Peripheral Nervous System
cranial nerves, spinal nerves, ganglia
General functions of CNS and PNS
Collecting information, processing and evaluating information, responding to iformation
Two types of nervous system cells
Neurons (nerve cells) and glial cells
Functions of neurons
electrically excitable and transmit and receive impulses
Functions of glial cells
Support and protection
What are some special characteristics of neurons?
High metabolic rate, extreme longevity and mostly non-mitotic, most cell bodies have one or more processes
What structures are part of the typical neuron?
Cell body, dendrites, axon, axon hillcock
Cell body of a neuron
biosynthetic centre
Dendrites
short processes that branch from the cell body and receive nerve impulses
Axons
transmit nerve impulses to other cells
Axon hillcock
connects to the cell body
Where do neuroglia exist?
CNS and PNS
Compare and contrast neurons and glial cells.
Glial cells are smaller, undergo mitosis and there are more of them. Additionally, glial cells protect and nourish while neurons are electrically excitable and transmit and receive impulses.
List four types of glial cells that are found in the CNS
astrocytes, ependymal cells, microglial cells, oligodendrocytes
What is an astrocyte?
blood vessel to neurons and form the blood brain barrier
What do ependymal cells do?
They produce CSF
What do microglial cells do?
They are part of the immune response
What do oligodendrocytes do?
generate myelin
What are the two major neuroglia of the PNS?
Satellite cells and Schwann cells
Describe a satellite cell
A glial cell found in the PNS that surrounds neuron cell bodies. They can be considered similar to astrocytes of the CNS.
Describe Schwann cells
A glial cell of the PNS that forms myelin sheaths around nerve fibers (insultation). They also help to regenerate fibers. They can be considered similar to the oligodendrocytes of the CNS.
List the three connective tissues of the nerve structure.
Endoneurium, perineurium, epineurium
What does the endoneurium surround?
Each axon
What does the perineurium surround?
Each individual fascicle
What does the epineurium surround?
around the entire nerve
What is the difference between the CNS and PNS?
CNS is brain and spinal cord. It processes and evaluates information to send to the effectors. PNS is the cranial nerves, spinal serves and ganglia. It acts as receptor of information to send to the CNS and acts as effectors for the response determined by the CNS.
What are the four major regions of the brain?
Cerebrum, diencephalon, brainstem and cerebellum
Describe the outer surface of the brain’s cerebrum.
It is wrinkled with gyri, which are folds, and suci, which are depressions between the folds.
Define gray matter in the CNS
Composed of cell bodies, dendrites, unmyelinated axons. It forms te brain cortex (brain surface) and forms clusters (cerebral nuclei).
Define white matter in the CNS
Myelinated axons. It is deep to the cortex.
What structures support and protect the brain?
The bony cranium, the protective connective tissue known as the meninges, the cerebrospinal fluid (CSF) and the blood brain barrier.
What functions does the CSF play?
Buoyancy, protection, transport of nutrients and waste
Which four ventricles contain CSF?
2 lateral ventricles, third ventricle and fourth ventricle
Where is the third ventrical located?
diencephalon
Where is the fourth ventrical located?
between the pons and cerebellum
List the three layers of cranial meninges from superficial to deep
dura mater, arachnoid mater and pia mater
What are the functions of the meninges?
separate brain and bones, protects blood vessels and contains CSF
What functions occur in the cerebrum?
conscious thought and intellectual functions
What is the surface of the cerebrum marked by?
sulci, gyri and fissures
What separates the left and right hemispheres of the cerebrum?
the longitudinal fissure
What is the function of the corpus callosum?
It connects the two hemispheres
List the lobes of the cerebrum.
frontal lobe, parietal lobe, occipital lobe, insula lobe, and temporal lobe
What occurs in the frontal lobe?
Voluntary motor function, concentration, verbal communication, decision making, planning and personality
What occurs in the parietal lobe?
general sensory functions
What occurs in the occipital lobe?
processes incoming visual information, stores visual memories
What occurs in the insula lobe?
memory, taste interpretation, consciousness
What occurs in the temporal lobe?
hearing and smell
Describe the diencephalon.
Final relay point for sensory information that will be processed.
What does the diencephalon include?
Thalamus, epithalamus and hypothalamus
Describe the thalamus.
Pair of oval masses that act as a relay point for processing of sensory information (except olfaction).
Describe the epithalamus.
Includes the pineal gland and the habenular nuclei.
Describe the pineal gland.
Contained in the epithalamus in the diencephalon. It secretes melatonin (circadian rhythm - sleep).
Describe the habenular nuclei.
Contained within the epithalamus in the diencephalon. It relays signals from the limbic system to the midbrain; involved in visceral and emotional responses to odor.
Where is the hypothalamus found?
diencephalon
What are the functions of the hypothalamus?
master control (ANS and endocrine system), regulates temperature and circadian rhythms, control of emotional behaviour and food and water intake
What is the infundibulum and where is it located?
It is found in the diencephalon and attaches to the pituitary gland located in the hypothalamus.
List the regions of the brainstem.
Midbrain, pons and medulla oblongata
What are the functions of the brainstem?
Acts as a passageway from the cerebrum to the spinal cord, and autonomic centres - reflexes for survival
Describe the midbrain
Part of the brainstem. Cerebral aquaduct connects ventricles (3rd and 4th ventrical), auditory reflex and produces dopamine.
Describe the pons
Part of the brainstem. Helps regulate breathing, receives auditory input and localizes sound.
Describe the medulla oblongata.
Includes the autonomic neuclei which includes the cardiac center, the vasomotor center and the medullary respiratory center. Also other nuclei involved in coughing, sneezing, salivation, swallowing, gagging and vomiting.
What occurs in the cardiac centre and where is it located?
It is located in the medulla oblongata and addresses heart rate and contraction strength.
What occurs in the vasomotor centre and where is it located?
It is located in the medulla oblongata and it regulates vasoconstriction and vasodilation.
What occurs in the medullary respiratory centre and where is it located?
It is located in the medulla oblongata and it regulates the respiratory rate.
Describe the functions of the cerebellum.
Coordinates and fine-tunes skeletal muscle, stores movement patterns, equilibrium and posture, receives proprioceptive (sensory) information and monitors the position of each body joint and its muscle tone.
How many pairs of cranial nerves are there?
12 pairs of nerves originating directly in the brain innervate parts of the head region.
What is the main function of the spinal cord?
It acts as a link between the brain and body.
What are the functions of the spinal nerves?
They act as a pathway for sensory and motor impulses and reflexes.
What are the main regions of the spinal cord?
Cervical, thoracic, lumbar, sacral and coccygeal
What is the tapered end of the spinal cord called?
Conus medullaris
What is the cauda equina?
A group of axons located inferiorly on the spinal cord.
What is the filum terminale?
Pia mater anchored to the coccyx.
List the spinal meninges and some of the related functions.
The dura mater fuses with connective tissue of the spinal nerves, the arachnid mater is the subarachnoid space = CSF, and the pia mater is made of delicate elastic/collagen fibers. Also the epidural space and the subdural space.
What is the epidural space?
Dura mater and periosteum (connective tissue, blood vessels, fat)
What makes up gray matter in the spinal cord?
dendrites, cell bodies, unmyelinated axons, interneurons and glial cells.
What makes up white matter (columns) in the spinal cord?
Myelinated axons
Where is the sensory nuclei located?
Posterior (dorsal) horns
Where is the somatic motor nuclei located?
Anterior (ventral) horns (voluntary)
Where are the automatic motor nuclei located?
Lateral horns
Describe a spinal nerve.
Anterior (ventral) root + posterior (dorsal) root. They travel within intervertebral foramen. Both motor and sensory axons.
Breakdown the 31 pairs of spinal nerves.
8 cervical nerves, 12 thoracic nerves, 5 lumbar nerves, 5 sacral nerves and 1 coccygeal nerve
