module 4 the better one

• The glial cells in the CNS include astrocytes, microglial, ependymal, and oligodendrocytes.
• The glial cells in the PNS include schwann and satellite cells.
• Both schwann cells and oligodendrocytes are glial cells that form myelin sheaths.
• The 5 major functions of the nervous system are:

  1. receiving sensory input
  2. integrating information
  3. controlling muscles and glands
  4. maintaining homeostasis
  5. establishing and maintaining mental activity
• The central nervous system is composed of the brain and the spinal cord.
• The peripheral nervous system can be split into sensory and motor divisions. The motor division can be split into autonomic and somatic divisions, and the autonomic division can be split into parasympathetic and sympathetic divisions.
• astrocytes are glial cells in the CNS that provide structural support, regulate neuronal signaling, contribute to the blood brain barrier, and aid neural tissue repair.
• microglial cells are glial cells that protect the CNS from infection and responds to inflammation by becoming phagocytic.
• Ependymal cells are glial cells found in the CNS that line the ventricles of the brain and central canal of the spinal cord. They circulate cerebrospinal fluid, form choroid plexus which produce cerebrospinal fluid.
• Oligodendrocytes are glial cells that myelinate axons in the CNS.
• Schwann cells are glial cells that myelinate axons in the PNS.
• Satellite cells are glial cells found in the PNS which support neurons, provide nutrients and protect neurons from heavy metal poisons.
• Diagram of a neuron in the CNS.

  A) cell body

  B) dendrites

  C) axon

  D) oligodendrocyte

  E) myelin sheath

  F) node of ranvier

  G) axon terminal

  
• A sensory or afferent neuron transmits information to the CNS from sensory receptors in the PNS. Most sensory neurons are found as pseudo-unipolar neurons which have a single axon.

  
• A motor or efferent neuron transmits information from the CNS to an effector of the body or can be found in the CNS. Most motor neurons are found as multipolar neurons which have a single axon and many dendrites.

  
• Bipolar neurons are specialized neurons that have a dendrite and one axon. They are usually found in special sense organs, such as the eyes and the nose.

  
• The membrane potential is the difference in electrical potential between the inside and outside of a cell.
• The resting membrane potential of -70 mv is induced by a high Na+ concentration in the extracellular environment, and K+ concentration and negatively charged proteins in the intercellular environment
• A polarized neuron has a negative membrane potential.
• A sodium potassium pump delivers 2 K+ ions into the cell, and 3 Na+ ions out of the cell, creating a charge difference and making the extracellular environment more positive.
• There are two type of protein gated channels: voltage channels, which are opened by a change in electrical property, and chemically gated channels, which are open by specific chemicals.
• Saltatory conduction is the conduction that occurs throughout a myelinated axon as the current jumps down the nodes of ranvier.
• The cerebellum helps maintain muscular tone, balance, and coordinates fine motor movement.
• The brainstem connects the brain to the spinal cord and is composed of three parts: the pons, the medulla oblongata, and the midbrain.
• Label this part of the brain.

  A) diencephalon

  B) midbrain

  C) pons

  D) medulla oblongata

  
• The medulla oblongata has ascending and descending nerve tracts running through it to convey signals to and from the brain. The structure also regulates heart rate and blood pressure. It is also involved with breathing, sneezing, swallowing, vomiting, and much more.
• The pons is located between the medulla oblongata and the midbrain. It functions as a bridge between the cerebrum and cerebellum. It controls much of the same things that the medulla oblongata controls.
• The main components of the diencephalon are the thalamus, the hypothalamus, and the epithalamus.

  
• Label this region of the brain.

  A) Thalamus

  B) Hypothalamus

  C) Diencephalon

  D) Epithalamus

  E) thalamus

  
• The thalamus is the largest part of the diencephalon. Ascending neurons run through it to contact the cortex. It influences mood and registers unlocalized uncomfortable perception of pain.
• The epithalamus contains the pineal gland which influences the onset of puberty and affects long-term cycles that are affected by the light dark cycle. It is also involved with emotional and visceral responses to odours.
• The hypothalamus is responsible for regulating body temperature, hunger, thirst, sleep, and circadian rhythms. It also plays an important role in controlling emotions such as anger and fear. It is connected to the pituitary gland via the infundibulum (hypophyseal stalk).
• Label the brain

  A) frontal

  B) parietal

  C) occipital

  D) temporal

  E) cerebullum

  
• Label this

  A) frontal

  B) parietal

  C) occipital

  
• The cerebrum is divided into 5 lobes: frontal, parietal, occipital, temporal, and insula.
• The frontal lobe in the cerebrum is in control of voluntary motor functions, motivation, aggression, mood, and olfactory (smell) reception.
• The parietal lobe is the principal center for receiving and consciously perceiving most sensory information, such as touch, pain, temperature, and balance. It is separated by the frontal lobe by the central sulcus
• The occipital lobe functions in receiving and perceiving visual input and is not distinctly separate from the other lobes.
• The temporal lobe is involved with olfactory and auditory sensations as well as memory.
• The insula is located deep inside the cerebrum and is involved with the perception of taste.