Exam #3

List the main functions of the nervous system.

Nervous System Functions (easy to memorize):

• Sensory Input → detects stimuli (internal/external)

• Integration → processes & decides (brain/spinal cord)

• Motor Output → responds via muscles/glands

Explain the structural and functional divisions of the nervous system.

CNS:

. Brain + spinal cord

• Main control center (processes information)

PNS:

• All nerves outside CNS

• Connects body to CNS (communication lines)

Functional Divisions (what it does)Sensory (Afferent) Division

• Carries signals TO CNS

• From receptors (touch, pain, etc.)

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Motor (Efferent) Division

• Carries signals FROM CNS

• Sends commands to muscles/glands

Motor splits into:

1. Somatic Nervous System

• Voluntary control

• Controls skeletal muscles

2. Autonomic Nervous System (ANS)

• Involuntary control

• Controls organs, glands

• Sympathetic → “fight or flight”

• Parasympathetic → “rest and digest”

Define neuron, describe its structural components, and relate each structure to its functional role.

A neuron is a specialized cell that receives, processes, and transmits electrical signals in the nervous system.

1. Dendrites (short, branched extensions) - receive incoming signals from other neurons.

2. Cell body: (contains nucleus & organelles) - integrates/decided what to do with incoming signals

3. Axon: (long fiber extending from soma) - conducts electrical impulses away from the cell body.

4. Myelin sheath (fatty insulation around axon) - speeds up signal transmission

5. Axon terminals (branching ends of axon) - release neurotransmitters to communicate with next cell

Describe the structure of the synapse.

is the small junction where one neuron communicates with another neuron or a target cell.

Send (axon terminal) → Gap (synaptic cleft) → Receive (postsynaptic receptors)

Classify neurons structurally and functionally.

1. Multipolar neurons: (efferent)

• found in brain and spinal cord (CNS)

• Function: Motor

2. Bipolar neurons: (afferent)

• Special senses (optic and olfactory)

• Function: sensory processing (vision and smell)

3. Unipolar: (afferent)

• found in sensory ganglia (PNS), so touch, pain, temperature

• Function: carry sensory information to CNS

1 Sensory (afferent) neurons

• carries signals TO CNS

• From receptors (skins, organs)

• Ex: pain, touch, temperature

2. Motor (efferent) neurons

• carry signals FROM CNS

• To muscles or glands

• Ex: movement or secretion

List six types of supporting cells in nervous tissue, and distinguish them by location and function.

CNS:

1. Astrocytes - support and anchor neurons, help form blood brain barrier, regulate nutrients and ions, repair tissues after injury

2. Oligodendrocytes - produce myelin sheath in CNS, one cell can myelinate multiple axons

3. Microglia - immune defense cells of CNS, remove pathogens and dead cells

4. Ependymal Cells - produce and circulate cerebrospinal fluid, help protect and cushion CNS

PNS:

1. Schwann Cells - form myelin sheath around axons, help with nerve regeneration

2. Satellite Cells - surround neuron cell bodies, provide support, nutrients, and regulation

Describe the structure of myelin sheaths.

is a fatty, layered wrapping around an axon that insulates it and speeds up nerve signals.

⚡ Key function link

• Fatty layers = insulation

• Nodes = signal jumping points

• Result: faster nerve impulse conduction (saltatory conduction)

Distinguish grey matter from white matter in the central nervous system.

Define nerve, and describe the structural components of nerves.

Define reflex, and list the basic components of a reflex arc. Distinguish monosynaptic reflexes

from polysynaptic reflexes.

Sketch a reflex arc consisting of stimulus, receptor, sensory neuron, interneuron, motor

neuron, effector, and response. Show how these neurons relate to the basic organization of

the nervous system.

Define convergent and divergent circuits and give an example of each.

Differentiate between serial and parallel processing.

Name the major parts of the adult brain.

Name and describe the locations of the ventricles of the brain.

Describe the distribution of gray and white matter in each part of the brain.

Identify the three subdivisions of the brain stem, and list the major structures in each.

Using the framework of gray matter versus white matter, relate the structures of the

brain stem to the general functions of this part of the brain.

Describe the structure and function of the cerebellum.

Name the three divisions of the diencephalon and their functions.

List the major lobes, fissures, and functional areas of the cerebral cortex.

Name three classes of fiber tracts in the white matter of the cerebrum.

Describe the form and function of the basal nuclei (ganglia).

Describe the locations and functions of the limbic system and the reticular formation.

Describe the meningeal coverings surrounding the brain, and explain how the

meninges and cerebrospinal fluid protect the structures of the central nervous system.

Explain how cerebrospinal fluid is formed, and describe its pattern of circulation.

Describe the gross structure of the spinal cord.

Identify the regions of white matter and gray matter in a cross section through the

spinal cord.

Describe the organization of the neurons in the gray matter of the spinal cord.

Identify the major ascending and descending tracts in the spinal cord, and indicate

the types of stimuli carried on each.

Trace the major neuronal pathways to and from the brain.

Outline the organization of the peripheral nervous system.

Describe the structural components of the peripheral nervous system.

Classify sensory receptors according to body location, stimulus detected, and structure.

Name the 12 pairs of cranial nerves, and describe the structures innervated by each.

Describe the location of a spinal nerve, and distinguish spinal roots from rami.

Describe the somatic innervation of the back, trunk, and limbs.

Define nerve plexus. Name the four main plexuses formed by ventral rami, and the body

region innervated by each. Describe the major nerves originating from each plexus.

Define dermatomes, and explain Hilton’s law of the innervation of joints.

Define the autonomic nervous system (ANS), and explain its relationship to the peripheral nervous

system as a whole.

Compare autonomic neurons to somatic motor neurons.

Describe the basic differences between the parasympathetic and sympathetic divisions of the ANS.

Describe the pathway of sympathetic innervation through cranial nerves and sacral spinal nerves to

the visceral organs.

Describe the effect of parasympathetic innervation on each visceral organ innervated by the

division of the ANS.

Describe the pathways of sympathetic innervation from the spinal cord to the effector organs in the

body periphery, the head, and the visceral organs.

Describe the effect of sympathetic innervation on each effector organ.

Explain the sympathetic function of the adrenal medulla.

Describe the role and location of visceral sensory neurons relative to autonomic neurons.

Explain the concept of referred pain.

Explain how visceral reflexes regulate some functions of visceral organs.

Explain how various regions of the CNS help to regulate the autonomic nervous system.

Briefly describe some diseases of the autonomic nervous system.

List the major endocrine organs, and describe their locations.

Describe how hormones are classified chemically.

Describe the basic interaction between hormones and their target cells. Describe three

mechanisms that control hormone secretion.

Name the basic divisions of the pituitary gland.

List the hormones secreted by the anterior lobe (NA and the cell type that secretes each). State

the basic functions of each hormone.

Explain how the hypothalamus controls secretion of anterior lobe hormones. Define

releasing hormones, and trace their path through the pituitary gland.

Describe the structure of the posterior lobe and the functions of the hormones it releases.

Describe the anatomy of the thyroid gland.

Define and describe the effects of thyroid hormone (TH) and calcitonin, and explain how TH is

secreted.

Describe the anatomy of the parathyroid gland and the function of parathyroid hormone.

Name the two divisions of the adrenal gland, and compare and contrast them in terms of their

structure and the hormones they secrete.

Describe the endocrine functions of the pineal gland, pancreas, thymus, and gonads.

Name a hormone produced by the heart, and define diffuse neuroendocrine system (DNES).

Briefly explain the endocrine functions of the placenta, kidney, and skin.

Define diabetes mellitus.

What organ produces and secretes glucagon?

What organ produces and secretes insulin?

What cell produces and secretes glucagon?

What cell produces and secretes insulin?

What is the effect of glucagon on blood glucose concentration?

What is the effect of insulin on blood glucose concentration?

What is the functional relationship between glucagon and insulin called?