A&P Lab 1 Practical #2: Nervous System - Chapters 15, 17, & 19

This flashcard set covers all of the content we'll be tested on for our A&P Lab 1 Practical Exam #2. It covers Chapters 15, 17, and 19 which cover the Histology of Nervous Tissue (Ch. 15), Gross Anatomy of the Brain and Cranial Nerves (Ch. 17), and The Spinal cord and Spinal Nerves (Ch. 19) respectively. Practical Exam #2 is 92% labeling.

To-Do List for flashcard deck:

• Anatomical language flashcards

• Diagram / labeling w/ location, physical description (function, etc as needed)

• Cranial Nerves 1-12

• Add any additional flashcards I need

• Edit and organize and re-order and clean up flashcards AND finish description

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REVIEW: Anatomical terminology

1. Toward the front

2. Toward the back

3. Toward the middle

4. Toward the side

5. Toward the head

6. Toward the feet

7. Closer to the point where a limb attaches

8. Farther from the point where a limb attaches

9. Near the surface of the body

10. Away from the surface of the body

1. Toward the front → Anterior / Ventral

2. Toward the back → Posterior / Dorsal

3. Toward the middle → Medial

4. Toward the side → Lateral

5. Toward the head → Superior / Cranial

6. Toward the feet → Inferior / Caudal

7. Closer to the point where a limb attaches → Proximal

8. Farther from the point where a limb attaches → Distal

9. Near the surface of the body → Superficial

10. Away from the surface of the body → Deep

What is the Nervous System?

• Master integrating and coordinating system of the body

• Continuously monitors and processes sensory information from the external and internal environment

• Every thought and action of human body is a reflection of the nervous system’s processes

How does the Nervous System work?

• Processes and integrates new information (“inputs”) with information previously fed into it to produce a response.

• Has two major divisions: CNS and PNS

What are the major divisions of the Nervous System?

Two major divisions:

1. Central Nervous System (CNS)

2. Peripheral Nervous System (PNS)

What organs/structures are found in the Central Nervous System (CNS)? Function?

• Brain and spinal cord

• Interprets sensory information based on that information and past experiences

What organs/structures are found in the Peripheral Nervous System (PNS)? Function?

• Everything in the nervous system except for the brain and spinal cord including: Spinal nerves, ganglia, and cranial nerves

• Connects the CNS to the rest of the body

Sensory vs Motor vs Mixed Division of Nervous System

Sensory (Afferent) Division: UP

• Sensory = Afferent division

• Carries nerve impulses to CNS from sensory receptors

Motor (Efferent) Division: DOWN

• Motor = Efferent division

• Transmits impulses away from the CNS to effector organs (muscles and glands)

• Splits into SNS and ANS

Mixed Nerves (Both Sensory and Motor)

• Nerve bundles containing both afferent (sensory) and efferent (motor) fibers traveling in parallel pathways.

• Ex: All 31 pairs of spinal nerves and mixed cranial nerves (CN V, VII, IX, and X).

What is a neuron? Function?

• Neuron = Nerve cell

• Transmits electrical and chemical messages throughout the body to control movement, senses, and thinking

What are the important structures of an neuron?

8 Structures:

1. Cell Body (Soma)

2. Dendrites

3. Axon

4. Myelin Sheath (via Schwann cells/oligodendrocytes)

5. Nodes of Ranvier

6. Axon Terminals

7. Myelin Sheath

8. Axon Terminals / Terminal Buttons

• Additionally, the cytoskeleton is important for structural support and substance transport.

What is an axon?

• Do this for the other parts of neuron later

• Long, thin, thread-like fiber projection / extension of nerve cell (neuron)

• Sends electrical signals away from the cell body to other cells

Label: Axon hillock

*Do this for the other parts of the neuron as well

• Location: At the junction where the cell body (soma) of a neuron transitions into the axon

What are the major divisions of the human nervous system?

REPEAT QUESTION

Two major divisions:

1. Peripheral Nervous System

• Everything but spinal cord and brain

2. Central Nervous System

• Spinal cord and brain

Label: Cerebrum

• Location: The “big brain” inside the skull at the top and front of the skull

• The largest, topmost portion of the human brain

• Function: Sensory processing, voluntary muscle movement

*Don’t confuse with the cerebellum (“the little brain”)

Label: Cerebellum

• Location: lower back of the brain, directly beneath the larger cerebrum and behind the brainstem

“Small brain” (think -ellum = small)

The cerebellum is located at thelower back of the head, beneath the large cerebral cortex and behind the brainstem

• Function: Maintain balance and posture, coordinate voluntary muscle movements

What is a nerve plexus?

A nerve plexus is a complex network of intersecting nerves that route sensory and motor signals between the spinal cord and specific regions of the body

What are the major nerve plexuses in the body?

5 Major Plexus:

1. Cervical Plexus

2. Brachial Plexus

3. Lumbar Plexus

4. Sacral Plexus

5. Coccygeal

Label: Cervical plexus

• First plexus of human body / at top (?)

• Superior to brachial plexus

Label: Cervical enlargement

• The region of the c-spine that gets wider

Label: Brachial plexus

• Think: Located at brachial artery / shoulder

*Not on the inside where the musculocutaneous nerve is

• Inferior to cervical plexus

Label: Intercostal nerves

• Intercostal = Between the ribs

Label: Lumbar plexus

• Location: Lower back (lumbar region), lying in the retroperitoneal space (behind the abdominal cavity lining).

Label: Lumbar enlargement

• AKA lumbosacral enlargement

• A widened, thickened region of the spinal cord that provides the neural connections for the lower limbs

Label: Sacral plexus

• Inferior to lumbar plexus

• Think: Above coccygeal / above area that goes into / behind pelvic bones

• A web of intersecting nerves located on the back wall of the pelvis that supplies motor and sensory function to the pelvis, buttocks, and lower limbs

Label: Conus medullaris

• Think: Looks like little cones

• The tapered, cone-shaped lower end of the spinal cord

Label: Filum terminale

• Fibers at the very end of the spinal cord // Delicate strand of fibrous tissue that anchors the lower end of the spinal cord to the coccyx

Label: Cauda equina

• Think: “Horse hair-like projections” AFTER spine ends

• A bundle of nerve roots that continues below where the spinal cord ends.

Label: Intervertebral discs

• Inter = Between

• Vertebral = Vertebrae

• Discs between vertebrae

• A fibrocartilaginous cushion that sits between adjacent vertebrae in the spinal colum

• Function: Shock absorber, allows spinal flexibility

Label: Intervertebral foramen

• Foramen = Opening

• Think: Small openings in spine near vertebrae

• A small, oval-shaped opening between adjacent vertebrae where spinal nerves and blood vessels pass from the spinal cord to the rest of the bod

• Spinal nerves exit spinal column through intervetebral foreman

Label: Spinal nerve

• Location: Along the length of the spinal cord

• Humans have 31 pairs of spinal nerves (and 12 CN) extending from the brain to the tailbone

• Spinal nerves exit spinal column through small openings called intervertebral foramina (think: “small holes'“) located between adjacent vertebrae

What is the breakdown for the spinal nerves?

31 Spinal Nerves in human body split into 5 sections:

1. Cervical: C1-C8

• Neck region

2. Thoracic: T1-T12

• Upper and mid-back

2. Lumbar: L1-L5

• Lower back

2. Sacral: S1-S5

• Pelvic region (sacrum)

2. Coccygeal (Co1)

• Started as 3 bones fused throughout childhood

• Located a the very bottom of the spine - the coccyx

CAN THE LADY SAVE CATS to remember the names + order of SN

Label: Cervical plexus

• A network of nerve fibers formed by the anterior rami of the first four cervical spinal nerves (C1–C4) located deep in the neck.

Label: Brachial plexus

• Inferior to cervical plexus

Label: Lumbar plexus

• Superior to sacral plexus

Label: Sacral plexus

• Inferior to cervical plexus and superior to coccygeal

• Collection of nerves in sacral spine

Label: Spinal curve

• The natural or abnormal alignment, direction, and degree of curvature of the backbone

Label: Dorsal root ganglion

• Dorsal = Back

• Looks like a bulge (Think: ganglion = bulge)

• Positioned in the intervertebral foramina (the small bony openings between adjacent vertebrae) AND found at very spinal level between spinal column

• A cluster of sensory neuron cell bodies located on the dorsal root of a spinal nerve just outside the spinal cord

Label: Dorsal root

• Dorsal = Back

• Connected to dorsal root ganglion and closer to the grey matter than the dorsal root ganglion is

• Emerges from the posterior lateral sulcus of the spinal cord

• A sensory nerve bundle that transmits information from the body's peripheral receptors to the spinal cord

Label: Ventral root

• Ventral = Front

• Location: Located at the front (anterior side) of the spinal cord where small groups of nerve fibers emerge to carry motor signals out to the body

• CLOSER TO VENTRAL MEDIAN FISSURE (big opening / slit in spinal cord cross section)

• Starts as tiny thread-like rootlets coming out of a groove from the front of the spinal cord

• Runs outward and meets the dorsal root (which handles sensory signals) just before they pass through a tiny opening in the backbone to form a regular spinal nerve

• Function: Motor control

Label: Epidural space

• Cylindrical, fat-filled compartment located outside the dural sac inside the bony vertebral canal

• Has a distinct yellowish hue and a highly vascularized, soft, compartmentalized texture

• Outside the protective dural sac of the spinal cord

• Location: Inside the spinal canal between the bones of the vertebrae and the outermost layer of the spinal meninges (the dura mater)

• is the outermost part of the spinal canal, located between the tough protective membrane covering the spinal cord (called the dura mater) and the inside walls of the bony vertebrae

• Runs the entire length of the spine

Label: Dura mater

• Blue layer

• Dura mater = “Tough mother”

• Outermost, thick protective meningeal layer

• Thick, tough, leather-like or rubberized membrane

DAP from superior to inferior

Label: Dura mater

BLUE LAYER

Label: Falx cerebri

• Top of skull inside

• Dural fold separating cerebral hemispheres

Label: Tentorium cerebelli

• Think: The “floor” of the skull / floor of “tent” if placed in skull

• Dural fold seperating cerebrum from cerebellum

• Location: Sits horizontally inside the cranium like a tent roof

Label: Falx cerebelli

• Small fold separating cerebellar hemispheres

Label: Subdural space

BLUE LAYER

Label: Arachnoid mater

SPIDER WEB-Y LOOKING

VERY HALLOWEEN-Y

Label: Subarachnoid space

LIGHT BLUE

• CSF inside of it

Label: Pia mater

• PINK (PIA = PINK)

• innermost, highly vascularized protective layer that forms a tight, form-fitting seal over the nervous tissue

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Label: Gray matter

• Gray Matter = Cell bodies and terminals

• Location

The gray matter of the spinal cord is a butterfly- or H-shaped region in the center of the cord that contains nerve cell bodies, unmyelinated fibers, and glial cells. It processes spinal reflexes and integrates incoming sensory and outgoing motor signals. You can learn more about these internal structures through the The Internal Anatomy of the Spinal Cord guide

• Three main regions with gray matter in the spinal cord

What regions of the spinal cord are made up of gray matter?

3 Main Regions:

1. Posterior (Dorsal) Horn

2. Anterior (Ventral) Horn

3. Lateral Horn

Label: Posterior Horn

• AKA: Dorsal horn

• Location: Posterior (back) section of the spinal cord’’s butterfly / “H-shaped” gray matter

• Position: Found on the back or rear side of the spinal cord inside the central gray matter region

• Orientation: Forms posterior projection (the upper or rear “wings”) of the butterfly-shaped gray matter

*Extends along the length of the spinal cord on the left and right sides

What is the function of gray matter?

1. Signal Integration

2. Controlling reflexes

3. Sending motor commands

Label: Gray commissure

• Location: At the center of the spinal cord, surrounding the small central canal (which contains CSF) and bridges the H-shaped columns of gray matter (between the anterior/ventral horn and posterior/dorsal horn)

• Description: Thin, horizontal strip of gray matter that connects the left and right halves of the spinal cord

What are the subdivisions for the gray commissure?

Two subdivisions:

1. Anterior gray commissure (in front of the central canal)

2. Posterior gray commissure (behind the central canal)

Label: White matter

• White matter = Axon therefore it transmits signals

• Axons give it the white appearance

• Location: On the outside (periphery) of the spinal cord surrounding the butterfly-shaped gray matter in the center forming the superficial boundary

• Divided into 3 main regions in spinal cord

white matter of the spinal cord is the outer tissue layer that surrounds the central, butterfly-shaped gray matter and acts as a signal highway connecting the body to the brain. [1, 2, 3]

Structure and Composition

• Appearance: It looks white because it is rich in myelin, a fatty insulating cover around nerve fibers. [1, 2]

• Contents: It consists mostly of myelinated axons (nerve fibers) rather than cell bodies. [1, 2]

• Organization: It is divided into three paired columns or funiculi:

  • Dorsal (posterior) column: Located in the back.

  • Lateral column: Located on the sides.

  • Ventral (anterior) column: Located in the front. [1, 2, 3, 4]

Function and Pathways

The white matter contains bundles of nerve fibers called tracts that transmit signals

What regions of the spinal cord does white matter make up?

3 Funiculi:

• Funiculi = Column

1. Dorsal (posterior) column

2. Lateral column

3. Ventral (anterior) column

Label: Dorsal/posterior funiculi

• Funiculus = Column

• Dorsal = back

TWO COLUMNS

Label: Ventral/anterior funiculus

• Funiculus = Column

Label: Lateral funiculus

• Funiculus = Column

Label: Posterior median sulcus

• Posterior = Behind

• sulcus = shallow groove

Label: Anterior median fissure

Fissure = Deep section

Label: Central canal

• Hole in the center running through the entire spinal cord

Label: Spinal nerve on spinal cord cross section of thoracic region

Label: Dorsal root ganglion

Dorsal= back

Ganglion = bulge

Label: Dorsal root

Label: Ventral root

Ventral = front

Label: Dorsal horn

Label: Ventral horn

Dorsal = back

Label: Ventral horn

Label: Lateral horn

Label: Posterior median sulcus

Label: Anterior median fissure

Label: Gray matter

Label: Gray commissure

Label: White matter

Label: Dorsal funiculus

• Funiculus = Column

Label: Ventral funiculus

• Funiculus = Column

Label: Lateral funiculus

• Funiculus = Column

Label: Central canal

Label: Cervical plexus

Label: Brachial plexus

Label: Lumbar plexus

Label: Sacral plexus

Label: Conus medullaris

• Description: Tapered, cone-shaped lower end of the spinal cord

• 
  

What are the peripheral nerves?

9 Main Peripheral Nerves:

1. Radial nerve

2. Median nerve

3. Axillary nerve

4. Musculocutaneous nerve

5. Ulnar nerve

6. Femoral nerve

7. Sciatic nerve

8. Fibular nerve

9. Tibial nerve

Label: Radial nerve

• Think: Thumb / “where I take a radial pulse”

• 
  

Label: Median nerve

Median = Middle (of arm in this case)

Label: Axillary nerve

Nerve in shoulder

*not musculocutaneous

Label: Musculocutaneous nerve

Label: Ulnar nerve

• Think: Pinky

• Location: Refers to structures in the forearm and hand located on the same side as the pinky finger

Label: Femoral nerve

• Think: Femur

• Location: Located in lower back, pelvis,and travels down the front of each thigh

Label: Sciatic nerve

THIGH

• Think: Runs from butt to leg

• Location: In the lower spine and runs down the back of each leg

Label: Fibular nerve

BUTT

Label: Tibial nerve

OUTSIDE

Label: Cerebrum

• Location: Located at the lower back of the brain, directly beneath the rear of the cerebrum and behind the brainstem

• Split into left and right hemispheres

• Has a bundle of nerves called corpus callosum that joins the two halves to send signals back and forth

• Description: Large, upper, wrinkled part of brain

Label: Cerebellum

• Location: Lower back of the skull and sits at the back of head, below the cerebrum and behind brainstem

• Has two hemispheres and a middle section called the vermis

• An inner branched white matter pattern → the arbor vitae or tree of life (Think: Looks like tree branches)

• Description: Small, tightly folded structure located underneath the back of the cerebrum