QUESTIONS:
A. (12 points)
Explain the anatomy of the ‘knee jerk’ (or patellar) *reflex* caused by tapping the patellar tendon below the right knee, including the parts of the nervous system that respond to the sensory input and cause the motor output. You may do this in list form.
Address the following:
- Which anatomical parts of the *spinal cord* — spinal cord region, roots, horns, rami — are used during the sensory and motor portions of the reflex arc (in order)?
- Which specific plexus, nerve(s), and muscle(s) are used in the sensory and motor activity?
- Although the brain is not involved in producing the motor response, which part of the *brain* is activated so that the person becomes AWARE that the knee was stimulated?
B. (8 points)
List the structures involved in taking blood from the left atrium, through relevant heart structures and delivering the blood to the capillaries of the myocardium of the anterior wall of the left ventricle, then back to the right atrium.
Include all relevant heart valves, chambers and major vessels.
left atrium
1. ________________________________________
2. ________________________________________
3. ________________________________________
4. ________________________________________
5. ________________________________________
6. ________________________________________
myocardial capillaries in anterior left ventricle wall
7. ________________________________________
8. ________________________________________
right atrium
Which anatomical parts of the *spinal cord* — spinal cord region, roots, horns, rami — are used during the sensory and motor portions of the reflex arc (in order)?
Introduction
The spinal cord is a long nerve tract that runs from the brain to the rest of your body. Every part of your body has a part of this nerve tract, and every part plays an important role in how we move and feel. The spinal cord region includes all of the main parts you need to know about when talking about reflex arcs:
Spinal cord region
The spinal cord region is the grey matter of the spinal cord. It contains neurons that convey information about touch, pain and temperature to your brain.
The central canal is a tube-like structure that runs through your spinal column from front to back, connecting with each vertebrae on its way (see image above). This can be seen in cross section as well as on an MRI scan. It contains an inner lining called endoneurium which provides structural support for any connective tissue found within it; this includes blood vessels supplying nutrients to tissues within our bodies!
Roots
The roots are the axons that extend from the spinal cord to the periphery. They are made up of nerve fibers and carry sensory information to the spinal cord, as well as motor information out of it.
Horns
The horn is the region of the spinal cord that contains the gray matter. It is located between the dorsal and ventral roots, which are branches of neurons found in this area. The horns contain cell bodies for motor neurons (nerve cells that control movement), as well as sensory fibers from these same motor neurons to their targets on muscles or skin receptors for touch, pressure and pain.
Horns can be divided into five categories based on where they are relative to other components: first-, second-, third-, fourth-and fifth-order horns.[1]
The first order consists of two sections called anterior horns; these are located anteriorly at their respective levels within an individual vertebrate’s spinal cord (namely: T1 and L2). They receive input from other structures such as muscle fibers or proprioceptors located outside them (e.g., joint capsules). These inputs project directly back onto neighboring portions within each respective segmental level before branching off again toward higher levels via three main pathways: corticospinal tract; rubrospinal tract; tectospinal tract; etc.[2]
Rami
The rami are the branches of the spinal nerve, and contain axons from sensory and motor neurons. They also contain blood vessels, lymphatic vessels, and sympathetic and parasympathetic nerves.
The anatomical parts used during the reflex arc are (in order): Spinal Cord Region -> Roots -> Horns -> Rami
The anatomical parts used during the reflex arc are (in order): Spinal Cord Region -> Roots -> Horns -> Rami. The spinal cord region contains neurons that transmit sensory information to other parts of your body and control muscles. This is called a simple sensory and motor pathway, or reflex arc.
The reflexes are important because they help us understand how our bodies work as well as what happens when they don’t work properly. They also help doctors diagnose spinal cord injuries by testing neurological function after injury has occurred.
Conclusion
This is an important concept to remember when studying the spinal cord and its functions. The spinal cord region is where the nervous system receives and transmits information from the brain and other parts of our bodies. The roots are what connect all of these structures together and allow them to communicate with each other. Then there are the horns and rami, which are two different types of tissue within this area.