Summary of the structural and functional classification of the nervous system

Structural classification: Two subdivisions

1.) Central nervous system and the peripheral nervous system. The central nervous system includes the brain, spinal cord and a complex network of neurons. It acts as the command center for the nervous system.

2.) The peripheral nervous system (PNS) consists of the nerves and neurons that reside or extend outside the central nervous system. Consisting mainly of nerves extending from brain (cranial nerves) and spinal cord (spinal nerves). They carry impulses from sensory receptors to central nervous system and back to necessary glands or muscles.

Functional Classification- concerned only with peripheral nervous system structures & is divided into two subdivisions:

1) Sensory or afferent division- nerve fibers that carry impulses to CNS from sensory receptors. Somatic sensory fibers- delivers impulses from skin, skeletal muscle & joints.

Visceral sensory fibers- delivers impulses from visceral (internal) organs.

2) Motor/efferent division- nerve fibers that carry impulses from central nervous system to effector organs, the muscles and glands, thus bringing about (effecting) a response. Somatic/voluntary nervous system- allows for voluntary control of skeletal muscles, although some activities may be reflexive.

Autonomic/involuntary nervous system- regulates events that are involuntary or automatic, smooth muscle, cardiac muscle & glands. Sympathetic and Parasympathetic bring opposite effects.

Tendons and Smooth Muscle

#13.) What is the function of tendons?

The tendon is a tough, flexible band of fibrous connective tissue and its main function is connecting muscle tissues to the bones. When a muscle contracts, it pulls on a bone to cause movement; the structure that transmits the force of the muscle contraction to the bone is called a tendon. Tendons can have several shapes ranging from wide and flat, ribbon and fan shaped.

 #38.) Harry was pondering an exam question that said, "What muscle type has elongated cells and is found in the walls of the urinary bladder?" What should he have responded? 

The type of muscle that has elongated cells and is found in the walls of the urinary bladder is the smooth muscle. Smooth muscles are found in many areas of the body, including the urinary tract, reproductive, and digestive system. Smooth muscles are composed of elongated, spindle shaped cells.  Smooth muscles in the bladder are in three layers, facing in different directions for strength. They allow the bladder to expand as more urine enters it, and they gently contract to aid urination when the bladder is voided.

Work cited:

 "skeletal muscles". Video. Encyclopædia Britannica Online. Web. 21 Sep. 2013. <http://www.britannica.com/EBchecked/media/153042/Skeletal-muscles-are-attached-to-the-bones-by-tendons>

Urinary bladder Image: http://www.ouhsc.edu/histology/Glass%20slides/37_05.jpg

 

Axial Skeleton and Appendicular skeleton

The Axial skeleton, the bones that form the longitudinal axis of the body and consists of 80 bones (centrally located). These include the skull (cranial and facial bones), hyoid bone, veritable column (Spine or backbone), sternum and ribs.

Four specific bones in the axial skeleton: Frontal bone, inferior nasal conchae, hyoid bone and vomer.

The appendicular skeleton is the part of the skeleton that includes the pectoral girdle and the pelvic girdle and the upper and lower limbs and consists of 126 bones. Primarily comprised of bones and is held together with ligaments, with cartilage as the connective tissue.

Four specific bones in the appendicular: Femur bones, Scapulae, Humerus and ishium.

Vocabulary

Epicondyle - A rounded projection at the end of a bone, located on or above a condyle and usually serving as a place of attachment for ligaments and tendons.

Facet - A small, smooth, flat surface, as on a bone or tooth.

Foramen- A hole or opening in a bone or between body cavities.

Fossa- A depression; often an articular surface

Process trochanter- a broad, flat process on the femur, at the upper end of its lateral surface (greater t.), or a short conical process on the posterior border of the base of its neck (lesser t.) .trochanter´ictrochanter´ian

Tubercule- A nodule or small rounded process.

Sunscreen Introduction, Sun Damaging rays and SPF protection

   While watching the sunscreen videos (sunscreen introduction, sun damaging rays and sun protection) I learned a few things that surprised me.

   I couldn’t believe that water resistant labels only work for such a short period of time. Does anyone really re-apply every 40-80 minutes? I know I never have I usually don’t reapply until I start looking a bit pink.

   Also it’s amazing that labels can be printed containing information that is so false such as “All day protection.” I will now be more aware when purchases SPF’s and reading back of labels. I always just paid attention to amount of SPF coverage and that was it?

   Another surprise was that a thin layer of lotion would not be as affect. Which made me wonder if there is a big difference in spray sunscreens verses lotions? I know the majority of people today use a spray sunscreen for convenience but is it really as affective as a thick coat of lotion?

I am obsessed with the sun and spend any moment I soaking it up. I still can’t believe I didn’t know some of the information about sunscreen protection.

Cutaneous: relating to, or affecting the skin.

Epidermis is the outer, protective, non vascular layer of the skin of vertebrates, covering the dermis.

Dermis is the sensitive connective tissue layer of the skin located below the epidermis, containing nerve endings, sweat and sebaceous glands, and blood and

Lymph vessel is a thin tube that carries lymph (lymphatic fluid) and white blood cells through the lymphatic system

Blister is a small bubble on the skin filled with serum and caused by friction, burning, or other damage.