sem.break'ing glass. :D

it's semestral break. once again.
i thought i would have learn a new topic this week. i miss discussions already. i looooooove to learn new in biology. i wanted to have biology classes. but unfortunately, some activities interrupt the classes. gosh. i wanted to rip them off and go on with the discussion. :D haha. kidding. **

anyway. enjoy vacation. :P

oh mm gii. **

i really wanted to learn a lesson. but we were caught in a rush by the un bazaar. so. it means we just had activities and works related to the CNS part 1. :D

but i'm really looking forward to learn the new lesson as soon as possible. :)

' -- LiFE IS A BiT HARD iF YOU DON'T UNDERSTAND WHAT iT MEANS. :) --'

i'm feelin' nervous. :D

nervous system. no relation to feeling nervous. :) **

nervous system. it is composed of two types: central nervous system and peripheral nervous system. central serves as the sensory system and refers to the brain and spinal cord. on the other hand, peripheral serves the input and output pathways of the commands of the nervous system. peripheral has two branches: somatic (one that controls skeletal muscles) and autonomic (one that controls visceral and cardiac muscles). in autonomic, it is still divided into two branches, the parasympathetic and sympathetic. parasympathetic is metabolism of the body while sympathetic is for body's alert system [the fight-or-flight scenarios, etc.].

' -- iT'S LiKE KAKAHiLO! :D haha. -- '

of course, if there's system, there's tissue. :) nervous tissue is made up of neuroglia or glial cells, and neurons. [i'll discuss this one by one, neuroglia first, then neurons. :) ]

neuroglia or glial cells are specialized cells in nervous system that allow it to perform noervous system function. it has several types for CNS and PNS. in CNS, it includes astrocytes or structural support cells, microglin or remore debris, oligodendrites or the myelin maker, and ependymal cells or covering and lining cavities. on the other hand, in PNS, there's Schwann cells or myelin producers and satellite cells or support cells.

neurons. it is the one that carries information from environment to other cells. it has part: dendrites or the info receiver, and the axon terminal or connector to a receiving cell. it has classifications according to structure and function. in structures, there's bipolar or containing either 1 axon or 1 dendrite, multipolar or containing 1 axon and many dendrites, and unipolar or a process that splits into central and peripheral projections. in functions, there are sensory neurons or the input neurons, motor neurons or the output neurons, and the interneuron or association neurons or the neurons that carry information between neurons.

' -- i THiNK i WOULD BE CRAAAAAZY. // :D -- '

in spinal cord and spinal nerves, there are different, rare and uncommon words to encounter. hah. get ready. ok ok. let's start.

spinal cord is located in a hollow tube running inside the vertebral column from foramen magnum to 2nd lumbar vertebrae. spinal nerves are pairs of nerves or segments the spinal cord is divided. cerebrospinal fluid is a fluid where nerves dangling loosely. meninges are series protective membrane that surrounds CNS, and have 3 layers: dura mater or the outer layer, arachnid mater or the middle layer, and the pia mater or the deepest layer. epidural space is a space filled with fat and blood vessels between the dura and the vertebral column. subdural space is filled with a tiny bit of fluid, between the dura mater and the arachnoid mater. subarachnoid space is filled with cerebrospinal fluid, between the arachnoid and pia mater.

** internal anatomy of spinal cord ** fissure are the deep groove on the CNS surface. sulcus is a shallow groove on the CNS surface. columns are the white matter sections of the spinal cord. horns are the gray matter sections of the spinal cord. commissures are gray and white, connect left and right halves of the cord so the two sides of the CNS can communicate. spinal roots are projecting from both sides of the spinal cord in pairs, fuse to form spinal nerves. dorsal root ganglion is a collection of sensory neurons that carry sensory information. ventral root is the one that carries motor informations. spinal nerves are the connection between the CNS and outside of it. mixed nerve is a nerve that carries both type of information: sensory and motor. plexuses are the complex branching patterns of mixed nerve. reflexes are the simplest form of motor output. familiar reflexes are withdrawal, vestibular and startle reflexes.

' -- AFTER THiS, WHAT'S NEXT? (: -- '

if i were the instructor to teach this to someone who is not familiar with this, i would have some drills and interactive games aside from the powerpoint presentation earlier discussed in the class. :) of course, those games and drills are related to the topic. :)

' -- AND THEN? -- '

i salute mr. manalo for simplifying the reporter's presentation and the topics. also, he made the class filled with excitement and encouragement to learn so i think that would be enough. but if i were to improve the topic, i would have different things [blah. :)] that they have never seen before. :)

' -- i THANK YOU. :D -- '

silky skin. :D

when we talk about the integumentary system, the layman's term for this skin, hair, nails and simply SKIN. :D

skin, as we all know in discussion, is the largest organ in the body where it covers all the body. it's the one of the misconceptions of people that the skin is NOT the largest organ. haha. :D some of its functions are to protect the body, to keep us from drying out, produces vitamin D with sunlight, to regulate the body temperature, and to act as storage for lipids that are necessary for energy. well anyway, there are three layers in skin: epidermis, dermis, and hypodermis or subcutaneous faschia.

epidermis is the outermost part layer of the skin. it is the visible part of the skin. it has no blood vessels or nerve cells, or avascular type. there are at least four or five sublayers of epidermis. most common of them are stratum corneum or the most outer sublayer of epidermis, and the stratum basale or the innermost layer of the epidermis. it contains the melanocytes or the cells that are responsible for the secretion of melanin, which is in charge of our skin color.

after epidermis, there's dermis. the dermis is in the middle of the epidermis and hypodermis. it is considered as the true skin. you can see most of the glands, nerves and fats here. examples of glands here are apocrine and eccrine. apocrine are found in the armpits and in the private area, etc. while eccrine are found in all parts of the skin.

the innermost layer is the hypodermis or subcutaneous faschia. you can find lipocytes or the fat cells that provides padding to protect deeper tissues of the body. [i thought of this cells as pork and beans in the illustration in the book. :D]

there are common accidents that involves the skin. including the scary BURNS. these burns are examined and identified through the size of the dammage of skin and the depth of burn. of course, there are different degrees of burns: first degree or the burn that damages only the epidermis, the second degree or the burn that damages the epidermis and a part of dermis, the third degree or the burn that affects the three layers, and the fourth degree that afftects up to the bone. in determining burns, there is the rule of nines that divides the body into regions and gives a percentage of body surface area values.

also, if there's skin, there's nails. nails are made from keratinized dead cells and covers them. what is visible is the nail body. the crescent moon-like is the lunula. and the a fold of tissue that covers nail root is the cuticle.

hair. on the other hand, helps regulate the body temp. and has shaft as its visible part and follicle or its root. the sebacious glands that are in our scalps secrete sebum or the antibacterial oil in hair.

many skin. saggy. haha ;D

nothing to learn. D:

there's no classes from sept28 to oct2. STRAIGHT!

it's because of the typhoon ondoy.

so there's no lesson learned. with the reporting. :D

but with thorough reading, yes. i want it to share but there's something that hinders me from it.

maybe i'll share it when the reporter reported her report [redundant, huh!].

okay okay. systems are still systems.

still the lesson. :D

till discussion begins. :)

--xiaoxi.