Biology report 2nd semester part 3

Nervous System part 2

• The Brain is a hierarchial organ that is divided into compartments, each with specific functions. It also has nerves attached to it, called cranial nerves. There are 12 pairs of cranial nerves and they can sensory, motor and mixed.
• The cerebrum controls the consciousness or movement & senses of a human body. Beneath it are the diencephalon, brain stem, and cerebellum. Each parts play an important role in coordinating the sensory and motor information of the cerebellum. Other parts of the brain allow humans to make connections between different types of sensory information and to compare current experience

Reaction;
The nervous system plays a significant role in providing our body to move and make contact with our surroundings. Without it, we won't be able to fuction properly.

Biology report 2nd semester part 3

Nervous System
is the body's computer
3 systems of the nervous system
Central nervous system:
controls all basic bodily functions and responds to external changes
Peripheral nervous system:
provides a complete network of motor and sensory fibers connecting the CNS to the rest of the body
Autonomic nervous system
parallels the spinal cord but is separated involved in control of exocrine glands, blood vessels, viscera and external genitalia
The nervous tissues are made up of two specialized cells:
1.Neuroglia or Glial cells
- cells in the nervous tissues that allow it to perform nervous system functions
2.Neurons
- all of the control functions of body are being transferred with the neurons.
- they work like messengers
Spinal Cord
- has 31 segments, each with a pair of spinal nerves
- ventral root is integral to motor functions and the dorsal root is integral to sensory functions
Pictures:
http://www.cedars-sinai.edu/images/468380_SPINALCO_copy.jpg
http://crystalskullworld.com/Neuron.gif

Biology report 2nd semester part 2

The Integumentary System

Definition:

• is comprised of the skin and its accessory components of hairs, nails and associated glands.

• Performs several vital functions besides protecting you from an invasion of disease-producing pathogens

• helps keep the body from drying out, acts as storage for fatty tissue necessary for energy, and with the aid of some sunshine, your skin produces vitamin D.

Skin:

• quite a large organ, easily weighing twice as your brain, approaching 20 pounds in an average adult

• 3 main layers:

1. epidermis:

   - layer of skin that we normally skin.

   - made up of 5 or 6 even smaller layers of stratified squamous epithelium

   - the epidermis is interesting for several reasons:

   - 1^st, it has no blood vessels or nerve cells.

   - 2^nd, the cells on the surface are constantly shedding being replaced with new cells that arise from the deeper region called, “ Stratum basale.”

   - the outermost surface of skin is actually a layer of dead cells called stratum cornerum

   - specialized cells called melanocytes are located deep in the epidermis and are responisble for skin color. They produce melanin, which is the actual substance that affects skin color.

2. Dermis;

   - another name: Corium

   - made up of the following components in the layer:

• capillaries

• collagenous and elastic fibers

• involuntary fibers

• nerve endings

• lymph vessels

• hair follicles

• sudoriderous glands

• sebaceous glands

• 2 main types of sudiferous or sweat glands:

  1. apocrine

  - secrete at the hair follicles in the groin and region as well as the armpits.

  2. eccrine

  - found in greater numbers on your palms, feet, forehead, and upper lip

3. Subcutaneous Fasci ( Hypodermis)

   - the innermost layer of the skin which is composed of elastic and fibrous connective tissue and fatty tissue.

Nails

- specialized epithelial cells originating from the nail root form your nails. As these cells grow out and over the nail bed, they become keratinized, foring a substance similar to the horns of a bull

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Skin Burns

When assessing the damage caused by the burns, there are two factors:

1. The depth of the burn

2. size of the area damged

Types of Skin Burn ( in order)

1. 1^st degree burn - damages the outer layer of the skin only

2. 2^nd degree burn - burns the entire depth of the epidemis and a portion of the dermis

3. 3^rd degree burn - affects all of the 3 layers of the skin

4. 4^th degree burn - burns that penetrate to the bone