heart

CARDIOVASCULAR

*heart- the pumping organ

*blood-transports Oxygen and nutrients

*blood vessels- passageways

HEART

-main organ of the cvs

-size of your fist

HEART WALL

-epicardium

-myocardium

-endocardium

Systole- heart contracts

Diastole- relaxation phase

Anastomoses- enable the heart to constantly receive a rich supply of blood

Autorhytmicity- the unique ability of the heart to contract on its own

Inotropism-causes the increase in heart rate

eyes?

EXTERNAL

• orbit- houses and protects the eyeball
• lacrimal apparatus- stores tears
• lacrimal gland-transports tears
• conjunctiva-lines the exposed surface of the eyeball

INTERNAL

• aqeous humor-bathes the iris, pupil and lens
• vitreous humor- occupies the entire eye cavity behind the lens
• eyeball

1. sclera- contains the cornea- allows light to pass through
2. choroid-contains iris-is a sphincter-contains pupil- the opening
3. retina- contains rods- active in dim light- contains cones-activ in bright light-contains the lens- controlled by the ciliary muscle

sense of hearing

The sense of hearing

In this week I have learned one of our sense organ the ears. Ear is the one responsible for hearing and maintaining our sense of balance. It is divide into three main structures namely external ear, middle ear and inner ear. External ear contains the auricle, the external auditory meatus and the tympanic membrane. The middle ear/ tympanic cavity contains the ossicles named as the malleus, incus and stapes, and the Eustachian tube. The inner ear/ labyrinth has three areas namely cochlea, vestibule chamber and the semicircular canals.

ENDOCRINE SYSTEM

-series of organs and glands in the body that secrete chemical messenger

FEEDBACKS
negative and positive feedback

3 basic ways of endocrine organs
-neural control
-hormonal control
-humoral control


DISEASES

1.ANABOLIC STEROID
2.HASHIMOTO'S DISEASE
3.GRAVES DISEASE
4.PHEOCHROMOCYTOMA
5.ADDISON DISEASE
6.CUSHING SYNDROME

HORMONES
-chemical messenger released by endocrine glands
NEUROTRANSMITTERS
-travel in neurons
-synapse
-short lived
STEROIDS
-powerful hormones

NERVOUS SYSTEM DISORDER

PARALYSIS:

SPASTIC

FLACCID

COMMON DISODERS

1.GUILLAIN BARRE SYNDROME-FORM OF NEUROPATHY

2.POLIO- ALCOHOLISM IS ONE F THE CAUSES

3.MYASHEMIA-ATTACKS AND DESTROY IMMUNE SYSTEM

4.BOTULISM-PARALYSIS CAUSED BY TOXIC SUBSTANCES

5.MENINGITIS- HAS TWO TYPES VIRAL AND BACTERIAL

6.SUBDURAL HEMATOMA

HUNTINGTON DISEASE

spinal cord

The spinal cord is a long, thin, tubular bundle of nervous tissue and support cells that extends from the brain (the medulla oblongata specifically). The brain and spinal cord together make up the central nervous system. The spinal cord begins at the Occipital bone and extends down to the space between the first and second lumbar vertebrae; it does not extend the entire length of the vertebral column. It is around 45 cm (18 in) in men and around 43 cm (17 in) long in women. Also, the spinal cord has a varying width, ranging from 1/2 inch thick in the cervical and lumbar regions to 1/4 inch thick in the thoracic area. The enclosing bony vertebral column protects the relatively shorter spinal cord. The spinal cord functions primarily in the transmission of neural signals between the brain and the rest of the body but also contains neural circuits that can independently control numerous reflexes and central pattern generator . The spinal cord has three major functions: A. Serve as a conduit for motor information, which travels down the spinal cord. B. Serve as a conduit for sensory information, which travels up the spinal cord. C. Serve as a center for coordinating certain reflexes

polarized cell and impulse conuction

polarized cell: cell at rest
deopolarized cell: more positive than resting
hyperpolarized cell: more negative than resting



impulse conduction is affected by the following:
1. presence of myelin sheath
2. diameter of the axon

which means that myelinated neurons travels much faster than unmyelinated
In non-myelinated axons, the nerve impulse is going to be produced when the action potential accross a membrane makes a wave of depolarization followed by a wave of repolarization. With the absence of the myelin, the impulse is transmitted continuously throughout the membrane.
In a non-myelinated nerve, once an end of the cell, the dendrite, is depolarized, the depolarization a.k.a., the action potential, moves along the nerve membrane, and the area of membrane immediately behind the depolarized section becomes repolarized.

NERVOUS TISSUE

NERVOUS TISSUE HAVE NO EPITHELIUM. IT HAS TWO TYPES THE GLIAL CELLS AND THE NEURONS. GLIAL CELLS ARE FOR SUPPORT ALLOWING NERVOUS TISSUE TO PERFORM ITS FUNCTION.IT HAS 4 TYPES IN CNS NAMELY MICROGLIA, EPEMDYMAL, ASTROCYTES AND OLIGODENDROCYTE. IT ALSO HAS 2 TYPES IN PNS THE SCHWANN AND SATTELITE CELLS. NEURONS ON THE OTHER HANDIS THE CONTROL FUNCTION IT HAS 2 MAJOR PARTS THE DENDRITES AND THE AXON. THE GAP BETWEEN NEURONS AND RECEIVING CELL IS CALLED SYNAPSE.

NERVOUS SYSTEM PART 1

WE LEARNED A LOT OF THINGS THIS WEEK ESPECIALLY ABOUT THE BASIC INFORMATION ABOUT OUR BRAIN AND SPINAL CORD. THAT THEY ARE THE MAIN DIVISIONS OF OUR NERVOUS SYSTEM. OUR NERVOUS SYSTEM IS DIVIDED INTO 2 PARTS THE CNS (CENTRAL NERVOUS SYSTEM) AND PNS (PERIPHERAL NERVOUS SYSTEM). OUR CNS IS COMPOSED OF THE BRAIN AND THE THE BRAIN STEM WHILE OUR PNS IS COMPOSED OF THE SPINAL CORD AND THE SPINAL NERVES. WHICH IS MAINLY TACKLED IN THIS WEEK. FOR EXAMPLE THE SO CALLED DEEP GROOVE IS THE VENTRAL MEDIAN FISSURE AND THE SHALLOW GROOVE IS THE DORSAL MEDIAN SULCUS. THE AREA WHERE THE NERVES HAS THEIR CELL BODIES IS THE GRAY MATTER HORNS.