View Full Version : Biology 101

11-03-2006, 02:01 PM
Biology Notes
Respiratory System
Inspiration- inhalation of air- rib cage moves up and out, diaphragm contracts and moves down- pressure in lungs decreases and air comes it
expiration- exhalation of air into the lungs- rib cage moves down and in, diaphragm relaxes and moves up- pressure in lungs increases and air is pushed out
Ventilation- breathing encompasses both inspiration and expiration
Respiratory Tract-
hair lining the nose, cilia, and mucus- clean the air warm and moisten it.
As hair leaves the body It picks up itís moisture and that causes you nose to drip- in the cold it condenses which is why you can see your breath.
The nose- nasal cavities- narrow canals separated from one another by a septum composed of bone and cartilage
1. ciliated cells - act as odor receptors. Nerves lead to the brain where impulses are interpreted as smell
The Pharynx-the throat- funnel passageway that connects nasal and oral cavities to the larynx.
1. nasopharynx- nasal cavities open above the soft palate
2. Oropharynx- the oral cavity opens
3. Laryngopharynx- opens into the larynx
Tonsils- form a protect ring at the junction of the oral cavity and pharynx- contain lymphocytes that protect against invasion of foreign antigens that are inhaled.
Pharynx- air and food ways cross because itís ventral with the esophagus.
Larynx- cartilaginous structure that serves as a passage for air between the pharynx and the trachea
Trachea- wind pipe- to connecting the larynx to the parimar bronchi. Its walls are made smooth- connective tissue with c- shaped cartilage rings.......................kind of like the tubes they give us for treatments and inhalers.
The bronchial tree-
Bronchus or bronchi(plural)-The trachea breaks into left and right tubes witch lead to the lungs the bronchi branch into a lots of secondary bronchi that lead to bronchioles. These lead to air sacs called alveoli(alveolusĖsingular)
Lungs- paired cone-shaped organs that occupy the thoracic cavity- the thoracic cavity is separated from the abdominal cavity by a muscle called the diaphragm. Each lung is enclosed by pleura- a double layer of serous membranes that produces serous fluid.
Alveoli- oxygen diffuses across the laveolar wall and enters the bloodstream
Surfactant- a film of lipoprotein that lowers the surface tension and prevents them from closing- lungs collapse if you donít have this film


Urinary System
Functions of Piss
1. Excretion of metabolic wastes-The kidneys excrete metabolic wastes- urea is a byproduct of amino acid metabolism
2. Maintenance of Water-salt and balance-kidneys maintain water salt balance in the blood.
3. Maintenance of Acid-Base Balance- The kidneys regulate acid/base balance in the blood. Ph should remain around 7.4-
Secretion of Hormones- kidneys assist the endocrine system in hormone secretion
Kidneys- paired organs located near the small of the back. Been shaped reddish brown in color.
Ureters conduct urine from the kidneys to the bladder- small tubes.
Urinary bladder- stores piss until itís pissed. Three opening two for the ureters and one for the urethra. Urethra- small tube that extends from the urinary bladder to an external opening- used to piss- longer in men because is goes through your dick and carries sperm to boot................ladies piss tube is not connected to their reproductive organs.
Pissing- Urination- micturition..........sensory nerves send message to the brain to pee- muscle relax and piss flow....................adults and older children have control of this function
Kidney structure
Renal cortex- outer layer that dips down in between a radially striated inner layer called the renal medulla- consists of cone shaped tissue masses called renal pyramids........Renal Pelvis is the cavity continuous with the ureter. Nephrons- produce urine- flows into collecting ducts neprhons are in the medulla renal pyramids..........................


Skeletal System
osteoblasts- bone forming cell
oseocytes- mature bone cell from osteoblasts
osteoclasts- bone absorbing cells
Bones are strong because theyíre made of mineral salts, calcium phosphate, and protein fibers
1. Compact bone- highly organized and composed of tube units called osteons. In a cross section bone cells called osteocytes lie in lacunae- which are tiny chambers arranged in concentric circles around a central canal. Osteocytes nearest the center of an osteon exchange nutrients and wastes and blood vessels in the central canal
2. Spongy Bone- has an unorganized appearance- it contains numerous this plates separated by unequal spaces. Built for strength like braces in a building...........the spaces of spongy bone are filled with red bone marrow- a tissue that produces blood cells.
Cartilage- more flexible gel-like and contains many collagenous and elastic fibers. No nerves, used for joints and is slow to heal. Cells called Chondorcytes- lie within lacunae that irregularly grouped
1. Hyalin cartilage- firm somewhat flexible- at the ends of long bones, nose and ends of ribs, in the larynx and trachea
2. Fibrocartilage- stronger then Hyaline- withstand tension and pressure, found where support is of prime importance- discs between the vertebrae and knee
3. Elastic cartilage- more flexible...........found in ear flaps and epiglottis
Fibrous connective tissue-contains rows of cells called fibroblasts separated by collgenous fibers- this tissue makes up the ligaments that connect bone to bone and the tendons that connect muscles to a bone at joints



Muscular System
Types of muscles
1. Smooth muscle- fibers are spindle shaped cells, each with a single nucleus. Smooth muscle is located in the walls of hollow internal organs and it causes these walls to contract. smooth muscle is involuntary.
2. Cardiac muscle- heart wall- fibers are uninucleated, striated, tubular, and branched which allows the biers to interlock at intercalated disks. Contraction is involuntary
3. Skeletal muscle- fibers are tubular, multi nucleated, and striated........they are the muscles attached to the skeleton. You can control these muscles
Function of skeletal muscles
1. Skeletal muscles support the body
2. Skeletal muscles help maintain a constant body temperature- ATP break down in the muscles heat the body
3. Skeletal muscles contraction assists movement in cardiovascular and lymphatic vessels- keeps the blood moving
4. Skeletal muscles protect internal organs and stabilize joints.- they have tendons that help hold bones together at joints.
Muscles work in pairs opposite of each other. The origin of a muscle isn on a stationery bone, and the insertion of a muscle is on a bone that moves.
A muscle fiber has many myofibrils. The sarcomere of a myofibril contain myosin and actin filaments, whole arrangement gives rise to the striation characteristics of skeletal muscle tissue. Muscle contraction occurs when sarcomeres shorten and actin filaments slide past myosin filaments.
Fermentation- supplies ATP without consuming oxygen.- when you all out of breath and shit, muscle can you fat, glycogen to make ATP.
Cellular Respiration- complete in the mitochondria provides most of the muscles ATP-
Nervous System-
Central Nervous system(CNS)- brain and spinal cord
Peripheral nervous system (PNS)- nerves
Neuron Structure-
Neurons- cells that transmit nerve impulses between parts of the nervous system
Neuroglia- support and nourish neurons
Sensory neuron- takes messages from receptor to CNS
Sensor Receptors- detect environment changes
Neurons have 3 parts
1. Cell body- contains nucleus and organelles
2. Dendrites- are the many short extensions that receive signals from sensory receptors or other neurons.
3. Axon- the portion of a neuron that conducts nerve impulses. Also called nerve fiber
Myelin sheath- covers axon, myelin is a lipid serves as a passage way from growth if the nerve is cut.


Spinal chord- communication line between the brain and the peripheral nerves that leave the chord.


The Brain
Cerebrum- largest part of the brain- last center to receive sensory input- carries out higher thought processes required for learning and memory and for language and speech. Split into two cerebral hemispheres
The cerebral cortex- thin but highly convoluted outer layer of gray matter that comers the cerebral hemispheres. Accounts for sensation, voluntary movement and the thought processes we associate with consciousness
Cerebellum- receives input from eyes, ears, joints and muscles about present position of body parts and receives motor output from the cerebral cortex about these parts should be located. Maintains posture and balance.
Brainstem- contains midbrain, the pons and the medulla oblongata
1.Midbrain acts as a relay station for tracts passing between the cerebrum and the spinal cord or cerebellum- ti has reflex centers for visual auditory and tactile responses
2. Pons means bridge- contains bundles of axons between the cerebellum and rest of the CNS. Regulates breathing rate and head movement reflex.
3. Medulla oblongata- regulates heartbeat, breathing and blood pressure. Also reflexís for vomiting , coughing , sneezing, hiccuping, and swallowing.


Autonomic system- regulates the activity of cardiac and smooth muscles and glands.- the involuntary nerves.
Sympathetic- shuts shit down for survival like when your running from the pigs. Starts the Emergency procedures, like adrenaline
Parasympathetic- relaxes shit when itís kick back time


Exteroceptors- senses shit outside the body
Interoceptors- senses shit within like blood pressure, blood ph
Chemoreceptors- respond to chemical substances.....used for taste and smell
Pain receptor- a chemoreceptor - chemicals released from damaged tissue
Photoreceptor- respond to light energy- eyes
Mechanoreceptors- respond to pressure- balance is from a response fluid pressure
Thermoreceptor- respond to temperature-
Sensation- impulses arrive at the cerebral cortex
Perception- interprets the meaning of sensations
Taste buds- embedded in the tongue- they take a weighted average of the different tastes and send it to the brain
Olfactory cells- used for the sense of smell-
sclera- outer layer of the eye
cornea- window of the eye
choroid- middle layer- towards the front it becomes the iris-regulates the size of the pupil- hole in the center of the iris where light enters the eyeball
Aqueous Humor- clear fluid in the anterior compartment
ciliary body- has the ciliary muscle with controls the shape of the lens for near and far vision
Rod cells- photoreceptors- more cells, better resolution, for seeing black and white- good for night vision
Cone cells- photoreceptors- detects color and bright light- allows detection of fine detail-
Nearsighted- people can see shit up close but no far away
Farsighted- people can see shit far away, but they canít read a book for shit.


Ear has 3 divisions
1. Outer ear- consists of the pinna(your frybread) and auditory canal- modified with hair and sweat glands to make ear wax to protect your shit-

2. Middle ear- openings called the oval window and round window- has three small bones- ossicles........................malleus(hammer), incus(anvil), stapes(stirrup)
Auditory tube(eustachian tube)o- thatís that shit that pops when you on a plane- permits equalization of pressure
3. Inner ear- Filled with fluid- Semicircular canals and the vestibule- for equilibrium- the cochlea(snail)- for hearing

Basically noise makes the middle ear bones shake- sends vibration to the inner ear- the fluid shakes tectorial membrane(little hairs) it up to the brain via the cochlear nerve where itís interpreted as sound-


04-16-2007, 01:01 AM
bringing it back.......

Black Man
07-02-2009, 02:07 PM
bringing it back...again.

07-02-2009, 05:33 PM
should put this in the information thread -

that thread is gonna get unstickied if not put to use by yall