Organization of Human Body 27.1-3
Organization of Human Body 27.1
Organization of the body
-levels of organization in the body:
Cells, tissues, organs, adn organ systems
-these parts work together and form large connections
Cells-basic unit of structure
-individual cells in multicellular organisms tend to be specialized
Specialized: uniquely suited to perform a specific func
Tissues-group of cells form a particular function
Epithelial- lines outside and inside body surfaces
-skin and lining of stomach
Connective - type that provides support for the body
-many produce collagen: function-strength and resiliency
Nervous - nerve impulse is transmitted through it
Muscle- movement of body
-involuntary or voluntary control
Organ- group of tissue comes together to perform single or several related functions
Example: Eye tissue: epithelial tissues nervous tissues, muscle tissues and connective tissues: all work together through a single func: sight
Organ systems- perform closely related functions
Brain and spinal cord- organs of the nervous sys.
-all organ interact to maintain homeostasis as a whole
Body system chart
Homeostasis
-describes the relatively constant internal conditions that organism maintain despite changes in internal and external environment environments
Feedback inhibition- keeping internal conditions within a certain range, never too far one way or the other
Non Living example: when the thermostat switches the temp above the set point the thermostat switches off , keeping the temp within narrow range
Feedback inhibition/ negative feedback: process in which a stimulus produces a response that oppose the original stimulus
Living example: warm environment and exercise causes body temp to increase,
-hypothalamus sense temp change and sends signals that start or stop cooling movements
-body temp decreases until its done (this is the same when its colder too)
The Liver and Homeostasis
-liver produces bile (aids in digestion of the fats)
1. protein is broken down for energy
-ammonia, toxic by product, is produced
-liver quickly converts ammonia to urea, less toxic.
2. The kidney later remove urea from the blood.
Liver converts dangerous substances including some drugs into compounds that can be removed from the body safely.
Roles
-regulating level of substance in body.
Ex: glucose
After we eat, glucose in blood rises, liver comes in by taking glucose out of the blood it keeps the level of glucose from rising too much.
-as body uses glucose for energy the liver release stored glucose to keep level of sugar from dropping
-important bc if we have too little glucose, nervous system slows down and u may lose consciousness and pass out
-two much glucose: grad damages eyes, kidneys, herat, even immune system
-happens in diabetes (high levels of glucose, changes occur in the pancreas or body cells that affect the cells ability to absorb glucose.
-failure of homeostasis with respect to blood glucose levels.
27.2 Humans System
skipped - digestive system
The Excretory System
-every living organism produces chemical waste products that are toxic and must get out of the system
-Ammonia , most toxic waste compound: produced when amino acid form proteins are used for energy
It’s converted to urea so it's not that bad for the body, but it also needs to get out the body
Excretion: process by which these metabolic wastes are eliminated.
What it includes skin, lung, liver,kidneys
-as well as the ureters, urinary bladder, and urethra
Function: excretes waste from the body
Skin
-removes excess water, salts, small amount of sweat
By releasing small amounts this process eliminates waste without u even knowing
Lungs
-blood transport carbon dioxide a waste product of cellular respiration, from body cells to lungs
-when exhaling, lungs excrete carbon dioxide + small amt of water vapor
Liver
-convert dangerous nitrogen-based wastes into urea (less toxic compound)
Urea is then transported through the blood → kidneys for elimination from the body
-processes and neutralizes toxins, if there's too many toxins or it's a type the liver can neutralize, there may be build up of toxins in the body.
Kidneys
-major organ of excretion
Fist sized organ , spinal column, lower back
Functions: remove excess water,urea,metabolic wastes from blood
-produces and excretes piss
-ureters transport piss from the kidney →urine bladder , where piss is stored until it's peed out through the urethra.
(scroll for picture)
Filters-blood enters a nephron (white thing at the top of kidney) through a capillary.
Reabsorption- as the filtrate moves through the tubule, water and important substances are reabsorbed through capillary walls into the blood
Urine excretion- once water and other important substances are revised by blood what u have left is piss. Collecting ducts (the thing that connects to the ureter) fathers urine and puts it in the ureter.
Filters-blood enters a nephron (white thing at the top of kidney) through a capillary.
Reabsorption- as the filtrate moves through the tubule, water and important substances are reabsorbed through capillary walls into the blood
Urine excretion- once water and other important substances are revised by blood what u have left is piss. Collecting ducts (the thing that connects to the ureter) fathers urine and puts it in the ureter.
Continued- activity of kidney is controlled by the composition of the blood itself influenced by the endocrine system
Example:
If you eat salty foods the kidneys will respond to the excess salt in your blood by returning less salt to your blood reabsorption.
If your blood glucose levels rise past a certain point the kidneys will even excrete glucose into urine.
Endocrine glands release hormones that influence kidney function
If the amount of water in your blood drops, the pituitary gland releases antidiuretic hormone (ADH) into blood.
-if blood contains excess water ADH secretion stops and more water is excreted.
The Circulatory System
-transports oxygen, nutrients, and other substances through the body and it removes waste from tissues
Circulation
Right side of heart: poor oxygen blood
Left side: rich oxygen blood
Right side of heart
Pulmonary circulation
-pumps oxygen poor blood from heart to lungs
-in the lungs, carbon dioxide diffuses from the blood, oxygen is absorbed into blood
-oxygen-rich blood then flows to the left side of the heart
Left side of heart
Systemic Circulation
-pumps oxygen rich blood to the rest of the body
-cells absorbs the oxygen that they need and load the blood with carbon dioxide by the time it returns to the heart
-aorta transport blood to the rest of the body, (the first artery/vessel) to carry the blood through systemic circulation
Arteries (endothelium, smooth muscle, connective tissue) , capillaries (endothelium), veins (contains valves, ensures the blood flow in one direction through vessels toward the heart)
Blood
-helps regulate body's transportation system, and components of blood (regulate body temperature, fight infections, and produce clots to minimize the loss of fluids from wounds
-human body 4-6 liters of blood
Plasma
-55 percent of blood
-90 percent water, 10 percent dissolves gas, salts, nutrients,enzymes, more etc.)
3 types of proteins
1.albumin, globulins, fibrinogen
Albumin
-important role in balancing osmotic pressure between blood plasma and surrounding tissues
Globulins -fight viral and bacterial infections
Fibrinogen is necessary for a blood to clot
Red blood cells
-most numerous cell in the body: red blood cells, erythrocytes
Function: transport oxygen
Produced: red bone marrow , as they mature and fill with hemoglobin, nuclei and other organelles are forced out
White Blood cells(leukocytes)
“Army” of circulatory system
-guard against infection, fight parasites, and attack bacteria
Different White Blood Cells
Macrophages: engulf bacteria
Lymphocytes :involved in immune response
B lymphocytes-produce antibodies that fight infection and provide immunity
T lymphocytes-help fight tumors and viruses
How is blood clotted?
1. Capillary wall breaks -blood vessel is injured by a cut or scrape
2. platelets take action-clump at the site and release the clotting factor(thromboplastin, triggers a series of reactions,
Thrombo converts the protein prothrombin into enzyme thrombin
3. clot forms, thrombin converts the fibrinogen into sticky fibrin filaments, forms a flot that seals the break until the capillary wall can regrow and heal
Lymphatic System
-is a network of vessels, nodes, and organs that collects the lymphs that leaves capillaries, “screens” it for microorganisms, and returns it to the circulatory system
-although human body is closed circulatory system, it some blood cells and plasma leaks out through capillary walls
-3 liters of fluid leave the blood in this way —> This fluid is lymph is reabsorbed into capillaries (not all of it)
Role in circulation
-lymph collects in a system of capillaries that slowly conducts it into a larger lymph vessels
-the pressure on the vessels from surrounding skeletal muscles, helps move lymph through system into larger larger ducts
-have valves that prevent lymph from flowing backwards
-ducts return lymph to blood through opening in veins (below shoulders)
Edema- when injury or diseases blocks lymphatic vessels lymphs can accumulate in tissues causing swelling
Role in Immunity
–lymph nodes act as filters trapping microorganisms,stray cancer cells, and debris
WBC destroy cellular trash
-when large number of microorganisms are trapped in lymph nodes the nodes enlarge
- swollen lymph nodes: swollen glands that are symptoms of certain kinds of infections
Thymus- T lymphocytes mature in the thymus before they function in immune system
Spleen-instead of lymph, blood flows through here, where is cleansed of microorganisms, damaged cells, and other debris
Role in Nutrient Absorption
-system of lymph vessels runs alongside the intestines
-vessels pick up fats and fat soluble vitamins from the digestive tract
-transports these nutrients into the bloodstream
Respiratory System
Note: What we breathe in and out, and Air flow
Gas Exchange and Transport
-inhale, diaphragm contracts and flattens, creating a partial vacuum inside a tightly sealed chest cavity.
-Atmospheric Pressure does the best and fills the lung as air comes in
-air enters alveoli and a delicate of network of capillaries diffuse across thin capillary walls
Diffusion
-oxygen from alveoli into capillaries is a passive process
Oxygen dissolve into the blood scream and then becomes bound to the hemoglobin in RBC
-ability of hemoglobin to bind oxygen increases the blood's oxygen carrying capacity more than 60 times
-When carbon dioxide diffuses from body tissues ->capillaries most of it enters the RBC+ water forming carbonic acid and the bicarbonate
-carbon dioxide dissolves in plasma or binds to hemoglobin and proteins in plasma
-processes are reversed in the lungs before the carbon dioxide is exhaled.
Air inhaled: rib cage rises, diaphragm contracts (goes down)
Air exhaled: RIb cage lowers, diaphragm relaxes
Breathing and Homeostasis
-controlled by medulla oblongata
-Sensory neurons in or near the medulla and in some large blood vessels gather information about carbon dioxide levels, and send info to breathing center
When stimulated
-breathing center sends nerve impulses that causes the diaphragm and chest muscles to contract
-the higher than blood CO2 level, stronger the impulse, if it reaches to critical point, the impulses are high and u have to breathe
Chapter 27.3
The Nervous System
-collects info about interanl and external environment, process that info and responds to it.
-Nerve impulses are carried through electrical