Tissues
Define tissue.
A tissue is a group of cells that perform a similar function.
Eliminates wastes such as urine and sweat.
Excretory System
Define homeostasis.
The ability to maintain a stable internal environment
Describe the role of the hypothalamus in a feedback loop.
The hypothalamus is found in the brain and acts as the control center of the feedback loop. Receptors pick up changes to a set point and send the info to the hypothalamus. The hypothalamus stores set points and determines the best course of actions. Signals are then sent from the brain to effectors that help to return the set point to the desired state.
Structures that are part of the circulatory system
Heart and blood vessels
Functional unit of the circulatory system where materials are exchanged.
Capillaries
Tissue that makes up the skin and body membranes.
Epithelial Tissue
Includes skin, hair, nails, and sweat glands.
Integumentary System
Give two examples of variables that must be regulated in the human body to maintain homeostasis.
Levels of oxygen, carbon dioxide, calcium and sugar
Body temperature, heart rate, blood pressure, blood pH
Explain the difference between a variable and a set point in a feedback loop. Give an example of each.
The set point is the specific value for each variable that must be achieved to maintain. homeostasis. For example, body temperature must be at 98.6 F and blood sugar must be 90 mg/100 ml.
Name 3 types of blood vessels
Arteries, veins and capillaries
Cells that transport oxygen and carbon dioxide.
Red Blood Cells / Erythrocytes
Give three examples of muscular tissue and describe the function of each.
1. Skeletal muscle - make up the muscles attached to bones; produces gross motor movement
2. Cardiac muscle - makes up the heart; contracts to move blood through the body
3. Smooth muscle - lines organs; contracts to move materials through the digestive, urinary, reproductive tracts; also lines blood vessels to help constrict and dilate the blood vessels.
Transports oxygen into cells and eliminates excess carbon dioxide.
Respiratory System
Describe the difference between a negative and positive feedback loop. Give examples of each.
A negative feedback loop reverses or counteracts the response and shuts off once the desired state is reached. Examples include: body temperature, blood pH, and levels of glucose, oxygen, carbon dioxide, calcium.
A positive feedback loop amplifies the response. Examples include: labor contractions, blood clotting, nursing a baby, ovulation.
Arteries typically transport blood _____ the heart while veins transport blood _____ the heart.
Arteries typically transport blood AWAY FROM the heart while veins transport blood TO the heart.
Functional unit of the respiratory system where oxygen and carbon dioxide are exchanged.
Alveoli
Packages, protects and connects.
Connective Tissue
Organs that make up this system include bones, cartilage, ligaments, and tendons.
Skeletal System
Describe the role of hormones in a feedback loop and include a specific example.
Hormones act as chemical messengers that trigger an effector to do something to help maintain homeostasis.
For example, insulin is released by the pancreas when blood sugar is too high which causes cells and the liver to take up glucose.
For example, glucagon is released by the pancreas when blood sugar levels are too low which causes the liver to breakdown glycogen and release glucose into the blood.
For example, calcitonin is released by the thyroid gland when calcium levels are too high causing calcium to be deposited in bone.
For example, parathyroid hormone (PTH) is released by the parathyroid gland when blood sugar levels are too low causing osteoclasts in the bone to release calcium into the blood.
Describe what happens to cool the body down when your body temperature goes above 98.6 degrees Fahrenheit.
Sweat glands are triggered to produce sweat that releases heat
Blood vessels dilate to release heat through the surface of the skin
The right atrium of the heart receives __________ blood.
Describe the role of villi in the body.
Villi are finger-like projections found in the lining of the small intestine where nutrients such as glucose, glycerol/fatty acids, amino acids, and nucleotides are transported into capillaries and lymph vessels and then travel to the cells in the rest of the body.
This tissue sends fast-acting electrical signals to control and regulate what goes on in the body.
Nervous Tissue
Helps protect the body from infection and disease.
Immune System
Describe the difference between stimulus and feedback in a feedback loop using body temperature as an example.
A stimulus is any change to the set point.
Feedback is always opposite of the stimulus and occurs due to the response of the effectors. In the case of a negative feedback loop, feedback causes the feedback loop to shut off.
For example, an increase in body temperature that results when exercising would be a stimulus. The increase in temperature would results in the sweat glands producing sweat and the capillaries dilating to release body heat through the surface of the skin. The feedback would be the decrease in body temperature that results from the release of heat through the skin. Once the desired temperature of 98.6 F is reached the feedback loop will shut off and the person will stop sweating an the capillaries will no longer dilate.
Describe the role of insulin and glucagon in maintaining blood sugar levels and include the organ where each one is produced.
Insulin is a hormone released by the pancreas when blood sugar levels are high. Insulin causes cells to take up glucose and the liver to store the glucose as glycogen which then lowers blood sugar levels.
Glucagon is a hormone released by the pancreas when blood sugar levels are low. Glucagon stimulates the liver to break down glycogen into glucose which then gets released into the blood and raises blood sugar levels.
Name the four chambers of the heart.
Right atrium, right ventricle, left atrium, left ventricle.
Describe what occurs when blood travels through the lungs.
Oxygen enters RBCs through the capillaries surrounding the alveoli and carbon dioxide leaves the RBCs, enters the alveoli and is exhaled.