Module 4 - Animal structure and function Flashcards
Homeostasis and the six factors:
organisms ability to maintain its internal environment. dynamic equilibrium of temperature, salt, oxygen, glucose, pH, and water levels. maintain and adjust depending on what is best for survival.
Ectotherms
(Greek for “outside heat”) derive most of their heat from the environment. Reptiles (except for birds), amphibians, and most fish and invertebrates are ectotherms.
Endotherms
Endotherms (Greek for “inside heat”) produce most of their heat by metabolic reactions. Birds and mammals are the most common types of endotherms,
internal negative feed-back systems
counteract the effects of changes in the internal environment and are principally responsible for maintaining homeostasis;
positive feedback systems
create cycles in which changes amplify themselves. changing conditions cause responses that enhance the change.
negative feedback systems contain three principal components:
- a sensor,
- a control center, and
- an effector.
The sensor detects the current condition, the control center compares that condition to a desired state called the set point, and the effector produces an output that restores the desired condition.
hypothalamus
regulator in vertebraes (thermostat)
organ systems
For example, the urinary system is an organ system consisting of the kidneys, ureters, bladder, and urethra;
Epithelial tissue
forms both membranes and glands. Epithelial membranes cover both internal and external body surfaces, forming the epidermis of skin and coating the outer surfaces of internal organs.
simple epithelium
Epithelial membrane which is only one cell thick
stratified epithelium
contain more than one cell layer. withstands considerable wear and tear. Stratified epithelium is found in the esophagus and in the skin
Connective tissue function as
a group of tissues that support and strengthen other tissues and help to bind the cells of other tissues together, such as skin or muscles. it has a large amount of extracellular matrix relative to cells.
Dense connective contain__ and some tissue examples:
tightly packed with collagen fibers. In tendons (which con- nect muscles to bones) and ligaments (which connect bones to bones),
Specialized connective tissue
includes cartilage, bone, blood, and lymph.
4 Major tissue types:
epithelial tissue,
connective tissue,
muscle tissue,
and nerve tissue
Lymph
consists largely of liquid that has leaked out of blood capillaries (the smallest of the blood vessels), plus white blood cells.
muscle tissue
The long, thin cells of muscle tissue are packed with two types of fibrous proteins that slide past one another when stimulated, shortening (contracting) the muscle cell.
Skeletal muscle
is stimulated by the nervous system and is generally under voluntary, or conscious, control. large muscles.
Cardiac muscle
spontaneously active, under involuntary (unconscious) control. desmosomes and gap junctions allow electrical signals to spread rapidly throughout
the heart, causing coordinated cardiac muscle contraction.
Smooth muscle is found
embedded in the walls of the digestive and respiratory tracts, uterus, bladder, larger blood vessels, skin, and in the iris of the eye. Smooth muscle produces slow, sustained contractions that are typically involuntary
nerve tissue
are specialized to generate electrical signals and to conduct these signals to other neurons, muscles, or glands.
Vertebrate organ systems include; (10)
respiratory, circulatory, lymphatic or immune, digestive, urinary, nervous, endocrine, skeletal, muscular, and reproductive systems
Closed circulatory system
confine the blood within blood vessels. worm
open circulatory system
bath organs in blood
the four major methods by which cells communicate with each other via hormones etc.
direct, synaptic, paracrine, endocrine
Fish hearts
Fish hearts consist of two main contractile chambers rather than 4: a single atrium that empties into a single ventricle. Blood pumped from the ventricle passes first through the gills, where the blood picks up oxygen and releases carbon dioxide. The blood travels from the gills through the rest of the body, delivering oxygen to the tissues and picking up carbon dioxide. Blood from the body then returns to the single atrium.
pulmonary circuit
(“pulmonary” lungs) directs blood from the heart through the lungs, where carbon dioxide is exchanged for oxygen, and back to the heart.
The systemic circuit
carries blood between the heart and the rest of the body, where oxygen is exchanged for carbon dioxide.
veins
(vessels that carry blood toward the heart), the superior vena cava and the inferior vena cava.
arteries
(vessels that carry blood away from the heart). The “left heart” deals with oxygenated blood.
Atrioventricular valves purpose
allow blood to flow from the atria into the ventricles, but prevent the blood from flowing back into the atria when the ventricles contract.
Semilunar valves
“half-moon”) allow blood to enter the pulmonary artery and the aorta when the ventricles contract, but prevent blood from returning as the ventricles relax.
direct cell communication
gap junctions link the cytoplasm of adjacent cells, allowing ions and electrical signals to flow between them. Direct communication occurs in many tissues, including the heart and brain. Direct communication is very fast but requires the cells to be in intimate contact with one another.
Synaptic cell communication
Diffusion from a neuron across a narrow space (synaptic cleft) to an adjacent cell.
Neurotransmitters. ex.
Acetylcholine, dopamine
Paracrine cell communication
Diffusion through the interstitial fluid to nearby cells.
Local hormones; Prostaglandins, histamine
Endocrine cell communication
Carried in the bloodstream to nearby or distant cells. Endocrine hormones;
Insulin, estrogen, growth hormone
Three classes of endocrine hormone;
- steroid hormones; estrogen
- peptide hormones, insulin
- amino acid derived hormones.
the cardiac cycle, step 1.
atrial systole
During each cycle, the two atria first contract in synchrony, emptying their contents into the ventricles, a process called atrial systole
the cardiac cycle, step 2.
ventricular systole
A fraction of a second later, during ventricular systole, the two ventricles contract simultaneously, forcing blood into arteries that exit the heart
the cardiac cycle, step 3.
diastole
Then, during diastole, both atria and both ventricles relax briefly and begin to fill with blood before the cardiac cycle repeats
hypertension
A pressure of 140/90 mmHg or higher is consider hypertension. High blood pressure.