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.
sinoatrial (SA) node
a pacemaker of the heart contractions.
plasma
constitutes 55% to 60% of the blood volume. it transports proteins, hormones, nutrients, and cellular wastes. It also contains a variety of ions; some of these maintain blood pH, while others are crucial for the functioning of nerve and muscle cells.
All three cell-based components of blood red blood cells, white blood cells, and platelets originate from cells that reside in;
bone marrow
Red Blood cells;
also called erythrocytes, whose major function is to transport oxygen. The red color of erythrocytes is produced by the large, iron containing protein hemoglobin
haemoglobin
trans- ports almost all of the oxygen carried in the blood. Each hemoglobin molecule can bind and carry four molecules of oxygen, one on each heme group. Hemoglobin takes on a bright cherry-red color when bound to oxygen and be- comes a deeper maroon-red color after it releases oxygen, ap- pearing bluish in veins seen through the skin.
Platelets
are pieces of large cells called megakaryocytes. Megakaryocytes remain in the bone marrow, where they pinch off membrane enclosed chunks of cytoplasm that become platelets. The platelets, which survive for about 10 days, enter the blood and play a central role in blood clotting.
White blood cells
called leukocytes, are larger than red blood cells, but they can crawl, change shape, and ooze through far narrower spaces than erythrocytes can, including through capillary walls. There are five types of leukocytes: neutrophils, eosinophils, basophils, lymphocytes, and monocytes. Leukocytes protect the body against disease. Monocytes, for ex- ample, enter tissues and transform into macrophages. Macrophages engulf bacteria and cellular debris; in the spleen and liver they also break down dead red blood cells.
how a wound is closed by a combination of clotting factors?
Injured tissue and adhering platelets (platelet plug) cause a series of biochemical reactions among blood proteins that lead to clot formation. damaged cells and activated platelets release chemicals that convert prothrombin into the enzyme thrombin.
red blood cells are regulated by;
negative feedback mechanisms
Thrombin’s role as an enzyme.
catalyzes reaction to produce fibrin meshwork catching red blood cells and sealing a wound.
Arteries carry blood where?
carry blood away from the heart, Compared to veins, artery walls are thicker and far more elastic.
veins carry blood where?
to the heart.
arterioles function
are microscopically narrow vessels (most are less than 300 micrometers, or 0.01 inches in diameter) that carry blood to capillaries. Their muscular walls are influenced by nerves, hormones, and chemicals produced by nearby tissues.
capillaries
receive blood from arterioles. Capillaries, walls are only one cell thick, the only vessels that allow the exchange of nutrients and wastes with the blood by diffusion.
interstitial fluid or extracellular fluid
acts as an intermediary between body cells and capillary blood. Gases, water, lipid-soluble hormones, and fatty acids can diffuse directly through the capillary cell membranes into the interstitial fluid. Some small proteins are ferried across the endothelium in vesicles. Small, water-soluble nutrients, such as salts, glucose, and amino acids, enter the interstitial fluid through narrow spaces between adjacent capillary cells.
what remains inside the capillaries unable to venture into the interstitial fluid?
Large proteins such as albumin, erythrocytes, and platelets remain inside the capillaries.
the lymphatic system functions (4)
- Returns excess interstitial fluid to the bloodstream.
- Transports fats from the small intestine to the bloodstream.
- Filters aged blood cells and other debris from the blood.
- Defends the body by exposing bacteria and viruses to lymphocytes and macrophages.
lymphatic capillaries are?
The smallest lymphatic vessels, resemble blood capillaries in that they branch extensively throughout the body and their walls are only one cell thick. Lymphatic capillaries are far more permeable than blood capillaries, however, and are absent from bone and the central nervous system.
lymph is;
interstintial fluid that has flowed into a lymphatic capillary.
a narrow vessel with thin walls that carries blood from capillaries to veins
Venule
the small mass of specialised muscle in the wall of the right atrium which generates electrical signals rhythmically and spontaneously and serves as a pacemaker
Sinoatrial node
Define organismal respiration
is the process by which organisms exchange gases with the environment, taking in oxygen and releasing carbon dioxide (CO2), in support of cellular respiration.
three adaptations of animal respiratory structures;
- Respiratory surfaces even those in contact with air remain moist, because cell membranes are always moist, and only gases dissolved in water can diffuse into or out of cells.
- Respiratory surfaces are very thin to minimize diffusion distances.
- Respiratory surfaces have a sufficiently large surface area to allow enough gas exchange by diffusion to meet the needs of the organism.
Gills Facilitate Gas Exchange what is their structure?
gills are elaborately branched or folded, in- creasing their surface area. Just beneath their delicate outer membranes, gills have a dense profusion of capillaries that carry blood close to the gill surface, where gas exchange oc- curs. Most types of fish protect their delicate gills beneath a bony flap, the operculum.
invertebrate respiratory system structure. (trachea)
The respiratory system of an insect consists of tracheae (singular, trachea), a system of branched, air filled tubes. Tracheae conduct air in and out of the body through openings called spiracles, arrayed in rows along each side of the body surface
Most amphibians also rely to a considerable extent on diffusion of gases through their skin, a process called
cutaneous respiration
counter current exchange systems in gills increase oxygen efficiency to __ lungs in humans only extract ____
80%
25%
The conducting portion of respiratory system in humans consists of;
a series of passageways that carry air into and out of the gas-exchange portion within the lungs, where O2 and carbon dioxide are exchanged with blood in lung capillaries. pharynx, larynx, trachea, bronchi.
trachea in a human
a flexible tube whose walls are reinforced with semicircu- lar bands of stiff cartilage.
Within the chest, the trachea splits into two large branches called
bronchi
Inside the lung, each bronchus branches repeatedly into ever-smaller tubes. Finally, these divide into
bronchioles
alveoli
microscopic air sacs where gas exchange occurs inside the lungs.
dust and bacteria carried by oxygen gets trapped in
mucus inside human lungs, this then gets coughed up
Intercostal muscles
muscles in between the rib cage.
diaphragm
muscles in upside down u shape, contracting them tightens creating a flatter shape, relaxing returns to upside down u.
the middle segment of the vertebral column between the cervical vertebrae and the lumbar region
Thoracic
the part of the hindbrain in vertebrates that controls automatic activity such as breathing, swallowing, heart rate and blood pressure
Medulla
Each hemoglobin
molecule can carry up to__ O2 molecules
4 oxygen molecules
neuron basic structure
A typical neuron includes four major structures:
dendrites, a cell body, an axon, and synaptic terminals
neuron functions (4)
- Receive information from the internal or external environment or from other neurons.
- Process this information, often along with information from other sources, and produce an electrical signal.
- Conduct the electrical signal, sometimes for a considerable distance, to a junction where the neuron meets another cell.
- Transmit information to other cells, such as other neurons or the cells of muscles or glands.
dendrites in neurons
recieve signals
Axon in neurons
conducts the action potential
synaptic terminals
transmit signals to other neurons
myelin
axon covering of which speeds up a conduction, formed by glial cells that wrap themselves around the axon. Each myelin wrapping covers about 0.2 to 2 millimeters of axon, leaving short segments of naked axon, called nodes, in between.
Skeletal muscle also known as __ meaning stripped.
Striated muscle, moves the skeleton.
Muscle fibres
Grouped muscle cells inside a muscle sheath.
The structure, beginning from the inside to the outside of a skeletal muscle; myofibril, , , etc..
Myofibrils, plasma membrane, muscle fibers, bundle of muscle fibers, connective tissue, muscle.
Can Voluntary muscles be controlled?
Yes they can consciously be controlled, for example skeletal muscles.
Muscles that cannot be controlled consciously
Involuntary muscles.
Hydrostatic skeleton
Earthworm type skeleton, invertebrate animals, fluid filled compartments provide support for the body structure.
Antagonistic muscle pairs.
A pair of muscles. When one contracts the other extends.
A muscle that flexes a joint
Flexor
A muscle that straightens a joint.
Extensor
Ligament connects __ to __?
Bone to bone.
Connective tissue that connects bone to muscle?
Tendon
Myosin heads are a part of what structure? And what is their function?
Thick filament. They attach to thin filament and flex with the use of atp to drive muscle movement.
4 main categories of animal body tissue:
- Epithelial,
- connective,
- muscle and
- nerve tissue.
Steroid hormones effect changes in the target cell by;
Diffusing through lipid but-layer and Bind to intracellular receptors. Only cells with appropriate receptors initiate a response.
Peptide hormones and amino acid hormones differ from steroids in what way.
Instead they bind to a receptor on the surface of a cell membrane rather than entering the cell. Initiating synthesis of a messenger molecule.
Double circulation is an..
adaptation in terrestrial vertebrates, which create two seperate circuits of blood, the pulmonary circuit and the systemic circuit.
where does de-oxygenized blood enter the heart first?
into the right atrium via the vena carva
Where does the oxygenated blood enter the heart after visiting the lungs?
to the left atrium via pulmonary veins.
which heart chamber has the largest muscle?
left ventricle.
