BioS255 comprehensive exam Questions and Answers

BioS255 comprehensive exam Questions and Answers Function of nervous system -Control of body's internal environment to maintain 'homeostasis' -Programming of spinal cord reflexes -Memory and learning -Voluntary control of movement Positive & negative feedback A positive feedback loop causes a self-amplifying cycle where a physiological change leads to even greater change in the same direction. A negative feedback loop is a process in which the body senses a change, and activates mechanisms to reverse that change. The name of the joint in the ankle talocrural joint characteristics of epithelial tissue cellularity, polarity, attachment, vascularity, regeneration Properties of synovial joints *Hyaline cartilage, joint capsule, synovial membrane, synovial fluid, ligaments* -Involve movement between joints The surface of the joint is covered by a fluid filled capsule. -The synovial fluid is trapped under the synovial membrane and acts as a lubricant between the bones. -Cartilage at the ends of the bone acts as a cushion and shock absorber. 3 protein fibers in connective tissues collagenous fibers, elastic fibers, and reticular fibers. chondroitin sulfate provides support and adhesiveness in cartilage, bone, skin, and blood vessels Sacrum— illium answer Keratin A fiber protein that is the principal component of hair, skin, and nails Sweat glands location and function Eccrine glands: help to maintain homoeostasis, primarily by stabilizing body temperature. Smaller glands and excretes on top of skin ((feet, forehead, cheeks) Apocrine glands: continuously secrete a fatty sweat into the gland tubule. ((armpit, groin, nipple area) Hard palate bone -formed by maxilla and palatine bones The shaft of the bone is called End- Epiphysis Middle/shaft --diaphysis Articular process of bone limits rotation What happens during osteoclasts Osteoclasts are responsible for aged bone resorption osteoBlasts are responsible for new bone formation 5 steps of endochondral ossification 1. Chondrocytes enlarge and matrix begins to calcify 2. Bone formation starts at the shaft surface 3. Blood vessels invade inner region of cartilage 4. Osteoclasts begin to break down spongy bone in center 5. Centers of the epiphyses begin to calcify Smallest unit (fiber) in skeletal muscle Sarcomere Steps that occur during muscle contraction 1)Action potential generated, which stimulates muscle 2)Ca2+ released 3)Ca2+ binds to troponin, shifting the actin filaments, which exposes binding sites 4)Myosin cross bridges attach & detach, pulling actin filaments toward center (requires ATP) 5)Muscle contracts 6)Ca2+ removed, which shifts actin filaments to original position, blocking binding sites 7)Muscle contraction stops action potential triggering -occurs when a neuron sends information down an axon, away from the cell body. 1. At rest, voltage-gated Na+ and K + gates are closed. 2. Chemical or mechanical stimulus causes a graded potential to reach at least (-55mV or threshold) This is "depolarization"2. Voltage-gated Na+ channels open and Na+ rushes into cell 3. Only a total of 20,000 Na+ actually enter the cell, but they change the membrane potential considerably (up to +30mV) muscle stimulation A Muscle Contraction Is Triggered When an Action Potential Travels Along the Nerves to the Muscles. Muscle contraction begins when the nervous system generates a signal. The signal, an impulse called an action potential, travels through a type of nerve cell called a motor neuron. What does a synergistic muscle do also called fixators, act around a joint to help the action of an agonist muscle. (iliacus, psoas major, and rectus femoris) hamstring group biceps femoris, semitendinosus, semimembranosus sodium-potassium ion Neuron has a negative charge at rest. Slightly positive charge sodium ions on the outside. During the firing, sodium ions rush into the axon causing depolarization. Potassium ions rush out of the axon causing it to return to its resting state (negative charge) What is a graded potential? changes in membrane potential that vary in size, as opposed to being all-or-none Phrenic nerve Carries impulses to the diaphragm from the brain. function of cerebrospinal fluid shock absorption, support weight of brain, nourishment and waste removal, Primary motor cortex the section of the frontal lobe responsible for voluntary movement Anti-diuretic hormone (ADH) A hormone produced by the pituitary gland when the body is dehydrated. It causes the kidneys to reabsorb more water into the blood making the urine more concentrated. Cranial nerves "wanders" The Vagus Nerve sympathetic activation occurs in anger or fear, leads to physiological arousal - increased vigilance, heart rate, and blood flow to the skeletal muscles, and decreased blood flow to the gastrointestinal system and skin (which is why arousal leads to cold hands and feet). Order of light passing through the eye cornea, pupil, lens, vitreous humor, retina, optic nerve Endocrine cell function secrete hormones into the blood metabolism. growth and development. sexual function and reproduction. heart rate. blood pressure. appetite. sleeping and waking cycles. body temperature. Hematocrit increasing and decreasing increase: dehydration Decrease: anemia, blood loss, overhydration Blood transfusion given to B- B neg blood types can only receive blood from B- or O- Tunica media layer composed of Smooth muscle cells that are supported by elastic fibers. Pressure pulls fluid interstitial space Hydrostatic pressure Calculate mean arterial pressure MAP = (systolic-diastolic)/3+diastolic Vascular resistance factors affecting resistance are blood viscosity, vessel length and vessel diameter Backflow of heart from pulmonary valve Narrowing of the pulmonary valve reduces the blood flow from the heart to the pulmonary artery and lungs. If the pulmonary valve don't close tightly, causing blood to leak backward into the right ventricle. QRS complex on EKG represents ventricular depolarization Calcium is required for initiation of muscle contraction stimulation of the heart blood clotting stroke volume calculation end diastolic volume - end systolic volume cardiac cycle A complete heartbeat consisting of contraction and relaxation of both atria and both ventricles innate and adaptive immunity innate/natural- general immune response, monocytes, neutrophils, NK cells adaptive immunity- antigen specific response, B cells, T cells humoral/cell-mediated are actually parts of both systems CD4 t helper cells T-cell needed for both humoral and cellular immunity. Recognize antigens. Artificially acquired passive immunity antibodies gathered from a human or other animal and are injected into an individual. Ex.) antiserum for a snakebite, rabies inspiratory capacity tidal volume + inspiratory reserve volume Brain and forceful breathing controlled by medulla oblongata