Anatomy & Physiology III Comprehensive Exam (BIOS255/ BIOS 255) | Questions & Answers | Updated 2026–2027 | Verified Q&A | Grade A

tps:// Anatomy & Physiology III Comprehensive Exam (BIOS255/ BIOS 255) | Questions & Answers | Updated 2026–2027 | Verified Q&A | Grade A Q: Describe positive feedback system? Answer Amplifies the change from the normal level. (Agrees with the change)Example: Childbirth, blood clotting Q: Describe negative feedback system? Answer Receptors detect when a level is too high or low, information is communicated via nervous system or hormonal system to effectors-the effectors respond to counteract the change bringing the level back to normal , involved in homeostasis Q: Is epithelial tissue vascular or avascular? Answer Avascular (no blood supply) Q: Why might epithelial tissue be described as polar? Answer It is characterized by cells with apical and basolateral membrane domains separated by adherens and tight junctions. Q: What roles does epithelial tissue play in attachment and regeneration? Answer Strengthen the attachment and form a selective molecular barrier between the epithelium and the underlying connective tissue Q: What are the three types of protein fibers in connective tissue? Answer Collagenous, Reticular, Elastic Q: Collagenous fibers Answer These fibers, made of collagen, are tough and flexible and resist stretching. Collagen is the body's most abundant protein, constituting about 25% of the total. Q: Reticular fibers Answer These are thin collagen fibers coated with glycoprotein. They form a spongelike framework for such organs as the spleen and lymph nodes and constitute part of the basement membranes underlying epithelia. Q: Elastic fibers Answer These are thinner than collagenous fibers, and they branch and rejoin each other along their course. They are made of a protein called elastin coated with a glycoprotein (fibrillin) Q: What is chondroitin sulfate? Answer most abundant GAG; It is abundant in blood vessels and bones and gives cartilage its relative stiffness Q: Where is chondroitin sulfate located? Answer abundant in blood vessels and bones Q: What is the function of keratin in the epidermis? Answer is the protein that protects epithelial cells from damage or stress. Keratin is extremely insoluble in water and organic solvents. It is the key structural material making up the outer layer of human skin. Q: merocrine glands Answer are widely distributed over the entire body, but are especially abundant on the palms, soles, and forehead. Their primary function is to cool the body Q: apocrine glands Answer Secrete their products by exocytosis - Salivary glands - Sweat glands - Pancreatic glands Q: sebaceous glands Answer produce an oily secretion called sebum (SEE-bum). They are flask-shaped, with short ducts that usually open into a hair follicle Q: Osteoclasts Answer Bone-destroying cells (remodel bones and cause them to release calcium) Q: Osteoblasts Answer bone forming cells Q: Six steps of endochondral ossification? Answer 1. Hyaline cartilage covered with fibrous perichondrium forms in the location of a future bone. Perichondrium produces chondrocytes; cartilage model grows henceforth. 2. Perichondrium becomes periosteum as it produces osteoblasts that deposit thin layer of bone around the center of the cartilage model (like a bony collar). Primary ossification center* created. 3. Blood vessels penetrate bony collar and invade primary ossification center. Center of model hollows out and fills with blood forming the Primary marrow cavity. Metaphysis forms. Secondary ossification center forms in the epiphysis of cartilage model. 4. (bone stage at birth) Secondary ossification center hollows out and fills with blood becoming the Secondary marrow cavity*. Primary marrow cavity enlarges. The joints of the limbs remain cartilaginous at birth. 5. Epiphyses fill with spongy bone. Cartilage is now limited to articular cartilage. Epiphyseal plate forms at one or both ends of bone persisting through childhood 6. Epiphyseal plate consumed, so gap between epiphysis and diaphysis closes forming a single marrow cavity. Bone can no longer grow. Q: Condyle Answer A rounded knob that articulates with another bone (occipital condyles of the skull) Q: Faucet Answer A smooth, flat, slightly concave or convex articular surface (articular facets of the vertebrae) Q: Heads Answer The prominent expanded end of a bone, sometimes rounded (head of the femur Q: Which bone constitutes most of the hard palate? Answer palatine bone Q: Diaphysis Answer shaft of a long bone Q: Metaphysis Answer The region of transition from cartilage to bone at each end of the primary marrow cavity is called Q: Epiphysis Answer the end part of a long bone, initially growing separately from the shaft. Q: synovial joints Answer also called diarthrosis; freely movable joints consists of: -articular cartilage -joint cavity -synovial fluid -joint capsule -fibrous capsule -synovial membrane Q: What type of mobility is observed in synovial joints? Answer Freely movable (diarthrosis; movements depend on design of joint) Q: Why is the talocrural joint classified as a hinge joint? Answer The malleoli of the tibia and fibula act to constrain the talus, such that the joint functions as a hinge joint, Q: Where is the sacroiliac joint located? Answer between sacrum and ilium What is a sacromere? Answer contractile unit of a muscle fiber ACh diffuses across the synaptic cleft and binds to receptors on the ______ Answer sarcolemma How many ACh molecules must bind to each receptor to open the ligand-gated ion channel? Answer 2 3 multiple choice options What is the effect of acetylcholine attaching to its receptor? Answer it is a neurotransmitter. It simulates or actives the next nerve cell as impulses pass down the a nerve. muscle twitch the response of a muscle to a single brief threshold stimulus incomplete tetanus a state of sustained fluttering contraction complete tetanus can be stimulated at such high frequency that the twitches fuse into a single, nonfluctuating contraction What are agonists? drugs that increase the action of a neurotransmitter What are antagonists? drugs that block the function of a neurotransmitter What are synergists? Muscles that may work in cooperation with the prime mover What muscles are part of the quadriceps group? rectus femoris, vastus lateralis, vastus medialis, vastus intermedius What muscles are part of the hamstring group? biceps femoris, semitendinosus, semimembranosus Describe the overall function of the nervous system? controls and coordinates functions throughout the body and responds to internal and external stimuli Properties of graded/local potentials? vary in magnitude (voltage) according to the strength of the stimulus. An intense or prolonged stimulus opens more gated ion channels than a weaker stimulus, and they stay open longer. Thus, more Na+ enters the cell and the voltage changes more than it does with a weaker stimulus. phrenic nerve innervates the diaphragm, pleura, and pericardium sciatic nerve nerve passes through the greater sciatic notch of the hip bone, extends for the length of the thigh, and ends at the popliteal fossa What are the functions of cerebrospinal fluid? buoyancy, protection, environmental stability location of the primary somatosensory cortex postcentral gyrus of parietal lobe location of primary motor cortex precentral gyrus of frontal lobe Mnemonic for cranial nerves Old Opie occasionally tries trigonometry and feels very gloomy, vague, and hypoactive. effects of parasympathetic nervous system on the circulatory system decreased heart rate and force; slight vasodilation of deep coronary arteries; vasodilation of blood vessels of most viscera; vasodilation, blushing of blood vessels of skin effects of sympathetic nervous system on the circulatory system increased heart rate; vasodilation & vasoconstriction of deep coronary arteries; vasoconstriction of blood vessels of most viscera & skin; increased clotting difference between endocrine and exocrine glands Endocrine-secrete hormones directory into blood/circulatory sys. Exocrine-secrete hormones into ducts What is the function of antidiuretic hormone increases water retention Hematocrit percentage of blood volume occupied by red blood cells How can hematocrit increase? RBC increased Plasma volume decrease What is agglutination? clumping of red blood cells With blood types what does the positive and negative refer to? if Rh antigen is present or not on surface of erythrocytes Calculate the mean arterial pressure (MAP) for a blood pressure of 120/75 90 3 multiple choice options Factors that cause vascular resistance blood viscosity, vessel length, vessel diameter Why do the AV valves open? pressure in the atria exceeds pressure in the ventricles Why do the semilunar valves open? Pressure in the right and left ventricles exceeds pressure in the pulmonary trunk and the aorta What does the QRS complex represent? ventricular depolarization and atrial repolarization What is the role of calcium in muscle contraction? Calcium binds to troponin and leads to the uncovering of the active site of actin What is the formula for cardiac output CO = HR x SV Does more blood enter the ventricle during atrial diastole or atrial systole? atrail systole If the innate immune system fails to remove pathogens, what aspect of the immune system takes over? Adaptive immunity What is the role of CD4 Helper t-cells? recruit other WBCs (B cells; Cytotoxic T Cells; Macrophages) to the area of infection; Activated by MHC II Naturally acquired passive immunity example is passing of IgA antibodies from placenta and breast milk from mother to infant Artificially acquired active immunity example is being given a vaccination of an attenuated virus that your body must fight off and create antibodies to Artificially acquired passive immunity example is giving intravenous antibodies to someone exposed to rabies Naturally acquired active immunity example is exposure to the chickenpox and creating antibodies due to the exposure Inspiratory Reserve Volume (IRV) formula IRV = VC - (TV+ERV) What is the role of Medulla Oblongata in breathing send signals to the muscles that control respiration to cause breathing to occur internal respiration Exchange of gases between cells of the body and the blood external respiration exchange of gases between lungs and blood surfactant on alveoli reduces surface tension and prevents each alveolus from collapsing during respiration Learn More You can also click on terms or definitions to blur or reveal them 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 types of respiration external, internal, cellular External respiration is the breathing process. It involves inhalation and exhalation of gases. Internal respiration involves gas exchange between the blood and body cells. Cellular respiration involves the conversion of food to energy. alveoli and capillaries site of gas exchange Sacromere unit of a muscle fiber what increases hemoglobin high altitudes function of surfactant Thin layer of fluid that covers the alveoli. Reduces surface tension of the fluid layer lining the alveoli, preventing the alveoli from collapsing during exhalation. Type II alveolar cells secrete surfactant ________ sweat glands are widely distributed across the body surface, ________ glands are located wherever hair follicles exist, and ________ sweat glands are found only in a few areas. merocrine, sebaceous, apocrine Which bones form the hard palate of the roof of the mouth? Palatine bones and maxillae The smooth, rounded articular process of a bone is termed a Condyle Endochondral ossification 31542 The smallest functional repeating unit of a skeletal muscle fiber is the Sarcomere Muscle contraction 351462 Triggering of the muscle action potential occurs after Acetylcholine binds to ligand gated ion channels in the motor end plate membrane. When a muscle is stimulated repeatedly at a high rate, the amount of tension gradually increases to a steady maximum tension. This is called Complete tetanus Graded potentials May be either a depolarization or hyperpolarization ADH is responsible for Production of concentrated urine Cranial nerve that wanders X A ray of light entering the eye will encounter these structures in which order? conjunctiva, cornea, aqueous humor, lens, vitreous body, retina Increase hematocrit High altitude The tunica media layer of blood vessels is primarily composed of what tissue? Smooth muscle MAP of patient with bp of 90/60 70mmHg Stroke Volume (SV) 60mL/beat Which of the following statements pertaining to the cardiac cycle is false? Most of the ventricular volumed is filled during atrial systole The primary role of CD4 T helper cells is Production and release of antibodies An exchange of gases between alveoli of lungs and capillaries of the pulmonary circulation is External respiration Which of the following scenarios would lead to an increase in hemoglobin's binding affinity for oxygen? Decrease in blood temperature