Review- A & P PDF

Review- A & P Levels of Organization 1. What are 6 levels of organization? Molecules: The chemical level, which consists of atoms, ions, and small molecules Cells: The basic unit of life and the smallest unit capable of reproduction Tissues: Groups of similar cells that work tog...

Review- A & P Levels of Organization 1. What are 6 levels of organization? Molecules: The chemical level, which consists of atoms, ions, and small molecules Cells: The basic unit of life and the smallest unit capable of reproduction Tissues: Groups of similar cells that work together to perform specific functions Organs: Two or more tissues work together for a specific function Organ systems: A group of organs work together Organism: The human organism 2. What is homeostasis? Homeostasis is the process by which living organisms maintain a stable internal environment, even when external conditions change. This process allows the body to function properly and survive. 3. How does negative feedback work in the body? Negative feedback loops in the body help maintain homeostasis, or a stable internal state, by counteracting changes to internal variables. The word "negative" refers to the fact that the feedback loop acts against a stimulus to bring it back to its set point. 4. Identify anatomical position, the three body planes and the different directional terms presented this week in class. Anatomical position: The position of the body in which the anatomical planes are described Body planes: Imaginary planes that pass through the body in the anatomical position. The three main planes are: Coronal (frontal) plane: Separates the front and back of the body Sagittal (longitudinal) plane: Separates the left and right sides of the body Transverse (axial) plane: Separates the upper and lower halves of the body Directional terms: Some directional terms include: Medial and lateral: Refer to how close structures are to the body's midline Ventral: Towards the front of the body Dorsal: Towards the back of the body Distal: Away or farthest away from the trunk or the point of origin of the body part 5. What are the differences between intracellular and extracellular fluid? The intracellular compartment consists of all the fluids inside cells; whereas the extracellular compartment consists of all the fluids outside of cells. The extracellular compartment is further divided into three sub-compartments, which are the plasma, the interstitial, and the transcellular sub-compartments. 6. Compare passive and active transport. Provide an example for each. The main difference between active and passive transport is whether energy is required to move molecules: Active transport Uses energy to move molecules from a lower concentration to a higher concentration. Examples include the sodium-potassium pump, the absorption of glucose in the human intestine, and the uptake of mineral ions by plant roots. Passive transport Moves molecules from a higher concentration to a lower concentration without using energy. Examples include diffusion, facilitated diffusion, osmosis, and filtration. 7. What are the differences between replication, translation and transcription in the cell? DNA serves as the molecular basis of heredity through replication, expression, and translation processes. Replication creates identical DNA strands, while transcription converts DNA into messenger RNA (mRNA). Translation then decodes mRNA into amino acids, forming proteins essential for life functions. Location In eukaryotes, transcription occurs in the nucleus, while translation occurs in the endoplasmic reticulum. In prokaryotes, transcription and translation can occur simultaneously in the cytoplasm. Initiation Transcription begins when an RNA polymerase protein binds to a promoter in DNA. Translation begins when a ribosome, initiation factor, and tRNA bind mRNA near a starting codon. Integumental 8. What is the function of epithelial tissue? Protection, secretion, absorption, sensation, glandular tissue Epithelial tissue lines body cavities, and hollow organs, and covers all internal and external surfaces of the body. The type of epithelial tissue and its location in the body determines its specific functions. For example, the epithelium in the bladder, urethra, and ureters allows these organs to stretch and expand. 9. Where would you find simple versus stratified epithelial tissue in the body and why? Simple epithelial tissue is found in areas of the body that are moist and experience less wear and tear, while stratified epithelial tissue is found in areas that experience more wear and tear: Simple epithelial tissue Found in moist areas like the lining of the blood vessels, stomach, air sacs, and intestine. Simple epithelium facilitates diffusion and absorption, and doesn't provide much protection to underlying tissues. 2 Stratified epithelial tissue Found in areas like the skin lining, pharynx, inner lining of salivary ducts, and buccal cavity. Stratified epithelium protects underlying tissues from mechanical and chemical stress. 1. What are the functions of the integumentary system? Protection: The integumentary system protects the body from injury, infection, bacteria, and sunlight. Thermoregulation: The integumentary system helps maintain a stable body temperature. Sensory perception: The integumentary system allows you to sense and respond to your environment. The skin contains nerve endings that detect touch, pain, and surface temperature. Vitamin D synthesis: The skin synthesizes vitamin D when exposed to UV radiation. Vitamin D is essential for healthy bones and immunity. Water storage: The integumentary system helps keep the body from becoming dehydrated by storing water. Waste removal: The integumentary system transports and gets rid of waste materials. The integumentary system is made up of the skin, hair, nails, and the glands and nerves on the skin. 2. What is the role of the sun in the production of melanin in the skin? The sun triggers the skin to produce more melanin, a pigment that protects the skin from ultraviolet (UV) rays: Explanation: The skin's cells contain melanin, which absorbs UV light and redistributes it away from the skin's deeper layers. This protects the skin's DNA from sun damage, which can cause burns, premature aging, and skin cancer. Tanning: When the skin is exposed to the sun, it produces more melanin, which darkens the skin and causes tanning. However, tanning doesn't prevent skin cancer. Other factors: Melanin levels are also influenced by race and hormone changes. 3 3. Put the following layers in order and the differences between each dermis, epidermis, hypodermis. The main differences between the epidermis, dermis, and hypodermis are their location, composition, and functions: Epidermis The top layer of skin that you can see and touch. It's made of epithelial cells and protects the body from damage. The epidermis also produces melanin, which gives skin its color. Dermis The middle layer of skin, located between the epidermis and hypodermis. It's made of connective tissue and contains hair follicles, blood vessels, and sweat glands. The dermis also contains collagen and elastin, which give the skin structure and flexibility. Hypodermis The bottom layer of skin, also known as the subcutaneous tissue or fatty layer. It's made of fat and connective tissue. The hypodermis cushions bones and muscles, regulates body temperature, and stores fat cells for energy. 4. What is the function of keratin? What other part of the integumentary system contributes to this? Keratin provides support and protection in your body. Your hair, nails and skin rely on the amount of keratin in your body for their overall health. Your glands and organs also contain keratin. Keratin is strong, so it won't dissolve in diluted acids, alkaline, solvents or waters. Collagen, calcium, 5. What are the functions of hair and nails? Protection, Sensation, Temperature regulation, Homeostasis, Waterproofing, pH balance Bone 1. Define bone bone, rigid body tissue consisting of cells embedded in an abundant hard intercellular material. The two principal components of this material, collagen and calcium phosphate, distinguish bone from such other hard tissues as chitin, enamel, and shell. Bone tissue makes up the individual bones of the human skeletal system and the skeletons of other vertebrates. 2. Define cartilage Cartilage is a strong, flexible connective tissue that protects your joints and bones. It acts as a shock absorber throughout your body. Cartilage at the end of your bones reduces friction and prevents them from rubbing together when you use your joints. 3. Define skeletal system The skeletal system is the body's framework of bones, cartilage, ligaments, and tendons that provides structure and support, protects organs, and allows for movement: 4 Structure and support: The skeletal system gives the body its shape and holds organs in place. Protection: Bones protect vital organs like the brain, heart, and lungs. Movement: Bones work with muscles to help the body move. Blood cell production: The skeletal system produces red blood cells. Mineral storage: The skeletal system stores minerals. Axial skeleton: The skull, spine, sternum, and ribs Appendicular skeleton: The bones of the extremities, including the arms and legs 4. What are the 4 classifications of bones and their shapes? The four main classifications of bones by shape are long, short, flat, and irregular. 5. What is the function of each kind of bone? Long bones These bones are longer than they are wide and are cylindrical in shape. Examples include the femur (thigh bone), humerus (upper arm bone), tibia (shin bone), and fibula (calf bone). Long bones act as levers, moving when muscles contract. Short bones These bones are roughly equal in length, width, and thickness, and are cube-like in shape. Examples include the bones in the wrists and ankles. Short bones provide stability and support, as well as some limited motion. Flat bones These bones are wider and less round than other bones, and are often curved. Examples include the ribs, sternum (breastbone), and the plates that make up the skull. Flat bones often provide strong insertion points for muscles and tendons. Irregular bones These bones do not conform to the above three types and have no characteristic shape. Examples include the vertebrae, sacrum, coccyx, and many facial bones. Sesamoid bones are another type of bone that are small and round, and are located in tendons. Examples include the patella (kneecap) and some metacarpal bones in the hands. Sesamoid bones protect tendons from excess stress and wear by reducing friction. 6. Define and list examples of bone markings. Bone markings, also known as bony landmarks, are distinctive features on bones that serve a variety of purposes. They can be used to identify bones, understand skeletal structure, and understand how bones interact with each other in the body. 5 Here are some examples of bone markings: Condyle: The lateral condyle of the femur is a bone marking that can be felt at the knee. Epicondyle: A bony area that is located on or above a condyle, and is often used as an attachment point for muscles or ligaments. Foramen magnum: A large opening in the occipital bone of the skull that allows the spinal cord to pass through. Vertebral body: The rounded, solid part of a vertebra. Vertebral arch: Made up of two laminae and two pedicles. Vertebral foramen: A central opening in the vertebra that is surrounded by the arch and the body of the vertebra. Bone markings can be categorized into three general classes: articulations, projections, and holes. 7. Describe the histology of bone tissue Bone is constantly remodeling throughout life, which ensures that bones can adapt to mechanical changes. During remodeling, osteoblasts produce new bone matrix, osteocytes mineralize it, and osteoclasts resorb old bone matrix. Histological analysis of bone is important for diagnosing malignancies. It can help identify malignant cells in the marrow spaces in case of bone metastases or hematological disorders. 8. What is the difference between compact and spongey bone? Compact bone tissue is composed of osteons and forms the external layer of all bones. Spongy bone tissue is composed of trabeculae and forms the inner part of all bones. 6 Structure Compact bone is dense and hard, while spongy bone is lighter and less dense with open spaces. found in the outer layer of long and flat bones has a higher capacity for calcium storage contains central canals that contain small blood vessels Function Compact bone provides strength and support, while spongy bone provides multidirectional support and is lightweight. ends of long bones and the interior of flat bones. Red bone marrow for blood cell production receives blood from the periosteum and marrow cavities 9. How are bones nourished and innervated? Bones are nourished and innervated by blood vessels and nerves that enter the bone through nutrient foramina, which are small openings in the diaphysis 10. What does Cartilage do? Cartilage is a strong, flexible connective tissue that protects your joints and bones. It acts as a shock absorber throughout your body. Cartilage at the end of your bones reduces friction and prevents them from rubbing together when you use your joints. 11. Explain the growth activity at the epiphyseal plate Bones grow in length at the epiphyseal plate by a process that is similar to endochondral ossification. The cartilage in the region of the epiphyseal plate next to the epiphysis continues to grow by mitosis. The chondrocytes, in the region next to the diaphysis, age and degenerate. Discuss the bones of the pectoral and pelvic girdles, and describe how these unite the limbs with the axial skeleton 12. Discuss the bones of the pectoral and pelvic girdles, and describe how these unite the limbs with the axial skeleton The bones of the shoulder region form the pectoral girdle, which anchors the upper limb to the thoracic cage of the axial skeleton. The lower limb is attached to the vertebral column by the pelvic girdle. Because of our upright stance, different functional demands are placed upon the upper and lower limbs. 7 Pectoral girdle The pectoral girdle, also known as the shoulder girdle, connects the upper limbs to the thoracic cage of the axial skeleton. The pectoral girdle consists of the clavicle and scapula. The sternoclavicular joints on each side are the only anatomical joints between the shoulder girdle and the axial skeleton. The pectoral girdle is highly mobile to allow for a wide range of upper limb movements. Pelvic girdle The pelvic girdle connects the lower limbs to the vertebral column. The pelvic girdle consists of the right and left hip bones, the sacrum, and the coccyx. The pelvic girdle is strongly united to form a weight-bearing structure that provides stability for the upper body. 13. Describe the bones of the upper limb, including the bones of the arm, forearm, wrist, and hand The bones of the upper limb include the humerus, radius, ulna, carpals, metacarpals, and phalanges: Humerus The upper arm bone, and the longest bone in the body aside from the leg bones. The humerus connects to the shoulder and elbow joints, and supports many muscles, ligaments, tendons, and parts of the circulatory system. Radius and ulna The two bones of the forearm, with the radius on the lateral side and the ulna on the medial side. The ulna is longer than the radius, and helps with movement of the arm, wrist, and hand. The proximal end of the ulna has a C-shaped trochlear notch that articulates with the humerus at the elbow. Carpals The eight small bones of the wrist that form the base of the hand. The carpals are arranged in two rows of four bones each, the proximal and distal rows. Metacarpals The five elongated bones of the palm of the hand, located between the carpals and the finger and thumb bones. Phalanges 8 The bones of the fingers and thumb, with each finger having three phalanges and each thumb having two. 14. Identify the features of the pelvis and explain how these differ between the adult male and female pelvis Female pelves are larger and wider than male pelves and have a rounder pelvic inlet. Male iliac crests are higher than females, causing their false pelves to look taller and narrower. The male sacrum is longer, narrower, straighter, and has a pronounced sacral promontory relative to the female sacrum. 15. Describe the bones of the lower limb, including the bones of the thigh, leg, ankle, and foot The lower limb has 30 bones, including the femur, patella, tibia, fibula, tarsal bones, metatarsal bones, and phalanges: Femur The thigh bone, the longest and strongest bone in the body, which supports the upper body's weight. The head of the femur articulates with the hip bone to form the hip joint. Patella The kneecap, a sesamoid bone that sits within a muscle tendon and protects it from rubbing against the femur. Tibia The larger, weight-bearing bone on the medial side of the leg. The tibia and fibula articulate with the femur to form the knee joint. Fibula The slender bone on the lateral side of the leg that doesn't bear weight. The fibula's distal end forms the lateral malleolus, the bony bump on the outside of the ankle. Tarsal bones The seven bones that form the posterior portion of the foot. The talus bone forms the ankle joint with the tibia and fibula. Metatarsal bones The five elongated bones that form the mid-foot. The metatarsal heads articulate with the proximal phalanges of the toes. Phalanges The 14 small bones in the toes, similar to the bones in the fingers. The big toe has two phalanges, while the other toes have three. The lower limb is divided into three regions: the thigh, the leg, and the foot. The leg is the area between the knee and ankle, and the calf is the back of the leg. 9 16. Discuss both functional and structural classifications for body joints. Describe the characteristic features for fibrous, cartilaginous, and synovial joints and give examples of each Structural classification Joints are classified by the material that makes up the joint and whether or not it has a cavity: Fibrous joints: Bones are connected by dense fibrous connective tissue, usually collagen. There is no joint cavity, so these joints are immovable or fixed. Examples include sutures in the skull, syndesmoses in the ankle, and gomphoses between teeth and their sockets. Cartilaginous joints: Bones are connected by cartilage, a semi-flexible connective tissue. Cartilaginous joints are less mobile than synovial joints and usually hold structures together. Synovial joints: These joints have a fluid-filled joint cavity within a fibrous capsule. They are freely movable and are the most common type of joint in the body. Examples include the shoulder and hip joints, which are ball and socket joints that can move in a full circle. Functional classification Joints are classified by the amount of movement they allow: Synarthroses: Joints that don't move at all. Amphiarthroses: Joints with limited movement. Diarthroses: Joints that can move freely in most directions. Nervous 17. Identify the anatomical and functional divisions of the nervous system Anatomical divisions Central nervous system (CNS): The brain and spinal cord Peripheral nervous system (PNS): Everything else, including nerves and ganglia Functional divisions Somatic nervous system (SNS): Controls voluntary motor responses and conscious perception, such as walking Autonomic nervous system (ANS): Controls involuntary functions, such as breathing and digestion Enteric nervous system (ENS): Controls the digestive organs 18. Relate the functional and structural differences between gray matter and white matter structures of the nervous system to the structure of neurons Grey matter consists of neuronal cell bodies and their dendrites. The dendrites are short protrusions (like little fingers) communicating with neurons nearby. 10 White matter consists of the long axons of neurons that transmit impulses to more distant regions of your brain and spinal cord. 19. List the basic functions of the nervous system Thoughts, memory, learning, and feelings Movement Senses Wound healing Sleep Heartbeat and breathing patterns Response to stressful situations Digestion Body processes, such as puberty and aging 20. Describe the basic structure of a neuron Cell body: Also called the soma, this part contains the nucleus and other organelles that are necessary for the neuron's function. Axon: This long tail-like extension sends messages away from the cell body. Dendrites: These tree-like branches receive messages for the cell. Sensory neurons: Carry information from the sense organs to the brain Motor neurons: Carry messages from the brain to the muscles to control voluntary muscle activity Interneurons: Connect sensory and motor neurons 21. List the glial cells of the CNS and describe their function The main types of glial cells in the central nervous system (CNS) are astrocytes, oligodendrocytes, and microglia: Astrocytes The most common glial cells in the brain, astrocytes provide structural and nutritional support for neurons. They also control the levels of neurotransmitters and ions, and maintain the extracellular environment. Oligodendrocytes These cells produce myelin, a fatty substance that insulates axons and allows electrical signals to travel faster. Microglia These cells act as the brain's immune system, detecting injury and disease, and removing dead cells and toxins. Ependymal cells 11  These cells line the brain ventricles and spinal cord central canal, and produce cerebrospinal fluid (CSF). CSF carries nutrients, hormones, chemical messengers, and waste between the brain and spinal cord. Radial glia These cells are thought to be stem cells that create other cells. They provide long fibers that help guide young brain cells into place. Glial cells make up about 50% of the brain's cellular volume, and outnumber neurons by a ratio of about 10:1. 22. List the glial cells of the PNS and describe their function Schwann cells, which form the myelin sheath satellite cells, which provide nutrients and structural support to neurons. 23. Distinguish the major functions of the nervous system: sensation, integration, and response Sensation The nervous system receives information about the environment through sensory neurons that take in information from the senses, such as sight, touch, and taste. Integration The nervous system coordinates the sensory information with other information in the body. The central nervous system (CNS), made up of the brain and spinal cord, evaluates information and makes decisions. Response The nervous system generates responses to the information it receives. The somatic nervous system (SNS) controls voluntary motor responses, such as the contraction of skeletal muscles. The autonomic nervous system (ANS) controls involuntary responses, such as regulating the internal environment. The PNS includes nerves, the autonomic system, and the somatic system. The autonomic system is further divided into the sympathetic and parasympathetic nervous systems. 24. List the sequence of events in a simple sensory receptor–motor response pathway The sequence of events in a simple sensory receptor–motor response pathway, also known as a reflex arc, is: 1. Reception A stimulus activates a sensory receptor, such as a change in temperature or pressure. 2. Sensory neuron The sensory neuron sends electrical impulses to a relay neuron in the spinal cord. 3. Interneuron The relay neuron connects the sensory neuron to the motor neuron. 4. Motor neuron The motor neuron sends electrical impulses to an effector, such as a muscle or gland. 12 5. Response The effector produces a response, such as moving your hand away from something hot. 25. Describe the components of the membrane that establish the potential resting membrane Ion distribution The RMP is created by the unequal distribution of ions across the membrane. The extracellular fluid (ECF) has high concentrations of sodium (Na+) and chloride ions (Cl−), while the cytoplasm has high concentrations of potassium ions (K+) and negatively charged proteins. Selective permeability The cell membrane is selectively permeable, meaning that ions can only enter or leave the cell through membrane channels. Diffusion and electrostatic pressure The RMP is determined by the balance of diffusion forces and electrostatic pressure. Diffusion forces drive ions across the membrane based on concentration gradients, while electrostatic pressure acts on ions based on charge attractions and repulsions. Pores Pores in the membrane allow ions to diffuse when the cell is not excited. At rest, more potassium pores are open than sodium pores, which contributes to the negativity of the intracellular space. Sodium-potassium pump The sodium-potassium pump actively maintains ion gradients by expelling three sodium ions and importing two potassium ions using ATP. The RMP is the electrical potential difference across the plasma membrane of a cell when the cell is at rest. Typical values of membrane potential range from –80 mV to –40 mV. 26. Describe the changes that occur to the membrane that result in the action potential When an action potential occurs, the membrane of a cell undergoes a rapid change in voltage: Depolarization: 13  The membrane potential increases as sodium ion channels open, allowing sodium ions to rush into the cell. Repolarization: Potassium ion channels open, causing potassium ions to flow out of the cell. Hyperpolarization: The membrane potential dips below the resting voltage. The resting membrane potential is the difference in charge across the membrane when the cell is not active. It's usually around -70 mV. To trigger an action potential, the membrane potential must change from the resting potential to the threshold voltage, which is around -55 mV. 27. Describe the structures found in the CNS and PNS The central nervous system is made up of the brain and spinal cord. The peripheral nervous system is made up of nerves that branch off from the spinal cord and extend to all parts of the body. The CNS is made up of the brain and spinal cord. The brain interprets signals from nerves to regulate how a person: o Thinks o Moves o feels Nerves The PNS is made up of nerves that branch out from the spinal cord and extend to all parts of the body. relays information from the brain and spinal cord to: o organs o arms o legs o fingers o toes Glial cells Glial cells are a type of cell that help neurons o find their destinations o form the blood-brain barrier o produce myelin. 14  Myelin is an insulating substance that speeds up the transmission of action potentials down axons. Receptors There are several types of receptors in the skin, including free nerve endings o Meisner corpuscles o Pacinian corpuscles o Ruffini endings These receptors respond to different types of stimuli, such as: o Pain o thermal stimuli o fine touch o vibration o pressure o stretching. 28. Distinguish between somatic and autonomic structures Both somatic and autonomic structures are part of the peripheral nervous system (PNS), which is the part of the nervous system outside of the brain and spinal cord. Somatic Controls voluntary actions, such as walking, and is involved in conscious activities like vision, smell, and hearing. Autonomic Controls involuntary actions, such as breathing and digestion, and is involved in unconscious activities 29. Describe the sensory and motor components of spinal nerves and the plexuses that they pass through Sensory information travels from the body to the brain through ascending tracts in the white matter of the spinal cord. Motor commands travel from the brain to the body through descending tracts in the white matter. Plexuses Spinal nerves pass through plexuses in the body, such as: cervical plexus brachial plexus lumbar plexus sacral plexus lumbosacral plexus Sensory components The dorsal root of a spinal nerve contains sensory axons that come from sensory receptors in the body, like the skin. These axons enter the spinal cord through the dorsal nerve root. Motor components 15  The ventral root of a spinal nerve contains motor axons that travel to muscles or other organs. These axons emerge from the spinal cord through the ventral nerve root. 30. Name the components that generate the sympathetic and parasympathetic responses of the autonomic nervous system Nerve fibers that secrete acetylcholine are called cholinergic fibers. Fibers that secrete norepinephrine are called adrenergic fibers. Generally, acetylcholine has parasympathetic effects and norepinephrine has sympathetic effects. The SNS the "fight or flight" response increases heart rate and blood pressure. The PNS Rest-&-Digest Made up in large part by the vagus nerve, which connects o Heart o Lungs o other organs. Muscles 31. Describe the different types of muscle Cardiac muscle Found only in the heart, this involuntary muscle is responsible for the heart's rhythmic beating. Smooth muscle Found in the internal organs and blood vessels, this involuntary muscle is not striated and has an oblong shape. Skeletal muscle Attached to the skeleton by tendons, this voluntary muscle is striated and controls movement and posture. Skeletal muscles come in pairs, and contracting one muscle in a pair moves a bone in one direction, while contracting the other muscle moves the bone in the other direction. 32. Explain contractibility and extensibility Contractility Muscles can only pull, not push. the actin filaments are pulled to the center of the sarcomere by the myosin head binding to ATP. Extensibility Muscles can stretch without tearing. A muscle's normal resting length can be stretched to about twice its length. Elasticity 16 The ability of a muscle to return to its original length after being stretched or contracted Excitability The ability of muscle tissue to respond to stimuli, such as hormones or motor neurons 33. Describe the layers of connective tissues packaging skeletal muscle Skeletal muscles are surrounded by three layers of connective tissue: Endomysium: The innermost layer that surrounds each muscle fiber and connects it to the neighboring fibers Perimysium: The middle layer that surrounds bundles of muscle fibers, called fascicles Epimysium: The outermost layer that surrounds the entire muscle Connective tissue also provides support to muscles, tendons, ligaments, nerves, joints, and bones. 34. Explain how muscles work with tendons to move the body essentially work as levers to move your bones as your muscles contract and expand are stiffer than muscles & have great strength. covered by a protective sheath called the synovial sheath o produces a lubricating fluid that helps move smoothly. 35. Identify areas of the skeletal muscle fibers Myofibrils Long protein filaments that run the length of the muscle fiber form its structure repeating bands of actin and myosin proteins o striated appearance. myofibrils contract→ entire muscle cell contracts Sarcomeres The contractile units of the muscle fiber. thick and thin filaments are bundled within the myofibril Sarcoplasmic reticulum regulates the concentration of calcium in the sarcoplasm, helps determine whether the muscle contracts Sarcolemma This is a delicate membrane that surrounds each muscle fiber. T-tubules 17  These transverse tubules surround the myofibrils help spread electrical excitation within the muscle cell Neuromuscular junction This is where the terminal of a motor neuron meets the muscle fiber is where the muscle fiber first responds to the motor neuron's signaling. Endomysium This contains nutrients and extracellular fluid to support the muscle fiber. Epimysium This is a protective covering that surrounds the muscle reduces friction between the muscle and other tissues and bones extends to form the muscle's tendons at either end. 36. Describe excitation- contraction coupling the rapid communication between electrical events occurring in the plasma membrane of skeletal muscle fibres and Ca2+ release from the SR, which leads to contraction. 37. Describe the components involved in a muscle contraction Muscle contraction involves several components, including: Nervous system The nervous system generates an action potential, or signal, that travels along a motor neuron to the muscle. Neuromuscular junction The motor neuron reaches the muscle cell at the neuromuscular junction. Acetylcholine The motor neuron releases acetylcholine, a neurotransmitter, which binds to receptors on the muscle fiber. This starts a chemical reaction within the muscle. Thin and thick filaments The filaments within the muscle fiber slide past each other. Thin filaments are made of actin, and thick filaments are made of myosin. The distance between two Z discs, or Z lines, is reduced when a muscle contracts. Calcium and ATP 18 These are cofactors, or nonprotein components of enzymes, that are required for muscle contraction. Calcium binds to troponin, which exposes the active sites on actin. Myosin heads can then bind to the active sites on actin, which initiates muscle contraction. Tendon The resulting force from the contraction is transmitted to the bone via the tendon. The sliding filament theory is the most widely accepted explanation for how muscle contraction occurs. 38. Explain how muscles contract and relax Contraction A nervous system signal causes the release of acetylcholine, which binds to receptors on the muscle fiber membrane. Relaxation When the nervous system signal stops, the chemical reaction stops and the muscle relaxes. The calcium ions are pumped out of the cell or back into the sarcoplasmic reticulum (SR), which decreases the amount of calcium in the cell. This reverses the chemical reaction and causes the muscle to return to a low tension state. 39. Describe the sliding filament model of muscle contraction The sliding filament model of muscle contraction explains how muscles generate force and produce movement. The model describes how the thin actin filaments slide past the thick myosin filaments within muscle fibers: 1. Stimulation An action potential reaches the muscle fiber, triggering the release of calcium ions. 2. Calcium binding The calcium ions bind to the protein troponin, which causes tropomyosin to move away from the actin-binding sites. 3. Myosin binding Myosin heads bind to the actin filaments, generating force. 4. Sliding The actin filaments slide past the myosin filaments, pulling the Z discs closer together and shortening the sarcomere. 5. Attachment and detachment The actin and myosin filaments repeatedly attach and detach during a single contraction. Identify the different body movements 19 Understand the principles of body palpation OTHER TERMS RELATED TO BODY POSITION Skeletal and Muscular System INCLUDE: Integration SUPINE: A PERSON IS LYING ON THEIR BACK WITH THEIR FACE AND UPPER BODY FACING UP. THE 40. Explain anatomical position HEAD, NECK, AND SPINE ARE KEPT IN A NEUTRAL Anatomical position, or standard anatomical POSITION. THIS POSITION IS OFTEN USED FOR position, is a specific way of positioning the body SURGICAL PROCEDURES AND AUTOPSIES. that serves as a reference point for describing PROXIMAL: MEANS CLOSER TO THE CENTER OF anatomy: THE BODY OR TO THE POINT OF ATTACHMENT TO Standing: The body is upright and facing THE BODY. forward. Arms: The arms hang straight down at the sides DISTAL: MEANS FURTHER AWAY FROM THE TRUNK OF THE BODY. of the body with the palms facing forward. Hands: The hands are held by the hips. INFERIOR: MEANS SOMETHING IS BELOW AN Legs: The legs are parallel with the feet flat on ANATOMICAL LOCATION OR NEAR TO THE FEET. the floor and facing forward. TRENDELENBURG: A PATIENT IS ON THEIR BACK Face: The mouth is closed with a neutral facial WITH THEIR HEAD DECLINED BELOW THEIR FEET AT expression. AN ANGLE OF ROUGHLY 16°. THIS POSITION IS 41. Explain the body planes OFTEN USED FOR LOWER ABDOMINAL SURGERIES The three main planes of the body are the coronal AND CENTRAL VENOUS CATHETER PLACEMENT. (frontal) plane, the sagittal (longitudinal) plane, and the transverse (axial) plane: Coronal (frontal) plane: A vertical plane that separates the body into front and back sections. Sagittal (longitudinal) plane: A vertical plane that separates the body into left and right sections. The mid-sagittal plane is the exact center line that divides the body into equal halves. Transverse (axial) plane: A horizontal plane that separates the body into upper and lower sections. This plane is often used in imaging techniques to create cross-sectional views of the body. The three planes run perpendicular (90°) to each other. 42. Identify the different body movements Rotation A twisting movement that can occur at a pivot joint, ball-and-socket joint, or within the vertebral column Dorsiflexion and plantar flexion Movements at the ankle joint, where dorsiflexion is lifting the front of the foot, and plantar flexion is lifting the heel of the foot 20 Inversion and eversion Movements at the ankle joint that involve rotating the foot, where inversion turns the sole inwards and eversion turns the sole outwards Protraction and retraction Anterior-posterior movements of the pectoral girdle or the mandible, where protraction moves the shoulder forward Depression and elevation Upward and downward movements of the scapula or mandible, where elevation moves the scapula and shoulder upward and depression moves it downward Flexion and extension Movements that decrease or increase the angle of a joint, where flexion decreases the angle and extension increases it Abduction and adduction Movements that occur within the coronal plane, where abduction moves a limb away from the midline of the body and adduction moves it toward the body 43. Understand the principles of body palpation Palpation is a physical exam technique that involves using your hands to feel a patient's body. Palpation can be used to examine any part of the body, including the abdomen, chest, mouth, vagina, and anus. It can help determine the size, shape, consistency, tenderness, and location of organs and body parts. Palpation can also help identify abnormal or irregular findings, and test for injuries or abnormal processes. 44. Locate various bony landmarks on the body Here are some bony landmarks on the body: Iliac crest: The highest point of the pelvis that extends from front to back. Anterior superior iliac spine: A sharp notch in front of the iliac crest. Posterior superior iliac spine: The most back part of the iliac crest, which can be identified by dimples at the level of S2. Ischial tuberosity: Also known as the sit bones, this is a large bony bump on the superior ramus of the ischium. It marks the side boundary of the pelvic outlet. Clavicle: Also known as the collar bone, this is a landmark that's easy to feel. It forms the sternoclavicular joint with the sternum. Acromion: A triangular process that juts out over the glenohumeral joint, and is located just lateral to the acromioclavicular joint. Medial malleolus: A prominence on the inner side of the ankle, formed by the lower end of the tibia. Lateral malleolus: A prominence on the outer side of the ankle, formed by the lower end of the fibula. Greater tubercle: A bony bump on the humerus that can be felt over the AC joint. Intertubercular groove: A divot that can be felt between the greater and lesser tubercles. 21  Lesser tubercle: A bump that can be felt between the greater tubercle and the intertubercular groove. Bony landmarks are also known as bone markings. Other types of bone markings include crests, fossae, processes, and condyles. Cardiovascular System: Blood and the Heart 45. Identify the functions of blood Blood has many functions, including: Transport: Blood carries oxygen and nutrients to the body's cells, and removes waste products like carbon dioxide. Protection: Blood clots prevent excessive blood loss, and white blood cells fight infection. Regulation: Blood regulates body temperature and pH levels. Hormone transport: Blood carries hormones throughout the body. Clotting: Platelets in blood clump together to form clots that stop bleeding and protect wounds. 46. Name the fluid component of blood and the three major types of formed elements Blood is made up of plasma and blood cells, including red blood cells, white blood cells, and platelets: Red blood cells: Carry oxygen from the lungs to the body's cells. They are small and flexible so they can fit through narrow blood vessels. White blood cells: Fight infection and disease. Platelets: Form scabs to stop bleeding and protect wounds. Plasma: A yellowish fluid that carries blood cells and platelets, and contains nutrients, proteins, hormones, and waste products. 47. Discuss the unique physical characteristics of blood Viscosity: Blood is five times more viscous than water and feels slightly sticky. Temperature: Blood has a high temperature of 38°C. pH: Blood has an alkaline pH of 7.35–7.45. Color: Blood is opaque red and its color changes depending on its oxygen content. When saturated with oxygen, hemoglobin brightens the color of blood, making it appear redder. When oxygen is removed, hemoglobin darkens the color of blood. 22  Composition: Blood is made up of plasma, which is a liquid that's mostly water, and blood cells. Plasma also contains proteins, electrolytes, and other substances. 48. Identify the composition of blood plasma, including its most important solutes and plasma proteins Water About 92% of plasma is water Proteins About 7% of plasma is made up of proteins, including albumin, globulin, fibrinogen, and prothrombin Salts Plasma contains mineral salts, such as sodium, magnesium, chloride, calcium, phosphate, potassium, and bicarbonate Other substances Plasma also contains sugars, fats, hormones, vitamins, waste products like urea and carbon dioxide, and respiratory gases 49. Describe the anatomy of erythrocytes Erythrocytes, also known as red blood cells, have the following anatomical features: Shape: Erythrocytes are biconcave, meaning they are thicker around the edges and thinner in the middle, giving them a donut-like shape. This shape increases their surface area, which helps them transport oxygen and carbon dioxide. Size: Erythrocytes are about 7–8 μm in diameter, smaller than leukocytes but larger than platelets. ALBUMIN Structure: Erythrocytes are made up of cytoplasm MAKES UP ABOUT 60% OF PLASMA PROTEINS AND enclosed by a cell membrane, and they lack a HELPS MAINTAIN THE BALANCE OF WATER IN BLOOD nucleus and other organelles. VESSELS Composition: Erythrocytes contain hemoglobin, a GLOBULIN protein that carries oxygen and carbon dioxide. Hemoglobin is made up of four globin proteins and THE SECOND MOST COMMON PLASMA PROTEIN, WITH a heme group, which contains iron. The iron in ALPHA, BETA, AND GAMMA GLOBULINS. ALPHA AND heme binds to oxygen, giving erythrocytes their red BETA GLOBULINS TRANSPORT LIPIDS, METAL IONS, AND color. FAT-SOLUBLE VITAMINS. GAMMA GLOBULINS, ALSO Production: Erythrocytes are produced in the red KNOWN AS IMMUNOGLOBULINS, ARE IMPORTANT FOR bone marrow through a process called THE IMMUNE RESPONSE. erythropoiesis. FIBRINOGEN Lifespan: about 120 days. A HIGH-MOLECULAR-WEIGHT PROTEIN THAT HELPS Destruction: Old or damaged erythrocytes are BLOOD CLOT. WHEN THERE'S AN INJURY, FIBRINOGEN destroyed in the spleen by macrophages in a TURNS INTO FIBRIN, WHICH TRAPS BLOOD CELLS, PLATELETS, AND PROTEINS TO FORM A CLOT. 23 process called eryptosis. The components of the destroyed cells are recycled. Anemia, polycythemia vera, sickle cell anemia, and pernicious anemia are all disorders that can result from a lack of healthy erythrocytes 50. Explain the composition and function of hemoglobin Hemoglobin is an iron-rich protein in red blood cells that carries oxygen and carbon dioxide in the body: Composition: Hemoglobin is made up of four globin chains, each containing a heme molecule with iron. Function: Hemoglobin's main functions are to transport oxygen from the lungs to the body's tissues and to carry carbon dioxide back to the lungs to be exhaled. Globin chains: The types of globin chains in hemoglobin differ between fetuses and adults. In adults, hemoglobin is usually made up of alpha and beta globin chains, while fetuses have epsilon, gamma, and zeta chains 51. Describe the general characteristics of leukocytes Leukocytes, also known as white blood cells, have several general characteristics, including: Function: Leukocytes defend the Colorless: Leukocytes are colorless. body against infection and disease Round: Leukocytes are round. by: Nucleus: Leukocytes have a distinct center membrane, or Locating the site of an nucleus. infection Motile: Leukocytes are capable of movement. Notifying other white blood No hemoglobin: Leukocytes lack hemoglobin. cells of their location Larger than red blood cells: Leukocytes are generally larger Fighting the invader by than red blood cells. producing antibody Amoeboid movement: Leukocytes usually do not have a proteins to attach to the constant shape because of their capacity for amoeboid organism and destroy it movement. Ingesting foreign materials Types: There are five types of leukocytes: neutrophils, and cellular debris lymphocytes, eosinophils, basophils, and monocytes. Destroying infectious 52. Identify the basic structure and function of agents and cancer cells platelets 24 Platelets, also known as thrombocytes, are cell fragments in the blood that help prevent and stop bleeding: Structure: Platelets are the smallest of the three major types of blood cells, about 20% the diameter of red blood cells. Their plasma membrane is a bilayer of proteins and lipids, with phospholipids forming the basic structure and cholesterol distributed throughout. Function: Platelets' primary function is to prevent and stop bleeding. When a blood vessel is damaged, platelets travel to the injured area and clump together to form a clot. When an injury causes a blood vessel wall to break, platelets are activated. They change shape from round to spiny, stick to the broken vessel wall and each other, and begin to plug the break. They also interact with other blood proteins to form fibrin. Fibrin strands form a net that entraps more platelets and blood cells, producing a clot that plugs the break. 53. Describe the three mechanisms involved in hemostasis The three main mechanisms of hemostasis, the physiological process that stops bleeding, are: Vascular spasm: Blood vessels narrow in response to damaged tissues. This is triggered by chemicals released by cells lining the vessel and pain receptors. Platelet plug formation: Platelets, cell-like blood particles, adhere to the damaged area and release serotonin, a hormone that causes vasoconstriction. Coagulation: Clotting factors, proteins found in blood, work with platelets to promote the formation of a fibrin clot. The Heart 54. Describe the location and position of the heart within the body cavity 25 The human heart is located within the thoracic cavity, medially between the lungs in the space known as the mediastinum. The area between the lungs organs in this area: o the heart o its large blood vessels o trachea o esophagus o thymus o lymph nodes o NOT the lungs. 55. Describe the internal and external anatomy of the heart Your heart walls have 3 layers: Endocardium: Inner layer. Myocardium: Muscular middle layer. Epicardium: Protective outer layer. The epicardium is one layer of your pericardium: The pericardium is a protective sac that covers your entire heart produces fluid to lubricate your heart keep it from rubbing against other organs made up of 2 layers: fibrous outer layer serous inner layer space between layers is filled with fluid that helps 56. Identify the tissue layers of the heart Epicardium: The outermost layer, made of loose connective tissue and mesothelium cells. It protects the heart's inner layers, produces pericardial fluid, and contains the coronary blood vessels. Myocardium: The thick, middle layer of the heart, made of specialized muscle cells called cardiomyocytes. The myocardium contracts and relaxes involuntarily to keep the heart pumping blood. Endocardium: The innermost layer, made of three layers: endothelium, elastic tissue, and subendocardial. It lines the heart's chambers, covers the heart valves, and contains blood vessels. The endocardium also contains small nerves that send electrical signals through the heart. 57. Relate the structure of the heart to its function as a pump The heart has 4 chambers, 2 atria and 2 ventricles, that work together as two pumps, working simultaneously: Atria: The upper chambers that receive blood entering the heart Ventricles: The lower chambers that pump blood out of the heart Septum: A muscular wall that divides the heart into two sides, keeping oxygen-rich and oxygen- poor blood from mixing 26 Valves: Valves prevent blood from flowing backward: Pulmonary valve: right ventricle Aortic valve: left ventricle Papillary muscles: These muscles contract to prevent blood from flowing backward into the atria Electrical signals: The heart's electrical conduction system controls the HR and contractions→ blood flow 58. Compare systemic circulation to pulmonary circulation Pulmonary circulation moves blood: heart ↔ lungs deoxygenated blood →lungs → absorb oxygen & release carbon dioxide oxygenated blood → heart. Systemic circulation moves blood btw heart → body→ Pulmonary circulation 59. Identify the veins and arteries of the coronary circulation system Coronary arteries:2 main are the left coronary artery (LCA) and the right coronary artery (RCA). These arteries branch off from the aorta, and supply blood →entire heart Left coronary artery (LCA): The LCA supplies blood to the left side of the heart. It branches into the left anterior descending artery (LAD), the left marginal artery (LMA), and the left circumflex artery (Cx). Right coronary artery (RCA): The RCA supplies blood to the right side of the heart. It branches into the right marginal artery (RMA) anteriorly and the posterior interventricular artery (PIv) posteriorly. Veins: Some of the veins of the coronary circulation system include the anterior cardiac veins, Thebesian veins, coronary sinus, great cardiac vein, middle cardiac vein, small cardiac vein, oblique vein of the left atrium, and posterior vein of the left ventricle. 60. Trace the pathway of oxygenated and deoxygenated blood thorough the chambers of the heart Oxygenated and deoxygenated blood flow through the heart's chambers in the following pattern: Deoxygenated blood: From the body, deoxygenated blood →superior & inferior vena cava→ right atrium→ right ventricle→ pulmonary artery→ lungs Oxygenated blood: Lungs ↑ oxygen →pulmonary veins→ heart→ left atrium→ left ventricle→ aorta→ body 27 61. Describe the structure of cardiac muscle Cardiac muscle cells are tubular and made up of chains of myofibrils, which are rod-like units that contain sarcomeres. Cardiac muscle cells are smaller than skeletal muscle cells and usually contain only one nucleus. Cardiac muscle cells transmit electrical signals through gap junctions, which coordinate the muscle's contractile activity. This allows the heart to contract and relax as a single unit, called a functional syncytium. Damaged cardiac muscle cells have limited ability to repair themselves. In the event of a heart attack, dead cells are often replaced by scar tissue. 62. Identify and describe the components of the conducting system that distributes electrical impulses through the heart A network of cells that generates and distributes electrical impulses throughout the heart: Function: controls the timing of the heartbeat sending electrical signals heart to contract and expand→ controls blood flow → heart & body. Parts: The main parts Monitoring the sinoatrial (SA) node Doctors use an electrocardiogram atrioventricular (AV) node (EKG) to monitor the cardiac bundle of His conduction system. Changes can bundle branches indicate serious problems. Purkinje fibers. 28 How it works: The SA node, AKA anatomical pacemaker, starts the sequence by causing the atrial muscles to contract →AV node→ bundle of His→ bundle branches→ Purkinje fibers→ ventricles to contract. 63. Relate characteristics of an electrocardiogram to events in the cardiac cycle A typical ECG tracing of the cardiac cycle (heartbeat) consists of a P wave (atrial depolarization ), a QRS complex (ventricular depolarization), and a T wave (ventricular repolarization). An additional wave, the U wave ( Purkinje repolarization), is often visible, but not always. 64. Describe the relationship between blood pressure and blood flow Your blood pressure is determined by two things: the amount of blood flowing through your arteries and the diameters (widths) of those vessels. The more blood that flows through the arteries and the narrower those vessels are, the higher your blood pressure will be. Blood pressure: The force of blood pushing against artery walls. Blood pressure is determined by the amount of blood flowing through arteries and the width of those vessels. 29 Blood flow: The movement of blood through the body. Blood flows from high pressure areas → low pressure areas; from arteries →capillaries →veins. Resistance: The force that opposes blood flow in the circulatory system. Resistance is largely due to the diameter of blood vessels. Narrower vessels= ↑ resistance &  blood flow. If cardiac function doesn't compensate for ↑ pressure in the arteries→ blood flow ↓ Vasodilation: In the arteries, ↓ resistance & ↑flow Vasoconstriction: ↑resistance & ↓ flow. 65. Summarize the events of the cardiac cycle The cardiac cycle is the performance of the human heart from the beginning of one heartbeat to the beginning of the next. It consists of 2 periods: 1. one which heart relaxes & refills with blood→ diastole 2. Period of robust contraction & pumping of blood→ systole 66. Compare atrial and ventricular systole and diastole systole are phases of the cardiac cycle that involve the contraction of the heart's chambers, diastole are phases when the chambers relax and fill with blood. Atrial systole: The atria contract, forcing the remaining blood into the ventricles. This is also known as the atrial kick. Ventricular systole: The ventricles contract, forcing blood out of the heart through the aorta and pulmonary artery. Atrial diastole: The atria relax and fill with blood. Ventricular diastole: The ventricles relax and fill with blood. 67. Relate heart sounds detected by auscultation to action of heart’s valves S1 is the sound created by the closing of the atrioventricular valves during ventricular contraction and is normally described as a “lub-”. S2, is the sound of the closing of the semilunar valves during ventricular diastole and is described as a “dub” 68. Relate heart rate to cardiac output Cardiac output is how many liters of blood your heart pumps in one minute- with this cardiac output equation: multiply stroke volume by heart rate. CO=HR×SV Cardiac output (CO): amount of blood pumped by the heart per minute Heart rate (HR): # of times the heart beats per minute 30 Stroke volume (SV): The amount of blood pumped by the heart each time it beats 69. Compare and contrast the three tunics that make up the walls of most blood vessels tissue that make up the walls of most blood vessels are the tunica intima, tunica media, and tunica adventitia. Tunica intima:The innermost layer that surrounds the blood and regulates blood pressure. It also prevents blood clots and keeps toxins out of the blood. Tunica media: The middle layer that contains elastic fibers and smooth muscle cells. It helps blood flow in one direction, and the smooth muscle can contract to narrow the blood vessel (vasoconstriction) or relax to widen it (vasodilation). The tunica media is usually the thickest layer, and the relative amount of smooth muscle and elastic tissue varies between different types of blood vessels. Tunica adventitia/externa: The outermost layer that contains nerves and tiny vessels. It delivers oxygen and nutrients to cells, removes waste, and gives blood vessels structure and support. Capillaries: are only one cell layer thick and only have a tunica intima, which allows for the exchange of gases and nutrients. Arterioles have the same 3 tunics as larger blood vessels, but the thickness of each is greatly reduced. 70. Distinguish between elastic arteries, muscular arteries, and arterioles on the basis of structure, location, and function distinguished by their structure, location, and function: Elastic arteries: Located near the heart, these arteries have a lot of elastic tissue in their middle layer and stretch in response to the heart's pulse. The aorta and pulmonary artery are examples of elastic arteries. Muscular arteries: These medium-sized arteries have more smooth muscle in their middle layer than elastic arteries. They branch off from elastic arteries and distribute blood to smaller arteries and arterioles. The radial, femoral, and brachial arteries are examples of muscular arteries. Arterioles: These small arteries receive blood from muscular arteries and carry it to tissues. They have a thick endothelial lining, but the tunica media is made up of only one or two layers of smooth muscle. Arterioles are also known as resistance vessels because they slow blood flow and lower blood pressure. All 3 types of blood vessels are made up of 3 layers: tunica intima, tunica media, and tunica externa. 71. Describe the basic structure of a capillary bed, from the supplying metarteriole to the venule into which it drains 31 Metarteriole: A short micro vessel that branches off from a terminal arteriole to supply blood to a capillary bed. Metarterioles have smooth muscle cells called precapillary sphincters that control blood flow to the capillaries. Precapillary sphincters: These circular smooth muscle cells surround the capillary at its origin with the metarteriole. They are normally closed, but open to allow blood to flow through and exchange to occur when tissues need oxygen or have excess waste products. Capillaries: Short vessels that connect arterioles and venules, allowing for the exchange of oxygen, carbon dioxide, nutrients, and waste between the blood and surrounding tissues. Venule: The blood drains from the capillary bed into a venule. 72. Explain the structure and function of venous valves in the large veins of the extremities Vein valves in the large veins of the extremities are one-way valves that help blood flow back→  by opening and closing to prevent blood from flowing backward: Structure: Each valve is made of two flaps, or cusps, that meet at the edges. Function: When blood flows toward the heart, the flaps open like swinging doors. If blood begins to back up in a vein, the flaps close to prevent backward flow. Importance: These valves are especially important in the arms and legs to prevent blood from flowing backward due to gravity. Location: Many veins, especially those in the arms and legs, have one-way valves. Relationship to muscles: The muscles surrounding the deep veins squeeze the veins, helping force the blood toward the  When valves break, blood can pool in the veins, potentially damaging them. 73. Distinguish between systolic pressure, diastolic pressure, pulse pressure, and mean arterial pressure 32 Systolic, diastolic, pulse, & mean arterial pressure are all different ways to measure blood pressure: Systolic pressure: The top number in a blood pressure reading, which measures the pressure in your arteries when your heart beats. Diastolic pressure: The bottom number in a blood pressure reading, which measures the pressure in your arteries when your heart relaxes. Pulse pressure: The difference between your systolic and diastolic pressure. For example, if your blood pressure is 120/80, your pulse pressure is 40. Measuring your pulse pressure can help you monitor your risk of heart disease. Mean arterial pressure (MAP): The area under the pressure/time curve, divided by the cardiac cycle time. MAP may be a more useful marker than systolic blood pressure because it's less dependent on where it's measured. Blood pressure readings can change depending on your activity level, stress, fluid intake, and other factors. 74. Discuss several factors affecting blood flow in the venous system The variables affecting blood flow and blood pressure in the systemic circulation are cardiac output, compliance, blood volume, blood viscosity, & length/diameter of the blood vessels. Several factors affect blood flow in the venous system, including: Pressure difference: The pressure difference between the atrium and venules Muscular tone: The tone of the venous wall muscles Compliance: The ability of a compartment to expand and accommodate more content Blood volume: A decrease in blood volume decreases flow and pressure Viscosity: The thickness of the blood, which affects its ability to flow Vessel length and diameter: Longer vessels have more resistance and lower flow External pressure: Pressures in the thoracic and abdominal cavities, which change during breathing Other factors that affect venous return include: Inspiration, Venomotor tone, The cardiac suction effect, Venous valves, & The skeletal muscle pump. 75. Identify the primary mechanisms of capillary exchange The 3 primary mechanisms of capillary exchange 33 Diffusion: The movement of gases, ions, small molecules, and lipid-soluble substances directly through the capillary wall. Transcytosis: Also known as vesicular transport. Bulk flow: The pressure-driven movement of fluids and small molecules through capillary membranes. Bulk flow is driven by two types of pressure: hydrostatic pressure and osmotic pressure. Capillaries connect arteries to veins, completing the circulatory system. Substances are exchanged between capillaries and interstitial fluid. 76. Distinguish between capillary hydrostatic pressure and blood colloid osmotic pressure, explaining the contribution of each to net filtration pressure Capillary hydrostatic pressure (CHP) & blood colloid osmotic pressure (BCOP) are 2 opposing forces that determine the net filtration pressure (NFP) of fluid in capillaries: Capillary hydrostatic pressure (CHP): The force of blood against the walls of a capillary. CHP is higher at the arterial end of a capillary, which pushes fluid out of the capillary and into the interstitial space. Blood colloid osmotic pressure (BCOP): pressure exerted by colloids suspended in blood, primarily plasma proteins. BCOP prevents water from leaving the blood vessel. BCOP is greater than CHP at the venous end of a capillary, which pulls fluid back into the capillary. Net filtration pressure (NFP) = CHP - BCOP is the difference between CHP and BCOP lymphatic system drains excess fluid from the capillaries and returns it to circulation. 34