Cells/Organ Systems/Skeletal System/Muscular System Flashcards
What are the four major types of tissues found in the body? Where would you find them?
- Epithelial: sheets of cells that line or cover various surfaces and body cavities (skin/lining of mouth/digestive tract/lungs/bladder/kidney tubules)
- Connective: supports the softer organs of the body/connects parts of the body together (diverse in where they are located)
- Muscle: cells that are specialized to shorten or contract resulting in movement of some kind (heart, skeletal muscle of tendons, smooth muscle of hollow organs
- Nervous: specialized for generating and transmitting electrical impulses throughout the body (brain, spinal cord, nerves)
Structure/Location/Function of each tissue discussed in class
How can you differentiate one tissue type from another?
-by the type of cells it contains
Difference between an endocrine and an exocrine gland
- Endocrine Glands: secrete products (hormones) into the blood for distribution throughout the body
- Exocrine Glands: secrete products into hollow organs or ducts (glands of mouth that secrete saliva and skin that secretes sweat)
What kind of fibers are found in connective tissue/what are their characteristics & functions?
- Collagen Fibers: made of protein/confer strength
- Elastic Fibers: made primarily of elastin/can stretch without breaking
- Reticular Fibers: made of collagen/internal structural framework for soft organs like the liver, spleen, lymph nodes
What are the components of blood?
- WBCs: immune defense
- RBCs: transport oxygen and nutrients and waste products of cells metabolism
- Platelets: participate in clotting process
What are the major cavities of the body/location/organs that are in each?
Anterior Cavities
- Abdominal Cavity- stomach area/ contains digestive organs, kidneys, liver etc.
- Pelvic Cavity- groin area/ contains bladder
- Thoracic Cavity- chest area/contains heart and lungs
Posterior Cavities
- Cranial Cavity- head/contains brain
- Spinal Cavity- the back/ contains the spine
What are the two layers of the skin and what types of cells/ extracellular materials are found in each?
- Epidermis: outer layer of epithelial tissue, stratified squamous epithelial cells
keratinocytes: provide tough waterproof protein (keratin)
melanocytes: give skin its pigment (melanin) - Dermis: inner layer of connective tissue/supports tissues
fibroblasts: produces collagen and other fibers
mast cells: releases histamine during inflammatory responses
wbcs
fat cells
collagen&elastin fibers for strength and elasticity
What are the functions of the skin?
- protection from dehydration
- protection from injury
- defense against invasion by bacteria and viruses
- regulation of body temperature
- synthesis of vitamin D
- sensation
What are the major types of cell junction/what function does each perform?
- Tight Junctions: seal the plasma membrane tightly together (digestive tract lining/bladder lining)
- Adhesion Junction/Spot Desmosomes: permit some movement between cells/allow tissues to stretch and bend (skin)
- Gap Junction: protein channels enable movement of materials between cells
What are cell junction constructed of?
-proteins
How is homeostasis maintained in the body?
-by negative feedback where deviations from the desired conditions are automatically detected and counteracted
Positive & Negative Feedback
Positive Feedback: change in controlled variable causes a series of events that amplifies original change (ex. childbirth)
-not a mechanism for maintaining homeostasis
Negative Feedback: deviations from normal are detected and counteracted (ex. homeostasis of body temperature
control variable, sensor, control center, effector
Four components of negative feedback system/function of each:
- Controlled Variable: any physical or chemical property that might vary from time to time and must be controlled to maintain homeostasis
- Sensor: monitors current value of controlled variable and sends info to control center
- Control Center: receives input from the sensor and compares it to the correct, internally set value of the controlled variable
- Effector: takes necessary action to correct the imbalance
The 11 Major Body Systems and their Functions:
Muscular: generates heat/produces movement
Urinary: maintains volume of body fluid/excretes waste
Respiratory: exchange gases/produce sound
Digestive: provides body with water and nutrient
Endocrine: produces hormones that regulate body functions/integrative functions
Reproductive: egg, sperm, genitals
Skeletal: protects, supports, stores minerals, produces blood cells
Lymphatic: returns excess tissue fluid to circulatory system, defense responses
Integumentary: protects from injury, infection, dehydration/ receives sensory input
Nervous: detects external and internal stimuli
Circulatory: transports materials to and from cells
Four Types of Tissue Membranes (location/function)
- Serous: line and lubricate internal body cavities/reduce friction between organs
- Mucous: lines airways, digestive tract, reproductive tract/lubricate surface, capture debris
- Synovial: line spaces in movable joints/lubricate the joint
- Cutaneous: form outer covering (skin)
What is the structure of compact and spongy bone?
Compact Bone: forms shaft and ends/ contains marrow space
Spongy Bone: trabeculae form lattice like supports/spaces may contain red bone marrow
What are the cells you find in bone tissue?/What do they do?
- Osteoblasts: young bone forming cells
- Osteoclasts: bone dissolving cells
- Osteocytes: mature bone cells
How does a fracture heal?
- After a fracture blood vessels supplying the bone bleed into the area producing a mass of clotted blood called a hematoma
- Fibroblasts migrate to the area for repair/some of them become chondroblasts and together they produce a fibrocartilage bond called a callus
- Osteoclasts arrive and remove dead fragments of bone and blood cells from the hematoma
- Osteoblast arrive and start the deposit of new bone (osteoid matrix)
What are the major bones of a skeleton?
- Long (limbs and fingers)
- Short (wrist bones)
- Flat (cranial, sternum, ribs)
- Irregular (coxal bone, vertebrae)
***Process of bone formation (ossification) in the fetal skeleton
Early Fetal Development: cartilage model forms/formed by chondroblasts (cartilage forming cells)
Later Fetal Development: osteoblasts replace cartilage with bone
Childhood: primary and secondary ossification sites are formed
Adolescence: elongation of growth plates
How do bones increase in length?
- bones increase in length by growth plates( where chondroblasts and osteoblasts remain active)
- deposition of new cartilage is concentrated on the outside of the plate/ conversion of cartilage model to bone is concentrated on the inside of the plate
What is bone remodeling?
Bone Remodeling: changes in shape, size, and strenght
- dependent on diet, excercise, age
- weight bearing exercise increases overall bone mass and strength
What bones make up the appendicular and axial skeleton?
Appendicular: bones of the appendages and their attached structures
-pectoral girdle, arms, pelvic girdle, legs
Axial: midline of the body
-skull, sternum, ribs, vertebral column
What are the regions of the spinal column?/How many bones are in each region?
Cervical(neck): 7 vertebrae
Thoracic(chest): 12 vertebrae
Lumbar(small of back): 5 vertebrae
Sacral(sacrum): 5 fused vertebrae
Coccygeal(coccyx): 4 fused vertebrae
How can you identify cervical, thoracic, and lumbar vertebrae?
Different types of joints/Location
- Fibrous: immovable (joints between flat bones of skull)
- Cartilaginous: slightly movable (joints between adjacent vertebrae)
- Synovial: freely movable (seperated by fluid filled cavity/ball and socket/hinge joint)
Structure of Synovial Joint
Hinge Joint: movement in one plane (knee/elbow)
Ball and Socket: more free movement than hinge joint
- to reduce friction there are disks of cartilage on either side of the knee called menisci/bursae which are sacs of fluid add more cushioning
- synovial membrane secretes synovial fluid as lubricant
- hyaline cartilage acts as cushion
Joint Capsule: synovial membrane and hyaline cartilage
Tendons: join bone to muscle
How many and what kind of ribs are there?/Which bones are ribs attached to?
- there are 12 pairs of ribs
- 10 pairs are attached to the vertebrae in the back, sternum in the front
- lowest 2 pairs are floating (attached to vertebrae but not sternum)
Diseases/Injuries of the skeleton and joints
Sprains: stretched or torn ligaments/heal slowly
Bursitis & Tendonitis: inflammation of the bursae or tendons
Arthritis: inflammation of joints
Osteoporosis: excessive bone loss
What causes osteoporosis/how do you prevent it?
- osteoporosis is caused by excessive bone loss
- getting enough calcium and vitamin D/ working out consistently can prevent osteoporosis
Skeletal, Cardiac, & Smooth Muscle
Skeletal Muscle: attaches to skeleton/provides strength & mobility
Cardiac Muscle: in the heart
Smooth Muscle: digestive tract, blood vessels, uterus, ureters
Structure of skeletal muscle
- Muscle Cell(fiber): contains many individual myofibrils
- Myofibril: cylindrical structures arranged in parallel
- Actin Thin Filament
- Myosin Thick Filament
- Sarcomere: segment of myofibril from one z line to the next
- Z-line
- Fascicle: bundles of muscle
Structure of skeletal muscle (contd.)
- Sarcoplasmic Reticulum: membrane bound chambers
- Troponin:
- Tropomysin: protein involved in muscle contraction
- T-tubule: tubelike extensions of the cell membrane
How are muscles innervated/what is a motor unit?
-Muscle cells are innervated by a single motor axon
Motor Unit: motor neuron and all the muscle cells it controls/smallest functional unit of a muscle contraction
What is a sarcomere/what components make up a sarcomere?
Sarcomere: contractile unit of muscle
- myosin: thick filament
- actin: thin filaments
What role does calcium play in muscle contraction?
- presence of calcium permits contractions
- calcium must be present for cross-bridges to form
Process of muscle contraction
Motor neurons stimulate muscle contraction
Acetylcholine is released from motor neuron at
neuromuscular junction
Electrical impulse is transmitted along T tubules
Calcium is released from sarcoplasmic reticulum (modified smooth endoplasmic reticulum)
Calcium initiates chain of events that cause contraction
1.
Calcium is released from sarcoplasmic reticulum
2.
Calcium binds to troponin
3.
Troponin–tropomyosin complex shifts position
4.
Myosin binding site is exposed
5.
Myosin heads form cross-bridges with actin
6.
Actin filaments are pulled toward center of
sarcomere
7.
Sarcomere shortens
Define Muscle Twitch/Summation/Recruitment
Muscle Twitch: small muscle contraction
Summation: occurs as successive stimuli are added together to produce a stronger muscle contraction
Recruitment: activation of additional motor units increases muscle tone
Where does the energy come from for muscle contraction?
- Stored ATP: direct energy source
- Stored Creatine Phosphate: converted to ATP
- Stored Glycogen: depends on whether oxygen is available/ 2 ATP in absence of oxygen, 36 in presence
- Aerobic Metabolism: complete metabolism of one glucose molecule/ yields 36 ATP
Slow Twitch & Fast Twitch Muscle
Slow Twitch: contract slowly, make ATP by aerobic metabolism, many mitochondria, well supplied with blood vessels, store very little glycogen, red muscle, used for endurance activities
Fast Twitch: contract quickly, rapidly break down ATP
fewer mitochondria, little or no blood vessels, store a lot of glycogen, white muscle, capable of anaerobic metabolism, used for brief high intensity activties
How does frequency of stimulation influence muscle contraction?
When the stimulation frequency was increased to the point in which muscle relaxation did not occur the amount of force progressively increased with each stimulus. When muscle twitches overlap, no muscles relax, and stimuli occurs one after another in a short amount of time, the muscle contraction is higher than if a single stand alone contraction had occurred; also known as wave summation.
How does contraction of smooth muscle different from skeletal and cardiac muscle?
Skeletal muscle: fastest
Cardiac muscle: moderate
Smooth muscle
–
Very slow
–
Partially contracted all of the time
–
Almost never fatigues
Muscular Disorder and Disease
-Muscular Dystrophy:
Genetic disease: Duchenne muscular dystrophy
Modified dystrophin protein enables leakage of Ca
++ into cells
Extra Calcium activates enzymes that destroy muscle
proteins
Muscle weakening and wasting
Muscle mass is replaced with fibrous connective
tissue
Life expectancy: approx. 30 years
- Tetanus: infection of deep wound by bacteria/ causes muscle to contract forcefully
- Muscle Cramps: caused by dehydration and ion imbalances
- Fasciitis: inflammation of fascia
