Exam 1 Review Flashcards
What is homeostasis?
maintenance of relatively stable internal conditions
Dynamic equilibrium
What are the components of a control mechanism (control system)?
- Receptor: monitors environment and responds to stimuli
- Control Center: Determines set point, receives receptor input, determines response
- Effector: receives input from control center, response either reduces or enhances stimulus
Explain what negative feedback is
The response reduces or shuts off the original stimulus
Most feedback in the body uses this
Ex: Regulating body temperature
Explain what positive feedback is
The response enhances or exaggerates the original stimulus
Ex: Enhancement of labor contractions due to oxytocin
What is the difference between autoregulation (intrinsic) and extrinsic regulation?
Autoregulation occurs automatically, wheras extrinsic regulation is controlled by the nervous and endocrine systems.
Define supine and prone
Both describe anatomical positions.
Supine is face-up
Prone is face-down
Define Ventral and Dorsal
Ventral means anterior (front)
Dorsal means posterior (back)
What are the three body planes?
Sagittal, Frontal (coronal), and Transverse (horizontal/axial)
What are the four abdominopelvic quadrants?
What are the nine abdominopelvic regions?
What are microvilli and what is their function?
Membranous extensions containing microfilaments
They increase the surface area available for absorption to occur
What are cilia and what is their functoin?
Cilia are long extensions containing microtubules
They help with the movement of material over the surface of the cell. Found in the respiratory and urinary tracts.
What are the functions of the plasma membrane?
- Physical Isolation
- Regulation of exchange with environment
- Sensitivity to the environment
- Structural support
What are the components of the cytoplasm?
Cytosol: the liquid component
Organelles: intracellular structures
What are the components of the cell membrane?
- Phospholipids
- Cholesterol
- Carbohydrates
- Proteins
What is an integral protein?
A membrane protein whose removal will disrubt/destroy the cell membrane
What is a peripheral protein?
A protein found either on the intracellular or extracellular side of the plama membrane.
Removal of these proteins will not disrupt the membrane
Explain the purpose of microfilaments.
They are found in microvilli and are used for anchoring. They also determine the fluidity of the cytosol.
Explain the purpose of intermediate filaments.
They stbilize
What is the function of microtubules?
They help move vesicles and organelles throughout the cytoplasm
They also are crucial for mitosis due to their role in the formation of spindle aparatuses
How do cilia prevent resistence and maximize efficiency for movement?
They only beat one way with a power stroke, in which the cilia is stiff, and a return stroke where it is limp.
Describe a tight junction
They prevent movement between cells. They can vary in their degree of tightness.
Frequently found in epithelial cells.
Composed of peripheral proteins from each membrane
What is a desmosome?
A cellular structure that keeps cells bound together.
They help resist shearing forces
What is a gap junction?
Cell-cell junction made up of proteins called connexins. They allow ions to pass between neighboring cells.
Useful for synchronicity
Is the plasma membrane impermeable, freely permeable, or selectively permeable?
Selectively permeable
What does the selectively permeable membrane restirct materials based on?
Size, Electrical Charge, Molecular shape, and Lipid Solubility
Which has a more negative charge: intracellular fluid or extracellular fluid?
Intracellular fluid is negative because of the presence of many negatively charged proteins.
Explain diffusion
Diffusion is a passive process by which molecules move from high concentrations to low concentrations (down the concentration gradient)
What are the factors that affect diffusion?
Distance, Molecule Size, Temperature, Concentration Gradient, Electrical Forces
What materials are able to diffuse through the plasma membrane by simple diffusion?
Lipid soluble compounds and dissolved gases
How do water soluble molecules enter the cell?
By channel mediated diffusion
Ex: Aquaporins
What is osmosis?
Diffusion of water across the cell membrane. Water moves to equalize the concentration of solutes on either side of the membrane.
Does the concentration of one solute effect the diffusion of another similarly sized and charged solute?
No. Each solute diffuses as though it were the only material in the solution.
What is osmotic pressure?
The force of a conceentartion gradient of water.
What is the difference between osmolarity and tonicity?
Osmolarity refers to the solute concentration of the solution, while tonicity is a description of how the solution affects the cell.
Describe Isotonic, Hypotonic, and Hypertonic.
Isotonic: no change in size
Hypotonic: cell will expand because it has more solutes, water diffuses into cell
Hypertonic: cell will shrivel because it has less solutes, water diffuses out of cell
What is crenation?
When a red blood cell in a heypertonic solution loses water and shrinks
Is vesicular transport active or passive?
Active
What is a uniport carrier? Give an example
They transport one kind of substrate across the membrane
Example: Glucose channel
What is a symport carrier? Give an example.
Move two or more substrates in the same direction across a membrane.
Example: Sodium-Glucose co-transporter
What is an antiport carrier?
Moves substrates in opposite directions across the membrane.
Example: Na/K pump
How is the concentration gradient for glucose maintained in the cell?
Glucose is converted to other products via glycogen and glycolosis so it doesn’t contribute to the concentration gradient any more once it is in the cell.
Explain secondary active transport?
When the gradient for one ion is used to drive the movement of another across the membrane.
Example: Na gradient allows glucose to enter the cell
Expllain how a primary active transporter is necessary for the functioning of secondary active transporters
The primary transport creates the concentration gradient that drives the secondary transport
What are the two types of endocytosis?
Phagocytosis and pinocytosis
Phago: usually to destroy something in immune response
Pino: intake of ECF
What are the four types of tissues?
- Epithelial
- Connective
- Muscle
- Neural
Explain what epithelial tissue does
It covers exposed surfaces, lines internal passages and chambers, and forms glands
What are the characteristics of epithelia?
Cellularity
Polarity
Attachment
Avascularity
Regeneration
How are epithelial cells maintained and repaired?
They are replaced by the division of germinative cells in the basal layer
What are the 8 types of cells?
- Simple Squamous
- Simple Cuboidal
- Simple Columnar
- Stratified Squamous
- Stratified Cuboidal
- Stratified Columnar
- Transitional Epithelium
- Psuedostratified columnar epithelium
What is epithelium always attached to?
Connective tissue
What is the difference between endocrine glands and exocrine glands?
Endocrine glands release hormones into the interstitial fluid whereas exocrine glands produce secretions onto epithelial surfaces through ducts
Explain the difference between paracrine and autocrine glands.
Paracrine glands secrete hormone that act on nearby tissues wheareas autocrine glands act on the gland/tissue that they are secreted from
Explain holocrine, apocrine and merocrine secretions
Holocrine: whole cell is released
Apocrine: part of the cell is released
Merocrine: vesicles are released
What are mucous (goblet) cells?
They are the only unicellular exocrine glands
Does connective tissue have contact with the environment?
No
What is the matrix (in connective tissue) made up of?
Fibers and ground substance
What are the three types of conective tissue?
CT Proper
Fluid CT
Supporting CT
What are the subtypes of Loose CT proper?
Areolar, adipose and reticular
What are the subtypes of Dense CT Proper?
Dense regular, dense irregular, elastic
What are the two components of a membrane?
Areolar and epithelial tissue
What is the primary function of a fibroblast?
They secrete hyaluronan and make ground substance viscous through the production of proteoglycans.
Their secretions also from large extracellular fibers
What are the three parts of connective tissue?
Matrix, fibers/ground substance, and cells
What is the origin of all connective tissues?
Mesenchymal stem cells
What do macrophages do?
They engulf damaged cells and pathogens through phagocytosis
What connective tissue cell type is associated with inflammation?
Mast cells release heparine (anticoagulant) and histamine, which cause an inflammatory response
What are the two types of microphages?
Eosinophils and neutrophils
What is the structural difference between collagin fibers and reticular fibers?
Collagen fibers are made of 3 coiled coils that are unbranched and resist tensile forces, whereas reticular fibers are made from just one coil and are branched. Reticlar fibers are able to withstand forces in many directions
Describe the structure of elastic fibers.
Elastic fibers are made mostly of elastin and have branched and wavy fibers. They allow stretching and returning to the original length.
What is the purpose of reticular fibers?
They support organs and can also act as filters
ex: removal of old RBCs in the spleen
Describe the structure and function of Ground Substance
Ground substance is clear, colorless, and viscous due to the presence of proteoglycans and glycoproteins.
It fills the spaces between cells and slows pathogen movement because of density
What are the two types of embryonic connective tissue?
- Mesenchyme
- Mucous connective tissue
What type of connective tissue is found only in the umbilical cord?
Mucus CT (Wharton’s Jelly)
What are the two epidermal pigments?
Carotene: orange-yellow pigment
Melanin: brown, yellow-brown or black pigment; protects skin from UV radiation
How long does it take for a cell to move from the stratum basale to the stratum corneum?
7-10 days
It remains in the stratum corneum ~2 weeks
What is the body’s first line of defense from the environment?
The cutaneous membrane (skin)
What are the general functions of the integumentary system?
1) Protection
2) Excretion
3) Maintenance of body temp
4) Production of melanin
5) Production of keratin
6) Production of vitamin D3
7) storage of lipids
8) detection of touch, pressure, pain and temperature
What type of epithelial cells make up the epidermis?
Stratified squamous
Describe to subcomponents of the integumentary system
Is the subcutaneous layer considered a membrane?
No, because it does not have epithelial and connective tissue
What is the difference between thin skin and thick skin?
Thin skin has 4 layers of keratinocytes, whereas thick skin has 5 layers.
Thick skin is only found on the palms of the hand and soles of the feet
Describe the stratum basalel.
The innermost epidermal layer which is made up of stem cells and is attached to the basement membrane by hemidesmosomes.
This layer forms the epidermal ridges that extend into the dermis.
Describe the stratum spinosum.
8-10 layers of keratinocytes that are formed from the division of stem cells. Cells are still dividing in this region.
Describe the stratum granulosum
3-5 layers of keratinocytes derived from the spinosum
these cells produce large amounts of heratin and keratohyalin
cells begin to die
Describe the stratum lucidum
The layer that is found only in thick skin that contains flat densely packed cells
This layer stains clearly, “lucidum”
Describe the stratum corneum
This layer is at the exposed surface and is composed of 15-30 layers of keratinized cells
What are Merkel discs?
Sensory receptors found in the epidermis
Describe the order of the layers found in the epidermis
What are dermal papillae?
They are projections from the dermis into the basal lamina layer. These increase the surface area for increased diffusion, and are also the reason that we have fingerprints.
What is insensible persperation, and how much is lost per day because of it?
Interstitial fluid is lost by evaporation throuogh the stratum corneum.
500 mL lost per day
What is the difference in blood color between oxygenated and deoxygenated blood?
Oxygenated is bright red, whereas deoxygenated is scarlet (dark red)
When does bile contribute to the color of an individual’s skin?
Only in pathological situations
Yellow skin = Jaundice
What is Addison’s disease?
Excess ACTH is produced from the pituitary gland which leads to the darkening of skin.
What is Vitiligo?
A condition in which melanocytes are lost leading to a loss of skin color. This is not a medical condition, but causes many social problems
What are the different type of skin cancers?
Basal Cell carcinoma: basal cells overgrow
Squamous: keratinocytes overgrow
Malanoma: melanocytes overgrowing (worst in terms of survival rates)
What are the ABCDE’s of skin cancer detection?
Asymmetry
Border
Color
Diameter
Elevation
What is cholecalciferol and what role does it play in the body?
Cholecalciferol is vitamin D3
Epidermal cells produce it in the presence of UV radiation.
It is converted into calitriol in the kidneys and the liver, which is used for the absorption of calcium and phosphate.
What condition is caused by insufficient vitamin D3?
Rickets
Describe the Dermis.
It is the layer between the epidermis and the subcutaneous layer.
It has 2 components:
- Outer papillary layer
- Deep reticular layer
Describe the paillary layer of the dermis.
It contains areolar tissue which has small capillaries, lymphatics and sensory neurons.
It has dermal papillae which project between the epitermal ridges.
Describe the reticular layer
Made of dense irregular connective tissue and ahs larger blood vessels, nerves, and lymphatic vessels than the papillary layer
It contains collagen and elastic fibers (CT proper)
What is Dermatitis?
An inflammation of the papillary layer that usually causes itchiness and/or pain.
What are cleavage lines?
lines representing the orientation of collagen and elastic fiber bundles
an incision parallel to these lines will heal easily, whereas an incision perpendicular to these lines will cause much more scarring
What do nerve fibers in the skin primarily control?
Blood flow
Gland secretions
Sensory receptors
Describe the hypodermis
Lies below the integument
Allows for separate movement of skin from underlying tissues
Made up of elastic areolar and adipose tissue
Has few capillaries and no vital organs
What are considered accessory structures of the integumentary system?
Hair, Hair follicles, sebaceous glands, sweat glands, and nails
Where is there NO hair on the human body?
Palms, soles, lips, anterior surface of eyeball, and portions of external genitalia
What are the primary functions of hair?
It protects and insulates and guards openings agains particles and insects. Also helps for sensation of touch.
What are arrector pili muscles?
They are the muscles that stand up hair and are under the control of the autonomous nervous system.
What are the two types of hair?
Vellus hair: soft, fine, covers most of body surface
Terminal hairs: heavy, pigmented; found on head, eyebrows and eyelashes
Explain the difference between apocrine glands and merocrine glands.
Apocrine glands are found in the arm pits and groin and secrete thick odorous fluid. These glands are either on or off. Controlled by ANS
Merocrine glands are found on the palms and soles and are controlled independently (some by ANS)
Describe the response to injury
- Bleeding occurs; mast cells trigger inflammatory response
- A scab stabilizes and protects the area. Granulation tissue forms from fibroblasts and endothelial cells
- Scab undermined by fibroblasts producing meshwork of new skin cells
- Scab is shed, epidermis is complete. Depression left behind until scar tissue forms enough
What is the rule of nines?
A way of estimating the percentage of skin that is affected by burns.
What are some of the effects of aging on the integument?
Decreased blood supply, function of hair follicles, elastic fibers, repair rate
Dermal thinning, wrinkling and reduced melanocyte activity
What are the primary functions of the skeletal system?
- Support
- Storage of minerals
- Blood cell production (red marrow)
- Protection
- Leverage
Describe the structure of a long bone
Diaphysis is the shaft: heavy wall of compact bone with a central space called the medullary cavity
Epiphysis is the wide part at each end; mostly spongy bone, coveret with compact bone
Metaphysis is where the diaphysis and epiphysis meet
What is hydroxyapatite?
Calcium phosphate reacts with calcium hydroxide to form these crystals in the bone that give it
What are the different types of bone cells?
Osteocyte: mature bone cell that maintains bone matrix
Osteoblast: immature bone cell that secretes organic components of the matrix
Osteoprogenitor: stem cell that divides to produce osteoblasts
Osteoclast: multinucleate cell that secretes acids and enzymes to dissolve bone matrix
What are canaliculi?
Cytoplasmic extensions of osteocytes
How are osteons aligned in compact bone?
They are aligned all parallel with the long axis of the bone, making it very strong when compressed in that direction
What are trabeculae?
The meshwork of supporting bundles and fibers in spongy bone
Where is red bone marrow typically found?
In the spongy bone within the epiphyses of long bones such as the femur
What is yellow bone marrow
Adipose tissue deposits within bones that are important energy reserves
Describe the periosteum
Has a fibrous outer layer and a cellular inner layer. The collagen fibers of the periosteum are continuous with those of the bone, adjacent joint capusles, and attached tendons and ligaments
What is the endosteum?
This incomplete cellular lauyer lines the medullary cavity and converfs the trabeculae of spongy bone. It is active in bone growth and repair because it contains osteoblasts, osteoprogenitor cells and osteoclasts
What is the difference between ossification and calcification?
Ossification is the process of replacing other tissues with bone whereas calcification is the specific process of depositing calcium salts into a tissue.
Calcification occures during bone ossification
What tissue do most bones originate as?
Hyaline cartilage
Describe the steps of intramembraneous ossification
1) mesenchymal cells differentiate into osteoblasts and the bone expands w/ spicules into nearby tissues
2) Spicules interconnect, trapping blood vessels
3) Over time, spongy bone structure is formed. This can later be reformed into compact bone
Describe the steps of endochondral ossification
1) enlarging chondrocytes within the calcifying matrix at center of shaft
2) blood vessels grow around the edges, cells of perichondrium turn into osteoblasts, leading to a superficial layer of bone
3) Blood vessels penetrate cartilage and reach central region, bringing with them osteoblasts that are able to begin to produce spongy bone in central region
4) As bone formation spreads from middle towards both ends, remodeling occurs creating the medullary cavity.
5) Capillaries and osteoblasts in epiphyses become secondary ossification centers
6) Articular cartilage remains exposed to joint cavity
What is appositional growth?
Bone matrix is added to the outer surface of the bones, increasing the diameter
What are the components of the cell membrane?
Describe the process of membrane transport
simple squamous
Simple Cuboidal
simple columnar
stratified squamous
stratified cuboidal
stratified columnar
What are the different types of connective tissues?
What are the components of the integumentary system?
What are the different types of glandular structures?
What type of cells are found in all connective tissue proper?
Fibroblasts and fibrocytes
What are aponeuroses?
Dense regular connective tissue that attach in sheets to large flat muscles
Similar histologically to tendons
What are neuroglial cells?
Cells that maintain the physical structure of neural tissues and repair the tissue framework after injury
What characteristic changes occur in tissue because of inflammation?
Inflammation leads to increased blood flow, increased vessel permeability and pain.
These cause increased temperature, O2 and nutrient deliver, activity and number of phagocytes and decreased toxins/waste products
What is necrosis?
As cells break down, lysosomes release enzymes that destroy the injured cell and attack surrounding tissues
What are Merkel cells?
tactile disks for sensory reception of touch
What are Langerhans cells?
Fixed macrophages throughout the epithelia that are active in uptake and processing of antigens for immune response.
What are melanosomes?
vesicles prodced by melanocytes that contain the melanin pigment
these vesicles enter the keratinocytes leading to skin pigmentation
What is the function of myoepithelial cells?
They squeeze apocrine glands in response to nervous or hormonal signals
Describe the structure of spongy bone
A matrix forms an open network of trabeculae with red marrow filling in the space in between.
Spongy bone is NOT organized into osteons
What minerals are found in the bone matrix?
Calcium phosphate: Ca3(PO4)2
Calcium hydroxide: Ca(OH)2
combine to form:
hydroxyapatite: Ca10(PO4)6(OH)2
What vitamins are crucial for healthy bones?
Vitamin C: collagen synthesis and osteoblast differentiation
Vitamin A: stimulates osteoblast activity
Vitamins K and B12: help synthesize bone proteins
Growth hormone, thyroxine, estrogens/androgens stimulate bone growth
What is the most abundant mineral in the body?
Calcium
How do PTH and calcitonin affect Ca2+ levels in the blood stream
PTH: increases Ca2+
Calcitonin: decreases Ca2+
Describe the steps in the repair of a fracture
1) Bleeding: large blood clot forms
2) Calluses form internally (network of spongy bone) and externally (cartilage and bone)
3) The external callus hardens into bone, the spongy bone expands, joining together the fracture, and fragments of dead bone are removed
4) The external callus swelling slowly diminishes over time and the bone returns to normal
What is a Pott’s fracture?
A common ankle fracture where one of the malleoli (end of tibia or fibula) break off
What is a comminuted fracture?
When a bone breaks in many places at once
What is a greenstick fracture?
A fracture of the distal radius
What does cephalic mean?
Toward the head
What does caudal mean?
Towards the tail
In what abdominopelvic region is the spleen located?
Left hypochondriac
In what abdominopelvic region is the appendix located?
Hypogastric
Which plane separates superior from inferior?
Transverse plane
Which plane separates right from left?
Sagittal plane
Which plane separates anterior from posterior?
Frontal plane
What are the components of the Ventral body cavity?
Thoracic Cavity
- Pleural cavities (L and R)
- Mediastinum: trachea, esophagus, vessels
- Pericardium
Abdominopelvic cavity
- Peritoneal Cavity
- Abdominal cavity: digestive glands and organs
- Pelvic cavity: bladder, reproductive organs, end of GI tract
What are the two components of serous membranes?
Parietal layer lines the cavity
Visceral layer covers the organ
What is the retroperitoneal space and what organs are found there?
It is the area posterior to the peritoneum and anterior to the muscular body wall
Holds the: pancreas, kidneys, ureters, and parts of the GI tract
Can two fluids have the same osmolarity, but different tonicity?
Yes
What makes up glycolipids? Glycoproteins?
Glycolipids: carbohydrates + phospholipids
Glycoproteins: carbohydrates + proteins
