Exam 1- Chapter 1 Flashcards
Physiology
study of how the body works to maintain life
Pathophysiology
how physiological processes are altered in disease or injury
How many steps in the scientific method are there?
4
What is the first step in the scientific method?
Form a TESTABLE HYPOTHESIS about observations
What is the second step in the scientific method?
Conduct and analyze EXPERIMENTS to test hypothesis
What is the third step in the scientific method?
Draw CONCLUSIONS about whether or not results support hypothesis
What is the fourth step in the scientific method?
Develop a THEORY
What is a theory?
general statement explaining natural phenomena that is based on proven hypotheses
What 3 things does testing of a hypothesis involve?
- Experimental and control groups
- Quantitative measurements performed blindly
- Analysis of data using statistics
When a new drug is first suggested by experiments, what is the very first step?
Its effectiveness and toxicity is tested first in tissue culture, rats, mice
If the drug is effective and safe after being tested in tissue culture, rats, and mice what happens next?
Clinical Trials
What are the steps of the clinical trials?
- Phase I Trials
- Phase II Trials
- Phase III Trials
- Phase IV Trials
Describe the Phase I Trials.
Toxicity and metabolism tested in healthy human volunteers
Describe the Phase II Trials.
Effectiveness and toxicity tested in target population
Describe the Phase III Trials.
Widespread test of drug in diverse population
Describe the Phase IV Trials.
Drug is tested for other potential uses
Define homeostasis.
maintenance of a state of DYNAMIC CONSTANCY
How are conditions stabilized in homeostasis?
above and below a physiological stepping via negative feedback loops
What 3 steps are involved in negative feedback loops?
- Sensor
- Integrating center
- Effector
What is the “sensor” portion of a negative feedback loop involved in?
Detects deviation from set point
What is the “integrating center” portion of a negative feedback loop involved in?
Determines response
What is the “effector” portion of a negative feedback loop involved in?
Produces response
What are the 4 types of regulatory mechanisms?
- Intrinsic Control
- Extrinsic Control
- Positive Feedback loops
- Negative Feedback loops
Describe intrinsic control.
Built into the organ being regulated
Describe extrinsic control.
Comes from outside of the organ
What are 2 examples of extrinsic control?
- Body temperature being controlled by the antagonistic effects of sweating and shivering
- Blood glucose levels being controlled by hormones (ex. insulin)
Is positive feedback abundant or rare? Why?
rare because it amplifies changes
What are 3 examples of positive feedback?
- It is involved in producing blood clots
- In females it is used to create the LH surge that causes ovulation
- Positive feedback between the uterus and oxytocin secretion occurs during labor
Provide 2 examples of negative feedback loops.
- Blood pressure control
2. Hormonal control of blood glucose
Describe specifically how blood pressure is controlled through negative feedback.
Lying down——> Stand up——> 1. Causes blood pressure to fall
- Blood pressure receptors are stimulated (sensor)
- Sensory nerve fibers transmit sensation to medulla oblongata of the brain (integrating center)
- Motor nerve fibers transmit motor signals to the heart, which increases heart rate (effector)
- Rise in blood pressure (negative feedback response)
Describe specifically how hormonal control of blood glucose is controlled through negative feed back WHEN EATING.
- Eat
- Blood glucose level rises
- Pancreatic Islets (of Langerhans)
- Insulin secretion increases
- Cellular uptake of glucose increases
- Blood glucose levels decrease
Describe specifically how hormonal control of blood glucose is controlled through negative feed back WHEN FASTING.
- Fasting
- Blood glucose levels decrease
- Pancreatic Islets (of Langerhans)
- Insulin secretion decreases
- Glucagon levels increase
- Cellular uptake of glucose decrease
- Glucose secreted into blood by liver
- Blood glucose levels increase
What are the primary tissues?
- Muscle tissue
- Nervous tissue
- Epithelial Tissue
- Connective tissue
What is muscle tissue specialized for?
contraction
What are the 3 types of muscle tissue?
- Skeletal muscle tissue
- Cardiac muscle tissue
- Smooth muscle tissue
Generally describe skeletal muscle.
Striated/Voluntary
Generally describe cardiac muscle.
Short/Striated/Involuntary
Generally describe smooth muscle.
Non-Striated/Involuntary
Is each skeletal muscle fiber controlled individually or as a group?
Individually
How does each fiber of skeletal muscle form? What does this allow?
- Forms by fusion of embryonic myoblasts
2. Allowing it to become large and multinucleated
How do skeletal muscle fibers line up?
Lines up in parallel with other fibers to form bundles
What type of cells is cardiac muscle made of?
Myocardial cells
How are myocardial cells of cardiac muscle branched?
to form a continuous fabric
What special features do myocardial cells of cardiac muscle have to provide mechanical and electrical interconnections?
intercalated discs
Are the myocardial cells of cardiac muscle individually controlled or controlled as a group?
As a group
Where is smooth muscle found?
many organs and tissues
What is smooth muscle controlled by?
ANS
What 2 things does nervous tissue consist of?
- Neurons
2. Supporting/Glial cells
What are neurons specialized for?
conducting electrical signals
What do neurons contain?
- Cell Body
- Dendrites
- Axons
What does the cell body of a neuron contain?
contains nucleus
The cell body is a _____ center
metabolic
What are dendrites extensions of?
highly branched extensions off the cell body
What is the function of dendrites?
receive inputs from other neurons
What are axons extensions of?
SINGLE LONG extension off the cell body
What is the function of the axon?
Conducts nerve impulses to other cells
What is the function of supporting/glial cells?
provide physical and functional support for neurons
How much more abundant are supporting glial cells vs neurons?
5x more abundant
How is epithelial tissue replaced?
Regularly replaced
What is the function of epithelial tissue?
Lines and covers body surfaces
Epithelial tissue consists of cells that form what?
membranes and glands
Describe squamous epithelial cells.
flattened
Describe columnar epithelial cells.
taller than wide
Describe cuboidal epithelial cells.
cube-shaped
How thick are simple epithelial membranes?
1 cell thick
How thick are stratified epithelial membranes?
Number of layers
What are simple epithelial membranes specialized for?
Transport
What are stratified epithelial membranes specialized for?
Protection
What does non-keratinized stratified squamous tissue consist of?
Living cells
What does keratinized stratified squamous tissue consist of? What do these cells contain
- Outer layer of dead cells
2. Water-resistant keratin
What are epithelial cells joined by? Function?
- JUNCTIONAL COMPLEXES
2. Increase strength and create barrier
What is epithelial tissue serrated from underlying tissue by?
Basement membrane
What are exocrine glands derived from?
epithelial cells
Where are the secretions from exocrine glands secreted and how?
Secrete onto epithelium via ducts
Exocrine glands can be _____ tubes or _____ called _____
- simple
- Clusters
- Acini
What are the secretions of exocrine glands controlled by?
surrounding myoepithelial cells
What does connective tissue have deposited in space between its cells?
Lots of extracellular material
What are the different types of connective tissue?
- Connective tissue proper
- Cartilage
- Bone
- Blood
What does loose connective tissue consist of?
collagen (fibrous proteins) and tissue fluid
What is an example of loose connective tissue?
Dermis of skin
What is dense regular connective tissue packed with?
fibers of collagen
How is dense regular connective tissue arranged?
- Can be regularly arranged (tendons)
2. Irregularly oriented (capsules/sheaths)
What is connective tissue- adipose specialized for?
Fat synthesis, breakdown, and storage
What is connective tissue- cartilage specialized for?
Support/Protection
What is cartilage made of?
Chondrocytes, and elastic cellular material
What does cartilage serve as a precursor for?
Bone
What does cartilage form for joint?
Articular surfaces
How is bone formed?
concentric layers of calcified material
What are the cell types of bones?
- Osteoblasts
- Osteocytes
- Osteoclasts
Describe osteoblasts.
bone-forming cells
Describe osteocytes.
trapped/inactive osteoblasts
Describe osteoclasts.
the bone resorbing cells
Define organs.
Are anatomical and functional units made of two or more primary tissues
Define systems.
are groups of organs working together to maintain homeostasis
What is the “largest organ”
skin
What is the outer protective layer of skin called?
cornified epidermis
What comes after the cornified epidermis?
Dermis
What is the final/inner layer of skin called?
hypodermis
What does the dermis contain?
- Connective tissue
- Glands
- Blood vessels
- Nerves
What does the hypodermis contain?
Fat
Most cells in organs are highly specialized or _____
differentiated
Many organs retain small populations of ___ ____ ___
adult stem cells
What is unique about stem cells?
less differentiated/ can become many cells types
What are two examples of stem cells?
- Bone marrow stem cells
2. Hair follicle stem cells
How do bone marrow stem cells function?
give rise to all of the different blood cell types
How do hair follicle stem cells function?
Can form the:
- Hair shaft
- Root sheath
- Sebaceous glands
- Epidermis
What is intracellular?
Inside cells
What is extracellular?
Outside of cells
What are intracellular and extracellular cells separated by?
cell’s plasma membrane
What is extracellular composed of?
blood plasma and interstitial fluid/tissue fluid