Physiology Lecture 1 Flashcards
What is physiology?
The study of how living systems (organs, tissues, cells) function or work
How is physiology different from anatomy?
Anatomy examines and describes the structures, while physiology examines the function
What is pathophysiology?
Physiology gone wrong
associated with disease or injury
Steps in the scientific method
- Make an observation
- Ask a question
- Do background research
- Construct a hypothesis
- Test your hypothesis by doing an experiment
- Analyze your data and draw a conclusion
- Communicate your results
What are the 4 major cell types?
Muscle
Neurons/nerve
Epithelial
Connective
What types of cells do PTs focus on?
Connective and muscle cells
Define a tissue? An organ? An organ system?
Tissue- Collections or groupings of differentiated cells possessing similar properties plus their extracellular matrix
Organs- Group of tissues in a living organism that perform a similar function (made up of one or more tissues)
Organ System- Two or more organs working together in the performance of a specific body function
What 4 types of tissues are there?
- Muscle tissue
- Nerve tissue (brain, ganglion)
- Epithelial tissue (organ lining)
- Connective tissue (blood, bone, tendons, ligaments, fat)
What is the extracellular matrix (ECM)
A three-dimensional network of extracellular macromolecules, such as collagen, enzymes, and glycoproteins, that provide structural and biochemical support of surrounding cells.
What is cell differentiation?
The process by which a unspecialized cell becomes a specialized cell
Specialization of muscle tissue?
Force production
3 types of muscle tissue
Skeletal
Cardiac
Smooth
Is skeletal muscle voluntary or involuntary?
Voluntary striated
Skeletal muscle fibers
myofibers
myo=muscle
What does botox do?
Denies innervation to skeletal muscle
Is cardiac muscle voluntary or involuntary?
Involuntary striated
How many nuclei per cell in cardiac muscle?
one nuclei per cell (as apposed to muscle cells)
Is smooth muscle voluntary or involuntary?
Involuntary
What does smooth muscle line?
Hollow organs
Nervous tissue consists of?
Nerve cells and glial (supporting) cells
Where can epithelial tissue be found?
- Lines the inner & outer surfaces of hollow organs and blood vessels
- Lines the inner surfaces of cavities
- Skin/nasal epithelium/roof of the mouth
Why is a patient at risk for infection when the skin is punctured?
Epithelial acts as a barrier
The barrier has been breached and provides passageway for infection.
Need to be careful with every patient that has a breach in skin
Where would you find simple squamous epithelial tissue?
Capillaries have simple squamous for diffusion. Oxygen has to move from one chamber to another.
Simple squamous found where movement of materials are needed.
What type of epithelial tissue is found on calluses?
Stratified squamous
Not in hands because hands are for sensation
Types of epithelial tissue and short definitions?
Squamous: Flattened in shape
Cuboidal: Equally wide and tall
Columnar: Taller than they are wide
What is popcorn lung and how does it occur?
a rare medical condition that damages the bronchioles, the lung’s smallest airways. Over time, inflammation associated with popcorn lung causes lung tissues and airways to scar and narrow, causing breathing difficulties.
Caused by vaping
Does epithelial tissue have a role in secretion?
Yes
Hormones (glands)
Sweat,mucous,enzymes
T or F. Epithelial cells tend to be further apart
False
Epithelial cells tend to be closely packed together
What is the primary function of the basement membrane?
Links the epithelial membrane to the underlying extracellular matrix (primary function)
Most important thing to remember about Connective Tissue?
Few Cells!!!
Lots of extracellular space and material!!!
Blood is considered a connective tissue
Types of Connective Tissue
Adipose tissue (fat)
Tendons/Ligaments
Bone
Blood
What is areolar (loose) connective tissue
Primarily located beneath epithelial membranes and glandular epithelium, binding these epithelia to other tissues, contributing to the formation of organs
Principle site of rapid fluid and gas exchange between blood and local tissue
What does the loose connective tissue provide space for?
Blood vessels, nerve fibers, and other structures
Gives flexibility to the tissue
What is dense regular connective tissue?
Collagenous fibers are oriented parallel to each other, are densely packed in the extracellular matrix, leaving little room for cells and ground substance
Where are dense regular connective tissues found?
Tendons
Ligaments
Provides strength
Where are dense irregular connective tissues found?
- Found in joint capsules
- Dermis
- Muscle fascia
- Fascia around organs
Where are chondrocytes found and what is their purpose?
Found in cartilage
Purpose is to produce and maintain the extracellular (cartilage) matrix
Where is cartilage found and what do they resist?
Found in articular joint surfaces of all movable joints in adults
Resists compression
ORGANS are composed of _________ tissues (_________) joined to form a structural unit that serves a common function
2 or more primary tissues
usually all 4
What are the intracellular and extracellular compartments seperated by?
Epithelial membrane which regulates the movement of materials between compartments
What is found in the extracellular compartments?
- Blood plasma
- Tissue fluid or interstitial fluid
- Cerebrospinal fluid
- Tubular ultrafiltrate (Kidney tubules)
- Sweat/mucus
2/3 of body water is found _____. The rest is found in ______ and _____.
in the cell (25L)
extracellular (12L) and blood (3L)
Where is interstitial fluid found?
Between the cells
CSF is considered interstitial fluid
Pathologies come from?
The reduced ability to maintain homeostasis
Most internal processes are maintained ________.
Within a Predictable Range= Within Normal Limits (WNL)
Homeostasis is a ______ not a _____ process.
Dynamic not a static
Functions _____ within a predictable and often narrow range resulting in _______.
Fluctuates, Dynamic Constancy
5 steps of homeostasis
- Stimulus produces chance in variable
- Change detected by receptor
- Input info sent along afferent pathway to control center
- Output info sent along efferent pathway to effector
- Response of effector feeds back to influence magnitude of stimulus and returns variable to homeostasis
What is a set point?
Establishes parameters that are acceptable (limits)
What is steady state?
Things or processes remain constant over time
How is homeostasis maintained?
Negative Feedback regulation
What is a negative feedback regulation?
An increase or decrease in the variable being regulated brings about responses that tend to move the variable in the direction opposite (“ negative” to) the direction of the original change
What is the difference between the thermoregulatory challenge caused by a fever and by exercising?
The setpoint on hypothalamus is reset with a fever, it isn’t reset when exercising
Not considered pathological because the change in body temp is a mechanism to fight the infection, unless it lasts too long
What is a positive feeback mechanism?
Self amplifying cycle in which one change leads to even more significant changes in the same direction
Is a positive feedback mechanism corrective?
No
What is the good thing about a positive feedback system?
Provide the body with the ability to produce significant changes in a relatively short period of time
What is physiologic reserve?
- Refers to excess physiologic capacity in organs and biological systems;
- At birth we have a substantial reserve
- It tends to decrease over time as cell numbers and cell functions decline.
