Ch. 1 The Study of Body Function Flashcards
Define homeostasis
The constancy of the internal environment that is the condition for a free and independent life
What environmental factors, materials, and internal secretions that are variables of homeostatic control?
Enviro Factors: pH, osmolarity, temperature
Materials: nutrients, water, electrolytes, oxygen
Internal Secretions: hormones, chemical signals
__% of homeostasis is regulated by negative feedback
95%
What is negative feedback?
When the response opposes or removes the signal
Effector opposes the initiating signal
Negative feedback can ____ normal state, but cannot ____ initial signal.
restore; prevent
Give some examples of negative feedback in the body
BP too high, slow down HR to try to decrease BP
BP too low, increase HR
Define positive feedback
Increasing the initial signal
Effector amplifies initiating signal
Give some examples of positive feedback in the body
Blood clotting, positive feedback amplifies response to clot
What are the 2 types of neural and endocrine regulation?
Intrinsic and Extrinsic
Intrinsic Regulation
Within the organ
ex: ability of vessels to constrict or dilate
Extrinsic Regulation
Regulation by nervous or endocrine (hormone) systems.
Nerve fibers can innervate organs, while hormones are secreted into the circulation to act on target organs
Nervous and endocrine systems are ____.
extrinsic (b/c it happens from outside that organ)
Discuss antagonistic effectors of homeostasis
Many factors (blood glucose, HR) are controlled by multiple effects, which have antagonistic actions, i.e., increased activity of one effector is accompanied by decreasing activity of antagonistic effector
Refined control
Balance of both [antagonistic effectors] –> ____?
Control
What are the 4 types of primary tissues?
Muscle
Nervous
Epithelial
Connective (CT)
What are examples of muscle tissue?
Skeletal, smooth, cardiac; specialized for contraction
Where are muscle tissues located?
Glands/vasculature
What are examples of nervous tissue?
Neurons and support cells
Sends signals (electrical)
What are examples of CT?
Blood, adipose (fat), bone, cartilage.
What is the matrix of blood?
Water
CT is embedded in ____.
Matrix
In what type of matrix is bone embedded?
Hard, calcified
Define organ
Two or more primary tissues
ex: heart contains CT and muscle
ex: kidney contains epithelial tissue and CT
Define organ system
Organs grouped by common function (cardiovascular system)
What makes up tissues, organs, and organ systems?
Cells –> Tissues –> Organs –> Organ Systems
Is skeletal muscle voluntary or involuntary?
Voluntary
Is skeletal muscle straited or smooth?
Striated
How is skeletal muscle arranged?
Arranged in parallel; each muscle fiber (myofiber) can be controlled individually (grade contraction)
Does skeletal muscle have one nuclei or is it multi-nucleated?
Multi-nucleated
What type of muscle tissue is this?
Skeletal
What type of muscle tissue is this?
Cardiac
Discuss Cardiac Muscle
Involuntary, Striated
Intercalated discs: contact between adjacent cells, couple cells mechanically and electrically (connects cardiac muscle); cells are coupled together to help accomplish tasks (ex: pump blood)
When atria are pushing blood into ventricles, ventricles must be relaxed in order to fill with blood –> temporally controlled
Also spatially controlled
What type of muscle tissue is this?
Smooth
Discuss smooth muscle tissue
Involuntary
No striations
Found in digestive tract, blood vessels, bronchioles
Control over vasculature dilation/contraction
What do neurons do?
Generate and conduct electrical signals
What are the parts of a neuron? What do they do?
Cell Body: nucleus located in cell body
Dendrites: short extensions off of the cell body, receive signals
Axons: conduct signals, can be up to a meter long
What are neuroglial?
Support cells for nervous tissue
Discuss the structure of epithelial tissue
One or more layers of epithelial tissue
Separated from underlying tissue by basal lamina or basement membrane
Any substance that enters or leaves the internal environment must cross an epithelium (epithelial barrier)
What are the 2 types of epithelial tissue?
Sheets of cells lining body surfaces
–ex: skin, endothelial cells
Secretory epithelia
–ex: sweat glands
Discuss the structural classification of epithelial tissue
Layering
–simple or stratified
Shapes
–squamous, cuboidal, columnar
Function
–exchange, transporting, ciliated, protective, secretory
Is the basement membrane of epithelial tissue a cellular structure or extracellular?
Extracellular
What do endothelial cells line?
Line innermost part of blood vessles, specialized type of epithelial cells
Why are exchange cells flat?
Allows for easier transfer
ex: located in lungs for CO2 and oxygen exchange
Why are ciliated cells necessary?
to move things along
ex: resp. tract, female reproductive tract
The beginning of respiratory tract is stratified for ____.
Protection
Squamous epithelial tissues
Flattened, diffusion, filtrations
Cuboidal Epithelial Tissue
Square
Excretion
Secretion
Absorption
Columnar Epithelial Tissue
Rectangular
Secretion
Absorption
–selective about what we transport
Exocrine glands
Outside
Sweat glands
Reproductive glands
Secrete something to external environment via duct
Endocrine glands
Hypothalamus
Thyroid
Adrenal
Secrete things into our internal environment
CT: Structure
Large amounts of extracellular material between different cells
CT, Cartilage, Bone, Blood…very diverse
CT: Ground substance (matrix)
Highly variable
Matrix fibers - collagen, elastin, fibronectin
CT: Cells
Fixed (cells that are stuck in matrix, very dense)
–blasts (build), clasts (breakdown), cytes (neither)
Mobile (defense)
