Chapter 1: The Study of Body Function

- Physiology - Hierarchy of living systems - Homeostasis - Primary tissues

Define: Physiology

The study of biological function, i.e. how
the body works

Living Systems Hierarchy (smallest to largest)

molecular/cellular, tissues,
organs, systems, organism

Cells

the fundamental unit

Tissues

groups of same cell type / collections of cells

Organs

multiple tissues with a common
function / collection of tissues

Organ systems

multiple organs/ collections of organs

Organism

multiple organ systems / all they systems put together

10 Organ Systems

Nervous
Endocrine
Reproductive
Integumentary
Circulatory/Cardiovascular
Respiratory
Digestive/Gastrointestinal
Urinary/Renal
Musculoskeletal
Immune

Musculoskeletal:

muscles, tendons, bones

Urinary/Renal:

kidneys, bladder

Digestive/Gastrointestinal:

digestive tract, glands

Respiratory:

lungs and air passageways

Circulatory/Cardiovascular

heart and vessels

Immune

white blood cells, spleen

Nervous

brain, spinal cord, sensory organs

Endocrine

pituitary gland, thyroid gland, etc.

Reproductive

ovaries, uterus, testes

Integumentary

skin

Define: Homeostasis

State of relative constancy of
the internal environment (a lot of our physical functions, functions to maintain balance in our body )

How is Homeostasis maintained?

• Through Negative feedback loops (ex) body temp, sodium, glucose, pH, oxygen)

• physiological Variables are maintained by homeostasis

ICF

• Intracellular Fluid

  • fluid within the cell

ISF

• Interstitial Fluid

  • fluid around the cell (within tissue)

Plasma

Fluid Component of blood (within blood vessels)

ECF

• Extracellular Fluid

  • Fluid outside of the cell

  • (includes ISF and Plasma)

Homeostasis & Negative Feedback: Sensors

Where changes in physiological Variables are detected (sense the changes )

Homeostasis & Negative Feedback: Integrating Centers

Where information is sent (coordinates output)

Homeostasis & Negative Feedback: Effector

Information from the integrating center causes the effector to produce change in the opposite direction. (Produces a reversal of initial change)

Define: Negative Feedback

An increase or decrease in a variable causes a
response to move the variable in the direction opposite the original change.

Define: Dynamic Constancy

• physiological parameters are not constant, but fluctuate around a set point

  • levels:

    • change over short amount of time

    • remains relatively consistent over long period of time

A physiological Variable

is a variable that changes

A set point

is a variable that doesn’t change

An Afferent Pathway

carry to (away from sensor)

An Efferent Pathway

carry away (exiting the integrating center)

Maintaining Body Temp

• Shivering : response to decrease in body temp

• Sweating: response to increase body temp

Primary Tissues

Muscle, Nervous, Epithelial, Connective

Function of : Muscle Tissue

for contraction

Function of: Nervous Tissue

generating & conduction of electrical events, and related support functions

Function of: Epithelial Tissue

forms membranes coving & lining body surfaces, or glands comprising of these membranes

Connective Tissue

• characterize by large amount of extracelluar material

  • ex) blood, bone, and cartilage

What tissue is this?

Muscle tissue: skeletal muscle fibers

What tissue is this?

Nervous Tissue: Neuron & Supporting Cells

What type of tissue is this?

Epithelial Tissue: Epithelial Membranes

What tissue is this?

Connective Tissue: Loose Conective Tissue

What tissue is this?

Connective Tissue: Bone