Chapter 1 - Intro to the Human Body

Anatomy definition

the science of what body structures are & the relationships among them (structure)

Physiology definition

the science of the body functions and how the body works (function)

Levels of organization (smallest to largest)

atoms, molecules, cells, tissues, organs, organ systems, organisms, populations of one species, ecosystem of different species, biosphere

integumentary system functions

protection, water retention, thermoregulation, makes vitamin D, detects sensations, stores fat/provides insulation

skeletal system functions

support/protection, provides SA for muscle attachments, aids body movements, stem cells that produce blood cells, stores minerals and lipids

muscular system function

participates in movements, maintains posture, produces heat

nervous system functions

nerve impulses reg. body activities, detects changes in the body's internal and external environments, interprets changes, & responds by causing contractions or glandular secretions

endocrine system functions

regs. body activities by releasing hormones (chem messengers transported in blood from endocrine gland or tissue to target organ)

cardiovascular system functions

heart pumps blood through vessels, blood carries nutrients & O2 to cells & CO2 & wastes away from cells & helps reg. acid-base balance, temp., & water content of body fluids, blood components help defend against disease & repair damaged vessels

lymphatic system functions

Returns proteins and fluid to blood, carries lipids from gastrointestinal tract to blood, contains sites of maturation and proliferation of B cells and T cells that protect against disease-causing microbes

respiratory system functions

Transfers oxygen from inhaled air to blood and carbon dioxide from blood to exhaled air; helps regulate acid-base balance of body fluids; air flowing out of lungs through vocal cords produces sounds

digestive system functions

physical and chemical breakdown of food, absorbs nutrients, eliminates solid wastes

urinary system functions

Produces, stores, and eliminates urine; eliminates wastes and regulates volume and chemical composition of blood; helps maintain the acid-base balance of body fluids; maintains body's mineral balance; helps regulate production of red blood cells

reproductive system functions

gonads (testes/ovaries) & associated organs...

females - fallopian tubes, uterus, vagina, & mammary glands
males - epididymis, ductus deferens, seminal vesicles, prostate, & penis

Characteristics of living organisms

- metabolism
- responsiveness
- movement
- growth
- differentiation
- reproduction

metabolism

the sum of all chemical processes that occur in an organism (catabolism/anabolism)

Catabolism

Metabolic pathways that break down molecules, releasing energy

Ex: digestive tract catabolizes proteins from food into amino acids

Anabolism

Metabolic pathways that construct molecules, requiring energy.

Ex: amino acids are used to anabolize new proteins that make up body structures (muscle, bone, etc.)

responsiveness

the body's ability to detect and respond to changes

movement

includes motion of the whole body, individual organs, single cells, and even tiny structures inside cells

growth

an increase in body size that results from an increase in the size of existing cells, an increase in the number of cells, or both

differentiation

the development of a cell from an unspecialized to a specialized state

reproduction

refers to either the formation of new cells for tissue growth, repair, or replacement or the production of a new individual

Homeostasis

The maintenance of relatively stable internal conditions

- dynamic condition
- conditions can shift within normal ranges

relationship between structure and function

structure determines function

why do living organisms need energy?

chemical processes, growth, movement, etc.

Information flow to coordinate body functions

draw out diagram

ECF

fluid outside the cell

ICF

fluid inside cells

ECF vs. ICF

ECF - more sodium and chloride

ICF - more potassium

interstitial fluid

fluid in the narrow spaces between cells

blood plasma

ECF within blood vessels

lymph

ECF within lymphatic vessels

cerebrospinal fluid

fluid in and around the brain and spinal cord

synovial fluid

ECF within joints

aqueous humor and vitreous body

ECF within the eyes

Internal environment

ECF because it surrounds cells of the body

External environment

the space that surrounds the entire body

Homeostasis vs. Equilibrium

homeostasis - conditions are balanced

equilibrium - conditions are equal

What do control systems do?

keep variables within normal range (maintain homeostasis)

Components of feedback loops

Receptor - body structure that monitors changes and sends input to a control center

Control center - evaluates input from receptors (usually brain/hypothalamus)

Effector - body structure that receives output from the control center and produces a response that changes the controlled condition

Response - alters controlled condition... returns to homeostasis

Positive feedback loop

a feedback loop in which change in a system is amplified

Negative feedback loops

A feedback loop in which a system responds to a change by returning to its original state, or by decreasing the rate at which the change is occurring.