body systems

important functions of human body

• support

• collection and evaluation of information

• transportation of oxygen and nutrients

• protection of internal organs

• obtaining nutrients from food

• maintenance of constant body temperature

endoskeleton

support

nervous system

collection and evaluation of information

in a closed system

transportation of oxygen and nutrients

coelem

fluid filled cavity that protects internal organs and allows muscles to contract without harming internal organs

coelem (function)

protection of internal organs

digestion

obtaining nutrients from food

homeostasis

maintenance of constant body temperature

organization of body

cell → tissue → organ → organ system

totipotent

able to produce a new organism

pluripotent

able to produce many cell types

blastocyte

specializes into outer and inner cell mass and layer

outer cell layers

embryonic support structures

inner cell mass

specializes into specialized stem cells and multipotent stem cells

specialized stem cells

specific cell types

multipotent cell types

multiple cell types

stem cells

differentiate into different cell types

four types of tissue in the human body

muscle, nervous, epithelial, connective (MENC)

epithelial tissue

• glands and tissues on interior or exterior body surfaces

• protects from dehydration and physical damage

• controls what enters and leaves cells in layers underneath it

• layer can be one or a few cells thick

• very regenerative

three types of epithelial tissue

simple, stratified, glandular

simple epithelial

single layer

stratified epithelial

multiple layers

glandular epithelial

secrete a product

squamous

flat

cuboidal

square

columnar

column

connective tissue

defends the body (white blood cells), cartilage and bone, accumulates and transports materials

macrophages

engulf and digest microbes—connective tissue

lymphocytes

make antibodies, attack virus-infected cells and cancer cells—connective tissue

adipocytes

fat cells—connective tissue

leucocytes

white blood cells—connective tissue

erythrocyte

red blood cells—connective tissue

nervous tissue

conducts signals rapidly, includes neurons (nerve cells)

muscle cells

permits movement, 3 kinds of muscles—smooth, cardiac, skeletal

importance of homeostasis

provides stable environment so chemical reactions can occur, feedback of information maintains homeostasis—hypothalamus in brain is important in regulation

negative feedback

prevents deviation from set point; not normal back to normal (ex: maintaining blood pressure)

positive feedback

increases deviation from initial value (ex: blood clotting, sweating)

electrical signals

neurons, fast communication

chemical signals

hormones and other chemicals, slower but longer lasting response

organs and organ systems

made of combinations of four types of tissues

integumentary, muscular, skeletal

cover, support, or produce movement

endocrine, nervous, reproductive

regulate body functions

circulatory, immune

transport or protect

respiratory, digestive, urinary (excretory)

involved in metabolism or excretion

hypothalamus

important for for regulation (homeostasis)

integumentary system

• includes skin, hair, and nails

• barrier against infection and injury

• regulates body temperature

• removes waste from the body

• protection uv light

epidermis

• outer layer, mostly dead cells

• cells make keratin protein

• melanocytes make melanin—skin protein

dermis

• inner layer

• contains blood vessels, nerve endings, glands, smooth muscles, hair follicles

• regulates body temperature—sweat glands

• sebaceous glands—make sebum (oil)

subcutaneous layer (hypodermis)

contains mostly fat (adipose cells)

cinomas

skin cancers that occur in non-pigmented cells; usually high cure rate

malignant melanoma

occur in pigmented cells; usually low cure rate

acne

from clogged oil duct and infection

psoriasis

inherited rapid growth of epidermal cells causing scaly white skin

hair

• protects scalp from uv light

• prevent particles from entering the body (nose, ear, eyes)

nails

• protects fingertips

• contain a lot of keratin

• grow from nail root

skeletal system

• supports the body

• protects internal organs

• provides movement

• stores minerals

• site of blood cell formation

bone structure

• solid network of living cells surrounded by calcium salt deposits

• haversian canals

• bone marrow

• periosteum

• ossification

osteocytes

mature bone cell

osteoblasts

build bond

osteoclasts

break down bone

haversian canals

contain blood vessels and nerves

bone marrow

red marrow produces blood cells

periosteum

tough layer of connective tissue

ossification

formation of bone tissue; most bone ossifies from cartilage

joints

• where two bones meet

• classified by range of motion allowed

  • immovable (sutures in skull)

  • slightly moveable (vertebrae)

  • freely moveable (hip, shoulder)

joint structure

ligaments, bursae

four types of freely moveable joints

ball and socket, hinge, pivot, saddle

ligaments

connective tissue that holds bones together

bursae

small sacs with synovial fluid (lubricates joint)

sprains

injury due to forcible twisting

arthritis

inflammation of joint

bursitis

inflammation of the bursa

rheumatoid arthritis

immune system attacks joints and deposits bone in them

muscular system

• three types of muscle tissue

  • skeletal, cardiac, smooth

skeletal muscle

• attached to bones

  • voluntary and striated

  • tendons

tendons

connective tissue that joins muscles to bones

cardiac muscles

• in the heart

• involuntary and striated

smooth muscles

• hollow organs (blood vessels, stomach)

• involuntary and nonstriated

muscle contraction

occurs when thin filaments slide over the thick filaments (shortens the sarcomere), atp is required

sarcomere

unit of a muscle fiber

thick filaments

myosin

thin filaments

actin

digestive system

food passes through, is broken down, and nutrients are absorbed; digestion begins in the mouth

mechanical digestion

chewing, physical breakdown into smaller pieces

chemical digestion

enzymes begin breakdown into smaller molecules; saliva contains amylase—breaks down carbohydrates

bolus

chewed clump of food that travels down esophagus to stomach

peristalsis

contraction of smooth muscle in esophagus—moves bolus to stomach

cardiac sphincter

closes esophagus once food has reached the stomach

stomach

performs chemical digestion using HCl (acid) and pepsin (digests proteins); performs mechanical digestion by churning food and fluids

chyme

churned food and fluids

pyloric valve

area where chyme is pushed through into the small intestines

small intestines

adds enzymes maltase, sucrase, lactase (carbs) and peptidase (protein); most absorption of nutrients occurs here

villi

increases surface area in small intestine

pancreas

behind stomach—produces insulin and glucagon which regulate blood sugar levels; produces enzymes that aid in digestion added to small intestine; produces sodium bicarbonate to raise pH

lipase

lipids

trypsin

protein

amylase

disaccharides

liver

above stomach; makes bile which dissolves lipids; bile is stored in gallbladder

emulsifier

for mechanical digestion

large intestine/colon

removes water from undigested material; bacteria help make vitamin k; waste material is left, passes through rectum out of body