Bio II Exam 1 - Part 1

what is the hierarchy of organisms?

cells, tissues, organs, organ systems, and organism

what are cells?

composed of organic molecules; assemble into tissues

what are the four main types of tissues?

connective, epithelial, muscle, nervous

what is the order of tissues from outermost layer to innermost?

epithelial, connective, then muscle (nervous controls all movement within)

what is epithelial tissue?

forms protective covering on the inside and outside of organs; has 3 main shapes (squamous, cuboidal, columnar)

what is connective tissue?

they secrete proteins that helps support the structure of organs and gives them unique properties

what types of connective tissue are there?

loose, fibrous, adipose, cartilage, bone, and blood

what is loose connective tissue?

under your skin; consists of fibroblasts that produce proteins like collagen and elastic; main job is to support epithelium

what is fibrous (dense) connective tissue?

composed of thick collagen; usually for constructing tendons and attaching bone to muscle

what is adipose connective tissue?

sits just below loose; made of adipocytes (cells that contain lipids); great for insulation

what is cartilage?

composed of collagen fibers; acts as cushion between bones

what is bone composed of?

contains collagen fibers; has osteoblasts (builds bone), osteocytes (osteoblasts that get trapped in bone) and osteoclasts (breaks down bone to access calcium reserves)

what is blood composed of?

all flowing within liquid plasma; platelets (helps blood clot), white blood cells (immune system), and red blood cells

what are the types of muscle tissues?

skeletal (attatched to bones by tendons and primarily for voluntary movement), cardiac (specific to the heart; connected via gap junctions to coordinate contractions), and smooth (surrounds certain organs- intestines and bladder- and function in involuntary contractions)

what is nervous tissue?

controls voluntary and involuntary contractions; composed of nerve cells and neurons

what is anatomy?

study of structure

what is physiology?

study of function

what is negative feedback in homeostasis?

control mechanisms that reduce or reverse a change in internal environment

what is positive feedback in homeostasis?

a change that triggers mechanisms to amplify that change (childbirth)

what is the integumentary system?

largest system in our bodies; skin can be divided into the epidermis and dermis

what is the epidermis?

outermost layer; consists of stratified squamous epithelium; new skin pushes the old skin up where it acquires keratin that helps skin be waterproof

what is the dermis?

contains a lot of connective tissue, blood vessels, hair follicles, sweat glands, and sensory nerves

what is hypodermis?

beneath both dermis and epidermis; contains adipose tissue

what condition is due to calcium deficiency?

rickets

what is the process for human digestion?

Ingestion, Digestion (mechanical and chemical), Absorption, Elimination

what is the role of the salivary glands in digestion?

the ducts secrete saliva which includes lubricant, buffers, antibacterial proteins, and enzymes to dissolve sugars

what is the purpose of the oral cavity in digestion?

the teeth perform mechanical digestion

how do we swallow?

under voluntary control and involves coordinated action of the epiglottis and esophageal sphincter (ring of muscle tissue)

what does the esophagus do in digestion?

pushes food (bolus) to your stomach

what does the stomach do in digestion?

sphincter allows food into the stomach while another sphincter keeps the food there during chemical digestion by the release of gastric juices

how does chemical digestion in the stomach occur?

1) the horomone gastrin is released which stimnulates the release of gastric juice from stomach pits lined with mucus, chief, and parietal cells

2) HCl and pepsin facilitate dissolving of proteins

3) churns and resulting dissolved food is called chyme

4) sphincter at the bottom of the stomach opens and allows chyme to enter the small intestine

what does the small intestine do in digestion?

divided into sections (duodenum, jejunum, and ileum) where digestive enzymes are released and later on absorbs digested nutrients

what does the pancreas do in digestion?

contains juices like alkaline fluids

what does the liver do in digestion?

procudes bile which consists of bile salts that are good for dissolving lipids

what does the gallbladder do in digestion?

stores and concentrates bile until release into the duodenum (bile salts can sometimes form crystals in the gallbladder which produces gallstones)

what does the large intestine do in digestion?

undigested material moves here after nutrients have been absorbed; purpose is to reabsorb water from undigested material and produce feces

what is it called where the large intestine meets the small intestine?

cecum

what is the appendix?

contains a collection of white blood cells and has minor role in immune system

what is the alimentary canal?

tube that runs from your mouth to butt

what do birds and worms have in their alimentary canals that are different from humans?

a gizzard (they store small rocks to help them pulverize their food)