Biology- physiology and anatomy part 1

Levels of life

atom, compound or molecule, organelle, cell, tissue, organ, organ system, organism

Tissue

a group of connected cells with a similar function (4 basic types)

4 basic types of tissue

connective, epithelial, muscle, nervous

connective tissue + structure

made of cells that form the body’s structure (ex. bone and cartilage)— they support and join other tissues; structure is cells scattered throughout the extracellular matrix; PROPER CONNECTIVE, SUPPORTIVE, AND FLUID

epithelial tissue

made up of cells that line inner and outer body surfaces (skin & lining of digestive tract); protects body and internal organs, secretes substances such as hormones

muscle tissue

made up of bundles of long, thin, cylindrical cells known as muscle cells with the ability to contract due to specialized proteins; (muscles attach to bones which enable the body to move)

nervous tissue

made up of neurons, or nervous cells, that carry electrical messages. nervous tissue makes up the brain and the nerves that connect the brain to all parts of the body

Organ

a structure that consists of two or more types of tissue that work together to do the same job

3 types of connective tissue

proper connective tissue, supportive, and fluid tissue

examples in epithelial tissue

epidermis: skin cells keratinized stratified squamous cells; is relatively impermeable

endothelium: lining of blood capillaries formed by simple squamous

urothelium: epithelium lining surface of the urinary bladder called specialized stratified columnar

3 types of muscular tissue

cardiac muscle, smooth muscle, and skeletal muscle

cardiac muscle

involuntary and only covers the walls of the heart (eg. Heart muscles)

smooth muscle

involuntary and usually covers walls of internal organs (eg. digestive tract)

skeletal muscles

voluntary and usually attached to skeleton — one cell has multiple nuclei to create energy & tear and repair (eg. bicep)

physiology

the study of the function of the parts of an organism

anatomy

the study of the structure of an organism’s parts

how are organs and organ systems regulated

by the nervous and endocrine system; nervous system controls all body’s activities and endocrine system secretes hormones to regulate these activities

negative feedback

a response to stimulus that keeps a variable close to a set value (turns a system on or off)

order of homeostasis

stimulus, receptor, signal, and response

what are the 12 organ systems

cardiovascular, lymphatic, digestive, endocrine, integumentary, muscular, nervous, reproductive, respiratory, skeletal, urinary, and immune

Positive feedback

response to an event would increase the likelihood of the event continuing until reaches an endpoint (example contraction during childbirth/oxytocin release or nursing mothers)

skeleta system consists of

bones, ligaments, cartilage

cartilage

type of dense connective tissue, made of tough protein fibers, that provides a smooth surface for the movement of bones at joints

ligament

band of fibrous connective tissue that holds bones together and keeps them in place

functions of skeletal system

support, structure, protecting internal organs, attachment surfaces for muscles, producing blood cells, storing minerals, and maintaining mineral homeostasis

How are mineral levels in blood maintained?

when mineral levels are too high, bones absorb them and store them as mineral salts. When its too low, bones release some of the minerals back into the blood

2 major divisions of bones

axial- bones along central axis such as cranium, vertebral column, ribs and sternum; appendicular is everything else

How do bones produce blood

inside bones, there are chutes of bone marrow which hold stem cells (unspecialized cells)

3 types of specialized cells in human bones + collective function

collective function of bone growth and mineral homeostasis; osteoblasts, osteocytes, osteoclasts

osteoblasts

(type of specialized cell in bones) makes new bone cells and secretes collagen that mineralizes to become the bone matrix; responsible for bone growth and uptake of minerals from the blood

osteocytes

regulate mineral homeostasis; directs the mineral uptake and release as needed

osteoclasts

dissolves minerals into bone matrix and releases them into the blood; they recycle and break down unneeded mineral lattice using acids and enzymes (to make available material for bone growth)

bone marrow

found inside the pores of spongy bone — the soft connective that produces blood cells

periosteum

tough fibrous membrane that covers and protects the outer surfaces of bone

what do all bones come from/grow from

cartilage (through ossification)

Ossification

process in which mineral deposits replace cartilage and change it to bone

where does ossification begin

begins at the center and works towards the ends (growth plates at the ends of long bone is where cartilage remains in the skeleton)

Locomotor system

skeletal muscle, skeleton, and nervous system

Tendons

connect muscle to bone (facilitate movement) and are white; made of fibrous connective tissue (skeletal muscle to skeleton)

Ligament

grey-ish yellow-ish and connect bone to bone for stability; made of fibrous connective tissue; flexible and elastic

Joint

place where two or more bones of the skeleton meet; works with muscles to be mechanical levers for movement

3 types of joints

partly movable, movable (synovial), and immovable

immovable joints

allow no movement due to bones being securely held together by dense collagen (ex. skull connected by immovable joints)

movable/ synovial joints

allow the most movement. bones at these joints are connected by ligaments

partly movable

allow only limited movement; bones at these joints are held in place by cartilage (ex. ribs, sternum)

types of movable joints

ball and socket, hinge, and pivot

Do tendons or ligaments take longer to heal?

generally, ligaments take longer to heal since they have less blood supply

ball and socket joints

allows movement in all direction (like hips and shoulders)

hinge joints

only move in 1 direction like a door (bend and straighten like knee and elbow)

pivot joints

rotation

Structure of joints (components)

cartilage, synovial fluid, synovial membrane, capsule

cartilage

cushion; reduces friction and absorbs shock

synovial fluid

reduces friction by lubricating joint (oily FLUID)

synovial membrane

makes synovial fluid

capsule

surrounds joint and holds in the synovial fluid

fractures

breaks in bone by excessive stress; healing when osteoblasts form new bone and bone cells travel to the break site and takes 2-3 months before compact and spongy bone form

osteoporosis

disease where bone loses mass and becomes more fragile; prevented by healthy diet (vitamin d and calcium); common in women going through pre-menopause because the stage affects how bones absorb calcium

rickets

softening of bones in children (usually due to vitamin D deficiency) which impacts the absorption of calcium which can lead to fractures and bowing

osteoarthritis

condition where cartilage breaks down in joints due to wear and tear; occurs with age, too

rheumatoid arthiritis

autoimmune disease where immune cells start attacking cartilage/joint lining.

skeletal muscle

skeletal muscle fibers bundled by connective tissue and provides support and allows muscle cells to withstand contraction; this connective tissue is also a path for nerves and blood vessels to reach the muscle

individual muscle cells

muscle fibers which contain individual contractive subunits called myofibrils

skeletal muscle extremely simplified zoom-in/break down

skeletal muscle; made of 10-100 muscle fibers; muscle fibers made of myofibrils; myofibrils have sarcomeres; sarcomeres consist of actin filament, myosin filament, and z line

muscle fibers

long & thin muscle cells with the ability to contract or shorten (thanks to connective tissue and sarcomeres)

different types of connective tissue

proper connective (like adipose), supportive (ex. bone and cartilage), and fluid (blood vessels and lymph vessels)

connective tissue structure

support and join other tissues; cells scattered throughout the extracellular matrix

cardiovascular system

transports oxygen, hormones, and nutrients to the body cells, moves carbon dioxide away from cells; heart, blood, blood vessels

lymphatic system

defends against disease and infection; moves lymph between tissues and the blood stream

digestive system

digests foods and absorbs nutrients, minerals, vitamins and water; esophagus, small intestine, large intestine and stomach

endocrine system

produces hormones that communicate between cells; pituitary gland in brain, hypothalamus, adrenal glands, ovaries, and testies

integumentary

protection from injury and water loss, physical defense from infections by microorganisms and temperature control; skin, hair, nails

muscular system

involved in movement and heat production; cardiac muscle, skeletal muscle, smooth muscle, and tendons

nervous system

collects, transfers, and processes information; brain, spinal cord, and nerves

reproductive system

produces gametes and se hormones; in females uterus, vagina, fallopian tubes, ovaries; in males penis, testes, seminal vesicles

respiratory system

brings air to sites where gas exchange occurs between blood and body cells or blood and air; trachea, larynx, pharynx, lungs

skeletal system

supports and protects soft tissues of the body; produces blood cells and stores minerals; bones, cartilage, and ligaments

urinary system

removes extra water, salts, and waste products from blood and body; controls pH, water, and salt balance; kidneys, urinary bladder

immune system

defends against disease; bone marrow, spleen, and white blood cells

Balancing water level homeostasis

water level too high; kidneys respond by producing larger value of urine (diluted/lighter) means its getting rid of excess water; if water level too low, kidneys will respond with concentrated/darker water to save

how is internal temperature regulated

thermal regulatory sensor in brain and nerves in skin sense a change; hypothalamus sends command to skin and blood vessels —— when cold, muscle cells contract causing hair to stand up and shivering (blood vessels near the skin constrict); when hot, blood vessels dilate to increase blood flow

how is internal glucose level regulated top to bottom is high and low

Beta cells in pancreas	Pancreas	Pancreas beta cells release hormone insulin which helps cells absorb glucose and turns glucose into glycogen to be stored in the liver
Alpha cells in pancreas	Pancreas	Pancreas alpha cells will produce hormone glucagon which causes the liver to turn glycogen (stored) into glucose

How are oxygen levels regulated

Blood vessels sense the O2 decrease and send signals to brainstem Chemoreceptor cells in the carotid body detect hypoxia in bloodstream

Brainstem Nerve impulses are propagated to effector tissues

Brainstem will tell breathing muscles (such as diaphragm) to work harder and faster Kidney produces more erythropoietin

adipose tissue

fat

cartilage (which type of connective tissue

supportive —- hard but flexible

fluid tissue example

blood vessels and lymph vessels

muscle contraction — how start (not first step its more of like a what initiates it)

signal from brain which goes through nervous system and releases acetylcholine

each muscle fiber contains how many myofibrils + what are they

each fiber contains hundreds of myofibrils — cylindrical organelles made up of two types of protein filaments (ACTIN = THIN MYOSIN= THICK)

extreme simplified sliding filament theory (sarcomeres)

myosin filaments use energy from ATP to glide along actin filaments through their cross bridges which ultimately pulls the actin filaments together and brings the z-lines closer

motor neurons

type of neuron that carries nerve impulses from central nervous system to muscles and glands

sarcoplasmic reticulum

inside of the sarcomere unit controls calcium inside muscle

nerve cells releasing acetylcholine (neurotransmitter) to muscle effect

causes calcium ions to release and binds onto the troponin site of actin filaments; this bond displaces tropomyosin and exposes the myosin binding site

muscle contraction; steps 1-3 (before the actual gliding)

nerve cells release acetylcholine (neurotransmitter) which releases calcium ions from the sarcoplasmic reticulum; this calcium binds to troponin units which displaces tropomyosin and exposes the myosin binding sites; myosin filaments attach to this site and form cross bridges (chemical reaction causes the formation)

muscle contraction (glide explained and rest)

ATP from the myosin head will break down into ADP + P which is released energy and enables myosin to glide/pull actin filaments causing muscle contraction; ATP then binds back to the myosin head and myosin detaches from actin causing the cross bridges to be broken; the glide ends when nerve stops sending acetylcholine (glide occurs when there is supply of calcium and ATP); when nerve impulse stops, calcium goes back to sarcoplasmic reticulum and muscle returns to relaxed position

osmoregulation

the process maintaining the balance of water and solute concentrations

hypotonic

when comparing two solutions, hypotonic refers to the solution with less solute (more solvent)

hypertonic

when comparing two solutions, hypertonic refers to the solution with more solute (like being salty)

isotonic

even balance of solvent and solute in a solution