KNAT Science

Kaplan Nursing

negative feedback

A primary mechanism of homeostasis, whereby a change in a physiological variable that is being monitored triggers a response that counteracts the initial fluctuation.

positive feedback

Feedback that tends to magnify a process or increase its output.

blood

* Connective tissue made of plasma, erythrocytes, leukocytes, and platelets
* Carries substances to and away from bodily tissues
* pH of 7.4

Platlets

aid in blood clotting and wound healing

Erythrocytes (Red Blood Cells)

participate in gas exchange with oxygen and carbon dioxide

Leukocytes (White Blood Cells)

protect the body against invading organisms and remove dead cells and other

waste from the body

vasodilation (body temp maint)

* widening of blood vessels
* Causes heat loss

vasoconstriction (body temp maint)

* narrowing of blood vessels
* less heat is lost

Hemostasis

to stop or control bleeding

3 steps of hemostasis

1. vascular spasm (vasoconstriction)
2. platelet plug formation (stick together)
3. Coagulation

Blood Grouping

determined by antigens (agglutinogens) on surface of RBCs

Type O blood

universal donor

Type AB blood

universal recipient

Arteries

carry blood away from the heart

Veins

carry blood to the heart

Capillaries

Tiny vessels that form a network around tissues

4 chambers of the heart

right atrium, right ventricle, left atrium, left ventricle

septum

Divides the right and left chambers of the heart

3 layers of the heart wall

epicardium, myocardium, endocardium

Tricupsid Valve (Right AV Valve)

regulates blood flow between the right atrium and right ventricle

pulmonary valve

regulates blood flow from the right ventricle into the pulmonary artery

mitral/bicupsid valve

regulates blood flow from the left atrium into the left ventricle

aortic valve

regulates blood flow from the left ventricle to the aorta

systemic circulation

circulation that supplies blood to all the body except to the lungs

pulmonary circulation

Circulation of blood between the heart and the lungs

systole

Contraction of the heart

Diastole

Relaxation of the heart

EKG (electrocardiogram)

a recording of the electrical impulses set off by the heart

EKG first wave (p wave)

indicates atrial contraction or systole

EKG second wave (QRS waves)

indicates ventricular contraction or systole

EKG third wave ( T wave)

indicates ventricular diastole

ST segment

flat line between S wave and T wave

respiratory system

Brings oxygen into the body. Gets rid of carbon dioxide.

Diaphram

primary muscle of inspiration

air-conducting portion

* air is delivered to the lungs
* larynx, trachea, bronchi and bronchioles

gas-exchange portion

* gas exchange takes place between the air and blood
* lungs, alveoli, and capillaries

Too much carbon dioxide in the blood

acidic, pH is too low

Not enough carbon dioxide in the blood

alkaline, pH is too high

external respiration

exchange of gases between lungs and blood

external respiration steps

a person inhales, alveoli fill with oxygen through diffusion, blood becomes oxygen-rich, blood leaves the lungs and travels through the left side of the heart where it is pumped into circulation

internal respiration

Exchange of gases between cells of the body and the blood

internal respiration steps

once blood enters circulation it reaches the capillaries, oxygen diffuses through capillaries into the cells, carbon dioxide diffuses from the cells into the capillaries, carbon dioxide content is higher than oxygen, oxygen-poor blood travels to the right side of the heart and moves through the pulmonary circuit

gastrointestinal system

the body's system for digesting food; includes the digestive tract, salivary glands, pancreas, liver, and gallbladder

small intestine

duodenum, jejunum, ileum

duedenum

* has more villi (finger-like projections)
* larger diameter which allows for more absorption of nutrients

large intestine

Absorbs water and forms feces

Acessory Organs

do not contribute to the process of digestion

Liver functions

Responsible for: The metabolism of fats, proteins, and carbohydrates. Excretion of bilirubin, cholesterol, hormones, and drugs. Enzyme activation. Storage of glycogen, vitamins, and minerals. Synthesis of plasma proteins, such as albumin, and clotting factors. Blood detoxification and purification. Bile production and secretion.

pancreas function

* regulates blood sugar (insulin & glucagon)
* Secretes pancreatic juice which breaks down all categories of food
* produces digestive enzymes for fats, carbs, and proteins

Gallbladder

stores and concentrates bile

enzyme amylase

chemical digestion

3 pairs of salivary glands

parotid (largest, in front of ears), submandibular (below the mandible), sublingual (smallest, bottom of oral cavity)

mechanical digestion

Physical breakdown of large pieces of food into smaller pieces

chemical digestion

Process by which enzymes break down food into small molecules that the body can use

Amylase

Enzyme in saliva that breaks the chemical bonds in starches

Pepsin

Enzyme that breaks down proteins in the stomach

Lipase

pancreatic enzyme necessary to digest fats

Peptidase

pancreatic enzyme that breaks down peptides into amino acids

Sucrase

produced in small intestine and breaks down sucrose

Lactase

produced in small intestine and breaks down lactose

Stomach disorders: Vomiting

results from irritation of the stomach and small intestine

stomach disorders: ulcers

occur from specific bacterium called helicobacter pylori

stomach disorders: peptic ulcer

condition in which the stomach acids digest the mucus lining of the duodenum (duodenal ulcers)

Liver Disorders: Cirrhosis

characterized by damage or death of liver cells, and replaced by connective tissue. This causes abnormal blood flow in the liver and interferes with its functions

liver disorders: hepatitis

inflammation of the liver, liver cells can die and be replaced with scar tissue

intestine disorders: Crohn's disease (irritable bowel disease)

includes a localized inflammatory degeneration that causes the wall of the small intestine to thicken

intestine disorders: ulcerative colitis (irritable bowel disease)

limited to the mucosa of the large intestine. The involved mucosa exhibits inflammation

intestine disorders: irritable bowel syndrome (IBS)

periodic disturbances of bowel function, such as diarrhea and/or constipation, usually associated with abdominal pain

intestine disorders: malabsorption syndrome

spectrum of disorders of small intestine that result in abnormal nutrient absorption

intestine disorders: appendicitis

inflammation of the appendix that usually occurs because of an obstruction

urinary system functions

waste elimination, osmoregulation of blood and water, hormone secretion

kidney

Filters waste from the blood like urea, water, salt and proteins.

Ureters

transport urine from the kidneys to the bladder

Bladder

stores urine

Urethra

tube leading from the urinary bladder to the outside of the body

renal artery

blood vessel that carries blood to the kidney

nephron

functional unit of the kidney

nephron two parts

renal corpuscle and renal tubule

renal corupscle contains \_______________ and \________________

glomerulus, glomerular capsule (bowman's capsule)

glomerulus

A ball of capillaries surrounded by Bowman's capsule in the nephron and serving as the site of filtration in the kidney.

renal tubule

duct that connects to the glomerulus and terminates at the tip of the medullary pyramid

renal tubule 4 regions

proximal convoluted tubule, loop of Henle, distal convoluted, and collecting duct

glomerular filtration

The first step in urine formation in which substances in blood pass through the filtration membrane and the filtrate enters the proximal convoluted tubule of the nephron.

tubular reabsorption

* process of reclaiming water and solutes from the tubular fluid and returning them to the blood
* fluid then travels to loop of Henle for more reasbsorption
* fluid then reaches the distal convoluted tubule where reasbsorption and secretion take place

tubular secretion

fluid that remains is called urine in the collecting duct, reabsorption of some water make occur

urine in the bladder

* stored until about half full
* when reached a neural impulse is transmitted telling a sphincter in the bladder to relax
* involuntary control

tubular reabsorption

Tubular reabsorption is the process by which the kidneys reabsorb useful substances, such as glucose, amino acids, and electrolytes, from the filtrate in the renal tubules back into the bloodstream. This process helps to maintain the body's fluid and electrolyte balance.

antidiuretic hormone (ADH)

Hormone produced by the posterior pituitary gland that stimulates water reabsorption from kidney tubule cells

urinalysis

the examination of urine to determine the presence of abnormal elements

Macroscopic Urinalysis

EXAMINATION OF URINE FOR COLOR, TURBIDITY, ODOR AND CHEMICAL MAKE-UP (NITRITES, PROTEIN, GLUCOSE, BILIRUBIN, ETC.)

Microscopic Urinalysis

Examination of a drop of urine under the microscope to detect RBC's, WBC's, fat cells, etc.

central nervous system

brain and spinal cord

peripheral nervous system

the sensory and motor neurons that connect the CNS to the rest of the body

afferent neurons (sensory)

Nerve cells that carry impulses towards the central nervous system

efferent neurons (motor)

Nerve cells that conduct impulses away from the central nervous system

somatic nervous system

the division of the peripheral nervous system that controls the body's skeletal muscles

autonomic nervous system

A subdivision of the peripheral nervous system. Controls involuntary activity of visceral muscles and internal organs and glands.

sympathetic nervous system

the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations

parasympathetic nervous system

the division of the autonomic nervous system that calms the body, conserving its energy

Cerebellum

A large structure of the hindbrain that controls fine motor skills.