Human Bio Unit 2

Front 1

CNS

Back 1

central nervous system
receives, processes, and sends information
made of brain and spinal cord

Front 2

PNS

Back 2

peripheral nervous system
carries information to and from the CNS and the sensory, muscle, and gland cells

Front 3

brain

Back 3

center for neural integration
2% of weight, 25% of oxygen

Front 4

3 functional regions of the brain

Back 4

1) hindbrain
2) midbrain
3) forebrain

Front 5

hindbrain

Back 5

- medulla oblongata
- cerebellum
- pons

Front 6

medulla oblongata

Back 6

located in hindbrain
- controls heart rate and respiration
- blood pressure
- reflexes (coughing, vomiting, sneezing, swallowing)

Front 7

cerebellum

Back 7

located in hindbrain
- coordinates body movement

Front 8

pons

Back 8

located in hindbrain
- connects higher brain centers and spinal cord
- controls breathing

Front 9

midbrain

Back 9

reduced in size in mammals

Front 10

brain stem

Back 10

made up of hind brain (besides cerebellum) and midbrain
- sensory filter

Front 11

forebrain

Back 11

in charge of emotions and conscious thoughts
- hypothalamus
- thalamus
- limbic system
- cerebrum
- pineal gland
- pituitary gland

Front 12

hypothalamus

Back 12

located in forebrain
- homeostasis of internal environment
- hunger, thirst, sex drive, temperature, bio clock
- produces hormones that affect pituitary gland

Front 13

thalamus

Back 13

located in forebrain
- receiving, processing, and transfer center
- input center for sensory data going to cerebrum, output centor for motor responses leaving cerebrum

Front 14

limbic system

Back 14

located in forebrain
- emotions
- basic behaviors

Front 15

cerebrum/cerebral cortex

Back 15

located in forebrain
"gray matter" - unmyelinated axons
- creates sensory perceptions:
- language skills, imagination, artistic talent
- most advanced
- decision-making, conscious thoughts, reasoning and math, personality traits

Front 16

pineal gland

Back 16

located in forebrain
- produces melatonin

Front 17

pituitary gland

Back 17

located in forebrain
attached to hypothalamus
contains two lobes: posterior and anterior
- helps hypothalamus regulate homeostasis

Front 18

spinal cord

Back 18

- contains billions of neurons that run to and from brain
- mediates many of the body's reflex responses

Front 19

reflex

Back 19

an unconscious, programmed response to a specific stimulus; involuntary response

Front 20

knee-jerk reflex

Back 20

simplest of all reflexes
- involves only 1 sensory and 1 motor neuron
- tends to be very fast
- prevents quadroceps from being overstretched

Front 21

meninges

Back 21

3 tough layers of connective tissue that covers the CNS
- functions to protect the brain and spinal cord

Front 22

meningitis

Back 22

when viruses or bacteria infect the meninges, highly contagious
- symptoms start with severe headaches, fever, stiff neck, and vomiting

Front 23

two subsystems of the PNS

Back 23

1) somatic nervous system
2) autonomic nervous system

Front 24

somatic nervous system

Back 24

stimulates skeletal muscle; involves some conscious control

Front 25

autonomic nervous system

Back 25

- relays signals to smooth muscle, cardiac muscle, and glands
- not under control of will and usually functions without our being aware of it

Front 26

two subsystems of the autonomic nervous system

Back 26

1) parasympathetic nervous system
2) sympathetic nervous system

Front 27

parasympathetic nervous system

Back 27

concerned with rest and rumination
when stimulated:
- slower heartbeat
- increased movements of smooth muscles in intestines
- secretion of salivary glands

Front 28

sympathetic nervous system

Back 28

prepares animal for emergency situations, "fight or flight"
when stimulated:
- characteristics of rage
- blood vessels in skin and intestines contract
- increased blood pressure
- more blood send to muscles
- digestive system shuts down
- dilation of respiratory passages
- adrenal glands release adrenaline

Front 29

adrenaline

Back 29

causes release of large quantities of glucose by the liver, skeletal muscles, and adipose tissue
- glucose provides extra energy source for muscles

Front 30

endocrine system

Back 30

works slower than nervous system
-system of glands that secrete hormones directly into bloodstream and exert specific effects on some target organ/tissue (like digestion, salt & water balance, metabolism, growth)

Front 31

hormones

Back 31

- steroids, proteins, or amines (modified amino acids)
- most under negative feedback control
- rapidly degraded in the body and usually by the liver (enzymes in blood break down amines)

Front 32

negative feedback control

Back 32

an increase in the substance inhibits the process that led to the increase

Front 33

male sex hormones, general

Back 33

collectively known as androgens, principle is testosterone
- produced by testes, starting early in embryotic development

Front 34

function of testosterone

Back 34

sperm production beginning at puberty

Front 35

secondary characteristics of male sex hormones

Back 35

- growth of the larynx, deepening of the voice
- growth of beard and pubic hair
- development of larger and stronger muscles
- stimulation of sweat glands to produce fatty acids
- may cause sebaceous (oil) glands in the skin to become overactive, resulting in acne

Front 36

female sex hormones, general

Back 36

collectively known as estrogens
- produced by the ovaries

Front 37

secondary characteristics of female sex hormones

Back 37

- breast development
- development of external genitalia
- determine distribution of body fat
- help prepare the endrometrium for implantation of the embryo (along with progesterone, which is also produced by the ovaries)

Front 38

adrenal cortex

Back 38

outer region of the adrenal gland
secretes male sex hormones and two major groups of adrenocortical steroids:
- glucocorticoids
- mineralocorticoids

Front 39

adrenal gland

Back 39

double gland consisting of medulla and cortex
- arose from 2 different tissues that grew together

Front 40

glucocorticoids

Back 40

secreted by the adrenal cortex
- help maintain glucose level in blood (by promoting breakdown of proteins and fats to glucose)
- suppress inflammatory responses to tissue injury or infection

Front 41

cortisol

Back 41

a glucocorticoid that helps maintain blood concentration of glucose between meals
- cortisol-like drugs (cortisone) are used as anti-inflammatory agents in the treatment of arthritis, asthma, etc

Front 42

mineralocorticoids

Back 42

secreted by the adrenal cortex
- promote Na+ reabsorption (by the kidneys)

Front 43

aldosterone

Back 43

a mineralocorticoid that simulates the cells in the kidneys to reabsorb Na+ and H2O

Front 44

result of a tumor in a woman's adrenal cortex

Back 44

facial hair and masculine characteristics

Front 45

adrenal medulla

Back 45

inner region of the adrenal gland
- secretes epinephrine (adrenaline) and norepinephrine (noredrenaline)
- functions to create conditions that prepare the animal for fight or flight

Front 46

thyroid gland

Back 46

secretes thyroid hormone and calcitonin

Front 47

thyroid hormone

Back 47

amino acid with iodine, secreted from thyroid gland
- increases metabolic activity of tissues throughout the body
- stimulates oxidation (breaking down to release energy) in mitochondria of various target cells, increasing energy availability and metabolic rate

Front 48

hyperthyroidism

Back 48

excessive amounts of thyroid hormone secreted from the thyroid gland
- higher than normal body temperature
- profuse perspiration
- high BP
- loss of weight
- irritability
- muscular weakness
- insomnia
- exophthalmia (bulging eyes)
controlled by anti-thyroid drugs or surgical removal or destruction of part of thyroid gland with radioactive iodine

Front 49

hypothyroidism

Back 49

caused by:
- malfunction of thyroid gland (treated by administering TH; if untreated, leads to weight gain and cretins)
- insufficient iodine in the diet (treated with iodine; if untreated could lead to goiter)

Front 50

calcitonin

Back 50

secreted by thyroid gland
- lowers the calcium level in the blood by:
1) inhibiting the release of Ca++ ions from bone
2) promoting Ca++ deposition into the bones

Front 51

posterior lobe of pituitary gland

Back 51

storage area for oxytocin and ADH (anti-diuretic hormone)
both hormones are secreted by the hypothalamus

Front 52

oxytocin

Back 52

stored in posterior lobe of pituitary gland; produced by hypothalamus
- causes contraction of uterine muscles

Front 53

anti-diuretic hormone (ADH)

Back 53

stored in posterior lobe of pituitary gland; produced by hypothalamus
- stimulates the kidney to absorb water (so it won't be excreted as urine)

Front 54

anterior lobe of pituitary gland

Back 54

secretes:
- prolactin
- growth hormones
- tropic hormones

Front 55

prolactin

Back 55

secreted by anterior lobe of pituitary gland
- stimulates mink production by the female mammory glands

Front 56

growth hormones

Back 56

secreted by anterior lobe of pituitary gland
- play critical role in promoting normal growth
- promotes protein synthesis and use of body fat for energy metabolism

Front 57

what results when growth hormones are deficient in a child

Back 57

pituitary dwarf

Front 58

what results when there is an oversupply of growth hormone in a child

Back 58

pituitary giant

Front 59

what results when there is an oversupply of growth hormone in an adult

Back 59

acromegaly

Front 60

tropic hormones

Back 60

secreted by anterior lobe of pituitary gland
- exert controlling action on endocrine organs
- thyroid stimulating hormones
- adrenal corticoid hormones
- follicle stimulating and lutinizing hormones

Front 61

thyroid stmulating hormones

Back 61

secreted by anterior lobe of pituitary gland
- stimulate thyroid gland to produce TH

Front 62

adrenal corticoid thyroid hormones

Back 62

secreted by anterior lobe of pituitary gland
- stimulate adrenal cortex to produce cortical hormones

Front 63

follicle stimulating and lutinizing hormones

Back 63

secreted by anterior lobe of pituitary gland
- stimulate the gonads to produce sex hormones

Front 64

pancreatic hormones

Back 64

secreted by the pancreas
- insulin
- glucagon

Front 65

pancreas

Back 65

a compound organ (not a gland), with 2 types of cells
1) cells involved in the production and release of digestive enzymes
2) islet cells

Front 66

islet cells

Back 66

cells in pancreas that produce 2 hormones: insulin and glucagon
- both are concerned with metabolism of glucose but effects are opposite

Front 67

insulin

Back 67

secreted by islet cells in pancreas in response to a rise in blood sugar or amino acid concentration
- lowers blood pressure in 2 ways at the same time:
1) stimulates uptake of glucose by muscle and fat cells
2) stimulates converstion of glucose to glycogen in liver and muscle cells

Front 68

diabetes mellitus

Back 68

- results from deficiency of insulin
- condition whereby the liver and muscles don't convert enough glucose into glycogen, and the liver produces too much glucose

Front 69

glucagon

Back 69

secreted by islet cells in pancreas; has opposite effect of insulin
- causes and increase in blood sugar by:
1) stimulating the breakdown of glycogen to glucose in the liver
2) stimulating the breakdown of fats and proteins

Front 70

parathyroid hormone

Back 70

produced by the parathyroid gland
- functions to raise blood levels of calcium (which plays a role in nerve impulse conduction, blood clotting, muscle contraction) in two ways:
1) stimulating Ca++ reabsorption in the kidneys
2) inducing certain bone cells to release Ca++ to the blood

Front 71

percentage of Ca++ found in bone

Back 71

98%

Front 72

5 contributions of the muscular and skeletal systems to homeostasis

Back 72

1) produce movement
2) protect body parts
3) store and release calcium
4) bones produce blood cells
5) bones support us against the effects of gravity

Front 73

muscle and bone movement

Back 73

- muscles and bones work together
- peristalsis (pulls food down throat)
- digestive tract
- cardiac muscles

Front 74

muscle and bone protection

Back 74

- bones protect soft organs like lungs and heart (not kidneys)
- bursi protect muscles from bones

Front 75

bursi

Back 75

fluid-filled sacs near joints between tendons and bones
- serve to cushion and protect muscles from bones

Front 76

muscle and bone calcium

Back 76

- important for nerve impulse and muscle contraction
- calcitonin sends message to calcium to be stored in bone
- if there is too much calcium in bones, parathyroid hormones cause bones to release calcium
- vitamin D helps calcium absorption in small intestines

Front 77

bone blood cells

Back 77

produced in bone marrow

Front 78

red marrow

Back 78

found in flat bones
- produces red and white blood cells

Front 79

yellow marrow

Back 79

found in hollow core of long bones
- stores fat

Front 80

endoskeleton

Back 80

made of cartilage and bone

Front 81

cartilage

Back 81

ears, nose, ends of ribs, knees, intervertebral discs, ankles, trachea

Front 82

bones

Back 82

significant deposits of inorganic calcium salts laid down in an extracellular metrix
- has the tensile strength of cast iron, yet 1/2 as heavy
- generally hollow - increases strength

Front 83

compact bone

Back 83

outside edge of bones

Front 84

spongy bone

Back 84

red and yellow marrow

Front 85

functions of bones

Back 85

- specific body movement
- support a part of body's weight
- protect an internal organ

Front 86

2 functional groups of bones

Back 86

1) axial skeleton
2) appendicular skeleton

Front 87

axial skeleton

Back 87

skill, vertebral column, sternum, ribs,
- assumes the skeleton's protective function

Front 88

appendicular skeleton

Back 88

bones of the limbs
- pectoral girdle
- pelvic girdle

Front 89

pectoral girdle

Back 89

2 scapulae and 2 clavicles

Front 90

pelvic girdle

Back 90

receives the weight of the upper body and transmits to legs or butt

Front 91

2 kinds of joints

Back 91

immovable and movable

Front 92

immovable joints

Back 92

plates of the skull (22)

Front 93

movable joints

Back 93

involve 2 bones held together by ligaments
- skeletal muscles bend skeleton at joints

Front 94

contractile proteins

Back 94

can change their form to elongate or contract muscles - produces muscle movement

Front 95

3 types of muscles and differences

Back 95

skeletal, smooth, cardiac
each differs in:
- physical appearance
- types of jobs
- speed of contraction

Front 96

skeletal muscles

Back 96

- close to 700 in human body
- attached to bone (except diaphragm)
- voluntary movement
- either flexors or extensors
- arranged in antagonistic pairs

Front 97

flexor

Back 97

(skeletal muscles)
bend the joint
eg: biceps

Front 98

extensor

Back 98

(skeletal muscles)
straighten the joint
eg: triceps

Front 99

structure of skeletal muscles

Back 99

muscle - muscle fibers (cells) - myofibrils - myofilaments

Front 100

sarcomere

Back 100

functional unit of the myofibril (skeletal muscles)
extends between Z lines
- when it contracts, the muscle contracts

Front 101

2 types of myofilaments

Back 101

thick filaments (composed of myosin)
thin filaments (composed mainly of actin)

Front 102

muscle contraction within sarcomere

Back 102

myosin molecules (on thick filaments) have club-shaped heads that act as molecular cross-bridges that interact with the thin filaments

Front 103

sliding filament mode of muscle contraction

Back 103

thick and thin filaments become linked together by molecular cross bridges which act as levers to pull the filaments past each other
- relaxation is a passive process

Front 104

motor unit

Back 104

a small number of muscle fibers innervated by one motor neuron during contraction skeletal muscles

Front 105

neuromuscular junction

Back 105

synaptic cleft between nerve and muscle fiber during contraction of skeletal muscles

Front 106

acetylcholine

Back 106

diffuses across the synaptic cleft and acts on the membrane of the muscle cell to initiate a new action potential there during contraction of skeletal muscles

Front 107

transverse tubules (T tubules)

Back 107

extensions of cell's plasma membrane that transmit the action potential deep into cells during contraction of skeletal muscles

Front 108

sarcoplasmic reticulum

Back 108

functions as a storage site for Ca++ ions
- when stimulated, becomes permeable to Ca++; Ca++ diffuses out and into myofibrils during contraction of skeletal muscles

Front 109

process of contraction in skeletal muscles

Back 109

nerve impulse -> T tubules -> Ca++ diffuses out and over to myofibrils -> binds to thin filaments ->conformational change -> exposes active sites on actin to the attachment of myosin heads -> contraction

Front 110

contraction of smooth muscles

Back 110

contractile proteins are present in a much less ordered arrangement (no sarcomeres)

Front 111

contraction of cardiac muscles

Back 111

function much the same as skeletal muscles