Human Physiology Flashcards
1
Q
Digestion
A
Breaks down large molecules into smaller, usable molecules & absorbing these smaller molecules
2
Q
Mouth
A
Where mechanical & chemical digestion begins
3
Q
Salivary Amylase
A
Enzyme that begins starch digestion in saliva
4
Q
Esophagus
A
No digestion, transports food from throat to stomach
5
Q
Epiglottis
A
Keeps food away from windpipe
6
Q
Stomach
A
Place for both mechanical & chemical digestion
Where protein digestion begins
It’s thick, muscular walls churns food & secretes gastric juice that contains hydrochloric acid & enzymes
7
Q
Hydrochloric Acid
A
Begins breakdown of muscle (meat) & activates the inactive enzyme pepsinogen to become pepsin
8
Q
Pepsin
A
Digests protein
9
Q
Cardiac Sphincter
A
At top of stomach
Keeps acidified food in stomach from back up into esophagus
10
Q
Pyloric Sphincter
A
At bottom of stomach
Keeps food in stomach long enough to be digested
11
Q
Liver
A
Breaks down & recycles red blood cells
Detoxifies blood - removes alcohol & drugs
Produce cholesterol
Produce urea from protein metabolism
Produce bile
12
Q
Bile
A
Emulsifies fats Neutralizes chyme (acidified food from stomach) entering small intestine
13
Q
Small Intestine
A
Where all digestion is completed (in duodenum) & where nutrients are absorbed
14
Q
Intestinal Enzymes
A
Amylase, protease, lipase, nuclease
15
Q
Pancreatic amylase
A
Digests starch & is secreted into small intestine
16
Q
Peptidases
A
Continue to break down proteins into amino acids
17
Q
Nucleases
A
Hydrolyze nucleic acids into nucleotides
18
Q
Lipases
A
Break down fats
19
Q
Villi
A
Line small intestine & absorb all nutrients released from digested food
20
Q
Pancreas
A
Produce enzymes that break down carbohydrates, proteins, lipids, nucleic acids & secretes them into small intestine
Produce hormones to control blood sugar levels
Produce sodium bicarbonate
21
Q
Sodium bicarbonate
A
Produced in gallbladder
A base that neutralizes stomach acid, enabling intestinal enzymes to be effective as they require a basic environment
22
Q
Large Intestine/Colon
A
Egestion - removal of undigested wastes
Vitamin Production - vit. K, B & folic acid
Reabsorption of Water
23
Q
Rectum
A
Egestion, removal of undigested waste
24
Q
Medulla in Gas Exchange
A
Sets breathing rhytm by monitoring carbon dioxide levels & by sensing changes in pH of blood
25
Artery
Carries blood away from heart
| Enormous pressure
26
Vein
Carries blood back to heart
| Little pressure
27
Capillary
Allows for diffusion of nutrients & wastes between cells & blood
28
Plasma
Liquid portion of blood, 90% water
| Contains: clotting factors, hormones, antibodies, dissolved gases, nutrients, wastes
29
Red Blood Cells
| Erythrocytes
Carry hemoglobin & oxygen, do not have oxygen
| Live 120 days, formed in bone marrow & recycled in liver
30
White Blood Cells
| Leukocytes
Fight infection, formed in bone marrow
| Die fighting infection
31
Platelets
| Thrombocytes
Clot blood
| Cell fragments formed in bone marrow from megakaryocytes
32
Sinoatrial Node
Heart's pacemaker
| Sets timing of contractions of heart
33
Systolic
120
| Measurement of pressure when ventricles contract
34
Diastolic
80
| Measurement of pressure when heart relaxes
35
Pathway of Blood
Right atrium - right AV - Right ventricle - pulmonary semilunar valve - pulmonary artery - lungs - pulmonary vein - left atrium - left AV - left ventricle - aortic semilunar valve - aorta - all cells in body - vena cava
36
Endocrine System
Secretes hormones
37
Hormones
Produced in endocrine glands
| Move through blood to specific target cell, tissue organ - produce short-lived or long-term response
38
Tropic Hormones
Stimulate other glands to release hormones - can have far reaching effect
39
Hypothalamus
| Endocrine System
Bridge between endocrine & nervous systems in times of stress
It sends signals to adrenal gland to release adrenaline
Contains body's homeostat & centers for regulating hunger/thirst
40
Growth Hormone (GH)
Anterior Pituitary
| Stimulates growth of bones
41
Luteinizing Hormone (LH)
Anterior Pituitary
| Stimulates ovaries & testes
42
Thyroid-Stimulating Hormone (TSH)
Anterior Pituitary
| Stimulates thyroid gland
43
Adrenocorticotropic (ACTH) Hormone
Anterior Pituitary
| Stimulates adrenal cortex to secrete glucocorticoids
44
Follice-Stimulating Hormone (FSH)
Stimulates gonads to produce sperm & ova
45
Oxytocin
Posterior Pituitary
| Stimulates contractions of uterus + mammary glands
46
Antidiuretic Hormone (ADH)
Posterior Pituitary
| Promotes retention of water by kidneys
47
Thyroxin
Thyroid
| Controls metabolic rate
48
Calcitonin
Thyroid
| Lowers blood calcium levels
49
Parathormone
Parathyroid
| Raises blood calcium levels
50
Glucocorticoids
Adrenal Cortex
| Raises blood sugar levels
51
Epinephrine (adrenaline)
Adrenal Medulla
| Raises blood sugar level by increasing rate of glycogen breakdown by liver
52
Insulin
Pancreas
| Lowers blood glucose levels
53
Glucagon
Pancreas
| Raises blood sugar levels
54
Thymosin
Thymus
| Stimulates T lymphocytes as part of immune response
55
Melatonin
Pineal
| Involved in biorhythms
56
Estrogen
Ovaries
| Stimulates uterine lining, promotes development & maintenance of primary & secondary characteristics of females
57
Progesterone
Ovaries
| Promotes uterine lining growth
58
Androgens
Testes
| Support sperm production & promote secondary sex characteristics
59
Feedback Mechanism
Self regulating mechanism that increase/decrease an action/level of a particular substance
60
Positive Feedback
Enhance existing response
| Childbirth
61
Negative Feedback
Common in system that maintains homeostasis
62
Central Nervous System
Brain & Spinal Cord
63
Peripheral Nervous System
All nerves outside CNS
64
Sensory (PNS)
Conveys info from sensory receptors/nerve endings
65
Motor (PNS)
Stimulates voluntary & involuntary muscles & consists of 2 systems
66
Somatic System
Controls voluntary muscles
67
Autonomic System
Controls involuntary muscles
68
Resting Potential
The charge change across the membrane when a neuron is not firing (-70mV)
69
Action Potential
The charge change across the membrane when a neuron is firing (30mV)
70
Depolarization
The change from a negative resting potential to a positive action potential
Opening sodium channels
71
Repolarization
The change from a positive action potential back to a negative resting potential
Opening potassium channels
72
Nervous System
Secretes neurotransmitters
73
Cones
Photoreceptors in retina, distinguish different colors
74
Rods
Sensitive photoreceptors in retina
| Do not distinguish different colors
75
Cornea
Tough, clear covering that protects eye & allows light to pass through
76
Humor
Fluids, maintain shape of cell
77
Iris
Colored part of eye
| Controls how much light enters eye
78
Lens
Focuses light onto retina
79
Pupil
Small opening, middle of iris
80
Retina
Converts light into nerve impulses that are carried to the brain
81
Auditory Canal
Ear canal, where sounds enter
82
Cochlea
Fluid-filled part of inner ear
| Sends nerve impulses to brain
83
Ear Bones
Hammer, anvil, stirrup; transmit vibrations from eardrum to oval window
84
Eustachian Tube
Equalizes pressure between environment & inner ear
85
Oval Window
Sends waves of pressure to cochlea
86
Semicircular Canals
Fluid-filled, helps maintain balance
87
Tympanum
Ear drum, vibrates as sound waves hit it
88
Excretion
Removal of metabolic wastes
| Includes removing carbon dioxide & water from cell respiration, & nitrogenous wastes from protein metabolism
89
Organs of Excretion
Skin, Lungs, Liver, Kidney
90
Kidney
Filters about 1500L of blood per day & produce about 1.5L urine
91
Nephron
Basic functional unit of kidney
| Carries out job in 4 steps; filtration, secretion, reabsorption, excretion
92
Smooth/Involuntary Muscles
Makes up walls of blood vessels & digestive tract under control of autonomic nervous system
93
Skeletal/Voluntary Muscles
Large & multinucleate, work in pairs; one muscle contracts & other relax
Bicep & tricep
94
Cardiac Muscle
Heart, generates its own action potential
95
Duodenum
First 10 inches of small intestine
| Where all digestion is completed
96
Lacteal
Structures within villi that line the small intestine & that absorb fatty acids & glycerol into the lymphatic system
97
Alveoli
Microscopic air sacs in the lung where diffusion of the respiratory gases, oxygen & carbon dioxide, occurs
98
Serum
Plasma without clotting factors
99
Polarized
Condition of an axon of a nerve when it's at rest, also resting potential
Na & K are pumped to opposite sides of the membrane
100
Wave of depolarization
The condition of an axon when an impulse is passing
| Also action potential
101
Myosin
Myofilaments that make up the thick filaments in skeletal muscle
102
Actin
Protein that makes up the thin myofilaments in skeletal muscle
103
Capillary
| Villus
Absorb amino acids, vitamins & monosaccharides directly into the bloodstream
104
Microvilli
Microscopic appendages
| Further enhance the rate of absorption
105
Gallbladder
Stores bile produced in liver
| Body can function without it
106
Constipation
Too much water is reabsorbed from the intestine into body
107
Diarrhea
An inadequate amount of water is absorbed back into body
108
Transport of Oxygen
Carried in blood by respiratory pigment hemoglobin
| Combines loosely with oxygen to form molecule oxyhemoglobin
109
Transport of Carbon Dioxide
The by-product of cell respiration, is released from every cell & dissolves in the blood
110
Carbonic acid-bicarbonate ion system
Maintains the blood at a constant pH of 7.4
111
Blood Clotting
Mechanism that begins with the release of clotting factors from platelets & damaged tissue
112
Anticlotting Factors
Constantly circulate in the plasma to prevent the formation of a clot or thrombus
Can cause serious damage in the absence of injury
113
Pulmonary Artery
Carries deoxygenated blood
114
Pulmonary Vein
Carries oxygenated blood
115
Steroid Hormones
| Lipids
Diffuse directly through the plasma membrane & bind to a receptor inside the cell that triggers the cell's response
116
Nonsteroidal Hormone
| Protein/Polypeptide
Cannot dissolve in the plasma membrane so they bind to a receptor on the surface of the cell, triggers a secondary messenger that converts extracellular chemical signal to a specific response inside the cell
117
Feedback Mechanism
Self-regulating mechanism that increases or decreases an action or the level of a particular substance
118
Positive Feedback
Enhances an already existing response
| Childbirth
119
Negative Feedback
Maintains homeostasis
| How body maintains proper levels of thyroxin
120
Neuron
Basic functional unit of the nervous system
121
Dendrites
Sensory
| Receive incoming messages from other cells & carry the electrical signal to the cell body
122
Axons
Transmit an impulse from the cell body outward another cell
123
Sympathetic System
```
Fight/flight response
Increase heart & breathing rate
Liver convert glycogen to glucose
Bronchi dilate & increase gas exchange
Adrenaline raises blood glucose levels
```
124
Parasympathetic System
Calms the body
Decreases heart/breathing rate
Enhances digestion
125
Reflex Arc
Simplest nerve response
Inborn, automatic & protective
Ex: knee jerk
126
Membrane Potential
A difference in electrical charge between the cytoplasm (negative charge) & extracellular fluid (positive charge)
127
Refractory Period
Period of repolarization
Lasts few milliseconds during which neuron cannot respond to another stimulus
Ensures that an impulse moves along an axon in 1 direction only since impulse can move only to a region where membrane is polarized
128
Synapse
A junction between 2 nerve cells
| Impulses pass by diffusion of a neurotransmitter
129
Homeostasis
Any self-regulating process by which biological systems tend to maintain stability while adjusting to conditions that are optimal for survival
130
Neurotransmitters
Brain chemicals that communicate information through brain & body
Relays signals between neurons
131
Filtration
| Nephron
Occurs by diffusion
It is passive & nonselective
Filtrate contains everything small enough to diffuse out of glomerulus into Bowman's capsule
Glomerulus -> Bowman's capsule -> loop of Henle -> collecting duct/tubule
132
Secretion
| Nephron
Active, selective uptake of molecules that did not get filtered into Bowman's capsule
In tubules of nephron
133
Reabsorption
| Nephron
Process by which most water & solutes that initially entered the tubule during filtration are transported back into the capillaries & thus back to the body
Tubulue -> loop of Henle -> collecting tubule
134
Excretion
| Nephron
Removal of metabolic wastes
| Everything that passes into collecting tubule is excreted from the body
135
Myofibrils
Fibers within cytoplasm of each skeletal muscle cells that run parallel to length of the cell
136
Sliding Filament Theory
Muscles contract as thick (myosin) & thin (actin) filaments slide over each other
137
Peristalsis
Automatic process that moves food through the digestive system
