Grade 11 Pre-AP Biology - Unit 4 Test Review

Homeostasis

process of maintaining a balance in an organism’s internal environment to sustain life

Physiology

study of how living organisms maintain homeostasis

Molecules → Organelles → Cells → Tissues → Systems → Organisms

Molecules → Organelles → Cells → Tissues → Systems → Organisms

Feedback Loop

Stimulus → Receptor → Control Center → Effector

Negative Feedback Loop

response decreases the effect of the stimulus

Positive Feedback Loop

response increases the effect of the stimulus

Stimulus

change in the environment

Receptor

part of the organism that detects the stimulus

Control Center

part of the organism that decides what to do about the stimulus

Effector

part of the organism that generates the response

Receptor sends information to the control center through an ________ _______.

afferent pathway (towards CNS)

Control center sends instructions out through an ________ ________.

efferent pathway (away from CNS)

Cranial

towards the head

Caudal

away from the head

Superior

higher

Inferior

lower

Posterior

back

Anterior

front

Lateral

closer to the side of the body

Medial

closer to the center of the body

Proximal

closer to the point of attachment (usually referring to limbs)

Distal

farther from the point of attachment (usually referring to limbs)

Sagittal Plane

person is cut symmetrically vertically

Frontal Plane

person is cut asymmetrically vertically

Transverse Plane

person is cut horizontally

Purpose of the Circulatory System

to move materials from place to place within an organism

Components of the Circulatory System

• Fluid

• Tubes

• Pump

Fluid (Circulatory System)

• moves through the system

• materials that are being moved are dissolved in the fluid

Tubes (Circulatory System)

• network of tubes through which the fluid travels

Pump (Circulatory System)

generates the force to push the fluid through the tubes

Open Circulatory System

• fluid leaves the tubes

• pumped onto the tissues of the organism

• fluids are recovered using a different set of tubes + recirculated

Closed Circulatory System

• fluids stay within the tubes at all times

One Circuit System

• fluid leaves pump

• goes to gills/lungs to pick up oxygen/get rid of CO2

• goes directly to the body

• after circulating in the body, fluid returns to the pump

Two Circuit System

• fluid leaves pump

• goes to gills/lungs to pick up oxygen/get rid of CO2

• fluid returns to pump

• pump pushes fluid out to the rest of the body

• after circulating in the body, the fluid returns to the pump

What are the compartments of the heart called?

chambers

Fish have how many chambers?

2

Amphibians + Reptiles have how many chambers?

3

Mammals, Birds + Crocodiles have how many chambers?

4

The blood coming back from the body will be __________.

deoxygenated

What is the advantage of a 4-chambered heart?

oxygenated + deoxygenated blood don’t mix

Pulmonary Circuit

blood from heart → lungs and v.v.

Systemic Circuit

blood from heart → body and v.v.

Path of Blood

• Deoxygenated blood returns to the heart through the vena cava

• Deoxygenated blood enters the right atrium → then goes to right ventricle

• Deoxygenated blood is pumped by right ventricle → lungs to receive oxygen and get rid of CO2

• Oxygenated blood returns to the heart via the pulmonary vein → left atrium

• Oxygenated blood → left ventricle which pumps the blood out to the body via the aorta

Vena Cava

vein that carries deoxygenated blood from the body back to the right atrium

Right Atrium

Right Ventricle

Left Atrium

Left Ventricle

Pulmonary Artery

artery from heart to lungs

Pulmonary Vein

vein from lungs to heart

Aorta

artery that carries blood from heart to rest of body

Septum

wall that divides the heart into two sides

Valves in Order

TPMA

Tricuspid

Pulmonary

Mitral

Aortic

Tricuspid Valve

blood from right atrium → right ventricle

Pulmonary Valve

blood from right ventricle → lungs

Mitral Valve

blood from left atrium → left ventricle

Aortic Valve

blood from left ventricle → aorta (→ rest of body)

Atrioventricular Valves

(tricuspid + mitral)

• allow blood to flow only in atrium-to-ventricle direction

Semilunar Valves

(pulmonary + aortic)

• prevent blood from flowing back into the heart after it leaves the ventricles

Diastole

filling of the heart

Systole

emptying of the heart as the ventricles pump

Neurogenic

needing the nervous system to tell it what to do and when to do it

Myogenic Muscle

special type of muscle that the heart is made out of

• heart muscle is able to generate its own signal within the heart itself

Sinoatrial Node (SA)

• cluster of cells that generate a small electrical pulse

  • causes atria to contract

Atrioventricular Node (AV)

• 2nd node that receives the SA’s electrical pulse

Pukinje Fibers

nerve fibers that run down the ventricles casing them to contract

P Wave

initial signal from SA causing atria to contract

QRS Complex

signal travels through Pukinje fibers to cause the ventricles to contract

T Wave

signal used to allow the heart to rest to prepare for the next beat

Heart Sound

“lub-dub”

“lub” → atrioventricular valves closing after blood has been pumped through

“dub” → semilunar valves closing after blood has been pumped through

Artery

blood vessel that carries blood away from the heart

Vein

blood vessel that carries blood towards the heart

Arteries will ____ when the heart beats/pressure is ____. Arteries will ______ in between heartbeats.

widen, high, narrow

Vasodilation

muscles relax to widen the arteriole

Vasoconstriction

muscles contract to narrow the arteriole

• occurs in areas of the body that are not currently being used + to conserve body heat in the extremities

Capillaries

• arterioles branch off into smaller blood vessels called capillaries

Cells give co2 and get oxygen at the _______.

capillaries

True or False: RBCs travel almost single file through capillaries

True

True or False: cells in the body can be more than two cells away from a capillary

False; all cells are no more than two cells away from a capillary

The walls of the capillaries are ___ cell thick

one

Veins and Venules

• heading back to the heart, capillaries merge together to form venules, and the venules merge together to form veins

Special Valves in Venules & Veins

• have special valves that prevent blood from flowing backwards

  • flexing of nearby muscles helps push the blood in the right direction

  • if valves wear out, blood can build up in areas causing varicose veins

Arteries (Area, Velocity, BP)

↓ Area

↑ Velocity

↑ BP

Venules/Veins (Area, Velocity, BP)

↓ Area

↑ Velocity

↓ BP

Capillaries (Area, Velocity, BP)

↑ Area

↓ Velocity

↓ BP

Proper circulation requires a clear pathway through the blood vessels. Excess fats and cholesterol can cling to the inside of the blood vessels. If this builds up it creates a ______ which ↑ __ and makes it harder for the heart to maintain _________.

blockage, BP, circulation

Sclerosis

condition where normally flexible tissue hardens + loses function

Atherosclerosis

condition where a blood vessel hardens because of the layer of fat accumulated inside it

If a blockage occurs in one of the coronary vessels that supply the heart itself, a ______ ______ may be necessary to ensure continued circulation to the heart. Blood vessels are removed from another part of the body and grafted to the aorta and the heart.

bypass surgery

Normally a little more fluid exists in the capillaries than is returned to the venules. This extra fluid accumulates in the spaces in between tissues and is called ________ _____.

interstitial fluid

Lymphatic System (DONT NEED TO KNOW FOR TEST)

• open circulatory system

• in charge of interstitial fluid/lymph

• has no pump + relies on movement/flexing of muscles to move lymph into ducts where fluid is delivered back to the main closed circulatory system

• filters fluids

Lymph Nodes (DONT NEED TO KNOW FOR TEST)

• areas where cells in your immune system are stored when not fighting infection

BP is measured in

mm Hg

Normal Diastolic BP

70-90 mm Hg

Normal Systolic BP

110-140 mm Hg

Ideal BP (Systolic/Diastolic)

120/80 mm Hg

Hypotension

Low BP

• not a problem unless causing fainting/weakness

• can be caused by sudden loss of blood/dehydration

Hypertension

High BP

• can cause serious problems like heart attacks, heart failure, or stroke

• can be caused by poor diet, lack of exercise, or diabetes

Blood is composed of…

• RBCs (45%)

• WBCs + Platelets (<1%)

• Plasma (55%)

Red Blood Cells are also called

erythrocytes